ENVIRONMENTAL RESOURCES ASSESSMENT

OF
COCHIN

A THESIS

SUBMITTED '10

THE COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY

IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF

DOCTOR OF PHILOSOPHY

IN

ENVIRONMENTAL PLANNING

UNDER THE FACULTY OF ENVIRONMENTAL STUDIES

P.V. BENJAMIN

SCHOOL OF ENVIRONMENTAL STUDIES,

COCHIN UNIVERISTY OF SCIENCE AND TECHNOLOGY

COCHIN — 682 016

MARCH 1998
 CERTIFICATE

This is to certify that this thesis is a bonafide record of research carried out
by Sri.P.V.Benjamin M.L.Arch., under our guidance, in partial fulfillment of the
requirements for the degree of Doctor of Philosophy of the Cochin University of
Science and Technology.

Cochin # 682 016 Dr.K.P.Balakrishnan, l)ril'\/l.—.V.Harindrarratharr Nair,

March 1998 Supervising Guide Supervising Guide
 DECLARATION

I hereby declare that this thesis entitled, "Environmental

Resources Assessment of Cochin is an authentic record of the
research carried out by me under the supervision of Prof (Retd.)
Dr. K.P.Balakrishnan and Dr.M.V.Harindranathan Nair, Lecturer,
School of Environmental Studies, Cochin University of Science
and Technology, and that no part of it has previously formed the
basis of award of any degree, diploma, associateship, fellowship
or other similar title or recognition.

Cochin — 682 016 “ ./ / PuVuBenjamin

March 1998
 Acknowledgement

I would like to record my deep sense of gratitude and indebtedness to Prof.

(Dr).K.P.Balakrishnan, Sreerangam, Diwan’s Road, Ernakulam and Dr.
M.V.Harindranathan Nair, Lecturer, School of Environmental Studies, Cochin University
of Science & Technology, my supervising guides, for their invaluable and inspiring
guidance as well as their ceaseless encouragement during the entire course of this study.

I take this opportunity to record my deep-felt gratitude to Dr. A.Mohandas, Prof

& Director, School of Environmental Studies for his ceaseless help and interest as well as
for providing me all the facilities of the School throughout my research work.

I owe much to Prof. Krishna Prasad, Dr. P.V.Ramaehandran, and Prof.

T.P.George for their opinions and suggestions during the course of this work.

I express my sincere thanks to Drs C.M. Chandramohanakumar, Ignatius

Kunjumon, K.R.Santhosh, K.Sajan, V.N.Sivasankara Pillai and N.R.Menon, the faculty
members of various departments of Cochin University of Science & Technology for their
timely invaluable help at various stages of this study.

I wish to express my gratitude to Dr. P.Rajalekshmy Amma and Sri. K.M.

Mathew of School of Environmental Studies for their help during the preparation of the
thesis as well as Sri. Peter and Sri. Alex, Research Scholars of the School, Sri. Biju and
my nephew Ajith Pottas for their co-operation at the final stages ofthis work.

And, I wish to express my heartfelt gratitude towards the authorities of Greater

Cochin Development Authority for according pennission to undertake this work. Also is
due, my sincere thanks to all the staff of School of Environmental Studies for their
goodwill and affection shown towards me during the entire period of this study.

Finally, I wish to acknowledge the unfailing inspiration, understanding and

forbearance shown by my wife Mary and son Ben.

Above all, words fail me when I remember the benevolence of The Almighty with
whose grace this endeavor could succeed.
 PREFACE

in the present global circumstances, no individual or country can remain

immune to the environmental impact of economic development and to the man­
made consequences of fast urbanisation. As a sequel to the interaction between
the population growth, technological advancement and scientific discovery, the
world of the historical past cannot persist into the changing condition of the
future. The overall conditions of the earth's environment have therefore
deteriorated and global risks have become more acute. This beckons the
necessity for a change in the perspective from the concept of growth at all cost to
the idea of a sustainable development.

Urbanisation is a fast—growing tendency in the developing countries, whereas

in the developed countries, it has more or less stabilised. All human activities
have an impact on the urban environment. These impacts can be categorised as
those resulting from (1) the extraction of environmental resources, (2) the release
of residuals to the environment and (3) the modification of environmental
regimes.

In the case of urban centres of the developing countries, corrective measures

for the environmental consequences of spontaneous or wrongly planned
developments are often prohibitively costly. Hence environmentally planned
development alone appears to be the solution for which, a compre-hensive
assessment of all the resources is an essential pre—requisite. An under-standing
of the prevailing environmental conditions is essential for the effective
management and execution of programmes for sustainable development.

The present work is a modest attempt at assessing the environmental

resources of Cochin, the industrial and business capital of Kerala and a fast
developing metropolis.
 CONTENTS

CHAPTER I PAGE

INTRODUCTION

CHAPTER II

PHYSIOGRAPHY (LANDFORM) 14

CHAPTER III

GEOLOGY AND GROUNDWATER 27

CHAPTER IV

SURFACE HYDROLOGY AND BACKWATER SYSTEM 48

CHAPTER V

CLIMATE 72

CHAPTER VI

VEGETATION 87

CHAPTER VII

SOCIO-ECONOMIC ENVIRONMENT AND BASIC AMENITIES 108

CHAPTER VIII

SUMMARY AND CONCLUSIONS 154

REFERENCES
 Chapter-1

Introduction

1.1 The Urban Scenario

The term ‘environment’ can be defined as the whole complex of

physical, social, cultural, economic and aesthetic factors which affect
individuals and communities and ultimately determine their form, character,

relationship and survival (Rau John, G. 1980). Natural environment

undergoes continuous change. This may be on a time scale of hundreds of

millions of years, as in the case of continental drift, mountain formation or

sea level changes (during ice ages); or hundreds of years as in the case of
the natural siltation and eutrophication of shallow lakes. Some of these are

irreversible and some cyclic. Superimposed on these natural processes are

those produced by man.

Even as a primitive hunter-gatherer, man’s use of fire must have

changed some natural environments. The effect of man’s action on
environment became widespread with the domestication of animals and the

introduction of agriculture. Man's impact on environment became very

serious with the development of industry when muscle power was replaced

by fossil fuel energy. In recent years, it has further worsened with the fast
increase of population and their concentration in a few cities along with a

higher per capita consumption of energy as well as other natural resources.

Vlfith the advent of modern technology, man's impact on environment

increased enormously which created conflict between human goals and

natural processes. In order to achieve greater short—term benefits, man

deflects the natural flow of energy, bypasses natural processes, severes food
chains, simplifies ecosystems and uses large energy subsidies to maintain a

delicate and artificial ecological equilibrium. This often results in irreversible

environmental degradation.

Another aspect of serious concern is the greenhouse effect and its

impact on the human settlements. The greenhouse effect is due to trapping

of an increasing quantity of infra—red terrestrial radiation by a variety of

gases being released into the atmosphere in continuously ‘increasing

quantities emanating from millions of industrial smoke stacks, motor
vehicles, waste dumps and other sources. The important green house
gases are CO2, methane, nitrous oxide and ozone. in nature, there was

balance between CO2 production during respiration and absorption during_

photosynthesis. This equilibrium got disturbed since the industrial revolution

and widespread use of fossil fuels. The atmospheric CO2 rose from 275
ppm in 1860 to 346 ppm in 1986, an increase of 26%. At the current rate of

increase the CO2 concentration is expected to reach 550 ppm by the year
2050 which will hike the global thermostat by 4 °C (Oliver and Owen, 1989).

An increase in the average global temperature would result in a thermal

 expansion of warmed up seawater and melting of the glaciers such as the

polar ice caps and a consequent rise in sea level.

Melting of glaciers has already begun as evidenced by the slab of ice

of size 25 x 99 miles that broke ofiifrom Antarctic ice field in 1987 and

splashed into Rose Sea. A one-meter rise in ocean levels induced by

greenhouse warming by 2035 AD as predicted, if occurs, would cause the

sea to move 30 meters farther inland along the American coast (Oliver and

Owen, 1989). Under such circumstances, the case of India also will not be

much different. It is reported that there is already an increase of 2.2 mm

annual rise in sea level in Cochin which will amount to 22 cms in the next

100 ‘years (Harish, 1993). When it happens, millions of people would be

forced to relocate; human stress, anxiety and discomfort would be severe.

International Panel for Climatic change (IPCC), has predicted a 31 cm rise

(lower scenario) by the year 2100 (IPCC, 1990).

There is a rapid social change in developing countries from a rural

agricultural nature to urban industrial society during the past few decades.

Cities in the developing countries have grown almost double the rate as that

of developed countries.

In India, the proportion of urban population went up from 19% of the

total population in 1965 to 27 % in 1990. The average annual urban

population growth rate was 3.7% in India (World Bank report, 1992) and

32% of the total urban populationfconcentrated in metropolitan cities of India.

At the beginning of this century, India had just one metropolitan city i.e.,
 Calcutta with 5.8% of the total urban population. This extreme polarisation

resulted in the increased density of population and increased economic

activities in metropolitan cities.

The growth of cities and towns has not been uniform. While cities
are growing bigger and bigger, the small and medium size towns are
showing negative trends (Kalyan, 1991). This led to over—concentration of

population and economic activities in all metros.

This unprecedented demographic growth together with persistent

financial stringency faced by the government has brought in its wake, a
serious inadequacy in social and economic infrastructure leading to fast

environmental degradation and deterioration of the quality of life for the

masses in all our metropolitan cities. The scene of Cochin is also not so
different from that of Bombay and other metropolitan cities, though
comparatively on a lesser scalejn every aspect.

1.2. Need for Environmental Resources Assessment in Urban Planning.

A great deal of damage has been done in the past, simply because
environmental planning was non-existent and/or because planners did not

appreciate the interplay of natural processes that affects their schemes.

National Environmental Policy Act (NEPA) was passed in USA in

1969 making it obligatory to prepare Environmental statement for activities

that are likely to affect environmental quality (Rau and Wooten, 1980). India
 is also having several laws to ensure environmental quality while specific
developments take place, such as Water (Prevention and Control of
Pollution) Act, 1974; the Air (Prevention and Control of Pollution) Act, 1974;

the Forest (Conservation) Act, 1980; the Wild Life (protection) amendment

Act, 1986. These laws are for ensuring specific environmental qualities.
The Indian Parliament passed the Environment (protection) Act in 1986,

which makes it obligatory to prepare an Environmental Impact Assessment

(EIA) report before embarking on major development programmes.

The existing environmental laws are found to be inadequate in

protecting the urban environment, since the laws are activity-specific. Each

kind of industrial development envisages only its specific impact on the

environment in the EIA studies. Hence, a comprehensive environmental
assessment—based planning (taking into account the already existing highly

urbanised areas as well as the suburban and rural fringes where future
urbanisation is imminent) is essential to streamline the growth of fast­
developing cities particularly in the developing countries where expensive

corrective measures are often not economically viable.

Due to lack of proper environmental resources assessment, the

development plans often failed to give proper consideration to environ­

mental aspects. Short term economic goals for 5-10 years or even a slightly

longer period, which is considered a long period by economists but,

environmentally and ecologically a very short and negligible time, is the root

cause for all the current environmental problems. In such short term
economic benefit—based planning, usually environmental aspects go
unnoticed. (For example, slow soil deterioration, depletion of aquifers,
accelerated eutrophication of large lakes, adverse effects of air and water

pollution on animals, plants and man and the deterioration of scenic quality

of the environment etc.). This state of affairs is due to the lack of proper

awareness about the environmental parameters amongst the economic

planners and physical planners.

Hence, this study is aimed at an assessment of the environmental

resources of a fast-developing metropolis — Cochin - with an aim to provide a

probable guideline for specific urban development in environmentally

compatible areas.

It is very difficult to find an urban settlement with all the

environmental parameters. If the settlement is totally in a coastal plain,
parameters of hilly areas will be lacking and if the settlement is totally in a

hill tract, the coastal parameters will be absent. Hence, a coastal city with

deep sediment strata and adjoining hill tracts and associated features will be

the most suited site for such a study. Cochin is such a coastal settlement

interspersed with backwater system and fringed on the eastern side by

|aterite—capped low hills from which a number of streams originate and drain

into the backwater system. The ridge line of the eastern low hills gives a
more or less well-defined water shed delimiting Cochin basin which help to

confine the environmental parameters within a physical limit which is very

advantageous in such a study. Hence Cochin basin covering an area of

 approximately 535 km? is selected for this study for the environmental
status assessment.

1.3. Need for the Study

Compared to many other parts of the country, Cochin enjoys an

atmosphere of communal harmony and social security. The availability of
necessary infrastructure facilities added to the amiable social scenario has

started luring large—sca|e investments in various activities from people

throughout India. This recent phenomenon has resulted in a rapid growth

boom, which is likely to go beyond the carrying capacity of the present

urban fabric resulting in various environmental problems.

Due to the improper siting of industries and settlements, Cochin, the

fast-developing metropolis of Kerala, is likely to face severe environmental

problems such as water and air pollution from industries, drainage problems

due to settlements developed in filled—up low—lying marshlands, sinking of

buildings due to unstable sub—surface conditions, contamination of ground­

water etc. Therefore, Cochin needs a careful environmental planning for

ameliorating the environmental problems inherited from the past as well as

for preventing unsound future developments.

This study aims at assessing various environmental resources of

Cochin, which may enable the physical planners to suggest appropriate

areas for long—term develop mental activities which are environmentally
feasible.
1.4 The Study Area

The study area is the Cochin basin lying between 9° 49' N to 10°14’ N and 76° 10' E

to 76° 31' E along the south western coast of India ( Fig. 1.1 )_. It includes the Cochin City

( the erstwhile municipalities of Emakulam, Mattanchery and Fort l<o.c.hi ), kalamassely

and Tripunithura municipalities and the adjoining panchayats ( Fig. 1.2’).

Cochin City, the business and industrial capital of the state, is the nerve centre of a

large urban agglomeration consisting of Alwaye, Parur, Perurnbavoor, Thrikkakkara,

Tripunithura, Kalamassery and Eloor lying around it. Cochin Port has trade connections

with the countries all over the world. At present, the city has an air port on Willingdon
Island, which facilitates business and tourist connections will: all parts of the world. Plow

the construction of an International /-‘-.ir port at Nedumbassery in the suburb of Cor,-hin is

nearing completion.

1.5 Limitations of the study

The environmental problems of any industrial city are very vast and complex
especially when located in a very low lying area with unstable geological substrate...
The Cochin City has an area of 94.88 Km2 and a population of 554,589
(Census - 1991 ). The central city area (Fig. 1.3) as envisaged in the Structure
Plan for 2001 proposed by Greater Cochin Development Authority ( GCDA ) covers an
area of 275.85 Krnz and the GClJi‘t =3-overs an area of '/32.00 Kmz (encompassing
definitive aclministative areas) whereas this study pertains to the entire Cochin basin,
 ”‘”3'‘‘ ‘3°- KERALA

25° 1I°J
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15°
901

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LIES BETWEEN BOUNDARIES
_ _ West- Laccadives sea
9° 49 N 10 10° 14 N and East -Muvattupuzha river basin
‘ _10South
750' E {O 75°- 31
Muvattupuzha river
E Nonh -Periyar river basin
basin
TOTAL AREA - 535 km2

Fig-1.1. LOCATION MAP

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 ADMINISTRATIVE UNITS WITHIN THE STUDY AREA
(COCHIN BASIN)
CITY CORPORATION

CORPORATION OF COCI-IIN
MUNICIPALITIES

KALAMASSERY
TRIPOONIT1-IURA
PANCHAYATS
VENGOLA (PART)
VAZHAKKULAM (PART)
KIZHAKKAMBALAM
CI-IOORNIKKARA(PART)
EDATHALA
CERANALLOOR
THRIKKAKARA
MULAVUKAD
NJARACK/~\L(PART)
ELAMKUNNAPUZHA
CI-IELLANAM(PART)
MARADU
KUIVIBALAM
UDAYAMPEROOR
MULAMTHURUTI-IY(PART)
THIRUVANKULAM
CHOTTANIKKARA
EDAKKATTUVAYAL(PART)
AMBALLOOR(PART)
POOTI-IRIKA(PART)
THIRUVANIYUR
VADAVUKODU- PUTHENCRUZ
MAZHUVANNOOR(PART)
AIKKARANADU(PART)
KUNNATI-IUNADU
MANEED(PART)
 NOT TO SCALE

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 ( NOT TO SCALE )

FigI—1.3 THE CENTRAL CITY AREA PROPOSED BY GCDA IN THE STRUCTURE PLAN FOR 200]
 9.

well defined by natural boundaries, covering an area of 535 Kmz. Due to

vastness of the study area as well as multitude of environmental parameters,
secondary data collected from National Environmental Engineering Research
Institute, Nagpur, Kerala State Pollution Control Board, Trivandrum, the various
departments of Cochin University of Science & Technology and Kerala Agricultural

University, Trissur, National Institute of Oceanography,Cochin , etc. as well as various

project reports and environmental assessment ( EIA ) reports prepared for
specific projects of various agencies like Fertilizers and Chemicals Travancore Ltd.
Cochin Refineries Ltd.,C0chin Port Trust, Greater Cochin Development Authority
and Corporation of Cochin were also consulted. Bore logs of deep bore wells and
those of foundation of buildings and bridges within the study area prepared by
foundation engineers were also used as secondary data.
1.6 Historical Background.

Priorto14”‘ century A D, the port of Musiris (present Kodungalloor)

on the north of Cochin was the main centre of commercial activities of Kerala, which

had trade connections with ancient Rome and Greece. In the year 1341 A D, a heavy
flood silted up the Musiris harbour and formed a natural harbour at Cochin by opening a

passage to the sea at Cochin ( Logan, 1901 ). This caused the shifting of harbour
activities and associated trades to Cochin from Musiris resulting in the sudden
urbanization of Mattancherry on the west bank of the back water system.

The new town of Ernakulam in the main land began to develop on

the east bank some where in 17"‘ century, even though the famous Ernakulam
 10

temple was there much before that and the place got the name after the
temple.

However, the urban evolution of Ernakulam can be traced back only

up to 1673 when Fr. Mathew got permission from the Dutch Governor to

build a church at Chathiath — a place in erstwhile Ernakulam town - the first

in Malabar, that the Carmelites ever built (Ernakulam Dist.Gazetteer, 1965)

Huzur court with appellate jurisdiction was set up in Ernakulam by

Col. Monroe in 1812 AD. Survey and settlement of wetlands known as the

‘K_andezhuthu' were done in the year 1821 AD (996 Malayalam Era) during

the time of Dewan Nanjappayya.

Survey and settlement records of garden land were done during the

period 1837-1838 AD.

An English school and an Allopathy hospital were commissioned

during the period 1840-1858. which later developed into the present day
Maharaja's College and General hospital respectively.

Roads were macadamized during the time of Thottakattu Sankunni

Menon (1860-79).

Extensive reclamation of the backwater started during the period

1879-1889 when the Ernakulam foreshore was greatly improved in terms of
recreation and road facilities.

Railway came to Ernakulam in 1905. Mattancherry became a

Municipality in 1912. Ernakulam was upgraded to the status of a
 Municipality in 1913, during the period of Diwan A.R.Banerji (1907-1914).

Piped water supply was provided for the public at Ernakulam by Diwan
Banerjee.

The aerodrome at Venduruthy was constructed during the period of

Diwan Sri. Shanmugham Shetty (1935-1941). He was also responsible for

the beautification and improvement of Ernakulam town and the foreshore

area and their electrification. The Rammohan Palace (the present Kerala

High Court building) was constructed in 1938.

Ernakulam thus gradually started to develop as an administrative

town, with the establishment of the Huzur Court and connected buildings.

Dry land was very scarce in the vicinity of the Huzur Court (former

Collectorate building) - the Administrative Secretariat of the Kingdom of

Cochin - which resulted in the need of either reclaiming land from the lake

or filling up the marshlands and canals for building purpose. This

conversion continued and large-scale transformation of wetlands into dry

area went on unabated along with the dredging and deepening of the
channel and the sand bar at the channel mouth for opening of Cochin as a

major port in 1940. The dredged material was added to the existing island

to transform it into the present Wellington Island.

The commissioning of Cochin Port as an year—round port was

responsible for the fast development of Ernakulam and suburban areas.
With the road connection to the mainland on the west and road and rail

connection to the east from the Island, the mainland on both sides began to
 develop fast in commercial activities. Along with this, the commissioning of

Pallivassal Hydro Electric Project almost at the same time resulted in the

rapid industrialisation and commercialisation of Cochin. The unplanned

and haphazard development resulted in rapid degradation of the natural

environment, which relentlessly continues.

The first step towards a planned development of Cochin was the

preparation of interim development plan for Cochin by the Town Planning

Department in the year 1966, which was further modified in 1968.

Cochin Town Planning Trust was formed in 1968 to implement the

plan. In order to satisfy the basic environmental requirements of the people

of the area, a Municipal Corporation was established in the year 1967

amalgamating three Municipalities of Fort Cochin, Mattancherry and
Ernakulam. In 1976, in order to co-ordinate the development of the region,

the Greater Cochin Development Authority was constituted. Ever since, at

least some balance is maintained between development and environment.

1.7 General Methodology

This study is carried out in the following stages: —

(1) ldentification and evaluation of various environmental resources of

Cochin.

(2) Identification of areas suitable for various kinds of developments on

the basis of each of the resources, individually.

 13

The methodology of assessment of individual resources is given in

the respective chapters on each resource. The environmental resources

are assessed under the following headings.

‘I. Physiography
2. Geology and groundwater
3. Surface hydrology and backwater system
4. Climate
5. Vegetation
6 Socio-economic environment and Basic amenities
and services

Broad environmental planning recommendations based on

environmental suitability of the different zones within the study area in
relation to the various resources individually and collectively are also given.
 Chapter - 2

Physiography (Landform)
2.1. Introduction
Land is the basic resource available to mankind for his habitat, which

unfortunately is limited. Hence, there is need for striking a balance between

the competing claims on land use. An appropriate land use should ensure
sustainability of land resources and optimum utilization. To achieve this
goal, a study of the physiography of the area including drainage pattern,
shape of the micro-watersheds within the area, land slope and drainage
density is a prerequisite. Development proposal of any area is to be
compatible with the characteristics of its landform. Landform is an important
determinant in the form and growth of a settlement and the distribution of
population. Besides, it also influences the drainage, transport, climate and
pollutant dispersion.

In steep slopes, poor grading and drainage practices aggravate

landslide problems. Artificial fills placed on impermeable substrata are often

rendered unstable by the build up of water pressure. Diversion of storm

water on to slopes has a similar effect. Undercutting of hillsides for roads

and houselots triggers landslides.

Another aim of physiographic studies is to limit occupancy of flood­

prone areas (valley floors) by activities such as open spaces and gardens
which are compatible with natural flood storage. However, flood plains in
 urban areas are usually occupied by slums or by housing colonies due to the

fact that information regarding chances 'of flood are suppressed by

unscrupulous land developers or others with various vested interests or lack
of information.

2.2. Methodology

The physiographical study was conducted with the help of contour

maps along with physical investigation of the study area. Relief map was
then prepared to locate the hills and valleys and geographical boundaries of
the study area (Cochin major basin) - lying in between Laccadives sea in the

west and the ridge line of Muvattupuzha river in the east 8. south and the
ridge line of Periyar in the north - the area which forms the catchment of
Cochin major basin. The micro—catchments of individual streams and the
ridgeline of the Cochin major basin were then marked. This also helped to
fix the physical boundary line of the study area. Microclimatic zones are also
identified from this physiographical study of the area extending over 535 km?

Waterbodies were also located from the physiographical study. Drainage

patterns of individual microcatchments and drainage density of the eastern
Iowhills were also assessed to find out the flood probability and other
difficulties in infrastructure development.

2.3. Discussion

Cochin is a coastal settlement interspersed with backwater system

and fringed on the eastern side by laterite-capped Iowhills from which a
 number of streams originate and drain into the backwater system. The
western part of the study area is a flat coastal zone, which forms a part of
the coastal plains of Kerala, and the eastern lowhills are part of the midland
region (Fig.2.1)

Evaluation of the physiography enabled to understand the various

characteristics of the drainage basin, which is very important in urban

planning. in the present study, with the help of contour maps, the boundary
of the Cochin major basin is identified. Since each drainage basin is
independent in many of the environmental characteristics, assessment of the
environmental resources is done within this framework. In the case of
Cochin major basin, the area is divisible into two major zones with entirely
different landforms (Fig.2.2). They are the eastern lowhills, a zone, which is

further divisible into minor watersheds (sub-basins) and the western flatland,

which is further divisible into many independent drainage planning areas

(Fig.2.3 £92-Lt)

2.3.1. EASTERN LOW HILLS.

This area comes within the midland region of Kerala (CESS Atlas, 88)

and is characterised by low hills and valleys. The area is geomorpho­

logically an etched plain characterised by |aterite—capped low hills with
streams in the valleys draining into tidal canals, which lie at the junction
between the two zones. The eastern low hills are running mostly in a north­
south direction.
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 This zone, which coversan area of 291 km? , is comprised of the 21
stream basins (Fig 2.4), or microcatchments_ each with independent
watershed area. The 21 major streams (vide Annexure 2—l) originate from
the eastern low hills, running mostly in westward direction in between these
lowhills, drain into the tidal canals which also run in a north-south direction

with linkage to the backwater system. These drainage basins have Iaterite
or lateritic soil with occasional rock outcrops. The tidal water channels of
Chitrapuzha, Eroor puzha, Poothotta thodu, Thudiyur puzha and Edappally
thodu separate this sloped lateritic land from the western flat land. Such a
peculiar physiographic nature makes the development planning for the
eastern part very intricate because the characteristics of a drainage basin
are very important in urban planning.

A catchment is drained by a hierarchical network of channels. It is

actually these channels which sculpture the valley in which they lie and are
therefore responsible for the overall orientation of the valleys and hill slopes
in an area (Ordway, 1971). The drainage pattern is the distribution of
streams or channels in an area, which is influenced by the slope of the land,
lithology and structure. The distribution and attitude of the rock system and

their arrangements also control the drainage pattern (Zumberg, 1961). A

study of the drainage patterns and drainage texture is helpful in the
interpretation of geomorphic features and understanding landform evolution
and such information is crucial in the location of appropriate land uses.
 18

Fine drainage texture of dendritic pattern indicates that rock

formations are impervious and the permeability is low (Tideman, 1996). Soil

formed in such areas is deep, heavy and slowly permeable. They are
subject to severe erosion hazards forming gullies at several places and are
less suitable for urban development. Such areas are scarce in the eastern
hill tracts of the study area. Medium textured drainage patterns of radial,
braided and pinnate types, which are characteristics of rock formations with

fractures and joints, are also absent. In the eastern lowhills of the study
area, drainage pattern is angulate, Rectangular and angulate
drainage pattern is normally associated with coarse drainage texture. In
such cases, hydraulic conductivity is high. _The soils are generally shallow
and coarse in texture. Erosion hazards may be mostly due to .«:l'eep slopes.
In general, coarser the drainage texture the higher the conductivity, which is

comparatively safer than the pinnate form in which simultaneous flooding of

the tributary valley occurs. Being angulate, chances of simultaneous

flooding of the valley of the eastern lowhills are less.

The dissection of the terrain is measured in terms of density of

channels. The drainage density is defined as the length of all channels in
the drainage basin divided by the basin area. The drainage density of
individual micro—catchment of the eastern lowhills region of the study area is

given in Table 2.1.

Areas with high drainage density are associated with high flood peak,
high sediment production, steep hill slopes, general 'difficulty of access,
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 19

relatively low suitability for agriculture and high development costs for the
construction of buildings and the installation of bridges, roads and other
facilities. Steep slopes with intricate drainage pattern may render most of
the areas in a drainage basin inaccessible with roads, which will be limited to

drainage divides only. Further, such areas are unsuitable for urban develop­

ment not only due to difficulties encountered in waste disposal but also due
to the reason that soil in such steep slopes are unsuitable for septic tanks.
Steep slopes cause landslides, particularly when disturbed. Such locations
in the study area are identified and presented in Fig.2.SE.

ln lands with gentle topography, construction of buildings will be easy.

But if the gently sloped or level ground is at the valley floor, the area may get

flooded during monsoon season (Fig.2.6). Not only that, the valley floors
width, hill slope gradient, channel density, discharge capacity etc, have
significant role in the generation of flood. Flood-prone areas of this region,
identified with the help of hydrological calculations are presented in Chapterlj
on Surface hydrology .

The lower the location in a drainage basin, the more likely are the
problems posed by upstream water use. The terrain tends to be more flat
and uninteresting also. But water supply and trafficability will be more as
well as construction difficulties will be comparatively less. Upstream is often

constrained by limited water supplies, steep tlerraces etc. Based on the

FIG 2.5 . SLOPE ANALYSIS
FIG -2. 6. VALLEY FLOORS (EASTERN LOW HILLS)
 20

above aspects, areas suitable .-for various developments in the eastern

lowhills of the study area are considered.

Another physiographic feature, which should be taken into account in

the Ianduse proposal, is the shape of the watersheds. Long and narrow
watersheds are likely to have longer time of concentration resulting in lower

runoff rates than more square water sheds of the same size which have a
number of tributaries discharging into the main channel near one point
resulting in flood at that point. This time of concentration also affects the
amount of water, which will infiltrate into the soil within the watershed. The

longer it takes to leave the watershed, the greater will be the ‘infiltration into

the ground. This aspect is considered in detail for the flood computation and

locating flood-prone areas in the chapter on surface hydrology.

An important physiographic feature of concern is land—slope, which

has a major role to play in Ianduse. According to law of falling bodies,

velocity varies as a square root of the vertical drop. Hence, if land—slope

increases 4 times, the water—f|ow velocity on the slope doubles. If the
velocity is doubled, the kinetic energy and consequently the erosive (or
cutting) capacity increases 4 times, i.e., the erosive capacity of the runoff
varies in direct proportion with land—slope. Also, when the velocity is
doubled, the quantity of the material that can be carried is increased by
about 32 times and the size of the particles that can be transported by
pushing or rolling is increased by 64 times (Tideman, 1996). Thus the
degree of slope sets limit on land use, both urban and agriculture.
 2]

A slope analysis of the eastern region of the study area has led to the

following categorisation depending on slope.

Areas with less than 5% slope is ideal for the development of play
fields and building construction. Areas with 5 - 20% slope is good for
building purposes, since construction is easy on these stable slope, chances
for erosion are very less and drainage will be efficient. Areas with 20 - 30%

slope are less suitable for construction activities. ‘Areas with above 30%
slope is least suitable for construction activities. Eventhough, usual
standard is 10% slope for building purposes, slopes up to 30% are
considered suitable in the eastern hills of Cochin since the subsurface is

very stable. Such areas are identified and located in the Fig 2.6.

2.3.2.. WESTERN FLAT LAND

The western flatland (Coastal Plain) comprises of 52 drainage units

covering an area of 115 km? (Annexure-2.2) and islands in the backwater
system with a total land area of 56.4 km? . The backwater system extending
to an area of 72.6 km? also comes within this zone.

This zone lies between the sea and the low hills. Two distinct areas

can be identified in it. They are: ­

a) Flatland interspersed with tidal canals: ­

This strip is only about 1 Km wide in the southern tip and about 6 kms
in the other areas and lies in a north-south direction more or less parallel to

the coastline. The Edakochi Kayal and Ernakulam Kayal separate this
 22

flatland from the western sandbars, which are branches of the Vembanad
estuary. This flatland zone covers a total area of 115 km? as calculated from

the maps.

In this area no drainage basins could be identified since the land is

flat with criss-cross roads and drains. However, there are distinct identifiable

drainage planning areas bounded by natural tidal canals or man—made

features like roads and railway lines which form independent drainage areas

in physiographical as well as from the drainage point of view. 51 drainage­

planning areas are distinguishable in this area (Fig.2.3).

The paddy fields in the flatland are being filled up for building
purposes. Hence the drainage direction is under constant change. The
eastern fringe of this flatland is rather high and sandy in nature, whereas
western part is covered with low paddy fields (most of them drying up in
summer), interspersed with land area 1-2m above MSL u’

b) Backwater Islands and Coastal Sandbars

To the west of the flatland, interspersed with tidal canals, is the island

zone in the backwaters and the sandbars bordering the Laccadives Sea,
which is separated from the flatland by the Edakochi Kayal and Ernakulam

Kayal (Fig 4.1). The sandbar and islands have a north-south orientation,
parallel to the Laccadives Sea. The area, from Andikadavu in the south to
Njarakkal in the north, comes within the study area. The total land area in
the Backwater island zone comes to 56.407 km? .
 23

Six sub zones are distinguishable in this zone. They are: —

1) Area from Andikkadavu to Edakochi in the south and Fort Cochin

and Mattancherry in the north — This is a coastal Iandstrip running parallel

to the Laccadives Sea and separated from the main land by the Edakochi
Kayal. Its total area is 24.897 km2. Its uplands are sandy and low lands are
clayey paddy fields interspersed by tidal canals.

2) Vypin strip from Njarakkal to Vypin - Its boundaries are the ship
channel in the south, local road in the north, Ernakulam backwaters on the
east and Laccadives sea in the west. It covers a total area of 17.097 km?

3) Willingdon Island - It covers an area of 6,556 km? surrounded by‘

backwater.

4) Panambukad-Vallarpadam Island - This Island lies in the Ernakulam

Kayal and covers an area of 2.984 km?

5) Bolghatty-Mulavukad Island - This covers an area of 2.357 km? and lies

in the Ernakulam kayal.

6) Small Islands - Behind the above-mentioned large islands there are a

few islets lying in the backwaters whose total area is about 2.516 km?

2.4. Summary and Conclusion

The study area, which is limited to the Cochin major basin, extending
over 535 km? in area, is composed of:­

(a) 21 stream catchments (sub basins) in the eastern hill tracts with a total
area of 291 km? ,
 24

(b) the flatland interspersed by tidal canals covering an area of 115 km? ,

(c) the islands in the backwater system and the land strip along the sea
coast together covering an area of 56.41 km? , and

(d) the water sheets with an extent of 72.59 km? .

The height of the flatland in the western part of the study area is only

about 1m above MSL at Cochin. This portion comes within the coastal
plains of Kerala. The eastern low hill tract, which comes within the midland
region of Kerala. suddenly rises from about 1m to 20—40m above MSl_ with
|l5m abuvx "Sh
occasional peaks of 60m and above. The maximum height is/\ near
Arakkapady in the northeastern corner of the study area, near Perumbavoor.

This creates drastic difference in the drainage pattern between the two
areas. In the eastern low hills, surface drainage is easy due to the
steepness while in the western part, surface drainage is difficult due to the
flatness of the area. This difference in the drainage pattern makes the two
areas hydrologically distinct.

In the eastern lowhills of the study area drainage pattern is angulate.

Angulate drainage pattern is normally associated with coarse drainage
texture. In such cases, hydraulic conductivity is high. The soils are
generally shallow and coarse in texture. The coarser the drainage texture,
the higher the conductivity. Erosion hazards may be mostly due to steep
slopes. Being angulate. chances of simultaneous flooding of the valley of
the eastern lowhills are less.
 In the eastern part of the study area, the hill tracts do not have a
continuous high ridgeline and through the gaps at several places, sea
breeze penetrates eastwards into the interior. However, the Puthencruz
basin (57.77 km? ), lies in a more or less north—south direction between the

two ridge lines which converges at Arakkapady in the north and diverges out
in the southward direction. This peculiar shape of the basin makes it free
from the influence of direct sea breeze. Besides this, there are several
smaller basins also with similar conditions. The presence of these kinds of
independent basins or depressions has a profound influence on the
microclimatic conditions and dispersion dynamics of pollutants from the
industrial areas of Ambalamugal and Udyogamandal areas.

The western flatland is interspersed with tidal canals and backwater

system. These make the road transport difficult wherever they are not linked
with the mainland by bridges. This keeps many islands within the highly
urbanised areas underdeveloped, though within the immediate proximity of
the highly developed areas. This situation has serious economic and socio­
logical implications.

However, the abundance of waterbodies facilitates easy water trans­

port and livelihood to many, by way of fishing. These waterbodies in the

western part are degraded clue to siltation, eutrophication and disuse in
many areas, which are to be improved by proper widening and deepening of

canals wherever necessary. Rejuvenated canals facilitate water transport

and drainage efficiency. Not only that, the abundant water sheets and
 26

paddy fields within the urban structure provide easy availability of space for

recreational Tacilities and parks by filling shallow waterbodies wherever

required after thorough investigation of the ecological impact of such filling.

As stated earlier, landforms decide the urbanistion pattern. In the

study area, waterbodies decide the settlement pattern in the western parts

and the ridg%ines of hills and floodzone of the streams decide the settlement
pattern in the eastern upland.
 Chapter- 3
Geology and Groundwater
3.1. Introduction

Geology (including soil) decides the dynamics of an ecosystem, which

forms the base on which physical planning is executed. Hence, the

influence of geological environment on man and viceversa has to be
observed and assessed properly before any physical planning is done.
However, oeology is usually neglected in planning either due to ignorance
or due to lack of sufficient information.

Geomorphology is the study of surface forms on the earth. Planning

without the knowledge of geomorphic processes can lead to a series of
omissions and commissions. Even if the planner is not an expert in
geomorphic subjects, an awareness of natural processes can be of great
assistance.

Good site planning and architecture that takes advantage of the

natural features of the site rather than obliterating them will reduce soil loss.

Soil is defined as the surface layer of earth supporting plant life. Land
characteristics that favour soil erosion under various kinds of development
can be recognised early in the planning process. Such information can be
used to plan land use including drainage planning that is compatible with
natural limitations and potentials of each area. Onsite sewage disposal is
the usual norm in suburbs. Bad design or failure to anticipate the site
 28

limitations can lead to septic tank failure, aesthetic problem where sewage

appear on the ground surface or in cut banks and ditches and even public
health dangers. Planners can avoid committing themselves to sites that
have such limitations, if they understand the soil condition.

Knowledge of runoff generation of various locations is also very useful

in planning processes. It allows one to recognise those parts of a landscape

that are likely to be major contributors of either storm runoff or ground water
recharge. Precautions may have to be taken to avoid this zone for
developmental activities or to detain water generated upon them. Zones that
allow ground water recharge and therefore augment the stream flow during
dry weather should be conserved so that they might continue their primary
function instead of being paved or polluted (Mo. Harg, 1969).

Groundwater, besides being a resource, which has to be exploited

judiciously, has profound influence on the geological stability. Excess
withdrawal of groundwater may result in seawater intrusion as well as cause
land subsidence in a coastal sedimentary area" like Cochin.

3.2. Methodology

The study area was first investigated for geomorphological

characteristics with the help of contour maps and field observations. This
was then studied in relation to bore-hole logs obtained from the foundation

engineers "to arrive at conclusions regarding geomorphological

characteristics. These bore-hole logs also revealed the litho-stratigraphy of
 .29

the study area. The various geological strata are studied in the order they
occur - one layer over the other - as revealed by bore hole logs.

Soil sample test results from 500 points in the study area co Ilected
from soil testing laboratory, Vytila, were utilized for evaluating the general status
of soil of the study area. For that, the whole study area was divided in to 4 types, viz.
1. Eastern hilly dry land, 2. Eastern wet land ( valleys) , 3. Western dry land , and 4.
Western wet land. The parameters selected are soil pH and macro nutrient status from
nitrogen ( as percentage of organic carbon ), available phosphorous and potassium
values.

Bore hole logs from Foundation Engineers ( F S Engineers, Cochin, Jain

Associates, Cochin and School of Technology, Cochin University of Science &
Technology ), deep bore well data from Kerala Water Authority and data from Central
Ground Water Board were utilized for the study of ground water regime.
3.3 Discussion

3.3.1. Geology and Geomorphology.

As revealed in the physiographical study, the Cochin basin is having two

physiographically and geomorphologically distinct zones running in a north - South

direction, viz ; the hilly eastern up lands and the western flat terrain which forms part of

the mid land region and coastal plains of Kerala respectively.

The Eastern part of the Cochin basin in as eroding area with mostly
lateritic low hills and their valleys formed by differential erosion and the western
part is a deposition area with the characteristic flat land form with
 30

meandering streams and shallow watersheets. The lateritic nature of the

eastern low-hills ensures their survival because of low erodibilty. On a local

scale, laterite formations, which may have originated beneath lower slopes
of valleys, are now found as summit copings, forming ridges, plateau or
small mesas because of its low erodibility (Thomas, 1974). Wherever
morphological changes have taken place and continue within the laterite
terrain, it is clear that surfaces unprotected by the laterite duricrust are
lowered more rapidly, unless they form bare rock hills (Thomas, 1974). This

kind of differential erosion has given rise to the present ‘etched plain’ of low
laterite hills in the eastern part of the study area. This proves that laterite­
covered areas are erosion resistant and stable.

The ‘valleys’ of such ‘etched plain’ are highly erodible and these
valleys are formed originally due to high erodibility. Human action further
“aggravate the erodibility by mechanical loosening of such areas or by
removing vegetation cover resulting in the formation of gullies in such areas
not protected by laterite duricrust (Thomas, 1974)

The western flatland portion is basically a deposition area. These

sediments were brought from the eastern hills by the streams in the study
area as well as from far off places by Periyar, Muvattupuzha, Pamba,
Manimala, Meenachil and Achankoil rivers which drain into the Vembanad

lake to which the flatland area is closely linked.

In litho—stratigraphy, the various geological strata are studied in the

order of their occurrence - one layer over another. This assessment is
 based on bore—ho|e logs obtained from foundation Engineers and
Geophysicists. The data from the foundation engineers reach up to a depth

of about 50 m (chart 3.1) while those of deep bore wells go up to a depth of

about ‘I00 m or more (Fig.3.2).

Bore—hole data from 50 bore holes (Fig 3.1.a 8. Table 3.1) distributed

mainly in the western part of the study area reveals a laterite layer, several

meters in thickness, at about a depth of 14 to 42 m. Over this laterite layer,

sediments of several meters in depth are seen which might have been
deposited over a long period. Below this laterite layer also, the material is
sediment itself.

Two distinct kind of geological strata exist in the study area. In the
western parts, the geological strata is that of sediments in layers of sand,
clay, clayey sand or sandy clay with a band of laterite at varying thickness

and varying sequences. The depth of these sediment layers go up to a

depth of 115 m in the Ernakulam M.G.Road area as revealed by various
bore hole logs. Any one of these layers forms the uppermost layer of the
soil. The strata of sediments in the western part bear close resemblance to

the general litho-stratigraphy of coastal belt of Kerala.

The litho-stratigraphic classification of the coastal sediment deposits

of Kerala was worked out by Raha and Rajendran (1983). The coastal
sediment of Kerala (including Cochin area) consists of Vembanad formation

(3—60m) with various kinds of sediment layers with an unconformity at its

bottom marked by laterite. Below this is the Ambalapuzha formation (3-whom)

E
d 1
d 2
d 3
.5 . 45
:1 5cl5
.= 3 .. E E 3 3 E E 4 5E
G < 55
CHART — 3.1. BORE LC)_GS

2 1 z z 5 E Q C 5' _ 5‘ 8
as
E E Q.2
E oi
w
9 EE
3E3E9EE~3
E“ 3 E“ 5; 3“ 93 E“ 5 E“ 5 E“ 3
1 §E\,( g‘ EE *5
HV § E:3)
5E
2.00 1.5! SAND
[3§ E g
. sunv
2.0 3.0cuw. L5
0-90. ‘OF 5°“ FILLED EAFHH “LL50 Hm" 0.5’ ~:.-°.F_‘T.°i._ 0.9 “LL50 Hm” FILLED EARTH
SANDY cuw
cunrev SAND 3_0
mm SHELLS V5.0SILW SAND "SAND
5.40 9.0

SILTY

CU" SILTY CLAY SlL1Y cmv SILTY Guy"

. .1'_—s:L’Iv
CLU ______ SAND
_ SILTY cu\Y

SILTY CLAV
27.0
13_o L/mznmc SUY GUY‘
LATEHIIIC 1&0 CLAY
I

255' 20.0*————j cuw S > SANDY CLAY

35.0’
23.5
22.0

' . 44.5­
30.6- 50;, ROCK 5"” CLAY unenmc
cuwev SAND _ 47 _3
SILTY SAND SAND

26,0 2g_0 SANDY CLAY CLAY

3's.9 _ cm 31.9 SAND
SAND

34.9 '
373 5‘"°" CU" 405 CLAYEY SAND so an END OF BORING I

CLAYsoFr
33.0 CLAY“
ROCK SAND5’WDY
‘ CLAY.’
31 .0

47. 5m END or aonwc Lnmmc

44.5
W’ 40.0
' SIL V T cw 37.o«
son ROCK 40 m END OF BORING 40-25 F" END 0" 3°"'"G son ROCK
‘5 M EIND OF BORING l 40 m ‘END or aonmc
( continued )
 7 8 9
(
10
Z
11 18 CHART 3.1. BORE LOGS (continued )'

I3EB1
Q
2 2 EII}
3 2 E =D’
5 E ud EF}2
2 . 2 3 2 5 2 E,
u5 EE1u2:4:5 L5
I: E )— > at g L9
f] 1.4
at at D
I! EU0!
3 E g E‘ E , E B E 5 nI
E
HEn E.
n‘- I'
5 EQEQ§ Q
1'8- ' 1.0
5 3\ Iran
4 05.0
cuwizv
2a VI

. 0.8 '—Fl-LEl3—ET:H— 0'9 153256”. SILTY SAND_

TOP SOIL CLAYEY smo 2 8 SILTY smo 1 .9 __,§_°_j B
' SAND
sun 3.0 SA '0'
5»0 -SAND snmr smo
ma
55

‘VA

4.5
‘ 4~0 ' snmr
cuwev smo SAND 7_5

4.5 14 6I
' cuw WITH SHELLS SMY CU“

LATERITIC.

snmr CLAY, CU” SILTY cuw

20.3
sn_rv

cuv

10.7’
250 snuv cuw
Sim! GUY SANDV cuv 10 m END OF aonmc
12.2 31 _5
CLAYEY SAND'

LATERITIC; 33,0
Guy I I CLMEY SAND 11-5 END or aonmc
3610
SAN”. 35.5 SIL nr CLAY

16.3 40 144mEND
5°" ROCK ROCK
155 m END OF BORING
»5m
OF BOIHING
END or aonmc EDEMEMRY
JECAYED WOOD
SAND

45.2m END or aonmc

(CONTDHH)
 13 14 15 16 17 18 UHAKI — ill. .UUI‘\'.I1i LUUD \UUl|l||lU|::U)

Eggddd
I '4 “­
4
1
D
D!
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E:2,
§2
03
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L‘!

1'5"
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2 0
3.0-0.8
at
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1::I'\I!

sun
‘
SAND
F 3
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55
ca
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FILLED
E
'
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2
u:
gn
1
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z
( 5A
[3
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(
E E u , E E, E E _ 5 E Q E B ( E g
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7°” 5°“ SAND TOP SOIL
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6.5- ' CLAY

"5-0: 3.0 SAND ' .
sum! smo 5'9" CL“ V SAND
. snmr CLAY . sum: SAND ISAND '~”.E"”'°
9.0 8.7 5.6 6 0
SILTY SAND 4-5
8.0.

5MY CU" LA1Enmc

cuw
suuv CLAY 3-5
CLAVEY SAND

_5.,_TYsnnv cuwCW
17.5 SIUY 11.5‘ 1 1 .0

Cw, DISINIEGRATED
nocx

suuv cuw ILATERITI" 15.0 CLAY

g7.o
ISILTY cuw DISINTEGHATED
305 3010LATERITIC
LATEFIITIC 19.5 21 0
29.0 '

CLAY CLAYEY
CLAY so:-‘r
35_o LATERITIC AND
ROCK
nocx s

cur
24.0
CLAYEY
39_0 CLAYEY
42.5
SAND
41.5 SAND
5[L1'y SAND 26m END OF BORING
41.8
4

SILTV CLAY SAND DISINTEGRATED

46,0­
‘ noon 30.0
45 .3 m END or BORING °'5'mEG"”E°
SAND 42.05 m END oFaoRI_NG ' ROCK
aam END or aonmc

so rn END 01: BORING 1 35m END or aonws

(CONTDUH)
 L.'l‘1At{'1' — 3.1. BURE LOGS ‘K Commuea }

19 20 El 22 23 E 4
c: E é/'\
El 99;I én
a—:: :21 2é/\I :..g§/\
E 56
U!

§/'\
e4 5 5 2 g s .g§/\
5 .35
m 5‘ ea 5 E 3
E g E gig , E SE E 5% E E B E ' g
E 35EanEanEan;’[2 5an E
Ill
I3 Q
E1 31 L] Q 13
{h {.5 I-I
31 [33 35 E
an

-0.9 1 .35
GRAVELLY 0.7 ’
smo sumr smo
now son

5 8 SUV SAND snmr SAND" SAND I‘

SAND L

CLAY 3.8 '

urenmc 3'8 7 1 5“, CW,‘
55 30 snnv cuw

2O 3.slur_cuw
s|L1'y CLAV SILTY SAND
5.2

Bm END 0:: aonme . 5.0

SILTY CLAY
5"‘T—Y CL” SILTY CLAY
24o
smov CLAY
26.0
cuw ’ DECAYED
' LATERITIC _.5|L1y CLAY __
29,0 tom END or aonms WOOD
cumsv
SAND

35.0

SAND QLAYEY sun

asm END or aonmc; 263 V

~ 156‘
SOFT 15mumanmc
FIOCK ENDOFBORING
CLAY

:nm' END or aonmc '5-°3"" END 0'‘ BORING

LATEHITIQ
CLAY‘

(CONTD....)
 9g8E Q'3"as
E3
’ _I
35 86 27 28 39 30
5 9I
< E’ 2g
I\nAL’) g
fl§ 5‘"H
§ '3 9
CHART — 3.1. BORE LOGS (con_tinued)A

a g 9 5
gI: n1Egl\I(§>8‘ I\2la’!<‘
D‘:
g E E E E 3 E 3 E I: E E E ‘E’
g I; E n
5QQ'3‘EC‘ E =1 ‘E EEEQE §5 )­

. V , smo
' 0-3 LATEHIIE TOP S0|L- '
- 4.5 .
0 4‘ 10!’ §0IL 10? SOIL ­
FILLED emm 0,3 1.0 1 0' ­
E:

. 8.0
. BOULDER 0.6

5.6SAND"
' snnv CLAY
unanmc SANDY CLAY
DECAYED SAND
cw, D|S|N1EGRA'l ED
SILTY CLAY "°°".
CLAYEY SAND '
WOOD

15.5, SOFY nocx CLAY WITH 5:5

SILTYwooD
DECAYED cuv 330'
HARD wooo
ROCK
9.0.

18.8

CLAY‘ '
S|LTY CLAY
SOFY HOCK ‘ 3»G5Il\ END OF BORING SAND v'_nH

L_ATEnm_c 12.5 I 15 5. SHELL

5”" C‘-AV LATERIIIC
233 16.0 HARD nocx
DISINIEGHATED
- -"CLAY

5‘”°* CL” ND OF BORING ROCK 23 5‘

’-"I'l‘?—7‘D HOCK ­
33.9 lE9rn END OF BORING SOFT ROCK
CLAYEY SAND HARD ROCK
3 SILTY cuw CLAY­
9_9_‘___ __ 27.Brn END OF eonme
40.5m END or aonme

20m END or: aonme

I

(CONTD"")
 _l 31
_; 32
i 33 34 35 36
LJr1A.1‘€1' — 'd.1. BUHE.‘ LOGS (continued)

fa]
Q
2
3 E D5g
‘§"’
(
‘f q
g§ §(-’
“-
3
'3
z uE
§
L3E
Q
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Q
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(
:1
an 3:1uU/\ E4:E);
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an ‘J EE
:1
n 3
a E
cf
I: Ins
V 3
Q‘I 2
fl
In E. g*£3 E EE EEEE:I:gEE :
LAIERITE CLAVEY
O.

3.o 4.0
cuwev smo4_O
CLAY“V
2.0 0.9 GRAVEL FINE smo SAND SM-Y SAN? 5”" SAND­
5M0
I UTERITB 5.0 COARSE SAND 4_3
7 .0 3-5
SAND'

6.8

CLAY snuv cuw

LATERITIC 5;-\|>.vD 51L1Y CLAY
9‘5 LATERITE
I 1 9_3 14.0 '~
Vcuw 24.4 cuw
suuv cuw
LATERITIC SILr_v smo ._,ngg,T.c

Iouslnreennsq
13.7.
0.3 23.0­ CLAY 20.0
3 ' _ CLAYEV smo 15.0

31.0
1052 TEFIITE
7.8’ LA
SANDY CLAY

ROCK‘
Lmenm .
23.5rn END or aonme SANDY CL"
355 ROCK suuv CLAY
SEDEMENTRY
‘ROCK
seoemsumv

35.0
56 4_ CEMENTED
m onme snuv CLAY SAND
15.0 42.0
41 mo or 3 ­
57.4m END OF BORING

41.0
5°" WC" W0or aonmc.
30m END
45m END or aonme

I7.3m END OF aonmc

I

(co}m3....)
:1
5 g_
QEE]
E
V
cl
E EEl
3
E E31
E
.
3 7 3 8 3 9 4 0 41 43
E:1 § :1
a E
E E‘ S E g E E E 2 B 2:M
E
=' E 5 » 9 g 5 . 3 9 5 -=9*4
§_ E
CHART — 3.1. BORE LoGs..(%cominued)

5 d 5
5 §' E.E E E E
n 1;: n :1 CI n
E \./ E E \/ E Q \./ E ’|~_l 5 \./ 5 § S \.I g E \./
L)
§

smn 3.0 0.5 ..’_'_LLE‘”i1. 5 IOP son

snuv cuw

SAND
“NE SAND SILYV
wnu sueu. 6.8 ‘ CIAY
SAND

snqv cuw
9'5 SILTY SAND ‘

snuv cm! 12.0

10.2

7 .0
5'|-" CU”. snuv cuv
cuwev smo
13.0 1 7.5 __
9.5 SANDY5‘LT' SANDY CLAY 1&8
umsnmc
smov cuv 17's’ 21-3 CLAY SUV CL"
1. 4.0-
=cLAv_
WITH COAL '
LA1 EFIITIC 25-0
cuwev
28.5 28.1
smo
smov cur “:21 '9. -290
31.2 30.8
cuwev _smo
‘CLAY
33_7 .____..__
cuwevnsmo 3&0
GFIAVEL . SANDY CLAY
wnn COAL - ‘ sorrnocx - sum! cuw
N40 SHELLS 30.6m END or: aonme W317:
2011! END OF aonme 39-9 SANDY CLAY 40.0
CLAYEY smo

43-0 WITH.
SANDY CLAY DECHED 45.5m em: or aonmq snmr cur
wooo
47.5

I1
SOFT ROCK 50m END or gonwc
49.4m END or aonmc. SM END OF Beams s.wo
(CONTDHH)
 CHART — 3.1. BORE LOGS (continued)

[25 Q 44
( d
43 45
I-Ll
I3 46
-1 . 47
.1 ' 48
9
9<
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ft '19 §-t' ‘n-15E nz E 3'
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2 g x z B E 5.../\;Br~
t:g".~.~Ԥ"
g EEE§‘"5
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E aEB <3
Q
E
-"
E -“:I..v
Q E -I3%
E n E "
...v::§v E
n E5-
9‘ >.«.
III E
m 5 m 3 5 3
n x n 2 Q Q E E E]. h E E
1_ GRAVEL _
SANDY CLAY iov SOIL
0-3 6 SUV SAND Q6 LAIEHIIIC CLAY SAND

2.0 3.8 ' 3_6

cuwev SAND 2.0} Sim’ SAND 1-7 1.3 I
LATEFIITE . 3'0 LATERIIIC CLAY . SAND SM‘-CUY
SILTY smo 5!”, CU“ 5 S
10.5 sumr smo
cuwev smo .
28 A 0 SANDV CLAY 9.0 SAND

WY5cm1cuw
23- 1.5:
29.0 _
1 1.4
SILTV SAND

14.8
SILYY CLAY

SOFT ROCK SEDEMENTFIY

nocx
8.5onsuwee
16.Bm ­
END OF aonmg
R0C:A1.=u SAND, 4;) END or aonme SUV CLAY‘
-10m sun or aonws

' 236
snuv cuw
LATERITE
41 .5 _
ulsunreenmed SOFT ROCK

9 B ROCK 45m END or aonmo

_ 32.5
LATF7F1|T|C

29.4

éILI_v cuy

"um END or aonmc _ smo

35m END OF BORING

(CONTDu")
 CHART — 3.1. BORE LOGS'(continued)
49
rd rd 50
9g,3A...aEE33 %'
JA"3>_
2*’
53EE,_2.
E EE"
2E “E5E~
cuw
wnm SHELLS

SILTY smo
6.5

10.5
SILTY CLAY

snmr cuw

205 LATERITIC
aw
‘ 24.0
223 smov cuv
SILTY SAND

2&5 30.5
umanmc
“ND. cuv
32m em or some 35_ 5

CLAYEYV smd

44'0 unenmc
46.0 cm
s5No

49.5 _END or aonmc-3

 I.-1 --
‘ I! ._. 9­
'7‘*'~‘~§,//<"x.3\\K.--
on 2- '1‘ ‘ II

E9

.5. _lJLI|FL

3.35 89. E o8~ EOo.. 5 con

3.035 #czws_zom_>zm “.0 Joorom

....I

.. -.... ... ._ 2.

..!_..;.. .. \.%v\J _. ­

Z .>.a .z__2<_.zmm .m_mmI» .0.£n_ .u.. .._n_..m ..

.mSoIom :om<wmmm mzfi .E§ .mzo_.:.oo4 no 332 mo". ... n- m._.m<H mmmmm.

50402105 92 wozw6m_u.o rcmmmzza z_I0O mmjo: mmom n_O ZO_._..<OO:_ mg _UZ_>>OIm &<_>_ .w fim - mi
 I

30 _j .
310 am J50 340 310 n 2 413 B 101214151320
OH: '8 B 3 225 3 9 9% E1
SI‘-' "“"SPc[/IMV
AV 20LN
USE
07E GEE OZE
005%
093

FINE
LOOSESAND CLAY 53:
RESISTANCE 1N'—-"— '“-T’
w/LATEnI.TE
2'3 - IN
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13
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SES PANAMPILLY NAGAR KOCHI
PALLIMUKKU, KOCH! - 16 DATE - 17 - 05 - '93
DATE - 30 - 03 ~ '93

Fig - 3.2. FRESH GROUND WATER AVAILABILITY IN

COCHIN SEDI MENTS
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 32

with various kinds of sediment layers. Below this is the Quilon

formation (0.5-130m) consisting of limestone, sandstone, clay, Iignite etc.
This is followed by unconformity (Gneiss, Charnockite, Leptinites etc.)

The basin is tectonically controlled with the development of a

sequence of terrigenous, fluviolacustrine and marine sediments.
Palaentological evidences indicate that the initiation of this basin had taken

place in the Late Eocene (55 million years before present [MYBP]) or
Oligocene (35-25 MYBP) time. The development of laterite and pebble bed
beneath the sediments in this area indicates a break in sedimentation and

regression of the area, a feature that exposed the sediments to weathering

and caused the formation of laterite.

This was followed by a transgression accompanying the Holocene

(10,000 years before present) rise of sea level. This rise of sea level
submerging the platform formed an embayment, which developed a
transitional clay peat horizon of marshy facies followed by an accumulation

of alluvial and deltaic estuarine sediments that accompanied the formation of

sand bars and dunes. This resulted in the development of the lagoon such

as the Vembanad lake and the Ashthamudikayal and several smaller ones
along the coastal tract (Raha and Rajendran, 1983).

Laterite can form only above the level of permanent water table in

areas where there is oscillatory (vertical) movement of the groundwater

(Thomas, 1974). Later, this laterite layer might have sunk below the sea
level, above which fresh sedimentation continued. Thus, the occurrence of a
 33

laterite layer in between two sediment layers may be due to any one or both

of the following causes: ­

. tectonic instability causing upheaval & sinking of the area

rise 8. fall in sea level during the period of the last ice age (Pleistocene —
600,000—1,200,000 years B.P) followed by the warming phase.

The sea level fluctuated with the advance and retreat of great
continental glaciers during the Pleistocene period. Sea level dropped as low
as 100 m during the last advance of glaciers, when large amount of water
was trapped in continental glaciers and rose again when ice melted
(Fakbndge,1960y

In the western part of the study area, the upper layers are clayey
and/or silty clay and extend to more than 10 m in most of the areas. Even
for normal residential buildings appropriate pile or raft foundations are
required with consequent high construction costs. Even with such types of
foundation, there is chance for the building to sink (E.g. Hotel Queen Mary,
High court junction, Ernakulam).

The various geological studies and observation on the western part of

the study area clearly indicate geological instability with every possibility for

aggravation by human activities. In an area of loose clayey and alluvial soil

deposits of upto 150 m and more, even a slight earth quake can be
disastrous since the buildings may sink due to its own weight during an
earthquake.
 L"! .l;».

Earthquakes (Reservoir Induced Seismicity) in many cases are

associated with sudden build up of load at a place as in Koyna dam in
Maharashtra. ldukki dam area in Kerala also felt tremors several times after

the dam was built. It may be because the equilibrium was disturbed due to

the weight of huge quantity of water, which was collected in the dam (Gupta,

1992).

Records during the time of the construction of the Cochin Port show

indications regarding the geological instability of Cochin. Earthquake was

reported in Cochin on 15”‘ January 1934 at 2.15 pm which resulted in the

subsidence of buildings on Willingdon Island (Bristow, 1934). This earth­

quake can be attributed to the crustal imbalance brought about by the weight

of an enormous quantity of uniformly spread sediments dredged from the

backwaters and deposited to a single area to form the Willingdon lsland.

Hence, the possibilities of the occurrence of earthquakes/tremors in

future can not be ruled out since millions of tonnes of earth is being brought

from the eastern lowhills to reclaim marshy areas of western flatland region
of Cochin for extensive construction activities. When the load on the crustal

plate exceeds the threshold level, it has to be relieved by an earthquake. In

Cochin with plastic calyey subsoil, such an occurrence can be disastrous.

The present trend of filling up of marshlands and backwaters may be

hazardous from a geological point of view.

Even though no geological catastrophe occurred in Cochin in the

recent past, we cannot consider Cochin to be geologically stable and free
 35

from such a chance. However, historical evidence clearly indicates

geological instability in the recorded past.

The Malabar Coast (of which Cochin is a part) was the scene of
severe earthquake in 1341, as a consequence of which Waypi (Vypin) lsland

was raised above the sea level (de Bellore, 1904).

Yet another earthquake occurred on 26”‘ July 1953 with a magnitude

of 5.0 in Reichter scale (Kusala Rajendran, 1982).

Also, it is alarming that recently the adjacent districts of Trichur and

Palghat experienced several tremors, which show that the Kerala region is
not immune to seismic activity.

These reports of seismic phenomena, or of subsidence and/or of

considerable rise and fall in the sea level along the Kerala coast necessi­
tated an assessment of the litho-stratigraphy and geomorphology of the
study area so as to enable one to locate geologically stable areas suitable
for urban development.

In the eastern part, the profile is that of lateritic soil followed by

laterite, which lies over the crystalline parent rock. Often the surface layer

itself is of laterite or is close to the surface. This laterite lying just above the

crystalline parent rock can bear very high amount of load. Hence the
eastern upland has considerable advantage over western flatland as far as

construction cost and geologic stability of multi-storied buildings is

 36

considered. This is of particular significance in view of the seismological

history of Cochin.

The sedimentary nature of the litho-stratigraphic structure of Cochin

may also be contributed by periodic subsidence and depostion of sediments

through ages (Bristow, 1938). Moreover, the geological section from the
litho-stratigraphical study indicates gradual sinking of the western part as
indicated by the gradual inclination towards the sea where the basin is
sinking.

3.3.2. Soil types of the Study Area.

The soil of the region can be broadly classified into sandy soil (in area

coming under Cochin Taluk and the area in northwestern part of Parur
taluk). Peaty or Kari soil (occurs as a small belt on the western part of
Kanayannoor Taluk) and lateritic soil on the eastern part of the region. The

sandy soil varies from pure sand to sandy loam.

The basic characteristic of the soil of the study area is that, the soil

throughout is invariably acidic. In the eastern lateritic area, the

pH varies from 4.5 to 6 in the case of wetlands (paddy fields) and 5.2 to 6.3

in the case of drylands. In the western flat land area, the pH is as low as 4.2

in many places and vary from 4.2 to 6 in wetland and varies from 4.9 to 6.5

in drylands.
 Macro nutrients

a). Nitrogen (expressed as % organic carbon)

in the eastern latentic land the percentage of the organic carbon

varies from 0.1 to 0.71% in the case of dry land and 0.08 to 1.12% in the
case of wetlands (paddy fields). In the western flatland area, the percentage

organic carbon varies from 0.17 to 0.69 %in the case of dryland and 0.13 to
0.85% in the case of wetland. The assessment shows more or less uniform

fertility status between highland and flatiands as far as percentage of the

carbon is concerned. Udayamperoor area shows very low organic carbon
content due to the loose sandy nature of the soil.

b) Phosphorous

In the northern part of the eastern highlands, the value of available

phosphorus is mostly above 32 mg/kg, while in the southern part of the
eastern highlands it is mostly between 10 to 32 mg/kg. The value of
available phosphorus in the south-eastern part of the flatland is as low as 3

to 4 mg/kg in most of the places, while in its south—western parts it is mostly

higher than 32 mg/kg, though there are sporadic lower values. In the
northern half of the western flatland also, the value is mostly higher than
32 mg/kg.

However, the Eroor area in the flatland lying near the Ambalamughal

industrial belt shows exceptionally high values as high as 108 mg/kg which
may be due to the effluents from the FACT.
 c). Potassium.

In the case of potassium, the dryland in the eastern upland shows

106 to 459 mg/kg in the northern part and 108 to 145 mg/kg in the southern

part. The value for wetland is 238 to 560 mg/kg in the northern part and 117

to 1122 mg/kg in the southern part.

In the flatland area, the value for potassium is 156 to 560 mg/kg in the

northern part of the dryland and 190 to 257 mg/kg in the southern part of the

dry land. The value of wetland is 291 to 347 mg/kg in the north and 168 to

392 mg/kg in the south.

Unusually high values of phosphorus seen in the Eroor area can be

attributed to effluents from FACT flowing into the Champakara canal.

If the soil does not allow water to drain away freely, the soil becomes

saturated and unsuitable for construction, farming or recreation without

artificial drains. Information on soil drainage is extremely useful for zoning
land as suitable or unsuitable for certain kinds of uses.

3.3.3. Groundwater

In order to analyse at groundwater level and availability, data from 50 bore­

logs of foundation engineers and data of groundwater from 7 wells (Fig3.4)

of Central Ground water Board are alluded to.
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 It is seen that during summer months. the water table goes as low as

10 -12 m below ground level in the eastern lowhills whereas in the western

flatland area even in summer the water table is only 1.5 to 3 m below ground

level (Table 3.3).

In the eastern uplands, the large—scale groundwater exploitation is

likely to cause the following problems: —

Drying up of nearby streams, open wells and ecosystem,

If the aquifer is too porous, toxic materials and germs from overland—polluted

rivers may pass into the ground water system (Fig 3.5.a).

Another aspect of serious concern is overexploitation of ground water

far above safe yield limit. In order to keep the withdrawal within the safe
yield limit, the rate of pumping should be adjusted so that over a period of
years (allowing for fluctuation of weather) the change in storage is zero and

the source is not depleted.

When water is pumped from a bore well, a cone of depression is

formed at the end of the suction pump and equilibrium is reached so long as

the recharge of the aquifer is sufficient to supply the pumpage. If it is not,

the cone of depression will continue to steepen and thus necessitating a

continuous deepening of the well, thereby increasing the cost of pumping.

When several bore wells are installed in close proximity, the cone of
depression of different wells intersect and only the deepest well among them

will get water. This will compel the neighboring wells to go deeper and this

competition in unplanned withdrawal of water may end up in legal battle

 Table - 3.3. DATA OF GROUND WATER LEVELS IN KOCHI
( CGwB WELLS)
Year - 1986
w JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC
No

1 _Dt/LVL Dt./LVL Dt/LVL Dt/LVL Dt/LVL DULVL Dt/LVL Dt/LVL D1/LVL D1/LVL Dt/LVL Dt/LVL
_ (12) 9.95 _ . (5) 10.20 . . . _ . . (23) 9.70 _ _ . . (11) 9 45 . .
2 _ _ (11) 2.93 . _ (4) 3 55 . . _ _ . . (29) 2.09 . . . _ (10) 2 05
3 . . (12)209 - - (6) 7.05 . . . . _ _ (23) 1.09 . . _ . (11) D85 .
4 _ (12) 1.30 . _ (l0)312 _ . _ _ . _ (22)2.6O . . . _ (9) 2.10 .
5 _ (12)755 . . (5)1251 _ _ _ _ _ _ 23)10 75 _ . . . (5)1291
5 _ (12) 2 34 _ . (6) 2.91 _ _ _ _ _ _ (23) 2.57 _ _ _ _ (11) 2.44
7 _ _ (12) 3 on _ . (10) 3 50 . . _ _ _ _ (27)2.02 . . . . (9)150 .
W No. - Well Number ; Dt. - Date; LVL. - Level; All levels are in metres below ground level.

Year - 1987
w JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC
No
Dt/LVL DULVL DULVL DULVL Dt/LVL DULVL DULVL Dt/LVL Dl/LVL DULVL DULVL Dt/LVL
1 (a) 10.10 . . _ _ (4) 10.30 _ _ _ _ _ _ (19) 7.50 _ _ _ _ (4)-3.92 . .
2 (7) 2.92 _ _ _ _ (4) 3.50 . . . . _ _ (25) o 77 . _ _ . (4) 2 19 _
3 (7) 1.50 . _ _ _ (.1) 2.10 _ . _ _ . . (20)135 . . _ _ (4)154 .
4 (7) 3.01 _ . _ . (3) 3.33 _ _ _ _ _ _ (19) 1.70 . . . _ (5) 2.57 .
5 (8)1220 _ _ . . (5)1291 _ _ . _ . . 120) 4 57 _ _ _ _ (4) 11 B1
6 (7) 2.93 . _ . . (5)313 _ _ _ _ _ . (20)1 40 . - . . (4) 2 65 .
7 (7) 2.33 _ . . . (5)3 60 . - . . . . (20) 1.44 _ _ _ _ (-1) 2.37 .
W No. - Well Number; Dt. - Date; LVL. — Level; All levels are in metres below ground level.

Year - 1988
w JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC
N0
D1/LVL Dt/LVL Dt/LVL Dt/LVL DI/LVL D1/LVL Dt/LVL DVLVL Dt/LVL DULVL Dl/LVL Dt/LVL
1 _ _ (5) 10.13 . . . . (25) 13.5 _ _ _ _ (17) 5.10 _ _ _ _ (7) 12.90 . .
2 . . (5) 2.90 . . . . (26)3.17 _ _ (24) 1.37 (18) 1.31! . - . . (8)238 . .
3 . (6) 2.30 . . . . (31) 2.25 - . (26) 1.54 (17) 1.36 . _ . _ (7)1.BB_ .
4 . . (5) 3.14 _ _ _ _ (31) 3.05 . . (20) 2.10 (15) 2.24 _ _ . _ (a) 2.04 ­
5 . (6) 12.46 . _ . . 25113.01 . _ (25) 9.16 (1B)B.9-1 - - - - (7) 11.53
5 - (6) 2.84 _ _ _ _ (25) 3 O5 - . - - (17) 2.24 . _ . - (7) 2.83 - ­
7 . (6) 3.09 . . (28) 3 62 . . _ (15) 1.64 . _ (B) 2.30 .
W No. - Well Number; Dt. - Date; LVL. — Level; All levels are in metres below ground level.

Year - 1989
w JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC
No
D1/LVL DI/LVL Dt/LVL Dt/LVL DULVL D1/LVL Dl/LVL Dl/LVL DI/LVL Dt/LVL DULVL Dt/LVL
1 13)10.17 . . . . . . (25) 10.4 _ _ _ _ _ _ (2) 7.55 _ . (-1) 9.32 . .
2 (14) 2.90 . . . . . . (29) 3.03 . . _ _ _ . (1)1.aa _ _ (5) 1.55 ' . .
3 (13) 2.32 _ _ _ _ . . (20) 2.57 . _ _ _ . . (2) 1.51 _ _ (4) 1.32 . .
4 (12)3.o5 - . . - . . (29) 2.03 . . _ . . . (1)2.-17 . _ (5) 2.05 . .
5 13)12.3B . . . . . . 2fl)12.94 . _ _ _ _ _ (2) 11.06 . . (4) 10.82 . .
5 (13) 2.59 . . . - _ . (25) 2.25 _ _ _ . - . (2) 2.92 . _ (4) 2.25 . .
7 (13)3.01 . _ . . . _ (23) 3.24 . - _ _ _ _ (2) 1.96 . _ (4)1.55 .
W No. - Well Number; Dt. - Date; LVL. - Level; All levels are in metres below ground level.

( contd.. )
( contd.. )

Table - 3.3. DATA OF GROUND WATER LEVELS IN KOCHI

( cows WELLS)
Year - 1990
w JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC
No
Dt/LVL Dt/LVL D1/LVL Dt/LVL DULVL Dt/LVL Dt/LVL DI/LVL Dt/LVL Dt/LVL DULVL Dl/LVL
1 (9)10 08 _ _ _ ‘ _ . (Z5) 9.08 . . _ . (25) 9.30 . . _ _ (13) $.47 _ _
23 (9)
. . .2.79 . . . .1.72
. (25) (29) 2. .El. .(24)
. . (25)1.B0
1.40 . _. _. (I3)
_ (12)! E5
1.47
45 (9)
_ . 12.28
(25)1.sa - (24) 2.42
. . 25)l2.3B . . __ _. . (14)
(24) 7.l3 2.50
. 13)10.95
67 .. .. _- __ .-_(25) 2.58
. . (25) . ._. .(24)
3.15 2.43 . _. _. _- _(13)
. . (24)1.eo 2.42
(1-:)1.9o
W No. - Well Number ; Dt. - Date; LVL. - Level; All levels are in metres below ground level.

Source 2- Cenral Ground Water Board

Location of CGWB wells

Well No. Location Depth

1. Thrikkara - near N G O Olrs. dugwell on high ground 12.65 rn.
2. Tripunilhura- in the premises of Registrar ollice, dugwell on even ground 4.40 rn.
3. Edappally - premises ol St. George Church , dugwell on even ground 3.40 m.
4. Fort Kochi - Thaluk ollice compound, dugwell on even ground 4.40 m.
5. Alwaye - premises of P W D ( B & Fl ) Ollice, dugwell on high ground 14.80 m.
6. Eloor North - south of Mettanam ferry, dugwell on stream bank 3.50 rn.
7. Varappuzha - premises of Chettibhagam L P Schoo|,dugwel| on even ground 4.42 rn.

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 40

between neighboring well owners, as in the case of several American states

(Dunne and Leopold, 1978). Hence, it is necessary to define the safe yield

of major aquifers and to control pumping rates on the basis of quantitative

prediction by geophysicists on how a new withdrawal will affect the whole

ground water system.

Drastic alteration of ground surface can reduce infiltration and thereby

cause a reduction of ground water recharge and of dry weather stream flow.

When the land is paved in urban areas serious reduction of summer stream

flow results (Franke and Mc. Clymonds, 1972). Land use plans should take
account of such deleterious effects of urbanisation.

In the western sedimentary area of Cochin basin, the aquifers are

confined and lie between layers of aquicludes of thick organic clay. ln such

cases, withdrawal of large quantities of ground water may lead to reduction

in pressure and thereby compaction of aquifers resulting in irreversible

subsidence.

The withdrawal of water from storage where it is being replaced only

at a slow rate or not at all is called "Groundwater mining”. It can provide

small supplies over a very long time, but if the source is over-exploited its
useful life is limited.

Compaction of the upper layer of soil when the piezometnc level is

lowered is a serious problem throughout the world. It is more serious in

clayey or silty soil because these materials have low permeability. They

release water very slowly, so that, decrease of head and the resulting
 4|

subsidence often take place over many years even after pumping is
curtailed. The damage resulting from subsidence and the compaction
throughout the world now amounts to 1005 of millions of dollars (Dunne and

Leopold, 1978). Differential settling disrupts canals. drains and river

gradients, there by reducing their conveyance capacities or at times
increases their velocities resulting in bank erosion. Differential settling can
also cause fracturing of drain pipes, well casing etc. or can crack buildings,
bridges and even roads as has happened in Mexico City (Loehnberg, 1958).

In Mexico City heavy groundwater pumping for Municipal supply

accompanying the growth of city has lowered the piezometric surface by
upto 2 m per year. This lowering of the piezometric pressure has caused the
overlying 50 m sediment material to subside at a rate of upto 30 cm/year by
1950, and by that time has lowered the central city upto 5-7 m (Loehnberg,
1958).

In Tokyo, Japan, the total local subsidence because of deep bore well
pumping of water exceeded 4 meters since 1892 and in order to retard
subsidence, rigid controls over ground water pumping for industrial and
domestic purposes were introduced in 1961 and 1963.

A more complicated situation exists in Venice, Italy, where the land is

sinking slowly as the Earth's crust bucklesunder the combined effects of

aquifer compaction as well as weight of enormous quantity of sediments

brought from the Alps by rivers. Venice and its neighboring main lands are
interconnected parts of the recent geologic sequence of unconsolidated
sand, silt and clay. The ground water, contained in the sediments, is
pumped from wells in Venice and neighbouring mainland. In the early 20”‘

century, rapid industrialisation led to heavy withdrawal of ground water from

these aquifers and thus lowering the water pressure in the underlying
sediments, which supported part of the weight of the overlying sediments.

This lowering of pressure led to compaction of the aquifer resulting in the

subsidence of ground surface. Measurement of subsidence for the period

1952-1969 was about 10 cm in Venice and about 14 cm at the centre of the

Marghera Wellfields in the mainland (Dunne and Leopold, 1978).

Yet another aspect of concern is excessive reclamation by dredging

of backwaters which will have serious repercussions not only in the ecology

of the backwater system but also in the groundwater quality. In Venice,

partial filling of lagoons and dredging of deep shipping channels
compounded the land subsidence problem by containing the high tides
gathered by strong winds which allowed the tides to penetrate farther inland

posing threat to the very existence of Venice. The proposed Vallarpadam

super tanker trans-shipment terminal and Gosris island development project

in Cochin have to be viewed in the light of what has happened in Venice.

In higher level confined aquifers (which is only a few m below the

ground surface), a lack of aquifer recharging and drying up of the surface

aquiclude, may result in the cracking of the upper layer of the earth causing

splitting of the buildings as has happened a few years back in Parur in

Kerala in a severe summer.
 The subsurface condition of Cochin is more or less similar to those

cases mentioned above. The depth of sediment in the western part of

Cochin is even more than 230 m. Recently, fresh water was struck at about

75 to 95 m below the ground level at several places very close to the

backwater system in the western flat sedimentary areas overlaid by
impervious clay layers. Medical Trust Hospital, located in this area, is
meeting most of its requirements by regularly pumping large quantities of

ground water. This finding has led to a series of borings at several places in

the central city by various large scale housing agencies, since pipe water is
scarce and costlier than bore wells in the long run. Unless this trend is
checked immediately, the tragedy of Venice may repeat in Cochin, perhaps

at a greater magnitude.

Such a subsidence, even at a smaller scale, can disrupt canals,

drains and river flows as well as cause fracture, warping and cracking of
buildings, roads, bridges, rails etc. Since, the western flatland portion of the

study area lies at an elevation of about 1.5 m above MSL, the consequences

of a subsidence to a depth of few meters will be tragic, to say the least.

in coastal areas the seawater may extend about 1 km landwards. In

unconfined aquifers in coastal areas, fresh groundwater occurs as a lens

over the heavier seawater. The depth of this fresh water below sea level is

approximately equal to 40 times the height of water table above sea level
(Dunn and Leopold, 1978). Such a balance is due to the density difference
between fresh and saline waters. Hence, each meter decline of the water
 44

table will cause a 40—m rise of the lower boundary of the fresh water lens to

maintain the balance referred to before. Heavy pumping therefore can

produce such a large cone of depression that saline water will eventually
invade the well from below (Fig.3.5.b). Saltwater intrusion is a serious
problem since paving of ground during urbanisation further worsen the
problem by reducing ground water recharge senously.

Another aspect regarding modification of water table is filling up of

marshlands and paddy fields for construction purposes, which will result in a

rise in the water table in the vicinity. This may lead to root suffocation or
death of existing vegetation due to exosmosis from the roots if the ground

water is saline. Further, a rise in water table will jeopardise the drainage
system also.

Also, the discharge of untreated municipal and industrial effluents

ofien contaminates the groundwater system altering its chemical and
physical properties. intrusion of saltwater is not only injurious to plant life but

also affects construction activities. The chemistry of groundwater in saline

area is of importance to foundation engineers where corrosive salty ground

water is present. Special ingredients are to be used in foundation piles in

such areas, thus adding to the cost.
 45

3.4. Summary and Conclusion

The study area comprises of two distinct geological regions. The

western part is a sedimentary area with all the characteristic features of
Tertiary sediment deposit areas of the coastal belt of Kerala and the depth of

the sediments go beyond 100 to ‘I50 m near the sea. This area is not ideal

for urban development from the geological point of view, as the sub -strata

are not stable. The clayey soil in most of the places has already caused
buildings and roads to sink either due to self-weight or because of vibration

due to traffic or construction activities of the adjacent buildings.

Future kirban developments in the western part should be restricted

taking into consideration the following findings of this study: —

Litho-stratigraphical evidence indicates periodic sinking and upheaval and/or

transgression and regression of the sea.

This area has a history of seismic activity,

Large scale filling of low lying areas can induce crustal imbalance leading to
tremors.

This area lies very near to sea level and hence a sea level rise induced by

global warming can inundate a large portion of this area depending on the

intensity of the global warming.

This area has a sedimentary origin with clay as the major component which
increases the foundation cost
 WU

Large scale reclamation and dredging of backwater system will induce not

only geological instability but also increased wave activity and intrusion of
tidal water further inland.

‘I In most of this area the groundwater in the upper strata is not potable and
unsuitable for construction purposes either due to salinity or high organic
content

Recently potable groundwater is being exploited on a large scale from a

depth of 70 to 90 m. V\fith the recent government ruling that treated public

water supply scheme will not cater to the needs of multistoried residential

complexes, excessive ground water mining is bound to increase. This may

lead to land subsidence and salt water intrusion in the near future.

Drainage is difficult being a flat terrain.

The eastern highland area of the study area falls within the midland
region of the state of Kerala. This eastern lowhills are geologically more

stable since the composition is either laterite or lateritic soil forming a épping
over a laterite layer, which in turn lies over crystalline parent rock. This kind

of litho-stratigraphy is very stable and hence good for urban developments.‘

It is found that the most urbanised western part is geologically not very good

for urban developments while the less urbanised eastern upland is good for

urban developments because of the following reasons: —

The sub strata are geologically stable in most oflthe areas, and hence the
foundation cost will be less,
 47

2. Also, onsite quarried laterite blocks / granite can be utilised thus reducing
construction costs,

3. Potable ground water is available,

4. There is adequate slope for efficient drainage.

However, in the eastern uplands the valley floors and steep slopes
should be avoided for building purposes.

The soil in the study area is of two distinct natures. Lateritic soil in the

eastern upland and sedimentary soils in the western parts with sandy soil
varying from pure sand to sandy loam and clay in varying proportions.
Paddy fields contain peaty soil which is extremely acidic. Udayamperur area

has sandy soil with extremely low organic content. Eroor area has a
remarkably phosphorous rich soil, which can be attributed to the pollution
from a fertilizer factory.
 Chapter - 4

Surface Hydrology and Backwater System

Introduction

Many of the environmental problems of Cochir‘. are hydrologic in

origin; like water-log;ginq/floods, sedimentation and pollution in the water
bodies as well as shoreline erosion.

Hydrology involves the study of water over and under land surfaces
Several aspects of the hydrologic cycle get drastically modified during
urbanisation, which in turn influences the whole urban environment. The
detailed knowledge about the runoff in an area enables the planner to
recognize the constraints and opportunities from which the prediction of the
nrilure and corist'->qiinn(:u.v. of any form of land developrnenl_ is poss:il)le.

Also, information about runoff producing areas is an essential input in

formulating zoning regulations.

The drainage basin in which some designs or planning is done olleri

forms a portion of a larger drainage basin whose downstream portion may

suffer from the effects of the design unless they are carefully planned. Also,

in some landscapes topographic limit of the drainage basin may not coincide
with boundary between subsurface drainage systems. Sometimes, inter
basin linkages are also established in the lower reaches of the stream during

floods. The drainage basin is a convenient unit for the understanding of

 .14)

hydrologic and geomorphic processes and for analysing the spatial linkages
between different areas that can affect both regional and site planning.

Deforestation, road and building construction or the spreading of

W.'_11.‘.t()!'} and :'.ow;.'igt: rrfllueulz-: rile, l(.>rit:l to poor soil t.lr.'iiu.'igt: mid liuizz will

increase storm runoff. Zones that produce storm runotf also 3,-ieéd sedi­
ments, nutrients, pathogens as well as other biological and chemical pollu­
tants. Thus, a detailed understanding of storm runoff production will shed
light on the pollutant load of various streams which will in turn enable the
planner to formulate the management techniques to minimise the pollution
levels of the surface water.

Drainage basin is the land that drains water, sediment and dissolved
materials through a common outlet at some point along a stream channel.
The term is synonymous with ‘watershed’ in American usage and
‘catchment’ or ‘sub basin‘ in most other countries. The boundary of a
drainage basin is known as ‘drainage divide’ in USA and as ‘watershed’ in

other countries (Dunn and Leopold, 1978). Thus the word can mean an
area or a line. In this study, the nomenclature “drainage basin" is used. The

study area is a major drainage basin, which is separated by ridgelines from

the Muvattupuzha river valley and Periyar river valley. The term "micro—
catchment" or “sub basin” is used for the drainage areas of small drains and
streams within it.

The rainwater, after interception reaches the ground and a part of it,

which infiltrates into the soil, is available to recharge the groundwater

 50

storage. When a storm exceeds the infiltration capacity, water spills and
flows down the slope as overland flow. When it reaches a stream channel, it
is called as storm runoff or direct runoff. If this exceeds the capacity of the

stream, there will be flooding.

The lower the infiltration capacity of the ground, the ltiglim will he llur
runoff and chances for flood hazard in the lower reaches of the stream. On

terrains with low permeability, the flood occurrence will be simultaneous to

heavy rains as in urban areas where the percentage of paved areas is very
high. Increase in magnitude and frequency of flooding is typical results of
urbanisation. These effects are greatest immediately downstream of the
urbanised area but decreases or fades away with the distance downstream.
The infiltration capacity of the urban areas is often lowered to zero, due to
the covering of parts of the drain catchments with impervious roofs, side
walks, roadways and parking lots. Also, the areas, which remain soil­
covered, are trampled to almost an impervious state, so that the volume and
rate of the overland flow is increased. Filling and/or covering as well as
clogging of natural drainage channels also contribute to floods and water­
logging problems, with ensuing health hazards.

Gutters, drains and storm sewers are laid in the urbanised area to
convoy the runoff rapidly to stream channels. Natural channels are often
straightened, deepened or lined with concrete to make them hydraulically

smoother. Each of these increases the drainage efficiency. However, the

trapping of waste materials by water supply and telephone conduits which
 5I

cross these drains, often result in floods. Moreover, during torrential rains,
the increased drainage flow is curtailed at the constrictions offered by
culverts and bridges.

A major aspect to be considered by planners is the flood possibility of

an area, which very much depends on the land use pattern. /\ typical
example is the incident of 1981, when a building of Jaipur University was
carried away and another crumbled as the earth beneath was washed away
by flood waters. This happened because the building was constructed at a
natural outlet of water, which was filled up assuming that such a large
watt,-iway was LlllllUt;tJ‘.’>LlLJly lll a thy area like Jaipur. llov-w_—:vc=i, lll 19331, the

tlocdwater from an unusually torrential rain took its natural course through
the tilled up tzhnnnt,-I caiiyiiig away the buildings; nlorig with it In many
places, buildings are being constructed in the floodway of rivers and rivulets

after filling up. Such floodways may deceptively appear unnecessary in

normal floods, but in case of unusually heavy Hoods the water Wlll t;lt;:.ir llE:3

way through the filled up area. This can be very devastating near the outlets
of valleys or watersheds.

Another influence of urbanisation on the hydrologic cycle is in the

ground water recharge. Due to the artificial imperviousness of the surface
soil layer in cities, the water falling over the land is wasted as surface runoll

rather than being availed for recharging the groundwater. Such a reduced
groundwater recharge, supplemented by increased exploitation, will result in

either a drastic lowering of groundwater table or saltwater intrusion;

 52

case of coastal cities. Another problem to be envisaged is the water erosion

associated with urbanisation of hill slopes. There are not yet any quanti­
tative estimates of the contribution of rill and gully erosion on urban constru­
ction sites, road cuts or mined areas and spoil heaps, all of which favour
severe erosion. The total cost of such accelerated soil erosion, both in
monetary terms and in human suffering, will be very high. Hence, it has
become imperative for planners to study the expected impact of the propo­
sed land use on hydrologic cycle and runoff process.

Cochin, is not only a coastal city, but also is interspersed with an

extensive backwater system and tidal canals forming a part of the
Vembanad Estuary which receives freshwater from several livers and salt
water from Laccadives sea. It not only sustains a rich aquatic fauna and

flora but also provides navigational facility including shipping.

4.2. Methodology

Individual microcatchments and drainage planning areas of Cochin

were identified with the help of contour and land use maps supplemented by

field investigations.

In the present study, run-off from the 21 catchments in the eastern

portion of the study area is calculated in relation to rainfall intensity, water
shed area and time of concentration. This run-off is compared to the
calculated discharge capacity of the corresponding streams, to find out,
whether the area is flood—prone. Such an analysis enables to identify the
critical areas to be preserved in order to avoid future llooding problems.
From the available records of annual peak rainfall data and hourly tabulation,

the annual series was formed for durations of 15 minutes, 30 minutes, 1 hr,
6hr;
3 hrs,/\12 hrs, and 24 hrs as given below (Unit mm /hr).

TABLE 4.1

ANNUAL SERIES OF RAINFALL DATA OF COCHIN

Duration 15 min 30 min 1hr 3hr 6hr 12hr 24hr

Year

1976 84.80 68.00 49.50 26.50 10.30 6.80 5.70

1977 120.00 84.00 56.00 24.80 11.60 11.30 8.10
1978 200.00 140.00 53.00 35.90 16.30 25.30 12.70
1979 136.00 94.00 48.30 23.00 16.20 7.20 5.60
1980 120.00 120.00 92.00 32.80 10.90 6.30 4.10
1981 120.00 120.00 100.00 20.90 13.20 7.70 6.60
1982 80.00 80.00 59.50 27.50 24.20 12.20 7.00
1983 140.00 90.00 50.00 16.40 10.30 5.00 4.60
1984 130.00 80.00 39.50 17.90 9.20 6.00 4.10
1985 96.00 88.00 73.00 41.60 13.80 7.10 5.40
1986 104.00 92.00 40.50 20.20 10.30 6.00 4.90
1987 88.00 82.00 36.20 18.90 21.80 12.20 6.30
1988 120.00 89.00 50.00 21.50 13.00 8.60 5.30
1989 120.00 120.00 100.00 48.20 13.00 8.00 6.30
1990 120.00 100.00 70.50 29.80 16.50 8.70 5.80
(Source: KUDP Report, 1992)
 54

To quantify the flooding problems in the eastern upland area, where

clear—cut identification of each microcatchment is possible, the maximum
intensity of rainfall (mm /hr) for 15 minutes, 30 minutes, 1 hr, 3 hrs, 6 hrs, 12

hrs and 24 hrs, derived from the rainfall data for a 15 years period (1976­
1€)0t)), were iizst.-Ll lo c:ilr.:iIl.'it(': Hl(.l run oil (I lorlon Ovorlriiirl l"-low) lroni (éncli

catchment. But in the western flatland area, definite slope of individual area

is not perceptible due to flat nature of land and criss—cross nature of roadside
drains. Hence this part of the study area is not considered for detailed
drainage calculations. The most accepted method of rainfall-runoff analysis

is the R£1tl()l'l£]l riinolf Mt')Hl0(J (Dunn and leopolcl, 1978). This method prodi­

cts peak runoff rates from data on rainfall intensity and drainage basin
characteristics.

Runoff will increase as water from more and more distant parts of the

catchment reaches the outlet. When the whole drainage basin is contri­
buting, tho (Jischurgo l>t;-<:oiiit::s u sloutly sluto How (0), Hit; quzmlily nl wliich

depends on the catchment terrain characteristics and precipitation intensity

(I) as described below

Qpk = 0.278 CIA

Where, Qpk is the peak rate of runoff (m3 ls .), 'l' is the rainfall intensity in
mm/hr, ‘A’ is the drainage area (km? ) and C is the rational runoff coefficient,

which is taken as 0.4 since the eastern upland portion of the study area is
mainly cultivated rural land. The value of C is usually assumed to remain
approximately constant during and between large storms for a given basin.
 55

The maximum intensity of rainfall (I) during a certain time interval (15,

30, 60 minutes etc.) for each catchment is chosen to calculate the above
peak runoff (Qpk) depending upon the time of concentration (Tc) for that
particular catchment. lf Qpk is calculated with an intensity for duration less
than the To the expected runoff will be an overestimate. Hence the selection
of appropriate rainfall intensity depends on the calculation of Tc as given
below (U.S.Soil Conservation Service, '72).­

H0..'lU
where Tc is the time of concentration (hr), L is the length of catchment along

the main stream from the basin outlet to the most distant ridge (ft) and l-l is
the difference in elevation between the basin outlet and the most distant

ridge (ft).

ll UIU dujuliuigu t;t.ipuclly ul u Cllijllllljl ltl lusts llluil lliu iunull ol lliu

catchment, it will result in flood.

In natural watercourses such as streams and rivers uniform flow

seldom occurs. Despite this deviation, friction flow formula for computing

discharges in natural streams assuming uniform flow conditions has been in

wide use (Dunn and Leopold, 1978) and is given below.

Thus the discharge, Q which stand for quantity expressed in is

UK) product of cross sectional area, limo and velocity

Q = AU = WdU, where Q _= discharge in m3 Is, A = Cross sectional

area in m2 .
 U = Velocity in m/5., W = Width in meters and d = Depth in meters

The velocity U depends on depth, slope (water surface gradient) and

is inversely proportional to the boundary resistance and is calculated using

Manning's formula (Dunn and Leopold, 1978), which is the most widely userl

formula to obtain the flow through open channels.

The equation is written as: ­

1 2/3 1/2
U = -——— R S
n.

U = Velocity in m/s

R = Hydraulic radius in m, ie, the ratio of cross sectional area of flowing water
to wetted perimeters,

(In the calculation of stream capacity, cross sectional area of the stream and

perimeter of the stream in water filled condition are taken for the calculation
of ‘R ‘)

S = slope of energy line (the energy gradient) and is approximately the slope of
the water surface.

n = Manning's coefficient of roughness which depends mainly upon the width

and surface roughness of channel, which for the present study area, is taken
as 0.050 — the value given for minor sluggish streams with weed growth and

variable cross section (Dunne and Leopold ‘78).

 ‘I 7

4.3. Discussion

4.3.1. Land Drainage.

’llir.: sliirly ;irt:.'i ('.‘-ll(I(')lll[J.'ti-;!llll(] !3fl.‘3 l<iri37 l‘.‘. (llVl("l(,!(l into two

geographically distinct zones: the eastern upland (291 km? ) comprising of

21 microcatchements (Fig.4.1) draining into the backwater system through
streams and the western lowland covering 244 km? including the backwater

system (72.59 km? ) as shown in figure.4.2_

The western tlatland (Coastal Plain) comprises of 5’| di‘aiiiago units

covering an area of 115 km? and islands in the backwater system with a
total land area of 56.4 km?

Due to the difference in topography, these two regions have distinc­

tive surface hydrological features and hence experience flood problems due
to different reasons. At the junction of eastern upland and the tidal canals,
flood may become a serious problem in the near future due to the following
reason. In the case of several catchments, such as Kadambrayar basin (81
km? ), Pallikkara basin (21 km? ), Puthencruz basin (57 km2) and Pulikkamali

basin (22 km? ), storm water from a very vast area gets collected at the exit
point of each stream and escapes into tidal canals through topographical
constrictions. The stream width is very narrow in those regions with the
floodway only a few hundred meters in width (Fig.4.3).
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Ph_0. THESIS.

SCHOOL OF ENVIRONMENTAL STUDIES.

PART- TIME RESEARCH SCHOLAR.

OCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY

SYSTEM

BACKWATER SYSTEM
FRESH WATER STREAMS" _

FIG - 4.2. FRESH WATER STREAMS AND BACK WATER

M
 133.5 2 %|

mozaioood

d>m._
4mzz<:o 9
//II

>47? D004 m

good mi; - O9

.z_m<m m<><mm_>_<o<v_ n_O zocbmm O_._.<_>_m_IOm m 413

 58

Changes made on the landscape alter the timing and amount of the
waterflow especially peak (flood) flow. Over a long time, this affects the
channel shape and stability. Channel stability changes are often delayed but

abrupt and may have unwanted and often costly results. Also, land—use
modifications in the upstream areas of hilly terrains increase the flood
frequency in the downhill regions, which were originally outside the flood

prone areas, due to reduction in the capacity of the streams because of

siltation and increase in peak flow.

Presently, the floodwater from the 21 stream sub—basins of the Cochin

major basin overflows to fill up the flood zone, which are mostly paddy fields,

on either side before reaching the tidal canals. The |arge—scale filling going

on in these paddy fields near these outlets for construction or plantation

purposes is sure to eliminate this llood zone. During heavy mini:-., lllli‘. lilluu‘

up land acts as a dam causing severe flood in the immediate upstream area.
When the flood water exceeds the holding capacity of these unintentional
‘dams’, the surging water is likely to carry away the filled up earth along with

the buildings creating flash flood in downstream areas, a situation similar to

that occurred in Jaipur as mentioned earlier.

In order to prevent such a disaster, those buffer zones are to be

declared as "fll|ing—free zone", so that, during very heavy rains, vast drainage

basins of the streams such as Kadambrayar (84 km? ), Puthencruz basin (54

km? ) can easily drain their flood-waters into the backwater system through
their flood zones.
 5‘)

In the U S A, flood prone areas are partitioned into two zones; the
flood fringe and floodway. The former is the area that would be inundated
by the 100—year discharge. In this area new buildings must be flood proofed

whose lower floors must be at a level that will provide protection against
immniziirm nnrl nq:iin:'.| <l.'iin:i§)<; lioiii llonling rlol)ri:e‘,_ In Him lloorlwuy, hull­

ding or filling is usually forbidden and the area is maintained as green space.
In USA, Federal Development Loans are not available for floodway land
(Leopold and Dunn, 1978). Development controls similar to that of U S A
may be adopted here also.

In the western parts, flood problem is local and it needs engineering

solution while in the eastern parts, the flood expected is of a regional scale,
which can cause wide damage if planning is not done in anticipation.

Flooding problem in the western part is in fact waterlogging caused

individually or as a net effect of the following reasons: ­

1. Absence of sufficiently wide drains with adequate slope connected to

tidal canals.

2. Improper location of housing colonies and commercial centers in

swampy areas after filling up.

3. Land originally above flood hazard becomes prone to frequent flooding

due to filling up of the surrounding low-lying areas to comparatively higher

levels for construction purposes, from where, during rains, water drains into
the originally highlands causing floods.
 60

In a recent study of the runoff of catchments and discharge rates of

the drains of Kathrukadavu - Pulleppady area it is seen that the average
efficiency of the drain is 43.31%. Out of the 34 catchments studied in the
area 12 have less than 25% efficiency, 25 have less than 50% efficiency and

25 have less than 75% efficiency and only one has 100% drainage efficiency
(Alex et al 1997). The above study is a typical example of the general
situation in all highly urbanised parts of the western flatland of the study
area.

This water—|ogging problem can be easily remedied by engineering

solutions (linking the road side drains to the nearest tidal canals), since, no
part in this area is more than 2 or 3 kms away from a major tidal canal and

the maximum extent of each catchment is only a few hectares. In this part,
tidal canals are of several meters in width and run in a north—south direction

more or less parallel to each other. Constructing roadside drains and linking

them to the tidal canals or backwater system at the nearest point is sure to
solve the waterlogging problem to a great extent in these parts where flood
is very frequent due to local depressions. Also, local authorities should
ensure the periodic maintenance of the drains.

In the highly urbanised western area of Cochin, plinth height of each

building in the catchment must be of the same level, which will prevent the

runoff from one plot of land flowing into another plot.

 61

4.3.2. The Backwater System

The Cochin backwater system (about 72 km? in area) is a part of the

Vembanad lake which spreads out in the 4 districts of Trichur, Ernakulam,

Kottayam and Alapuzha and covers an area of about 210 km? . Studies of
lime shell deposits suggest that this backwater system formed a part of the
Laccadives sea until the upliftment of the coastal regions of Ernakulam and

Alapuzha districts in the year 1341 AD (Rasalam and Sebastian, 1976).

The Vembanad lake receives most of its fresh water supply through a

network of rivers: the Pampa, Achankoil, Meenachil and Muvattupuzha rivers

in the south and Periyar in the north. These rivers also bring sediments,
plant nutrients and toxic pollutants.

About 7,200 ha of the Vembanad lake come within the study area. It
is comparatively deeper in navigation channels where the depth varies from
8 to 12 meters, whereas in other parts, it is 0.75 to 5 meters. The width of
the bacl<wnter system varies from 100 m to 9 krns. The backwater system is

fringed with wetlands, a good part of which has been already reclaimed.
The extent of the backwater is continuously reduced by siltation and land
reclamation. The backwater system has two permanent openings to the
sea, one at Cochin and the other at Azhikod, through which seawater enter

the estuary system.

In the study area, the backwater system is connected to the

Laccadives Sea (Arabian sea) with a 450 rn — wide channel which provides a
Gateway to the tidal currents as well as ships to the Cochin harbour. The
 62

In the study area, the backwater system is connected to the

Laccadives Sea (Arabian sea) with a 450 m - wide channel which provides a

gateway to the tidal currents as well as ships to the Cochin harbour. The
tide is mixed diurnal/semi diurnal. The amplitude of spring tide is of the
order of 1.6 m. The larger area of the Cochin backwater results in large tidal

flow through the gut. The flow rate averaged over the tide through the gut is

4000 m3 /s during spring tide and 2000 m3 /s during mean tide (personal
communication from Cochin Port). The mean sea level at Cochin is 0.64 m
above chart datum as given in Tide Table '93 (Table 2.1).

At present, the wave action in the backwaters is insignificant.

However, the proposed deepening and widening of the ship channel to suit
the needs of the proposed Cochin-Val/arpadam Container Trans—shipment
Terminal Project may considerably increase the wave action in the
backwaters which may lead to serious erosion problems along the shore­
lines of the islands and Cochin Marine drive as has happened in the case of
Piazza San Marco of Venice, Italy.

The main freshwater inflow to the backwater is during monsoon

period when Periyar in the north supplies about 350 m3 /s while, in the south

Achankoil, Pampa, Manimala, Meenachil and Muvattupuzha rivers together

supply about 900 m3 /s (Kerala Water Authority). This fresh water inflow into

the Cochin backwaters causes a very high flushing rate during monsoon
months. Given a total backwater area of approximately 300 km? (including
other parts of Vembanad lake) and an average depth of 1-2 M, complete
 Along with the freshwater, sediments are also transported through the

streams and rivers, which are deposited either in the flood plains or in the
backwaters where new landforms are being created. This is the process by
which mudflats and islands are created in the Cochin backwaters. Thus

geologic processes are closely linked with hydrologic cycles.

The saline water inlet into this backwater system is through guts at
Cochin and Azhikod, as mentioned earlier. The salinity in the backwater is a
function of the distance from the sea and of fresh water flow from the rivers.

The highest salinity value is recorded during pre—monsoon season

(Vasudevan, 1992). The large riverine freshwater inflow during the south­
west monsoon season (June-September) drives out the entire saline wedge
during ebbflow. In between the haline (salt) and freshwater conditions, there

is an intermediate mesohaline condition. During June and July there is very

low surface salinity whereas below 2 m depth mesohaline condition exists.

A further lowering of salinity values is noticed during August and September.

A monthly distribution of salinity is shown in Fig.4.4.

The vegetation and animal types of the backwater system show

considerable seasonal changes due to the salinity variation. During the pre­

monsoon season (January to April), vegetation adapted to salt condition

alone thrives and the migration of marine fishes and prawns also occur.
During monsoon (June to September), when saltwater gets flushed out, the
vegetation and animals adapted to freshwater proliferate and a luxuriant
growth of vascular plants like Water Hyacinth (Eichhornia crassipes), the
 . . L.u4..h»l
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o oo.o nm.o on.o nv.n p..~ mm.o no.9.

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. o nH.o ~o.ma na.m~ ma.m~ nv.q~ mn.oH mp.o~ n mm.nH aw mm on an mo.mn mo.m~ Hn.o~ nm.HH o oo.o ~m.nH on mm ad on vn.v~ no Ha n~.q. o mm.m om ma mm am am mm m~.~m mm ma om.HH

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 64

During monsoon (June to September), when saltwater gets flushed out, the
vegetation and animals adapted to freshwater proliferate and a luxuriant
growth of vascular plants like Water Hyacinth (Eichhornia crassipes), the
African Payal (Salvinia auriculata) occurs. These plants often obstruct water

transport particularly in tidal canals. These weeds die and sink to the bottom

as soon as the estuarine water becomes saline. Some animals and plants
can survive in both the conditions and such organisms exist throughout.

The high primary productivity and rich production of phytoplankton

and zooplankton in the backwater system sustain a rich fishery. This is
because, most of the fish larvae are voracious feeders of the plankton found
abundantly in the backwaters. Maximum fishery occurs during the inter­
monsoon months of October to April (Silas and Pillai, 1975).

The Vembanad lake sustains 150 species belonging to 100 genera

and 56 families of fishes (Kurup, 1982). Among them, the commercially
important fish species are Metapenaeus dobsoni, Penaeus ind/cus, Meta­
penaeus manoceros, Grey mullets (Mugil sp), Daysciaena albida, Sead bass
(Lates calcarifer), Marine Catfish (Tachysurus sp), Half beak (Hyporhampus
sp), Tarpon (Megalops cyprinoides), Perch (Lutjanus), Pearl spot (Etrop/us
suratensis), Penaeid prawns, Palaemonid prawns (Macrobrachium), Edible
crab (ScyIIa serrata), Black clam (villorita siprinoides) and Penaeus
monodon.

Besides, there is seasonal pisciculture of prawns alternating with

paddy cultivation in bunds extending over an area of 6000 hectares in the
 65

The clam V///or/ta cyprinoides var. ‘Cochinensis’form extensive beds

in the Cochin backwaters, which is a cheap protein source for a large section
of the people and a raw material for the manufacture of cement and lime
(Nair, '75). Oysters of the species Crassostrea madrasens/s are abiiridnnt in

the Cochin backwaters throughout the year, especially in some places near
the harbor.

The backwater system is subject to serious pollution from many

sources. The industrial wastes from various factories in and around Cochin

ultimately reach the backwater through the various rivers and drains. Also,
the residues of pesticides used in Ernakulam, ldukki, Kottayam and Ala­
puzha districts ultimately reach the backwaters to pollute it. The nutrients or

chemicals may be beneficial for aquatic animals and plants (since rich in
nutrients) or may be toxic and detrimental to their growth (if it contains
industrial / domestic effluents and agricultural residuals including pesticides).

Large quantities of effluents are being discharged from various

industries. The main sources of pollution in the southern side are Travan­
core Sugars and Chemicals — Thiruvalla, Hindustan Paper Corporation­
Velloor; and Mc. Dowell Company - Cherthala. The main sources of
pollution in the north are the industries located at the Alwaye, Kalamassery —

Ambalamugal industrial belt. At the downstream of Alwaye, the industries in

the Eloor area cause pollution by the toxic substances like mercury and
insecticides. The main polluting industries in the catchment of the back­
waters are those of Rayons, Aluminium, Chemicals, Fertilizers, Rare Earths,
 66

Insecticides, Zinc and catalysts ( Table - 4 . 3. ). Traces of these Waste

_ discharges are found in water samples and are also found to accumulate in
the sediments and in living organisms in the backwaters (Table-4.2)

The concentration of trace metals in the water, sediments and biota of

Cochin backwaters (KWBSP Repot, 89) is as follows, (ranges of highest

concentration encountered) concentration is expressed in ppm ie pg/litre and
pg/g dry weight in biota.

Table 4.2
Water Sediment Diota
Crassostrea madrasensis(Oyster)
Vi//onra cypnnords (Clam)
Cadmium (Cd) 8.0 - 10.5
Copper (Cu) 1.0-1.2 4.8-5.6 32.5 - 38.5
Iron (Fe) 7.2-7.7 72-93 1900 - 2400
Lead (Pb) 7.0 - 7.5
Manganese (Mn) 5.2 - 7.6
Zinc (Zn) 3.5-4.0 3.1-3.2 960 - 1400
Mercury (Hg) 0.05 - 0.07
Significant concentration of organochlorine pesticides was reported in

the black clam and fish from the Vembanad Lake with a still higher concen­

tration near agricultural areas. Although DDT has been banned inter­
nationally, the same and its derivatives DDE and DDD were found in the
black clams from the backwaters and channels. Low concentration of
Dieldrin, Endrin and Endosulphan were also detected in the clam samples
(KWBSP, 1989). Many parts of the backwater system, which are tradi­
 B I._
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Ph.D. THESIS. #

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SCHOOL OF ENVIRONMENTAL STUDIES.
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HIGH RISK AREAS

FLOOD PHONE ZONE I ' .

' 4 . 5. ' OCHIN UNIVERSITY OF SCIENCE AND TECHNOLCGY

 67

tionally used for coconut husk retting, are characterised with anoxic
condition, putrid smell, high turbidity, presence of phenolic compounds and
Hydrogen Sulphide. Most of the fishes and other aquatic animals desert the
vicinity of retting grounds (KWBSP, 1989).

Also, it is reported that excessive sedimentation within the stream

channel can ruin the spawning habitats of fishes. The deposits of eroded
materials can reduce the conveyance capacity of the channel, especially
from urban drains. The mulching of small areas cleared for urban constru­
ction in the hilly areas can effectively prevent erosion from such areas which

adds to the sedimentation in the water bodies (Wischmeir and Meyer, 1973).

Another method of soil erosion control is terracing of hilly areas.

The backwaters also receive large amount of sewage effluents from

the urban and semi-urban settlements along its coast, such as Cochin
Corporation, Tripunithura, Kalamassery, Alapuzha, Alwaye, Perumbavoor

and Kottayam. This leads to a high concentration of coliform and other

faecal bacteria in water, sediments and shorelines (Samy etal, 1981).

The high concentration of faecal bacteria in the backwaters may

make fish, shrimps and clams to be unsuitable for human consumption.
High concentration of coliform bacteria was detected in fishes and bivalves

collected from Cochin backwaters (Quasim and Madhupratap, 1979) render­

ing them unsuitable for human consumption.

 63

4.4 Summary and Conclusion

The various aspects of hydrology applicable to the land surface of the

study area i.e., the rainfall—runoff relationship and the drainage efficiency of

streams is calculated. Various environmental implications arising out of

these observations are dealt with in this chapter. The salient features of the
backwater system are also assessed.

The study area (535 km? ) is divisible into 3 regions with distinct
surface hydrology characteristics.

(1) The eastern upland (291 km? ) with the highest point 115 m above
MSL and comprising of 21 sub-basins or micro—catchments draining into the

backwater system through streams.

(2) The western flatland (115 km?) interspersed with tidal canals and the
islands in the backwater system (56.4 km? )_

(3) The backwater system (72.59 km? ).

The eastern upland area, being a sloped terrain generates a fast

runoff and is hence prone to erosion. In this area, physiographical study
reveals the presence of 21 sub-basins drained by a stream except a few
which are having basins shared by 2 or 3 streams with interbasin linkage. In

this study, the runoff that would have generated in these sub-basins when
rainfall intensity (maximum in 15 years) corresponding to the time of
concentration of each sub—basin is calculated using the rainfall data from
1976-1990. Thus the discharge capacity of the sub-basin exit points (the
 69

point at which these streams drain into the tidal canals) was calculated. If
the discharge capacity of a channel is less than the runoff of a catchment, it
will result in flood. Such flood-prone areas within the study area are located
and marked in the plan (Fig.4.r5). Such areas are not suitable for urban
development, since these areas, if reclaimed and buildings constructed, are

liable to be washed away by the surging floodwater (Fig.4.6). Also, such

reclaimed areas act as unintentional earthen dams breaking free flow of
flood water and cause damage to agriculture and rural settlements in
upstream areas by frequent floods though they are at present free from flood
hazard. Such areas are marked in the plan as filling-free zone or areas
where only regulated development is permitted.

The western flatland (115 km? ) interspersed with tidal canals is

having a different hydrologic character. Being a flat terrain, interlinked
throughout by urban drains and tidal canals, definite sub—basins are not
distinguishable in this highly urbanised area. In these areas, the only hydro­
logic problem is waterlogging either due to closure of drains or due to
improper location of drains. This problem can be solved by engineering
solution linking roadside drains to the nearby natural tidal canals.

The islands in the backwater system are rural in nature and hence
sufficient natural channels are present to meet the current drainage
requirements. In future, when urbanisation takes place, drains are to be laid

up with proper slope and hierarchy and are to be linked to the backwater
system at the nearest point.
 TABLE -4 .3. MAIN WATER POLLUTING INDUSTRIES IN THE
STUDY AREA

NAME OF OF 0'5’ DISCHARGE QUANTITY

INDUSTRY LoCATIoN CI-IARCE MAIN POLLUTANTS INTO

(|Itres per
daYI
I=ERTILIzERS a. pH,BOD,COD,SS,DS,CHLORlDES,FLUOFI|DES,PHOS­
CHEMICALS UDYOGA- PHATES, FREE AMMONA,/XMMONIACAL NITROGEN, PERlYAR
TRAVANCCRE MANDAL 70400000 HExAvALENTCHRoMIUM,ARSENIC,vANADIUM,
LICI. NITFIATES,OIL&GFIEASE­
FEFITILIZERS II. pH,BOD,COD,SS,DS,CHLOFIlDES,FLUOFI|DES,PHOSPHA

Ltd. OIL&GHEASE
CHEMICALS AMBALA_ 31 400 000 TES,FREEAMMONA,AMMON|ACAL NITRoCEN,HExA CI-IITRA­
TRAvANCoRE MUGAL - ' VALENTCHRoMIUM,ARSENIC,vANADIUM,NITRATEs, PUZHA
COCHIN AMBALA- , CHITRA­
HEHNER-|-Es MUGAL 7,aoo,ooo - pH,BOD,COD,SS,SULPH|DES,O|L&GREASE PUZHA
INDIAN RARE UDYOGA_ pH,,CoD,Ss,DS,CRLoRIDES,FLUoRIDEs,I=IIosPHATES,
EARTHS Ltd MANDAL 3,000,000 AMMCNIACALNITRCCEN,LEAD,zINc,SU .PHlDES, PEFIIYAR
SULPHATES,a-Emitters,b-Emitters
HINDUSTAN pH,I3oD,CoD,SS,Ds.sULPHIDEs,CRLoRIDEs, UNTH|­
INSECTICIDES UDYOGA- 2 O44 O00 ELUoRIDES,PRosI=HATES,sULI=RATRs,I=HENoLIC, THODE
Ltd. MANDAL - - COMPOUNDS.,ENDOSULPHAN,D.D.T.,B.H.C.,ZINC.
OIL&GFIEASE.
CRL-DALMER AMBALA_ pH,BOD,COD,SS,O|L&GF1EASE,PHENOL|C COM- CH|TRA~
LAwRIE Ltd. MUGAL 35.000 POUNDS,S ULPHIDES, PUZHA
CYANIDE,FLUOH|DES,CHROMIUM,
ITRAVANCCRE

HINDUSTAN CI"IITRA­
Ltd.

OFIGANIC AMBALA- 1 200 000 pH,BOD,O|L&GREASE,PHENOLlC COMPOUNDS, PUZHA

CHEMICALS MUGAL ' ' CYANIDES,FLUORIDES,CHFIOMIUI\/LSULPHIDES.
Ltd.
INDIAN UDYOGA_ pH,Ss,soD,oILa.CREASE,I=REE
ALUMINIUM Co MANUAL 3,650,000 AMMoNIA,AMMoNIACAL NITRoGEN,NIcI<EL, PEFIIYAFI
Ltd. CHRCMIUM, LEAD, ZINC, COPPER.
CoMINCo pH,SS,DS.Z|NC,SULPHlDES,SULPHATES,COPPER,FLUO
BINANI ZINC EDAYAR 550,000 RIDES,MERCURY,CADMIUM. PEFIIYAR
Ltd.

HINDUSTAN ERNA- 12 657 pI-I,I3oD,CoD,sS,Ds,,oILa.C.REASE,PHENoLICcoMI=oU BACK­

LEVER Ltd. KULAM ' NDS, SULPH|DES,N|CKEL, I=LUoRIDE,NITRoCEN. wATERs
CARBCRUNDU EDA_
M UNIVERSAL
Ud PPALLY 1,156,000 pH,BOD,SS,DS,OlL&GFIEASE MUTTAR
TRAvANCoREc
HEMICALSEMA pH,SS,PHENOLICCOMPOUNDS,OIL3nGREASE,COPPER,
NUFACTURING UDYOGA‘ 72"5°° CHLCRIDES,FLUoRIDEs,CHRoMIUM,LEAD. PEHWAR
Cq_»Ud_ MAN DAL
TRAVANCDRE PERUM- pH,aoD,CoD,SS,DS,oILa.GRI:ASE,
RAYONS Ltd. BAVOOFI 45'°°°'°°° AMMONIACAL N|TFIOGEN,SULPI-.!DES,Z|NC. PEWYAR
PERIYAR
CHEMICALS EDAYAR 3a,ooo pH,BOD,COD,SS,DS,,O|L&GFIEASE PERIYAR
Lld.
UNITED pH,SS,O|L&GFIEASE , COPPER,NlCKEL,ZlNC.
Ltd. NITRoGEN,cHRoMIuM.
CATALYSTS EDAYAR 537,000 FREE AMMoNIA,AMMoNIAcAL PERIYAFI
COCHIN UDYOGA_ pH,BOD,O|L&GREASE,MANGANESE_ NICKEL, TITANIUM,
RUTILES CYANIDES, CHRCMIUM.
MINERALES II. MANUAL 5o,ooo COPPER, ZINC, CADMIUM, MERCURY, LEAD, PERIYAR

SOUFICE:- KERALA STATE POLLUTION CONTFIO L BOARD

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 70

The Cochin backwater system is a part of the Vembanad Lake, which

covers a total area of 21,050 hectares. About 7,200 ha of this area lies in
the study area. The width of the backwater system varies from 100 m to 9
kms and a depth of about 0.75 to 5 meters. The ship navigation channel
within the backwater system is 8-12 m deep. The backwater system is open
to sea at Cochin and Azhikod. The water is saline during summer months,
which is flushed out during rainy season. After the monsoons, the salt—water

intrusion takes place gradually inwards through these guts. This periodic
(seasonal and tide induced) variation in salinity and nutrient supply supports

a rich aquatic fauna and flora in the backwater system. Extensive land
reclamation and increasing pollution (industrial and urban) has already
started to take its toll in the fishery resources.

The following environmental planning guidelines are suggested based

on this study.

Many of the environmental problems of Cochin are hydrologic in

origin because hydrologic cycle gets drastically modified during urbanisation.

The drainage basins, on which some modifications are done, often form a
portion of a larger drainage basin and hence these modifications may
inadvertently affect also other areas of the drainage basin as well, unless
they are carefully planned. Hence, drainage basin dynamics give a better
understanding of hydrologic and geomorphic processes for analysing the

spatial linkages between different areas that can affect both regional and site
planning
 71

In order to avoid floods, it is necessary to assess the possibilities of

flood hazard in an area and to provide adequate drain size for peak
discharge in any storm. Peak discharge must be estimated from the size of
expected rainstorm and from the characteristics of the catchment. Unlike
water supply or sewerage facilities, storm water drainage system offers little

scope of subsequent improvement essentially because, the system is gravity

dependent

In the land area of the western low-lying region, the main hydrologic

problem is waterlogging due to absence of slope. Hence water gets logged

in the depressions and in the areas where there are no drains or where the
drains are blocked by various reasons. Waterlogging also occurs due to
inadequacy of drain size and/or due to unnecessary meandering of drains
through low-lying areas. Another serious problem is that land originally
above waterlogging levels becomes prone to frequent waterlogging due to
filling up of surrounding low-lying areas to comparatively higher levels for
construction activities.

The waterlogging problem in the western flatland can be easily

remedied by engineering solutions (linking the road-side drains to the nearby

tidal canals), since no part of the area is more than 2 or 3 kms away from a
major tidal canal and the maximum extent of a catchment is only a few
hectares. Proper drainage planning in all the drainage planning areas will
solve the problems if executed along with proper maintenance system.
 Chapter-- 5.
Climate
(H Introduction
Climate plays a decisive role in the evolution of all human
settlements. it determines the hydrology, ecology, socio—economic
development as well as urban evolution. Thus climate deserves clue
weightage in land use planning and industrial location. Any planning without
proper assossirioiit ol the motoorologirnl z.1s.:p(;~(:t:=. may lu:1(.| to VVl'(.)Il{') l(‘)(.‘.£lll()ll

of various land uses resulting in avoidable environmental degradation.

Climate of an area has an important. bearing on its ambient air quality.

Meteorological aspects along with physiography play a crucial role in

determining the concentration of pollutants, which depends on dispersion or
dilution 0|" pollutants. ‘l he general dispersion pattern and direction ol
movement of air pollutants can be understood from the wind climatology and

relating it with physiography. Improper location of industries without consi­

dering the meteorological aspects may result in severe air pollution in
sensitive areas.

Sources of Air Pollution can be natural or man—made. Methane and

hydrogen sulphide emissions from marshlands are the main natural source
of air pollution in Cochin, but it is not yet quantiliod. Man—made pollutants

are:— (1) Oxides of S_u_lp_hur and Nitrogen, (2) Carbon compounds (3)
Particulate matter. Also, there are photochemical compounds (also called
secondary pollutants because in the presence of reactive hydrocarbon, solar
energy is absorbed by N02 to form photochemicals).

Atmospheric stability, which is determined mainly by the vertical

therinnl profile over :1 [)|.'lC(-‘., is imlimtivo of the wiml S-‘.l.’1ill{'1, priiiii-.iii.~.ily in li~.v~

vertical, which in turn. governs the pollutants dispersal. Highly unsftable

conditions, characteristic of a steep vertical decline in temperature, result in
thorough mixing and hence dilution of pollutants. Stable conditions, on the

other hand, are characterised either by a vertically isothermal layer or

with an increasing temperature (inversions) which results in low mixing and
poor dispersal of pollutants.

Depending on the height at which the inversion occurs, the ground

level pollutant concentration can vary. lf the base of the inversion is above

the effective stack height (H), that base line virtually act as a lid below which

a rapid build up of pollutants takes place. If the top of the inversion lies
below the effective stack height, the pollutants will not reach the ground and

consequent build up take place only at higher elevations. However, once

the inversion breaks, a sudden high doze of pollutants is likely to reach the

ground. If the inversion base is below but its top is above the stack height,
the dispersion is completely inhibited. However, in such conditions also,
high ground concentrations are likely to occur when the inversion breaks
after sunrise. Usually inversions are found during night and early mornings.

Atmospheric dispersion of pollutants from stacks depends upon many

interrelated factors. They include the physical and chemical nature of the
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 74

effluents, the meteorological characteristics of the environment, the location

of the stack, and the nature of the terrain down wind from the stack. High

wind speed increases the diluting action of the atmosphere. Hence low
ground level concentrations downwind from the stack.

5.2.. Methodology
The climate of Cochin is studied on macro (regional) and micro (local)

levels to assess the way it influences the general living conditions. For that,

average monthly mean data on rainfall, temperature and humidity data for
the period 1931 to 1960 (Table 5.1), 3—hourly wind rose data for one year

(Fig.5.1) are used.

To obtain the pollution scenario of the study area, monthly mean

concentrations of different air pollutants from 16 stations during 1990
(NEERI-Report, 1991), mixing height data (Anilkumar, 1986) for 12 months

from 9 stations (Fig.5.6) are utilised. This data interpreted in relation to

physiographical aspects and urbanisation pattern of the study area facilitates

the demarcation of different zones based on pollution climatology.

5.3. Discussion

5.3.1. Macroclimate

Macroclimate is the general climate of the area. Cochin enjoys a

tropical climate with intense radiation during the months of December to
May. The relative humidity is very high due to the proximity of the sea and
l

the interspersal of water bodies. This makes the life uncomfortable

 75

particularly in summer months during night time between 8 P.M.to midnight

and early morning hours (the lull between land and sea breezes) when the

wind velocity is very low (Fig.5.1). This kind of climate necessitates the area
to have human settlements with its own characteristic orientation &
ventilation.

There are two rainy seasons 1. The southwest monsoon during June,

July and September, and 2. a weaker northeast monsoon (also considered

as the retreating phase of the southwest monsoon (during the months of
October and November) with a brief dry spell between the two during early
October (Fig.5.2). The yearly average rainfall is about 300 cms. Since the
rainy season extends to about 6 months, drainage is very important
particularly when urban settlements are developed. Not only that, since
there is continuous rain during rainy season any moclilication ol the land
surface without due consideration to the rainfall climatology, is likely to
cause denudation in the eastern sloped terrain due to erosion and water
logging in the flat areas.

The driest month is January followed by February, December, March,

April and November respectively. These months are the most ideal for
construction activities as the number of man-days lost due to heavy rains will
be minimum.

The hottest months (November to April) coincide with the time when

the sun is positioned below of 9° N latitude (Fig.5.3) ). So, during

a year, south-faced slopes are more exposed to the sun making it very
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 SOLAR CHART

FIG - 5 .3. SOLAR CHART FOR (COCHIN) LATITUDE 9°

NORTH
 76

uncomfortable, particularly since the humidity is very high. Hence, south­

ward slopes in a hilly terrain as in the eastern lowhills of the study area are
less suitable for human occupation being exposed to the sun tor about 8
months annually (Kukreja, 1978).

The relative humidity, which is a major determinant of human comfort,

is minimum during January followed by December, February, March, April

and November with about 88%, 71%, 72%, 74 %, 75 % and 78%

iuspucltvely ('lutJlt.: L). l). Mtixiimim humidity is ob:;L:iveLt tluimg .lu|y_ /\t.|{}tl:‘.|

and June with about 89%, 88% and 88% respectively. The hottest months
of the year is April with a daily maximum of 31.4 0 C with a diurnal variation

of about 60 L) and coolest month of the year is July with maximum 28.1 0 C

and minimum 23.7 0 C (Menon and Rajan, 1989). It can be said that the
study area is free from winter season and has only rainy season and
summer SSE-ISOH.

Since the relative humidity is very high, maximum ventilation is to be

ensured while urban colonies are designed. The buildings are to be oriented
-‘so as to obtain maximum ventilation in relation to wind direction during the

most humid and hottest months. Also, buildings are to be designed with
minimum incidence of sunrays on the south sidewalls or appropriate shade

trees are to be planted on the southern side of buildings.

5.3.2. Microclimate

Microclimate is the precise climatic condition in a locality, l (2., it lL.)lL)l:x‘

to the more immediate climate experienced by specific areas within the

region. The various localised conditions, which affect microclimate. are
identified as follows (Fig.5.4).

The study area has a seashore of 17.5 kms. This shoreline is

continuously exposed to (1) salt sprays from the sea, (2) a high albedo from

the white sand and water surface and (3) very high daytime temperatures
radiated lrorn the hot sand. Also, the atmosphere is extremely humid. /\lt
these-make the zone microclimatically distinct resulting in a characteristic
ecosystem.

The coastal plain lies to the east of the shoreline. It has a micro­
climate characteristic of such areas with the presence of direct sea breeze,
high humidity and very low diurnal variation in temperature and humidity, but

with lesser albedo and atmospheric salt content compared to the seashore
arr.2a.

The hill tract lies along the eastern parts of the study area. The four
distinct characteristics of the hill tract have profound influence on the
microclimate.

(i). Relief.

The higher elevations are more exposed to wind action. Since the

hills are very low and the ridge line is not continuous, most of these regions
get either direct or indirect sea breeze except the upper (northern) reaches
: ::.;..<.II
(J
)
1.

BENJAMINQ PM

Ph.D. THESIS.

PAF{T- TIME RESEARCH SCHOLAR. SCHOOL OF ENVIRONMENTAL STUDIES.

COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY

(1)
Z
<
._l
D.
J<
I­
U)
<2:
O
o SEA SHORE

Fig - 5 .4. MICRO CLIMATIC ZONES

 of the Puthencruz basin which is sheltered on the west from the sea breeze

by the continuous (about 15 kms long) hill tract from /\rai<l<ar3nr_ty to

Sasthammugal (Fig.5.4). This hill tract runs in a north-south direction
an opening at the southern end (Sasthammugal) only. Such a shellcror}
condition from sea breeze as well as absence of waterbodies provides this

area with a sharp diurnal variation in temperature in non—monsoon months.

Also, such a physiographic condition prevents to a certain extent the polluted

air from Ambalamugal—l<arimugal industrial area, lying on its west, from ente­

ring this sheltered area during daytime. During the nighttime the wind dire­
ction is mostly towards south, southwest and west and hence the area :'sma—

ins comparatively tree from pollution though very close to the tndustrial bait.
ll<:m:<:, llii:; purl ni ."-llltiy iil(ZJl iz; lnrli-:r .".lll|(t(,J lnr ltiltirri (:><paii:f.i(,in:?. oi uit):m

settlements, with other economic and infrastructural considerations due.

(ii). Aspect.

Aspect is the orientation of the slopes of a hill. The aspect of the

ground and its angle of slope have an important bearing on the amount of
sun's radiation it receives at different seasons and hence the microclimate.

(1) South slope: — Since Cochin lies at about 9° N, for about 8 months in a year,
the sun will lie l(iw;.n<_l:; |llUt1()tIH1 (l igi.!).(5) ;.ui(l lit:n(:t:, lll(:!‘.()lll|lUl'll!1lt)[)l_t3‘.(')l

hills receive more concentrated solar rays for most part of the year and
thereby becoming warmer than flat terrain.

(2) North s|ope:— Coldest slope for most of the year

(3) East slope: — Warm and sultry mornings and mild afternoons
 79

(4) West slope: — Cold mornings and hot and windy afternoons.

Northwest, north, northeast and east aspects are the most ideal for
residerttial development in the eastern low hills region of the study area,
from the solar radiation point of view.

(iii). /xltilurle.

Increase in the altitude results in the reduction of temperature by

about 0.60 C for every 100m. This will have considerable ecological effect.
in the study mea, the ii‘iu;—<iintiin level dillerence is only about ‘I 1.5 in teibovc

MSL and hence, altitude is not an important climatic element.

(iv) Vegetation.

Vegetation has profound influence on the microclimate at a local level

when sinztll areas are (I()l1.‘Si(.‘i(’!l'O(i, But in the stnrly :.m3.'i, COVv.:i(:.'i incur: or

less uniformly with vegetation, zoning based on vegetation cover is not

possible and hence excluded.

CT. .3/3. Air Pollution Climatology

The following meteorological parameters were considered in the

i.l':it3(J5SlllUlll ol uir pollution distribution pattern in the study area. ‘the
direction and speed of the transport of air pollutants as well as its dilution are

mainly governed by the wind. Based on wind data (Fig.5/l) and mixing
height characteristics mainly within the Cochin corporation area (Anilkumar,

1986), and monthly mean concentrations of different air pollutants from 16

 80

stations (Fig.5.5 & Table 5.2) during 1990 (NEERl—Report, 1991) the air

pollution scenario for the study area is worked out.

Road traffic and industries are the major pollution sources in the study

area. Automobiles are significantly contributing to the air pollution; about

one hundred thousand vehicles are said to be scooting in and around
‘Cochin daily.

The major industries in Cochin are located in 2 clusters (Fig.5.7) — one

at Ambalamugal — Karimugal area and the other at the Udyogamandal ­
Kalamasserry — Edayar area. The main industries in the first cluster are —

Hindustan Organic Chemicals, Fertilizers 8. Chemicals Travancore Ltd.,

Milma Dairy Ltd, Carbon & Chemicals Ltd., Traco Cables Ltd., Cochin
refineries Ltd. and Brahmapuram thermal power plant. The main industries
in cluster 2 are Hindustan Insecticides Ltd., lndan Hare Earths Ltd., Travan­

core Cochin Chemicals Ltd., Premier Tyres Ltd, Chackolas Spinning &
Weaving mills, Carborundum Universal l_td, Travancore chemical Manu­
facturing Co.Ltd., Kerala Acids & Chemicals Ltd, Sreechitra Mills, Indian

Aluminium Co.Ltd., Periyar Chemicals Ltd, United catalyst India Ltd.,

Cominco Binani Zinc Ltd., Fertilizers & Chemicals Travancore Ltd and
Hindustan Machine Tools Ltd.

i5(>in('; ol lliotst: ll1(.ll.I:3lll(;‘S rt;-lc-.'i:;u l.'.u'g_1(.=qiiziiililiounlnir pollulznil:--; and

their dispersion is a function of the following aspects.

 ~@
bell!

Ph.D. THESIS. BENJAMIN. F‘.V.

"/'
\ soo m 200m 2000m 4000 metres ‘"5

SCHOOL OF ENVIRONMENTAL STUDIES.

PART- TIME RESEARCH SCHOLAR.

.7‘ “if
OCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY

MONITORING STATIONS

KARIMUGAL. _ IRIMPANAM.

,.\,«,~;\p~,-s
BRAHMAPURAM. KADAYIRUPPU. .
THIRUVANIYUR. TRIPOONITHURA: THIRUVANIYUR(B), ­
PERINCALA. PUTHENCRUZ.
WTITLA C.R.L. GUEST HOUSE. MULANTHURUTHY. THIRUVANKULAM. THRIKKAKARA. CHOTTANIKKARA. AMBALAMUGAL.

SAMPLING LOCATIONS.
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 8|

1. General Climatological Factors

2. Physiographical aspects which influence the wind pattern and hence the
distribution pattern.

3. Controlling factors at the source such as measures taken to control

pollutant emissions and stack height of chimneys.

The pattern of pollutant distribution is assessed in relation to wind

climatology and physiography of the area. An important factor in the
pollution climatology is the (Jll(.‘(3tl()ll ol the wind when the 13[)t.‘L)(l i:-; llllllllllLllll

i.e., during night and early morning hours.

The winds are mostly from west (westerlies) during daytime and carry

pollutants towards east or southeast during daytime (Fig.5.1). The night

time winds are either absent or very weak north-easterlies (Figs.5.1 & 5.8)
and hence pollutants are not transported to long distances resulting in the
accumulation of pollutants in the vicinity of source. Although during South­
west monsoon months the day as well as night time winds are towards east,
the pollution levels are low due to the scrubbing effect of the rains.

The continuous unidirectional (mostly westerlies) wind during day­

time results in the dispersion of pollutants in mostly in an easterly direction

only. This could have created serious air pollution in the localities east of the
industrial clusters.

However, due to the unique physiographical feature of the hill tract

running in a more or less north-south direction perpendicular to the direction
of the day wind, there is continuous upward thrust for the wind when it
 .,

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comes close to the ridges. This together with the high wind velocity keeps
the polluted air from reaching the ground level, protecting the human
population in the valleys of the hill tracts during daytime. Further the high
wind velocity facilitate the last dilution of the pollutants.

During night—tir:‘.e, winds are either absent or blow weakly towarcls S

and SW direction during Jan- Feb; SE, S and SW during September; E, SE,
S & SW during Mar & May; E, SE & S during April; E, S 8. W during June,
October & November; E during July, August and SW during December.

Pollution llazzirtl will be mziximum during invn‘.-r:=.i(>n:; 0: l:3()lll(3lll'l.'1l

conditions which inhibits the disperson of pollutants resulting in high ground

level concentrations. In Cochin, such conditions are maximum during

December, January and February (Anilkumar, 1986). Thus the areas in the
direction of night wind during these months in relation to the major industrial
pollution :=.(_nii(:u:'. /\llll')il|nltlll{']ll| Kmiiritigtil nr0:.i rind Floor--K:ilriirlri:-moiry

area - will have considerable increase in atmospheric pollution. Hence, most

of the densely populated areas in the western flatland in the proximity of

pollution sources are high—risk areas both in the case of normal industrial

pollution or during a disaster (as happened in Bhopal). The consequences

of an industrial disaster can be severe particularly during the calm nights of
winter months when dispersion of pollutants is minimum and ground level
concentrations maximum. Such zones lie in South and Southwest side of
both the industrial areas.
 This study reveals that the place most sale from pollution is the upper

reaches of Kadambrayar, Puthencruz, Churnikkara and Pallikkara basins

(Fig.5.4). Also, during daytime, when strong winds blow towards east, these

areas will have lesser pollution, which is due to following reasons. (1) There

will be thorough mixing and hence dilution when winds are strong and (2)
during daytime when winds blow towards east, these areas will be on the
leeward side of the ridge hills which separates them from the pollution
sources. Kanjiramattom, Pulikkamaly, Churnikkara and Thrikakkara East
basin are also safer when compared to western flatland area. From a
pollution point of view, the Panchayats lying in these sub-basins suitable for

urban development nit; Vengoln, l<i7_h:.1l<l<atnt):.1lam, Etlzilhnln, Clllllllll<l<Lll'.'.l.

Kunnathunadu, Thrikkakara, Aikkaranadu, Poonithura, Maneed, Edal<l<a‘ttu—

vayal, Amballoor, Mnlarnthurulhy, Chottanikkara and part of Vadavu|<odu—

Puthencruz. However, some parts of these Panchayats lying in the south of

Ambalamuga|—Karimugal industrial cluster may be subjected to occasional
[)t)||Illit)|I pmhlmn:-. t:lll(‘.D tlm llllllll--lllllt) wintl (lllt_1()ll()ll it; lownnltz lhnl .-zirlu,

Besides these, some areas far off from the pollution sources such as
Udayamperoor, Kumbalam and Chellanam Panchayats and Cochin taluk
areas of Cochin Corporation as well as the areas free from the night—time
wind direction such as Nayarambalam, Kadamakkudy and Elamkunnapuzha
panchayats may also be free from air pollution from major industries within

the study area.

 34

5.4. Summary and Conclusion

Cochin is a fast-developing industrial metropolis lying in central

Kerala, the southern state of India. Being a tropical coastal settlement, the
Lllllltllll .'m(J (lnirrinl v.'iii.=.ilir)n Ill l<.:inpuri.iltliu :nl(l |lllllll(ll|y li‘. not vury

significant. It can be said that the study area is free from winter season and
has only rainy season and summer season.

The study area enjoys a vigorous Southwest monsoon season and a

mild North—east monsoon with an yearly average rainfall of about 300 cms.
Since the rainy season extends to about 6 months, drainage is very
important particularly when urban settlements are developed. Not only that,
since there is continuous rain during rainy season any l11()Cllll(‘.£lll(2-il ml‘ Ih<;­

land surface without due consideration to the rainfall climatology, is likely to

cause denudation in the eastern sloped terrain due to erosion and

waterlogging in the llat areas.

Since Cochin lies at about 9° N, for about 8 months in a year, the sun
will be towards tho :;l()lll|l rind liuncu, llm 1)0lll|l(lFll u|0|><,=:'. 0|" hills l(2(‘.(llV(_)

more concentrated solar rays for most part of the year and thereby becom­
ing warmer than flat terrain. Hence, south slopes in a hilly terrain as in the
eastern lowhills of the study area are less suitable for human occupation.

Northwest, north, northeast and east aspects are the most ideal for resi­
dential development in this region from the solar radiation point of view.

The relative humidity also is very high making it necessary to have

human settlements with appropriate orientation and ventilation so as to
 X5

obtain maximum ventilation in relation to wind direction particularly during

the most humid and hottest months. Also, buildings are to be designed with
minimum incidence of sunrays on the southside walls without which
appropriate shade trees should be planted.

Cochin the industrial capital of l<cr:il:1. The major ll‘.dtt.“.ll’l().'.>‘ are

located in 2 clusters in the study area — one at Ambalamugal - Karimugal

nmn nnrl the other :it the ll('lyo,q.:irnanclal — l<al:imasserry — Ed."lV{_lF nmn.

Some of these industries release large quantities of air pollutants and their
dispersion is a function of meteorologicaland physiographical aspects. An
important factor in the pollution climatology is the direction of the wind WI‘.Cll

the speed is minimum ie, during night and early morning hours pszrticufariy
during winter season. Rainfall also is a major clnlorminant in thtr riiiriiity oi"
the ambient air due to the scrubbing effect of rains, which reduces the
concentration of atmospheric pollutants.

The winds are mostly from west (westerlies) during daytime and carry

pollutants towards east or southeast. During nighttime, winds are either

absent or very weak north—easterlies and hence pollutants are not trans­
ported to long distances resulting in the accumulation of pollutants in the
vicinity of source.

Pollution hazard will be maximum when inversions or isothermal

conditions occur, since such a condition blocks the dispersion of pollutants

and results in high ground level concentration. Such conditions are found to

be maximum during December, January and February in Cochin. Hence the

 HO

areas in the direction of night wind during these months in relation to the
major industrial zones will have considerable increase in atmospheric
pollution. Thus most of the densely populated areas in the western flatland

are high-risk areas both in the case of normal atmospheric pollution or

during a disaster (as has happened in Bhopal).

As far as the location of the existing industries is concerned, the ideal

[)|.'I(;u would huvn lmmi llin nxlrnmn noiilh wcml portion of lhn nliirly nr«..‘n no

that the interior_of the city and all the densely populated areas would have
been relatively free from pollution. ln such a case most of the spread of the
pollutants NOU|d have been over the ocean.

This study reveals that the places most safe from pollution is the
ll[)[)L:l iu.'.i(;liu:~; ul K;i(l.'nnlwi‘:.iy.'ii'_ l"1il|iui1(;iu'/, (‘,liiiiiiil<|t.'ii.'i, l‘.'il|il\k.'ii.'i

Kanjiramattom, Pulikkamaly, G-Humilekara. and Thrikakkara East basins.

/\l:;o_ durinq daylimo, wh(_:n strong winds blow towards east, these areas will

have lesser pollution, which is due to physiographical peculiarities. Besides

these, some areas far off from the pollution sources such as Udayamperoor,
Kumbalam and Chcllanam Panchayats and Cochin laluk areas of Cochin
Corporation and the areas free from the night time wind direction such as
Nayarambalam, Kadamakkudy and Elamkunnapuzha panchayats may also
be free from air pollution from major industries within the study area.
 Chapter- 6

Vegetation

6.1. Introduction

Plants have an important role in the preservation of soil as well as

moisture conservation. Extensive root system of the vegetation binds the
soil particles while the canopy intercepts the rain and thereby reduces the
force of falling water. Moreover, abundance of leaf litters fesults in higher
infiltration rates thereby reducing the runoff. A reduction in runoff reduces

the siltation in water bodies and thereby conserves its storage capacity
l'(!13llHiEl[] in .11 r'C(lti(7ti:<l llonrl lir:qtit::ncy and inlcnsily.

Vegetation has a prominent role in ameliorating microclimate. This is

attained by directing the wind, shading the incoming radiation and by evapo­
transpiration from the trees. It has been recorded (Federer, 1971) that a
single isolated tree by evaporating 400 litres of water per day accounts for
about 2,30,000 kilocalories of energy, the equivalent of cooling of five
average room air conditioners (each 2,500 kcal/hr) running 24 hours a day.

The air conditioners while only shift heat from indoors to outdoor, the
evaporation from the trees actually reduces the heat.

Also, vegetation is found to be efficient in noise reduction. In many

areas of the metropolitan cities noise levels exceed 120 dB which is the pain
threshold level. Even short-term exposure to noise at 150 dB leads to
 88

contraction of blood circulation, body exhaustion and nervousness, dilatori­

ness of the eye, stomach and intestines (Gupta, 1979). A vegetation belt of
130m or more gives significant reduction of noise level (Smith, 1970).
Nevertheless, even a relatively narrow strip of plant material in urban areas
holds a major potential for noise reduction.

Vegetation plays an important role in pollution reduction by active

stomatal absorption of polluting gases as well as providing vast areas of
leaves for settling of suspended particulate matter. Decrease in atmospheric

turbidity by vegetation has been recorded (Gupta, 1979).

Vegetation can be utilised for economic returns also. Urban forests

can be planted in wastelands for timber yield as well as for firewood.
Firewood is the source of energy for more than one third of the world
population and for many people the real energy crisis is the daily scramble to

find wood they need to cook their food.

Besides the above environmental and economic functions, the plants

also serve various physical and aesthetic functions like defining boundaries,

creating enclosures, making barriers, directing views, providing color in the

environment, emphasizing texture of the building walls, providing shade to
building, relating buildings to surrounding landscape, giving scale to the
building, forming background to structures, creating visual interests in the
form of focal points, etc.

Vegetation of any area is determined by different combinations of

edaphic, climatic and biotic factors.
 8‘)

Each plant needs a particular soil pH for its best growth and most of
the plants prefer neutral to slightly alkaline condition.

Another decisive factor is the water table. If the water table is very
high, it will adversely affect the growth of plants by devoiding plants of the
necessary soil aeration, which may make the plants, stunted and in extreme

cases may lead to the death of the plants. Further, the roots of plants
usually never grow below the level of water table. Such a shallow root
system can result in uprooting of large trees during strong winds.

Many shrubs and herbs are very susceptible to damage due to

flooding. Even two or three days of flooding may Cause damage to plants

due to water logging and lack of soil aeration while mangrove vegetation
needs rhythmic diurnal tidal flooding for its survival. Mangroves are unique

plant species by the fact that they are established in the ecotone zone
between terrestrial ecosystem and estuarine ecosystem. They are very
tolerant to periodic salinity variations and tide—induced root submergence
and exposure.

Salinity of the soil, if very high, causes physical dryness in the soil by

causing exosmosis from the roots resulting in the death of the plant.
Further, near the seashore, salt spray can scorch the leaves of plants.
However, there are lots of plants like coconut trees, which are resistant to
high soil salinity and sea—salt sprays.

Each climatic condition is best suited for a particular kind of

vegetation. Some plants prefer full sun, some prefer semi-shade and some
 ‘)0

others full—shade conditions. Some plants are adapted to high altitudes

while some others prefer low altitudes.

6.2. Methodology

The study of the vegetation was carried out to identify trees. shrubs
and climbers of aesthetic and/or economic value to provide information on
the germplasm. A field survey in the study area was conducted, herbarium
prepared and the plants were identified according to the system of
classification followed by George Bentham and Joseph Dalton Hooker in
their work GENER/e\ PLANTARUM. Rather than a detailed taxonomic

survey, an ecological / environmental planning approach was 'ta!<en in this

study of environmental resources assessment. Hence, only trees. perennial

shrubs and perennial climbers are included, since they only have profound
influence on the environment.

The plants were morphologically identified by comparing the chara­

cteristics with descriptions given in books (Annexure 6.1), being the best and

the most convenient method because morphological characters are easily

observable in the field itself with a hand lens or dissection microscope or

light microscope in the laboratory. Not only that, there is a weIl—knit termi­
nology to describe morphological variations for differentiating innumerable

morphological variations for the identification of species.

Floral characteristics such as inflorescence, type, position, flower

symmetry, ovary position, number, size, shape and union of floral leaves in
 91

each whorl, their modification and various other associated features and the

characters of bracts, bracteoles, and pedicels were used in the identification

of species. The characters of fruits and "seeds as well as vegetative

(Zll.'ll:I(.Z|l!llZ¥ll(iI3 :il:=.u li«:|p«.=(l in llu.» l;.1><(m0nii<: 5(.lt:nlilir‘..'ili(’m of lrr:rr:'., !1|llllt')EL

and climbers of economic, aesthetic or medicinal value.

6.3. Discussion

Natural vegetation of the study area exists in its pristine form in small

sacred groves (Sarpakavu) which are religicusly retained in old 2~linc=‘u house

compounds and in the mangrove stands on the shorelines of the backwater

system. This natural vegetation in the study area coincides with the
characters of tropical rainforests (Pandya etal, 1989). /\ccorcling to him,
tropical rainforests are characterised by tall, dense, evergreen, broad—leaved

trees, lianas and vascular epiphytes and is much stratified. The number of
trees is very high.

The vegetation of the area can be classified basically into two types —
1. General vegetation of the area without specifying ecological adaptation,

2. Eco-specific vegetation such as mangroves and beach vegetation.

6.3.1. General Vegetation

In Cochin, altitude—based vegetation difference is negligible since the

altitude variation in the study area is less than 115 meters and hence the
mesophytic vegetation is more or less uniform throughout the study area
even though localised luxuriant or stunted growth is observed depending on
 92

edaphic variations. In the eastern Iowhills (with lateritic soil, low water table

and easy drainage), even though the plants seen in the western flatland also
grow, the nature of the growth varies to that extent as dictated by the
edaphic difference.

The western flatland, mostly about 1 m above MS|___ shows a distinct

edaphic condition of clayey / sandy—c|ay / sandy soil with a very high water

table. In this area, the predominant mesophytic vegetation is Cocos nucifera

(Coconut), /lrocn (,‘£'lt(,‘C/lll (/\recanut), Samaclora /n(.l/ca (Kar‘ingotta),

D/pterocarpus indicus (Pine), Hydnocarpus wightiana (ll/larotty) and bamboo

thickets. Most other native mesophytic trees, shrubs and climbers, though
identified in the study area, occur very scantily and that too mostly as
individual plants. A list of ecologically significant plants (trees, shrubs, and
Wt)()(ly <;liinl)t.:r:;) .'iro given in /\lll‘.(!)(tll'(‘. 6.1.

A large prevalence of exotic trees is observed both in the eastern

Iowhills and western coastal plain (Annexure 6.2). Natural regeneration
seems to be very low for the native plants as young plants and seedlings of

native trees are rarely met with during field reconnaissance survey, except
for a few species.‘ If this trend continues, the alien species are likely to
replace the native species from the scene as they now occur only as isolated

patches or individually with very low regeneration capacity. This is

environmentally very undesirable since birds and animals in the area are
ecologically adapted to the native vegetation and this kind of transformation
to alien vegetation is sure to upset the food chain and thereby the
 93

ecosystem, though the quantification of the damage is not possible. Hence,

it is suggested that, as far as possible, the planting of native species must be

recommended in urban aesthetic planting schemes instead of going for the

ephemeral beautiful flowers of the alien species with due consideration to
aesthetic appeal.

6.3.2. .Shoreline vegetation

A zone-wise study was attempted along the shoreline since the

nature of vegetation is found to change even within a few meters away from
the backwater as well as the sea.

The shoreline of Cochin can be broadly divided into seashore and

shorelines of the backwaters including tidal canals. ‘those slioieliiies ditltsr

in their exposure to furies of nature and hence develop different kinds of

vegetation.

6.13.2.1... Vegetation of the backwater shores (Mangrove and associated vegetation)

This exists in patches in the shorelines of the backwater system,
particularly, in the intertidal areas (Fig.6.1). These plants, that once
relentlessly protected the shores, are now being destroyed to residual
remnant stands.

The plants are found to reveal remarkable zonation even within few
tens of meters from the backwater system. In the waterward and landward
edges of intertidal areas (Zone I ‘), vegetation is found to be exclusively
mangrove species, whereas in the areas above the high tide level (Zone 'll)
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 94

remnants of mangrove species alo-ng with mesophytic vegetation are found

to co-exist.

Zone I Intertidal areas.(Mangrove Vegetation)

1. Brugu/"era cylindr/ca - tree.

_ Bruguiera gymno/haze - tree
IN)

3. Rhlzophora mucronata - tree.

4. Acanthes ificifofius - Shrub
5. Avicennia officina/is - Tree
6. Cande/Ia cy/indrica - Tree
7. Cara!//a integerrima - Tree
8. Excoecaria aga/Iocha‘ — Tree
9. Pandanus spp - Tree
10_Sonnerar/‘a caseo/arts - Tree
11. Clerodendron merme — Shrub

Zone ll Land just above high tide level

1 . Acanthes ilicifolias - Shrub

2. Adenanthera pavonia - Tree
3. Aifanthus malabaricum - Tree
4 . Anacardium occidentale - Tree

5. Artocarpus heterophylla - Tree

6. Artocarpus lrztegrifolia - Tree
7. Artocarpus hirsute - Tree
8. Bambusa spp. - Tree
9. Barringtonia recemosa - Tree
1 0. Cafophyllum fonophylium - Tree

11. Cerbera odollum - Tree

12. Cocos nucifera - Tree
13. Dendrocalamus spp. — Climber
14. Eugenia jambolana - Tree
15. Hibiscus ti/iaceous — Tree
16. Hydnocarpus wightiana - Tree
17. /l/Iangifera indica - Tree
1U. /\/cm/In Odo/r//ii Eiliiuli
19. Odina wodier — Tree
20. Oroxy/um spp. - Tree
21. Pithecolobium saman - Tree
22. Sapindus /aurr/ol//us — Tree
23. Spondias mang/fera — Tree
24. Terminalia catapa — Tree
25. T/iespes/a popu/nea — Tree
26. Thevetia nerifo.-’i'a — Shrub
27. Vateria indica - Tree
28. Vatica spp. — Tree
29. Vitex negundo - Shrub

Not only the mangrove trees prevent soil erosion, but they also aid in
the building up of land in the following way. Some early successional
species of the waten/vard side extend even to a depth of about one meter
into the water. The intermeshing of proproots of these trees along with the

pneumatophores (breathing roots) collect suspended particles in water and

result in the gradual formation of land. The thick mesh of roots prevents any
chances of erosion also.

Also, the shallow water protected by the intertwining prop roots of the
mangrove trees forms an ideal fish breeding areas (Liberero, 1984).
Mangrove trees have a significant role in the production of food for fishes in
 96

coastal waters. it is estimated that (Odum, .1976) mangrove trees produce

about one metric ton of dry organic matter / hectare I year in the form of
leaves which fall into the water and slowly disintegrate to form food for small

fishes and other small aquatic animals, which in turn form food for large
fishes. Also, the mangrove ecosystem forms ecotone with edge effect
resulting in the maximum productivity of aquatic life and species diversity.
Mangrove forests form ‘a protective zone in the shallow areas in the
backwaters, which is an ecological edge.

Removal of this protective zone for developmental purposes, as was

done in most of the backwater shorelines of Cochin, has caused serious
erosion problems and might have contribLited substantially to the decline of

fish productivity. It is reported that destruction of mangrove forests lead to

the reduction in production of food for aquatic life (Odum, 1976).

Also, these stands of mangrove trees, with their proproots protect

coastal area from severe storm. The mangrove trees also provide firewood
if selective cutting is done without upsetting the system.

The shorelines of the inland waterways of Cochin are prone to

erosion due to the removal of mangrove forests, which once protected the
shorelines from erosion. The stabilization of the shore is important both to

prevent loss of land by erosion and also for prevention of sitting up of

waterbodies, which affect water navigation particularly in the case of tidal
canals.
 The mangrove vegetation in the study area is under severe threat
from firewood collectors and by extensive backwater reclamations by land
developers and agriculturists. Hence, there should be not only legislative
measures for the preservation of existing mangroves but also mangroves
should be grown in Iow—lying wastelands adjoining backwaters. New
mangrove plantations can be developed by the following inexpensive
method.

The seeds of viviparous mangrove trees germinate while on the tree

itself and fall down after sprouting after developing anchoring roots. Such
germinated seedlings collected without damage from mangrove forest areas

should be preserved in estuarine water for sowing on mud flats exposed

during low tides. The sowing is best done when the tides are at their lowest
and water has drained off so that seedling do not drift away. The seedlings

anchor in the mud flats and put forth supporting roots within one year and
attain about 2 meters height ln 2 years producing pneumatophores which
bind the mud. The seedlings require no maintenance and no watering. In
the estuarine regions of Cochin, Rhizophora mucronata and Bruguiera
roxburghiana are the two species of mangrove vegetations suitable for this

kind of propagation. Also, in planting programmes, selection of species

conducive to the natural zones will ensure maximum survival of the plants.

6.3.2.2. Beach Vegetation.

Field survey of the beach zone vegetation in the study area from
Njarackal in the north to Chellanam (Fig.6.2) in the south was carried out.
 TABLE - 6 . 1. MAIN LOCATIONS OF MANGROVES IN THE
STUDY AREA

S|.No Location Main species

1 KANNAMALI. Rhizophora mucronata, Acanthus ilicifolius, Avicennia
‘ALONG T'D"‘L CANALSI officinalis, Bruguiera cylindrica, Bruguiera
gymnorrhiza,Cerbera odaIIam,Thespesia populnea
Excoecaria agallocha.
2 PAMBA|- Acanthus ilicifolius, Avicennia officinalis, Rhizophora
MOOLA mucronata, Thespesia populnea.
3 WILLINGDON Avicennia officinalis, Acanthus ilicifolius, Rhizophora
ISLAND mucronata.
(SOUTHERN TIP1
4 ISLETS NEAR Rhizophora muéronata, Avicennia officinalis, Excoecaria
COCHIN agallocha, Clerodendron inerme, Acanthus ilicifolius,
HARBOUR Pithecolobium saman, lpomoea palmata.
5 PUTHUVEYPU Avicennia officinalis, Excoecaria agallocha, Clerodendron
g‘C‘)3Lj3T“HEETREr‘q3ELr’:3)° 0” inerme, Acanthus ilicifolius,.
6 PUTHUVEYPU Acanthus ilicifolius, Excoecaria agallocha, Avicennia
R‘/f[’J‘5N5ATM‘g:k‘;YRP§AE|;‘) officinglis, Rhizopho_ra mucronata, Bruguiera cylindrica,.
Bruguiera gymnorrhuza, Clerodendron inerme, Thespessa
"populnea,
7 MALIPPURAM Acanthus ilicifolius, Clerodendron inerme. Bruguiera
cylindrica, Excoecaria agallocha, Avicennia officinalis,
Cerbera odollam, Thespesia populnea.
8 VALLAR- Rhizophora mucronata, Avicennia officinalis, Acanthus
PADAM ISLAND ilicifolius, Sonneratia caseolaris, Thespesia populnea,
(SOUTHERN 5'05) Bruguiera gymnorhiza, Bruguiera cylindrica,CIerodendron
inerme.
9 THANTHONNI Avicennia officinalis, Acanthus ilicifolius, Rhizophora
ISLAND mucronata, Bruguiera cylindrica
(soumenw sums;
10 MANGALA Avicennia officinalis, Rhizophora mucronata,Acanthus
VANAM (NEAR om ilicifolius, Pithecolobium saman.
RAILWAY STATION)
11 VALAPPU Rhizophora mucronata, Avicennia officinalis, Bruguiera
cylindrica, Excoecaria agallocha, Acanthus ilicifolius,
Clerodendron inerme.
12 NJARAKKAL Rhizophora mucronata, Avicennia officinalis, Bruguiera
cylindrica, Excoecaria agallocha, Acanthus
ilicifolius,C|erodendron inerme,Thespesig3opuInea.
 ‘UV mil .

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 98

The study revealed that vegetation in the area shows zoning pattern or the
existence of plants in belts parallel to coastline. Roughly three belts are

distinguishable.

Zonel

These are the front rows of plants inhabiting the highly saline soil of

the coastal area, exposed to salt spray and sand blasting due to fierce
winds. The following plants are found to grow successfully in this zone.

Acacia auriculiformis —Tme

Adhathoda vasica - Shrub
Agave americana — Shrub

Agave victoria—reginae — Shrub

v-.4>.<~>r\>e
/\/'1IIl(/Odolmx .57‘-2 — Shrub

- Casuarina equisetifo/ia — Tree

Cocos nucifera — Tree

.@.".°7
Drucaena fragrans - Shrub
/;_-"up/io/‘bra ti/uca/Ii - Tree
. Hibiscus tiliaceous — Tree

. Ipomoea bi/oba - Climber

. Moririda tinctoria - Tree
. /l/luh/enbeckia — Shrub

. Opuntia spp. — Tree

. Pandanus utilis - Shrub

. Solidago canadensis - Shrub
. Spinifix Iittoralis - Herb
. Vinca rosea - Shrub
. Yuca aloifolia - l-lerb
 99

Zone ll

This is an area which has plants protected from the flying sand and
salt spray by the coastal plants of Zone—l or by natural barriers like
sandbanks or sea walls. Plants in this belt tolerate a good deal of salt in the
soil and in the air; only that, they require a barrier between them and the
open sea. The lee side of the sea wall all along the coast from Njarackal to
Chellanam forms the Zone—ll. Many of the plants in Zone-l also thrive well in

Zone—ll. The following plants are found to grow in this zone

1L
Aca/ypha w//kes/ana - Shrub
/\(7/'lITl.f~.‘ snpofn - Tree
Ad/num obesum - Shrub
Alpinea spp. - Herb
Asparagus plumosus - Climber
Asparagus spp. - Climber
Bougainv/'//aea g/abra — Shrub

Caesa/pinia pulcherrima - Shrub

Ca//istemon /anceo/atus - Tree
3s0.<=°>I.<>°¢“.4>.c~‘;\J

. Ca/otropis gigantea - Shrub

—L —L . Carissa carandas - Shrub
. Casuarina equisotifo/Ia -Tmo
. Cestrum diurnum — Shrub
_g_A_\ -l>CAJl\J . Cocos nucifera — Tree

_l U’!
. Cordyline spp - Shrub
_L 03 . De/onix regia - Tree
._x \I . Dracaena spp. - Shrub
_\. Q . Elaeis guineensis - Tree
—} LG
. E/y!/Irina indica — Tree
 100

20. Eugenia janibo/ana — Tree

21. Ficus bengalensis - Tree
22. Ficus radicans - Climber
23. G/oiiosa siipur/):.i - Shrub
24. Hibiscus rosa—sinensis — Shrub
25. Hibiscus syriacus — Shrub
26. /pomoea biloba — Climber
27. /xora coccinea - Shrub
28. /xora parviflora - Tree
29. Lawsonia a/ba - Shrub
30. Ma/pighia coccigera - Shrub
31. Muntingia calabura - Tree
32. Nerium ind/‘cum — Shrub
33. Po/ya/lhia /ongi/‘o/I:-i -Tme
34. Pithecolobium du/ce - Tree
35. Rhoeo disco/or — Herb
36. Ricinus communis - Shrub
37. Sansevieria trifasciata - Herb
38. Terminalia catapa - Tree
39. Thespesia populnea - Tree
40. Thevetia nerifolia - Shrub
41. Vinca rosea - Shrub
42. Vitex negundo — Shrub
43 . Zebrina pendu/e - |~-lorb

Zone4H

This Zone lies towards the eastern side of Zones I 8. II, and is
occupied by plants which seems to tolerate mild soil salinityi but do not stand

the rigors of Zones I & ll. Most ofthe rnesophytic vegetation of the study
 |()l

1‘PJ
area is found to grow in this zone. The following treei~‘:~‘.-kshrubs and climbersI I
\ . ‘, "‘ ‘ X 1‘~ ,;;Ir
~4

were identified in the area. " ‘,“.T,:_;_.l,_:r__ ”_ "'_'_

_\ Acacia auriculiformis —Tree

/lilcmllms I'Il(,l/{I/)(.lI'l'C(l — Tree

A//amanda violacea — Climber

Antigonon Ieptopus - Climber

Aralia spp. — Shrub
Areca catechu - Tree
Asystasia spp. — Shrub
Azadirachta indica — Tree
3.co.o°.o=.v~.4>.c»>\>

. Bauliinia purpu/‘ea - Tree

__k g . Bougainvillea glabra - Shrub
_\ l\) . Caesalpinia pulcherrima - Shrub
_\ 03 . Caesalpinia cor/‘aria — Tree
_.\ A . Cal/iandra lzaemalocephala. — Shrub
_\ U1
. Carica papaya — Tree
._.\ CD . Cassia fistula - Tree
A \' . Cassia siorneu - Tree
__x
. Ceiba pentandra
O) - Tree
(0 . Clerodendron thomsonae
_\ - Climber
M O . Coleus blumei - Herb
M _\ . Eranthemum spp. - Shrub
l’\J T0
. Erythrina indica - Tree
l\J CA. Eucalyptus spp. — Tree
l\J A _ Ficus bengalensis — Tree

l\.) U‘! . Ficus pumila — Climber

. Ficus religiosa
M O) - Tree
27. Ficus retusa - Tree
28. Gardenia jasminoids - Shrub
 I02

29. G/yricidia maculata - Tree

30. Hibiscus rosa-sinensis - Shrub
31. Hydnocarpus wig/itianurn - Tree
32. /xora coccinea - Shrub
33. Jasminum spp — Climber
34. / .<igei'siro(a/77/?) f/Os-rc.-ginae — Tree

35. Lagerstroemia indica — Shrub

36. Lawsonia alba — Shrub
37. Ma/pighia coccigera - Shrub
38. Mangifera /ndica — Tree

39. Michelia champaka - Tree

40. Mi’//ingtonia hon‘ensis - Tree
/11. M/nius()p:; uluiiji Troo
42. A/Iorus alba - Tree
43. Muntingia ca/abura - Tree
44, /Viurraya exolica - Shrub
45. Ner/um o/ea/ide/‘ — Shrub
46. Odina wodier - Tree
47. Pe/tophorum inerme — Tree
48. Petroa vo/ubilis ~ Climber
49. Pithecolobium saman — Tree

50. Pithecolobium du/ce - Tree

51. Plumbngo C8[)Ol‘)S/S - Shrub
52. Plumeria acutifolia - Tree
53. P/umeria alba - Tree
54. Plumeria rubra — Tree

55. Pongamia glabra — Tree

56. Psidium guajava — Tree

57. Quisqua/is indicus - Climber

. Saracu indica - Tree
59. Spathodea campanulata - Tree
 l(l_l

60. Spondias mangifera — Tree

61. Swiotenia mahogany - Tree
62. Tabernaemontana coronaria - Shrub
63. Tamarindus ind/cus — Tree
64. Theobroma cacao — Tree
(55. T/iumbe/‘g/a grand/'f/ora - Climber
66. Vitex negundo - Shrub
67. Zizyphus jujuba - Tree
During the monsoon months, strong winds from the west along with

high water level increase the strength of waves, which erode a large extent
of beach at Munambam and Chellanam areas causing considerable
destruction to land and properties. This is a major environmental problem in
the coastal zone of Cochin. Even though, sea walls were constructed all
along the coast, in many places it failed to check the rage of the waves as is

evident from the disappearance of sea wall at several places in Munambam

and Chellanam area.

There are good many plants, both native and alien species that
withstand the fury of the nature to a great extent in the coastal area.
Vegetation will considerably solve the coastal management problems like
beach protection by binding the soil particles with their roots in areas prone
to water and wind erosion. The vegetative cover (trees) also provides
windbreaks against strong winds which frequent the coastal areas. Only,
man has to imitate the natural protection system by planting appropriate
species in the respective zones.
 I0/l

6.4. Summary and Conclusion.

A comprehensive study of the species diversity of vegetation is an

important pre-requisite for the assessment of environmental resource of any

area. The vegetation of any place is determined by edaphic, climatic and

biotic factors. Such a study will enable the authorities to propose
appropriate planting materials from the trees, shrubs and climbers of
economic, aesthetic and medicinal value which have proven capacity to
grow success-fully in the various edaphic and microclimatic conditions of an
area.

In the study area, edaphic and climatic zonation is clearly

distinguishable with their own characteristic vegetation types due to its
unique physiography. However, this vegetation, originally tropical rainforest,

is drastically modified by biotic influence. of urbanization and increased

agricultural activities. The vegetation in its original form exists only in a few
sacred groves and mangrove forest bits.

Alien species, which were once introduced for aesthetic planting or for

agricultural purposes, are found in large numbers among the vegetative

cover of the western flatland area, whereas, alien plantation and agricultural

crops have significantly replaced the native vegetation in the eastern upland
area.

In Cochin altitude-based vegetation difference is negligible since the

altitude variation in the study area is less than 108 meters.
 105

The western llatland shows a distinct edaphic condition of clayey or

sandy—clay or sandy soil with a very high water table. The land is less than 1

motor above MSI. at Cochin. In this area, the predominant mosophytic

vegetation is Cocos nucifera (Coconut), Areca catechu (Arecanut),
Samadera /ndica (Karingotta), Dipterocarpus /ndicus (Pine), Hydnocarpus
wigliliana (Marolty) and bamboo thickets. Most other native lIlL.‘3.iUpllyl|()

trees, shrubs and climbers, though identified in the study area, occur very
scantily and that too mostly as individual plants.

Natural regeneration seems to be very low for the native plants

except for a few species like Samadera /ndica, D/'pr'erocarpus indicus.
'1'/iespesia popu/nea, Mac/‘anga ind/Ca, A/stonia scholar/s and a few species

of Eugenia (all of which regenerate naturally only in isolated pockets), while

alien species of P/'1/loco/ol.)/"um sa/"nan, Po/(op/io/‘um ino/‘nu’, D0/onix /'egi'u,

Muntingia ca/abura and Lucaena /ucocephala show vigorous regeneration in

the western flatland area.

If this trend continues, the alien species are likely to replace the
native species from the scene as they now occur only as isolated patches or
individually with very low regeneration capacity. This is environmentally very

undesirable since birds and animals in the area are ecologically adapted to
the native vegetation and this kind of transformation to alien vegetation is
sure to upset the food chain and thereby the ecosystem, though the
quantification of the damage is not possible. Hence, it is suggested that, as
far as possible, the planting of native species must be recommended in
 I 06

urban aesthetic planting schemes instead of going for the ephemeral

beautiful flowers of the alien species with due consideration to aesthetic
appeal. Also, the pollens of the alien species are likely to cause allergic and
other health problems.

The shore line vegetation shows pronounced zoning - the species

composition changes within a few tens of meters from the shore line - both
near the sea as well as backwaters. In the case of backwater shores, the
waterward edge of intertidal zone is predominantly occupied by mangrove
species of Brugu/era roxburghiana, Rh/zophora mucronata and Accanthus
i’//cl/r.)//'1/s‘. UUll|ll(_l tliis, ubotit 12 ineingrove species occupy the laiitlwzwcl

edge of intertidal zone. The land just above the intertidal zone has about 36
species of trees and shrubs, which are the combination of mangrove and
mesophytic vegetation.

This zoning is disturbed in many places either due to human

intervention or due to acute steepness of the shoreline. If the land suddenly

rises from the backwaters, only the second and/or the third zone will be
present. In the study area fifteen major locations of mangrove vegetation
are present besides the occasional existence of a few isolated mangrove
species here and there along the backwater shorelines.

For the prevention of backwater shore erosion and fisheries

protection, mangrove replanting should be done along with the conservation
of existing patches.
 107

/\ sirnilnr '/onnlion pur'ull(:,-I to sliorolinos is observed in the vegetation

near the sea. The first layer of plants is that which can withstand the contact

with waves of the sea with its salt. Nineteen species of trees, shrubs and
Oiili.:l groieiid covers are lound to grow in this zone successfully with
regeneration. Protected either by the above—mentioned vegetation or by the
sea wall is the second zone, where, 46 species of trees, shrubs or climbers
are found to thrive. These plants can be ideally planted in this zone in future

planting programmes. Behind the second zone of beach vegetation, there

exists a region, which is not exposed to the direct impact of the sea, but with

traces of salt in the soil. 66 species of trees, shrubs and climbers are
identified in this zone which can he used for future planting scliomer; in the

sand bars from Njarakal to Chetlanam where these plants occur in natural
condition or cultivated condition and found to survive.

Except the mangroves and beach vegetation in zones 1 and 2, almost

all the species survive in the eastern upland where they can be best utilized

for planting schomos depending upon the local oduphic and microclimatic
conditions.
 Chapter - 7

Socio-economic Environment & Basic Amenities

7.1. Introduction
Assessment 0'.’ the socioeconc-mic condition of an area is a pre­
requisite for environmental planning. Comfort in urban life lies in the
condition of basic amenities and services because they in turn decide the
status of health & sanitation, commutation and recreational facilities etc. The
llllullllIllE2llIi.'1ll::2,t'-t(:|!IIl!!l§;.!Yl: (..:)([)iIll(i|l!{_/t ltitat wit’: .1 (Ltl,'l1nt,'tllll.‘!l'. uvt,-I

stretching of the existing fabric of basic amenities and services. The unique

geographical settings of the study area a further bizrrten which

necessitate a proper evaluation of the present status of the socio-economic
conditions.

The important basic amenities and services to be considered for

environmental planning are (1) housing (2) water supply, (3) drainage, (4)
transport facilities, (5) pt.-irks & playgrounds.

A projection of the future population and its sex—age structure helps in

estimating future human and economic resources, expected school—going

population and related requirements, future growth of the city and
requirements of food, water, sanitation, housing and health services. The
major concern of demography - the science of population - in socio­
economic studies is to assess how the general social & cultural factors are
related to population structure. The census report serves as a primary data
 IU‘)

source for administrative purposes as well as for economic 8. social research

and planning. The census also contributes to our knowledge of the changes

in the occupational and industrial composition, in its level of literacy &

economic development and trends in population growth 8. distribution. Such

a comprehensive outlcol-< is essential in future urban planning.

Urbanisation leads to the transformation of agricultural land into built­

up areas with the concomitant problems regarding water supply, drainage,
garbage and sewage disposal etc. Out of about thirty infectious diseases
communicated through environmental agents and vectors, at least twelve
have been identified to be ,c-rcpagated through waste materials. Hence, the

identification of problems associated with waste disposal and evolving

solutions to tlio-st; [.).'UtJl!.:ll!S loim an l:l1[_)()l't£]lTt part of any city planning work.

Social environment and economic environment cannot be segregated.

Economic upgradation or degradation of an area brings about drastic
changes in sociological aspects. Such a gradual socio-economic degenera­
.1

tion is clearly seen in the case of Mattancherry.

Throughout the world, the grc==,wtt1 of cities has introduced a lot of

socio-economic problems in which social justice is denied to a majority of its

population - the slum dwellers, the pavement dwellers and squatters who
live in abject poverty (Fig.7.1).

The traffic problem in urban areas is assuming serious proportions

due to the inability of road expansion to catch up with the rapid increase in
the vehicle population This situation brought about by space and i'esot:rC:0
 l3M~
12MJ
1lM~
1OM­
9M­ TOTALPOPULATION
8M­ SLUMPOPULATION
7M—

5M­
4M—
3M"
2M— 5:
1M A

CBDMBHAKPNLJAC
C CALCUTTA , B BOMBAY,D DELHI, M. MADRAS , B BANGALORE, H HYDERABAD, A AHMADABAD

K KANPUR , P PUNE, N NAGPUR, L LUCKNOW, JA JAIPUR, C COCHIN

Source: * Gupta (‘92)

** Corporation of Cochin

Fig - 7 . 1 . ESTIMATED URBAN POPULATION AND SLUM

POPULATION IN 12 METROPOLITAN CITIES FOR
1990' AND CORPORATION OF COCHIN'
 ll0

constraints, not only increases the pollution load in the urban environment by

idling of vehicles and frequent traffic jams, but also causes substantial loss

to economy by increased fuel use and wastage of transit time. It also affects
adversely the health, social and cultural life of the community, aesthetics of

buildings & monuments etc. The loss and trauma induced by frequent
accidents should also tn: considered in this context.

In Ernakulam town (the central part of the Cochin city), the population
was only 14,038 in 1875, 15,467 in 1881, 17,870 in 1891 and 21,901 in 1901
(Menon, 1902) which has increased to 5.6l lakhs now (Fig 7.2). The opening

of Cochin Port and the commissioning of Pallivasal Hydroelectric Project in

19305 resulted in last industrialisation and comn'ierciali:sation of Cochin with

corresponding population explosion and consequent changes in the socio­

economic scenario

"/.2.. Methodology

For the socio-economic analyses, census reports provided the

primary data. Also, data from various government departments and
institutions relating to the 26 panchayats, 2 municipalities and the Cochin
Corporation, which either fully or partially come within the study area, were
also depended upon to obtain a comprehensive picture.

Published data as well as those obtained through personal

communications with various institutions and governmental agencies like

Kerala Water Authority, Kerala State P.W.D, Regional Transport Office,

Polico department, Cochin Port Trust, Corporation ol Cochin, Groutor
 2O:&JDlOQnI. \\ _
\$s>>nxmmV

»mm» FmmF Ema» «ems mkm»

____________O

:o.am.SQo&

EEUOU LO ZOE.<.mOnaOU Hzmmmaa “HO <mm< 2<ADM<Zmm ma QZ<

x\\\ cocoa
oooomm ooooom \ Aoooomm ooooom \\\ geese“
oooomv

Z2/OH 2<d§<zmm mdzzfimmm Ba‘ ZH EH2/OMO ZOEQJDLOL N. .\. mm

 lll

Cochin Development Authority etc, provided the basic information on which

the existing status of the basic amenities and other infra-structure were
assessed. Annexure 7.1)

7.3. Discussion

The study area includes the most urbanised area of the most
’urbanised district in the state of Kerala (Census, 1991). The study area
(:ornprising of Cochin Corporation, '2. inunicipalitios and ?.6 panchayals,
either fully or partially, holds about 48% of the population of Ernakulam
district while occupying only 29.63% of its area.

7.3.1. Population structure <31 distribution

The analysis of census data reveals the spatial variation of population

density, which help in identifying certain characteristic problems of
population distribution. It is found that the densities are high in the low-lying

areas adjoining the water sheets (Fig.7.3). The population density in the
western part excluding backwater area is 41.54 persons I hectare, while in
the eastern part it is only 9.86 persons / hectare (Census, 1991) The
variation is seen to be of lesser magnitude along the coastal axis, but is very

prominent in the eastern axis. Ironically the most suitable land for urban
expansion lies most unutilised.

This analysis gives an insight into the future population distribution.

The rational approach to future population distribution will be to even out the

density histogram. This will mean that the increase of the percentage of
 wj_I oz<._

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u._aUo.._ an m:owU.:o EZ

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population in high—density areas will have to be kept marginal. This
restriction will be justified considering the overcrowding and deficiency of
services in these zones. At the same time, allocating larger percentage of
population to low density areas may not be economically feasible. The
rational approacli will be to emphasize on the medium density zones.

a) Sex cornposition

In t|i«- sliirly iiiun, the sex composition by 1991 consi.is is £5().'l(3%

male and 49.84 % female which is a rather balanced sex composition.

ti) 5 itCi‘L1<:y ziiirt i’.',in:ily si/(.1

The 1991 census data reveals a literacy level of the population above
6 years age is 93.26 %. The literacy rate for males and females above 6
years is 96.25% and 90.27% respectively which is higher than the district
level literacy. Higher level of literacy is reflected in the higher standard of
living as well mi lliu clmico for HlYH.l”Ul' fuiiiillua (Fig 7.4). In 1971, the lltuiucy

rates of the central city area was 69.44% and the average family size was
6.33 persons (G.C.D.A Structure Plan, 1982) which further reduced to 5.81
by 1981 when the literacy rate increased to 79.5% (Census, 1981). With
further increase in literacy rate, this value reduced to 5.08 percent by 1991
(Consiis, 1901) and is oxpoclod to b0 5 or oven I0!-IH by 2001. Thu plimniiig

significance of the size of household is in areas such as housing where

demand for smaller houses is expected to increase.
 MN; >£Z<m E >u<mmFE D

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.:mwb¢mvm~_c.

ZEAUOU 7: ZO_.H<Am—m mfim >A=Z<,m QZ< >U<Mm—,5A E. Em

 c) Employment and livelihood

The labour force can be divided into 3 categories - main workers,

marginal workers and non—workers. In 1981, the percentage of main
Vi/lJl|.t.,'ll; lll llii: <ti.;v:!.:._:l :;!ly i!l(_:i_l '-.'~/;,i:.; Z3f5.i‘3i%‘i*?i Llltd flint Ul it::Ji'g:i1al workers

(those who have worked for only a small part of the year) was 2.82%.
Totaling the two together, the participation rate comes to 28.64%. By 1991,
the study area had a working force of 6.46 Lakhs — 32% of the total
population. against a projected 30.18% (GCDA Structure ptan 2001) —
comprising of 4.06 l_al<li (30.2%) main workers and 2.4 l_akh ('l.8'?/U)
marginal workers. Thus the working force rose by 3.36% compared to 1981
(Fig. 7.5). This increase in employment - much above the earlier projections
- reveals an economic growth faster than the predicted rates - thus
generating increased job opportunities.

The distribution of main workers in the Cochin City Corporation,

Kalamasserry and Tripunithura municipalities and 26 Panchayats which
Come either fully or parrlially within the study erea is us. l0ll0ws:— (Fig‘/.6)

1) Agricultural sector

This sector (Cultivators and agricultural labourers) constitutes 15.06% of

the working force of the study area in 1991. This sector is likely to weaken

further with urban expansion.

2) Workers in other categories

a) Livestock, forestry, fishing and hunting

mmmxzozfi mpzmozmamo E

_maH

mmmxmoiu mhzmozmnmo E

mezmnzmafiaammaz:o>?zH9$emma:e<m mswafl

_wa_
.<mm< >935 NEH E mmwmmoa no ZOE.Dm=ME.mHQ mm? >mooE<u .0.» “Em
 114

They together form 5.66% of the total working force. Because of the
existence of vast lagoons and water bodies, there is very high potential for
the growth in the fishing sector.

b) Mining and quarrying

Since there are only a few minerals of commercial importance in the study
area, mining & quarrying contribute only very little to the employment
opportunities and hence the percentage of workers in mining and quarrying
is very low and comes up to only 0.76 "/0 of the total workin9 force.

c) Manufacturing, Processing, Servicing and Repairs.

This sector, which forms the economic base of central city, engages 17.79%
of the total workers of the study area. Household industries form 1.03% of
the total work force and those of other than household industries 16.76 %.

An increase in this sector is necessary to provide a strong economic base to

the population of the area.

d) Const: uction

In 1981, 4.47% of the city population was engaged in this sector, as against
2.71 in 1971. lly I991, in spite of including several :—;low»-growing riiral areas,

this proportaon has risen to 8.58%. Such a fast growth in this sector, despite
mechanisation of construction activities, is a clear indicator of urbanisation
boom.
 e) Trade and Commerce

The population engaged in trade and commerce in Cochin central city was

16.6% in .1981 which grew to 18.59 % for the entire study area by 1991
indicating an increase in trade and commerce: activities as in the case of
construction sector.

f) Transportatior‘./storage and communication — 12.19 %

g) Other services

The other services ‘rclude professional service. jobs in offices. institutions

and administration, sees and marketing etc. Tie labourers engaged in this
service sector in the central city area was 37.42% in 1961, 27.77% in 1971

and 28.94 % in 1981. which decreased to 21.37‘; by 1991. This decreasing

trend indicates that ratio of employment if ‘his services. is actually
decreasing while in a.:' other sectors and espec ally in manufacturing, trade

and commerce are Increasing. This is a szrcng indicator or’ the trans­
formation of the city ?Tom an administrative tows ‘.3 an industrial/commercial

metropolis.

7.3.2. Housing

In 1991, there were 2,636,038 householce 7 the study area while the

number of houses was merely 2.60.597 leav ”; a backlog of 5,441 units.

This was an improvement from the 1981 situatcn, when the deficit in the

central city area alore was 9,000 units. Sucr a reduction in the housing
shortage during the East decade is 'r:%cative c‘ a spurt in emnomic growth
 116

as well as construction activities which is reflected in :he increase in the

construction labour force as mentioned earlier. However. the increase in the

number of houses failed to meet the demand, brought about by the rapid
population growth and a consequent increase in houser: as due to financial,

technological and administrative constraints.

By GCDA estimates, about 30 per cent of all the rcuses in 1981 were

in the category of Kutcha Construction with inadequate facilities and poor

environmental quality which required alteration, mociication or repairs to
keep them habitable. Also, it was estimated that only 1 2-‘ lakh units of 1981

stock would continue to serve the function during 1991 and only 1.12 lakhs

will remain in habitable condition in 2001 (GCDA Structure Plan - 2001).

The average family size in the Cochin central C'T'_-" area during 1981

was 5.9 persons per household, which was reduced to 5.08 (for the whole

stucy area), within a span of 10 years (Fig 7.4). This c'e:.'ease in family size

is likely to accelerate in future which implies that the fu:'..'e requirement will

be a larger number of smaller houses.

The 1991 census report reveals that in the old parts of the
Corporation (which includes Mattancherry and Fort Koch" .vhere there are a

large number of slums, 8.75% of the families share tt*e ‘ “ouses with other

families, whereas, in the new area of Cochin C:":oration (part of

Kanayannoor taluk) only 1.66% share their house .‘n“.h other families
(Tabie.7.1).
 TABLE — 7 . 1 HOUSING SHORTAGE'

LOCAL BODY AREA No. of No. of Housing

( kmz) Houses Households Shortage
COCHIN
CORPORATION (PART
39.58 43,296 47,448 4,152
KOCH] TALUK
COCHIN
CORPORATION (PART
' 55.3 60,455 41,476 1,021
KANAYANNOR TALUK)
KALAMASSERY 27 11,430 11,436 6
TRIPOONITHURA 18.69 10,415 10,434 19
VENGOLA 35.65 7,049 7,079 30
VAZHAKKULAM 19.64 5,351 5,389 38
KIZHAKKAMBALAM 31.57 5,340 5,348 8
CHOORNIKKARA 11.01 5,010 5,017 7
EDATHALA 15.98 5,655 5,655
CERANALLOOR 10.59 4,104 4,106 2
THRIKKAKARA 27.46 10,448 10,468 20
MULAVUKAD 19.27 4,247 4-,248 1
NJARACKAL _ 8.6 4,348 4,350 2
ELAMKUNNAPUZTIA 1 1.66 8,970 8,971 1
CHELLANAM 17.6 5,955 5,955 0
MARADU
KUMBALAM
12.35 6,769 6,769
20.79 4,669 4,688 19
O
UDAYAMPEROOR 24.8 5,557 5,582 25
MULAMTHURUTHY 21.47 4,535 4,545 10
THIRUVANKULAM 10.49 3,966 3,966 0
CHOTTANIKKARA 12.68 3.356 3,386 30
EDAKKATTUVAYAL 26.28 3,465 3,467 2
AMBALLOOR
POOTHRIKA 22.6 3,810
25.53 4,244 3,815
4,248 54
THIRUVANIYUR 21.91 4,371 4,376 5
VADAVUKODU— 36.89 5,595 5,612 17
PUTHENCRUZ
MAZHUVANNOOR 49.11 6,059 6,062 3
AIKKARANADU 25.65 3,873 3,875 2
KUNNATHUNADU 26.86 5,014 5,022 8
MANEED 26.2 3,241 3,245 4
TOTAL 713.27 260597 266038 5441
CALCULATED FROM 1991 CENSUS REPORT
THE CALCULATION IS FOR ADMINISTRATIVE UNITS WHICH FORM PART OF THE STUDY AREA EITHER FULLY OR PARTIALLY.
 There were about 34 major slums (harbouring about 25,000 people)

in the in Cochin city itself in 1988. i.e., 5% of the city population as given in

Table 7.2 (Report of the Cente.'—State team for integrated development of

Cochin and adjoining islands — lviarch, 1988). By 1996, the total nurnser of

slums and squattef settlements have grown to 272 (with a populaucn of

120,102 living in 21334 households), the locations of which are shown in

figure 7.7, comprising 21.27% of the total population of Cochin corporation.

Gravity of the probfem is less aarming compared to the situation in other

lndian cities (Fig 7 3 & Table 7.3), but effective planning can prevent the

situatio." from deteriorating furtne'

Cochin is having two kinds of slums — slums resulting from rapid

deterioration of economic activities as in the Mattancherry area and the
slums formed by migration of labourers due to rapid industrialization and
increased commercial activities as in Ernakulam area.

The development of Cochin port and consequent rapid progress in

Ernakulam area as well as the traffic congestion on the two bridges
connecting Mattancherry to the mainland prompted the shifting of business

activities from Mattancherry to Ernakulam. This shift in the economic

activities created sudden unemployment problem in Mattancherry making

the people economically weak, vrltich made the members of a family unable

to segregate from the parental house due to financial constraints. This has
resulted in a peculiar situation where several families are forced to stay in a

single house creating over—congestion and consequent degradation in the

 224m: .32:

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 TABLE - 7.2. MAJOR SLUMS IN COCHIN

SL NO Name of Slums Populatio'No. of No. of Persons

houses house hold.per house

213 Manthara
Soudy Colony 564
Cheliparambu 110 70
15 76
15 8.06
7.33
Pulaya Colony 220 16 49 13.75
45 Pulimoottil
Puthiyaveettil Parambu
Parambu 617144
121101222
17 14.40
5.10
67 Adhikarivalappu
Thundi Parambu ' 935
200106
29 138
52 8.82
6.90
8 Thuruthi colony 1943 221 287 8.70
10North
11 Eraveli
of 1983 262
Varma&Co. 399285
63 7.57
9 Kochuparambu Valiaparambu 2346 148 327 15.89
65 6.33
12 Cerlaikadavu 1267 109 184 11.62
13 Kalvathy Canal 182 590 850 8.27
14 Near
15 Near Metal Box Co.Junction
Perumanoor Edappa 183
140 30
45 32 4.67
5: 4.07
16
1?
Kochukadavanthra
Near Railway
3487759
line.Ponekka’ 12
59
18
5.9
6.42
18 North of Ekm. Stadium Bus 182 3 48 4.88
19Old
20 Chilavannur 202108
452545254.06
21 Near E.S.I. Hospital 86 19 204.32
22
Railway Station 4.3
23Near
24
P&T Compound,
Koithara Elamku
area 190
Vathuruthy area 18335199310.55
9175268
36730497
98 4.14
25.0
25
26 Panikkassery
Military Parambu
Parambu 223 40 46
40 8.93
5.58
27 Kavilampilly
28 Ponoth Padam29
135 31929
54 60
4.655.90
29 Velloparambu
30 Kavappilly Colony 130 2671266.47
460 71 5
31
32 East of St.Agnes‘Church
Vadayar Parambu 4521 7 85 56.42
4.2
 Table. 7.3.

Slums 8 Squatter Settlements in the Stu¢.LAree

No. Name of Slum Household Popln Area
21 Kuri]<kuzh'1
Vy]-een Colony Parambu27 16815610200.440.98
3 Kalvathy Colony -69
4 '1'huruthy/Panan Colony 404 2168 3.46 369 0.53
5 .’3 I’. (I-wlfllly. Flo]lull-'1-'21-'1.=1\/I1 78 ‘H2 1.4
(; |:'I.IV-.:l i (I-Jlolly 290 1.350 1.8‘)
7 -31:31 l[Jc":l'i:1lfll’)U Colony Dn. 3 314 1751 1.’/:3
89 Rahn1:—_m1'e: Colony 187
I-L‘-_:s:;'ar1 Colony 121_02O
"113 0.43
0.4
10 Gale-sett Colony 401 2700 2.17
11 Kochu/Valia/Banglow Parambu colony 353 2010 2.6
12
13 Chaliparambu Colony
Pandaraparambu Dn.4 37
Colony 97 "588 1.28
207 0.68
14 ]3:—_'u'.:ar Road Colony 27 178 0.25
15 Cherlaikadavu Colony/ P.Parambu 51 397 0.42
16Adhikaryvalappu
17 Bigben Colony 9 158
Colony 1098940 0.1.
7'­
18 1-’..:.nl..'1l;hip;Jrambu
19 Mangalathuparambu
MKS Parambu Colony Colony 2
230153 177‘
1'.'>6IJH
20 Colony 901 0 I99I
21 Maliekalparambu Colony 201 1276 1.82
22 Valiamalothuparambu Cololny 137 870 0.97
23
24Krishnan
JDStreetnairColony
edavazhi Colony
135 73512 670.87
0.12
25
26 Kudumbi Colony
Mahajanavadi 3768192
Colony 3790.35
0.85
27
28 Chundiparambu Colony 59 553 0.?
Bazar South Colony 12 60 0.8
29
30 Kocheriparambu
Thengakood Colony31
Colony 233168
1117 2.1
0.28
31
32 Ajantha Cinema Colny
Juthan parambu Colony170
32 1010
181 0.42
1.2
33 Pulaya Colony
34 Manthara Colony 22 1320.71
68 390 0.4
35
36 Chakkamadom
Kembri colony37
Colony 212190
11980.68
2.28
37
38 Meparambu
Anakket Colony
parambu Colony50
91 297
532 0.9
1.31
39 Veli Colony 102 502 2
40 Murukkuthara Colony 20
33 117
161 0.28
0.14
41 Marakkadavu Colony
42 Mini Colony 77 416 1.81
43 Kochangadi
44 St.John PattomColony 3_l 1112
Colony 186 170 0.5
3.6
45 Nazareth Colony
46 Ammaimukku 3147208
Colony 2350.72
0.69
47 Fishermen Colony-Fort Cochin 108 1822 2.5
48 Panayappilly Colony
49 Srambikkalparambu Colony124 639
47 252 1
0.49
50
51 Rameshwaram
KiliyampadamColony
Colony310
1421716
7863.68
4.6
52 Loreth Colony 37 198 0.92
 53 Chirakkapadam Colony 41 199 .o_
m

54 Chnuluzhathu Colony 67 340

55 Muulamkuzhy Colony 45 226
56 A D Pnram Colony 30 168 O H H­

57 PT Jacob Road Colony 24 132

58 Vnttamakkal Colony 330
59 Saudi North Colony 196 1053
60 Aryad Colony 158 920
(1 _.
Odnmpilly Colony 26 135
62 Palm] l"l.';‘l|-(OT. (folony 18 108 D O w 0'

63 Mundamveli WesL Colony 128 658 JA1N-H .Nc.g.N..

64 M.m.—n:horry (Iolony 220 1198 QmNUumwwmUQQ

65 Mann Colony 10 JI:

ll 1: Mounnmuhuxypulnmhn Culuny 31 171

67 HabnkknLLy Colony 12 113
68 Halljan C0lony—Dn15 62 303
69 Chcmmuen Flsherlos Colony 132 512
70 Houlamkuzhy Beach Road Colony 55 313
7] Palliparambu Colony 27 168
72 Kannammaly Bus Slop Colony 76 4'30
73 Chullikkal Muslim Colony 7B 402
74 Chulllkkal west Colony 46 315
75 Karuppatti paramhu Colony 29 175
76 Volluvoliparambu Colony 50 235
77 Aramcherry CH Parambu Colony 37 250
79 Chakkaraidukku Colony 60 253
79 Puduvassorry paramhn Colony 27 no
B0 MorLhnndnnpnrumhn Colony 55
Bl M.':<|.-Ippn L Iyluodu Co I (my 74 lilil
B2 Pulllparamhu Mosquo Colony 106 577
B3 Alathnkutly Colony 105 304
34 Ambadl Valappu Colony 31 209
35 Kunnupuram Colony 54 294
36 Chirattappalam Eastfiwost Cololny 127 740
87 Karlngathuruthy Prambu Colony 480
83 Bandakka parambu Colony 150 799
39 Devaswom parambu Colony 67 367
90 Pandikudy 27 129
91 Palamarathil purambn 127 760
92 Tommassery colony 137 690
93 Kochupally road colony 54
94 DLB colony 36 216
95 Bell fisheries colony 16 87
96 Jayalekshmy theatre road 45 230
Valummel colony 450
98 Poklavparampu colony 39 220
99 Pallichal colony 49 235
100 Indiranagar colony 175
101 Marampilly colony 54 286
102 Nadakav colony 36 130
103 Kadebhagam colony 02 410
104 KM? oil mill colony 130 657
105 Pandarachira colony 56 290
106 Omasanam road 216 1183
107 Moopan colony 34 180
108 Federal bank colony 25 140
109 SP Puram north colony B7 460
110 SP Puram south colony 130 ' 780
111 Pullardesom colony 22 130
112 S D P Y west colony 130 645
113 S D P Y west puramboke colony 58 348
114 Pipe lino north colony 100 576
115 Pipe line south colony 146 784
116 K E K colony 15
117 Talappiparamb colony 150 850
110 Kacheryppady colony 71 401
119 Kaduthanath colony 120 700
120 Kammathi madom colony 100 607
121 Patlu'.nertl.ukando1n
122 Tangal nagar colony180
colony 1'15 4.45
72
123 Pokkanamuri
124Kannangatt
Toppithara colony
colony 151 5.02
270717.2
125
126 Ithithara colony 1.8
127 Puttaluth colony 64 71
Vilakkanozhath colony 36
1.20 Konam—porumpadappu colony 100 2.2
130Companypparamb
129 Aquinas colony
131 Parnbaimoola
colony
130103
colony 207 5.34
7.3
132
133 Paruthithara
Ayyankali colony
colony 30823.46
134
135 V A T
Vathuruthi colony
colony 118
1100 3.8
5.2
136
137 .'4er.:1l box
Pueliyad colonycolony 27
60 0.36
3.1
138
139 Meenchira
Mahatma colony
colony 5837 1.1
0.85
140
141 Nikathilroad
Kotheri colony
colony 36382.06
1.2
142
143 Porandoor
Perandoor north colony
Rly bridge 52
colony 1.35
35 0.9
144
145 Elamakkara colony 12 0.37
146Kurumba
147 Pottaiyl colony
Changadampokku colony124 501.88
11
colony65102'34
- 011.3
148
149 Chullikad fishermen
Kllruppmnbmlaln colony
colony 47 L137 091I
150 Knippllly colony
151Clnornalipparalnb
(.'hnt.h0ly Colony '.}‘. 11.0
11 942 I .
IJ.l2
152 colony 45 0.21
153 Mothara colony — Padivattom 06 432 0.55
154
155 EI:tukatLu colony
Karuvoliopadam 14312175
colny 0.251
156 Karukapally
157 Pottakkuzhi colony 87 48
colony 27 0.09
0.08
158 Ulladan colony 8 42 0.32
159 Doshabhimanl
Perandoor south colony 48 281 1.15
160 road colony 35 245
161 Sastha tomplo colony 8 42 0.06 0.65
162Panakkapparamb
163 Karathatt colony 2737150
colony 172 0.4
0.85
164 Puzhakkarappndam colony 27 168 0.56
165 Clnottlyal; colony 64 367 1.36
166
167 Talipparamb
Ulakampara colony
colony 145
18 856
72 2.25
0.49
168 Tannuthara colony
169 Nedurntotturnkal 2515
colony 150
691.35
0.28
170
171 Kamsan colony
Kodalipparamb 24 50
colony 111 0.58
250 1.2
172
173 Kothappadypparamb
Uzhinjath colony
colony 27 96
152513 5.71
0.82
174 Kannoth colony 56 290
175 Clnoruviruppu colony 42 160 0.781.2
176
177 Nodupallichal
Tadipparamb colony 47
colony 20 250
101 0.71
0.59
178 Kadappath colony 38 210 0.76
179 Kanniyambuzha colony19
25 95
1320.41
0.48
180
181 Chullikkad
Nechoor colony
kadavu colony 21 142 00.7
27
182 Madavanathazhe colony 36 181
183 Vennalapara colony 28 122 0.17
184 Vennala colony
185 Michabhoomi 5235222
colony 1851.66
0.75
186
187Alinchuvadu colony
Vattamthitta 22 112
28 167 0.3
0.62
188 Thuruthy;l — Vannala 18 120 0.52
189 Chavell veli 18 98
190 Thalamitcam 12 52
191 Mannarkara 32 175 U1 \I
192 Vadakkathara 47 260
193 Vattathipadam 27 165
194 Kuruppampadam 26 140 OP-‘OOOD

19!) Ano1.Lipz)1'eJmbu 10 52
11» M.|l’l‘.I|n'Ilillllllll 68 341!
197 I11‘./«:1 |aumlJnt_; -zulony 45 24!;
198 Voalutlmla colony 82 521
199 SL. .Io::epl1's colony 48 260
200 lltlill. juI.Ly l’()rl(l colony 4'! 2311
201 (7mn[mnyp.'numlm colony 2'! 118
'/.02’. 'I'.mI.uuni I.lnnul.lm colony 62 191
'/.0.) l’u::lIpenk;-J colony III! 16!}
204 Shanmughaputam colony 111 570
205 Erattukkulangaracolony 14 34
206 Pullechundil colony 17 100
207 Kuruppuchira colony 21 120
208 Choorepparambu colony 15 86
209 Pozhakkara colony S71
..l|| 'l.:I.u[nn.Jm z‘r)ltI.'I‘,/ 21! 14!‘:
..ll l-1.11:.-]»|;.|I.l |p]uII .IluluIl 101)
.41.: :3 I-‘ H I-nul roluny no 1! -I
213 E R G colony 4!
214 Kemakathu parambu 1.’!
2l5 .lar_]a'joovan Pam colony 24 128
216 l’nnoLh colony 31 lm‘
7.17 Kndappnramlm colony 24 1-12
210 Mannullipadam colony 32 132
219 Town hall colony ll! 143
220 KotLakkanal colony 30 17?, ooo --«coco v"-BJLJ---' -.-u'.\I>-.~.:~L.:c-\'

221 Cllannallllnnkml colony 102! 53:1:

222 Neal Kuvlllna Lhoutro zu 15.
223 Stadium colony 553 245.
224 Padlyathukulam west colony 2a 116
225 Mooppan colony 22 188
220 Vol lnyi p.-armnlm colony 46 213 3000

227 Kallungal colony 10 80

223 Kissan colony 197 979
229 Mothlrapadam 29 118
230 Chammani colony 18 101 0.13
231 Karanakkodam 18 97 0.41
232 Labour colony 55 326 1.24
233 Kathrukadav colony 24 168 0.32
234 E W S colony 110.1 6566
235 Harshalling yard colony 171 923 1.721
235 Vottuva colony 39 237 0.85
237 Kuthappady colony 6.1 317 0.6
233 P 8 T colony 106 576 0.42
239 Koothappally colony 45 281 0.6
240 Kudumbi colony 73 452 .38
241 Old Kudumbi colony 226 1220 .49
242 Udaya colony 205 1182
243 Manikandanthuruthu colony 27 143 .65
244 Fathima church colony 12 62 .33
245 Ambalamchery colony 17 S2 coon»-H .42
245 Shipyard colony B9 512 1.4
247 Pottanamkory colony 18 10?. 0.12
243 Parambithara colony 14 17B 0.18
249 Atlantis colony 21 124 0.2
250 Ambedkar colony 179 1.27
251 A I school colony 27 148 0.38
252 Kolyatharathodu colony 177 1060 7.8
253 Chllavannor colony 56 248 1.23
254 Milltariparambu colony 27 163 0.51
255 Chilavannoor bund 60 335 1.5
255 Koiythara puramboke colony 38 188 0.3
257 Cheriya Kadavanthara colony 28 160 0.25
250 Pulaya colony 31 167 2.0
259 Konthuruthy colony 40 191 0.55
260 Chaithannyapuram colony 28 160 0.3
261 Fishermen colony 76 385 3.24
262 Paduva lane 45 202 0.20
263 Njarakedavu 60 248 0.92
264 Mini Gandhinagar colony 20 122 0.4
265 Petta colony 32 180 0.55
266 Juhilnn road mouth colony 61 7.10
267 KadavanLhara gas plant colony 40 xufl 0.0
263 Valappikadavu 25 138 0.43
269 Kadavilcheri 21 120 0.71
270 Thaippilodathu puramboke colony 12 96 0.33
271 Ambadithazham 10 97 0.2
272 Thykoodam bund colony 17 102 0.0
273 Thykoodam church colony 62 323 1.35
 Ongny \_
u..\_
E
/
31) m
- '\_ \- "'53 n­
Lu
'S
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. ‘Q L\
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wnrno_u cl ’-'*"""'—’/'Y'l.§l/’J::")‘ ‘- ­
,_.._ i
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NOT.TO SCALE

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FIG - 7 .7 .LOCATION OF SLUMS some=-com=onAno~orcocm~

 118

immediate environment. Thus, the whole area oe-generated IFIIO an urban

blight in planning terms. Hence, any future devecpment proposals for an

area should take into consideration the possibTEties for de;’adation in

another area because of that.

The recent rapid growth of Cochin brought 2 large numbe' of migrant

labourers from other parts of Kerala as well as tram Tamilnadu. Several

slums are in the formative stages particularly in Thrikkakara area where job

opportunities underwent a sudden boom by arge—scale construction

activities as well as various industrial activities me my related to ‘he Central

Export Proxssing Zone (CEPZ). adequate

With the absence of
accommoda-ion facilities. the labourers, most of’ whom unskilled and

underpaid, are forced to live in hutments withou: proper basic amenities.

Such areas will degenerate to major slums if appropriate housing projects

are not envisaged and implemented soon.

Unless immediate steps are taken by the authorities to rehabilitate

these urban poor, the children of the slums are likely to create serious social

problems by becoming anti-social elements as in the other major cities.

Also, the unhygienic conditions in the slums can px»/ide breeding grounds

for pestilence.

7.3.3. Water Supply.

Cochin did not have potable water even at o’-den times and drinking

water used to be brougn’: by boat from ,’=.‘\-:-'aye. 20 miles from. Cochin

(Logan, 1901}. Filtered water from Chowara was first broug“. through
pipeline for distribution in Emakulam during the time of Diwan A.R.Banerji

(1907-1914). This systematized scheme had 2.3—mi|lion litre/day plant to

serve a total target of about 20,000—population i.e.. 115 lpcd (Emakulam

District Gazetteer.'65.)

The Kerala Water Authority, an autonomous body under the

Government of Kerala, is responsible for the public water supply system in

Cochin. Since. the groundwater in the highly pooulated western flatland

area is mostly saline and/or with dissolved gases. :.".e public water supply
system has to be depended upon, even for wasaing and construction
purposes.

The two fresh water sources on which the regional water supply
scheme depends on a_re (1) the Periyar River which lies to the north of the

study area and (2) the Muvattupuzha River which lies towards the east as

well as south of the study area. This system derives most of its
requirements from Periyar River at Alwaye. The Alv.-aye water works is the

major water supply installation on the Periyar River. which has got 5 intake

points from which water is supplied after treatment to the major portion of the

study area. There is one intake point in the Muvaftupuzha River, which
serves the remaining parts in the southeast including Ambalmugal —
Karimugal industrial zone. The quality of water in the Periyar and
Muvattupuzha River is generally satisfactory after i:"..-'3 adoption of normal

methods of drinking water treatment. In the hilly a'eas, treated is

 120

pumped to overhead tanks, which serve as storage tanks

and thendistributed. In lowlands, water is directly pumped into
the distribution system with overhead tanks to serve as hydrostatic
pressure balancing tanks.
The summer flow of rivers estimated to be 133m 3/ sec

(Joy1992 ) and that of Muvattupuzha river is estimated to

be 33 m“/sec which would be sufficient to meet the water
requirement of the region if properly tapped along with efficient
supply system. There is already a severe gap between the
demand and supply.
The Central Public Health Engineering Organisation's
manual on water, water supply and treatment stipulate the
following standards of per capita water supply.
Community population Per capita requirement of drinking water.

(Litre per capita per day)

Less than 10,000 population -— 70 to 100lpcd.

Between 10,000 to 50,000 -— 100 to 120lpcd
Above 50,000 -- 120 to 200 lpcd
In 1914, when the public water supply scheme was
introduced in the area covered by the present Cochincorporation,
the supply was 115 lpcd, whereas at present , it is only 35 lpcd,
while it should be 120 to 200 pcd asper standards. In the
adjoining municipalities and panchayats, water supply is worse
 TABLE-7.4JNATERSUPPLYSCHEMESHVTHESTUDY
AREA

Present Per Capita Proposed Per

Name of Scheme Area supply of drinking
water Capita Supply
of drinking

1. water
(1) (2) (3) (4)
Supply scheme Tripunithura 30 lpcd 125 lpcd
water

for Tripunithura Municipality

2. — do - Cheranalloor Cheranalloor 30 lpcd 140 lpcd
Panchayat
3. World Bank aided Chellanam Sub 20 lpcd in rural 80 lpcd in
Scheme for south zone. area, 40 lpcd in rural area.
GCDA zone. trial area.sub
Thrikkakara urban and
west and Central Kumbalam sub urban and indus- 150 lpcd in
industrial
ZOY1F_‘.- area.
Kalamassery sub
zone.
Choornikkara
Keezhmadu

4. Puthencruz Puthenxruz
water supply Poo—house
thrikka 15 lpcd 80 lpcd for
connect­
Scheme Aikkaranadu
Vadvucode ions
for 40 lpcd
street
Thiruvaniyoor pipes.
5. Scheme
waterfor supply Thiruvankulam S lpcd 40 lpcd
Thiruvankulam
6. Mulanthuruthy
— do — forVillages.
Mulanthuruthy 5 lpcd 40 lpcd
7. Augmentation
water supply
of Cochin City 35 lpcd 150 lpcd
supply to Cochin
Corporation
8. water supply scheme Njarakkal 20 lpcd 70 lpcd
to Njarakkal and Edavanakhdu
adjoining panchayats Elamkunnapuzha
Kuzhuppally
Nayarambalam
Pallippuram
Mulavukadu etc.
Chennamangalam
Cbittattukara
 The distributio“ system suffers many drawbacks. Many of the
pipelines, which were laid during the initial installation (in 1914 for the
Ernakulam area), are still in service. These pipelines often cross the drains

and are partially damaged due to aging. Especially, in the thickly populated

western parts of Cochin, the pi es are heavily corroded resulting in heavy

lossof water due to leakage. Also, at times of low water pressure drain
water get into the water supply system, thus oontaminating it. This is the
cause of the periodic outbreak of gastroenteritis and other water—borne
diseases in these areas.

As early as in 1984, from a field study conducted by National

Environmental Engineering Research Institute, Nagpur (NEERI, 1984), the

following observations were made.

The water waste assessment test was conducted and the rates of leakage in

the mains and in the service connections (including public hydrants) were
found to be very high.

Rectification of leakage of the very old pipe is practically impossible. Hence,

these_pipes are to be replaced urgently with new ones with higher diameter

size considering the likeiy increase in population.

Loose deposits and waste matter are present in the distribution mains. As
this is highly hazardccs to health, revamping of the existing distribution
system seems imperative.

Since 1984, no mac" repair/recfiiroatioii work in the water supply system

has been reported " wave undeftaken. in the light of the NEERI
 observations, the problers associated with the water supply system now
might have worsened further and are likely to aggravate in future.

Apart from the above problems associated with the water supply system,

the following aspects at the intake points deserve immediate attention

without which serious problems can crop up in future.

a) The drainage outfalls from the riverbank municipalities of Alwaye and

Perumbavoor are discharged directly to the Periyar River upstream at points

fainy close to the intake wells.

b) The summer flow in the Periyar River, the major source of the water supply

scheme, is found to be low particularly during drought years. Since the

headworks are situated not very far from the river mouth, the hazard of
saltwater intrusion from the backwater system, particularly during high tides,

has to be given due consideration. For example, in 1983, salt water reached

the intake wells at Alwaye and the water supplied was saline. But in the

Muvattupuzha River the intake well is situated far upstream at Piravom,

where the ingress of salt water is unlikely.

c) Also, some of the major chemical and metallurgical ifidustries of the state
located in Udyogamandal, Eloor belts discharge their effluents into the
Periyar river at points only a few kms downstream ‘."=":2 intake area. The

discharge of water containing mercury from the Travancore Cochin

Chemicals Ltd. (TCC) and acid & insecticide wastes from the Hindustan

Insecticides Ltd. (HIL), has to be viewed with concerr. No systematic study

is known to have assessed the chances of transport: :7 of these cc ;utanis

along .-.i‘.n the saisne water front :ne backwater system eastwards to reach

the axe;-intake area during summer months, particulary in higr. tide

situatcns.

The Edamalayar dam regulates the water flow in the Periyar river.
Hence the reservoir discharge has to be regulated, particularly during
sumrne’ months, to keep a des:.'ed minimal level of water flow that can
ensure freedom from contamination of water near the intake wells with due

allowance for irrigation needs.

The ground water in most parts of Coastal belt of Cochin is saline and

hence not potable. However, even though close to the backwater/sea, in

some i:-:ations potable fresh we or ‘s available at a depth of about 75 to 80

meters in archaic riverine sedirnertts or as perched aquifers in the upper

layer of sediments. ln such areas water exists in a condition of hydrostatic

equilibrfrn with the saline water of backwaters/sea. An indiscriminate

withdra.-.ei can upset the hydrostatic equilibrium resulting in salt-water

intrusion into these aquifers.

However, the eastern upland portion of the study area is endowed

with a':-ndant quantities of potable ground water, whid: is generally
protecte-3 from contamination by the relatively impervious 0.‘-erlying lazerite

layer. Tie water is being preserziéy used by individual ho'_eeh.olds in

rural areas, but can be exploited on a larger scale after due assessmen‘. of
7.3.4. Solid waste (gar:a-e) disposal
Garbage ::L;ection and disposal is a 'outine function of any local body

and one of its ITCSZ serious duties in the _‘:an area. The Cochin Municipal

Corporation has conducted a sample 8;.-‘.5,’ and the quantity of generation

per day of garbage is assessed as 377 tor-es (Gopalaknshnan, '97). Out of

these 377 tonnes. 270 tonnes are from ::‘.*.estic waste and the remaining

107 tonnes is he combined generation :‘ commercial, institutional, road

sweeping, drain cleaning, clinical wastes and construction & demolition
sources i.e. domestic generation is 0.48 kghead/day, combined geieration

0.67 kg/head/day. Density of waste is assessed to be 414 kg/m3 . The

calonfic value of the waste is less than 15.-C K Cal /kg and 40% of the waste

is cornpostable. 10 to 12 % of the waste is recyclable paper, plastics. metal,

coir, coconut husk, coconut shells, glass etc at the source of generation. But

by the time it gets into the dust bin or cciection vehicle, many recyclable
fractions may be removed by the rag pickers. The hotel waste generation in

a day is about 12 tonnes containing a very high percentage ‘of leftover food,

which could be used to feed animals. Vegetable, fish and meat markets
generate 36 tonnes cf ccmpostable waste pef day. An annual increase of 5­

10% in waste generation can be anticipates‘ due to increase in population

and change in the life style. It is calcuaied that by 2001, the waste
generation may be the tune of 450 tor-as per day but with a lesser
dens=ty than the cfescnt garbage, resultfig in a higher volume to ‘be
hancezl.
 By the study done by the Corporation of Cochin (Gopalakrishnan,

1997) about 40 to 45% of waste gets accumulated in roadside margins,

drains, and open spaces. The percentage of wastes disposed by various
ways is detailed below:

Domestic. Communal storage - 330%

individual bins(doorto door collection) — 0.4%
open throwing — 46.6%
on plot disposal - 17.0%
recovery — 3.0%
Commercial communal storage — 37.0%
direct collection - 8.0%
open throwing - 46.0%
recovery - 9.0%
Hospital at source in plastic bags — 64.0%
(Clinicalwastes) communal storage -27.0%
incineration - 3.0%
open throwing - 6.0%
In the Cochin Corporation area, solid waste is coilected from roadside

communal bins and also directly from shops, hotels and houses manually by

the use of handcarts, wheelbarrows, tillers, tractor-trailers and a few

automatic loading trucks as primary collection vehicles. This waste is then
transferred to open sub depots from where secondary collection vehicles like.

ordinary tractors and tractor trailers carry the waste to land fill sites where

the dumped waste is covered with a layer of earth daily. This kind of waste
disposal in low-lying regions of the thickly populated western flatlan: area

can contaminate the groundwater with chemicals, organic matter as well as

disease germs. Also, it provides excellent breeding grounds for mosquitoes,

housefiies etc. Moreover, at present the City Corporation owns not many
landfilling sites and now filling is done in small private lands, most of which

are unsuitable for the purpose.

A series of health and environmental issues emerged from the poor

service and management of solid waste disposal. 50% of the waste
accumulates in the city - about 150 tonnes a day. Two major health hazards

of the city are directly linked to the inadequacy of solid waste disposal - the

large-scale mosquito breeding and flooding during monsoon. Cochin

Corporation is spending about Rs.3OO lakhs per annum to reduce mosquito

breeding by applying chemical larvicides and to reduce drain blockage by

annual cleaning prior to monsoon, which is caused mainly by dumping of

wastes into drains.

Ground and surface water contamination due to leachate percolation

is another environmental problem. The most obvious environmental
damage is bad aesthetic condition due to uncontrolled‘ c’:_=.rnps. Multiple

handling of wastes causes health risks to workers. Handling of clinical

wastes is more hazardous.

in the eastern upland, the garbage disposal is hot yet a serious

problem because of the availability of plenty of land. B:‘. in the weeter
flatland area with the high density of population, it is rather‘ citficult prc':'em
 since the quantity of garbage generated is nearly 9,44,637 x 0.48 kg :'ey =

4,53,426 kg per day. Here, the disposal is a serious problem due to a very

high water table and lack of enough space for local waste disposal. Hence,

the accumulated wastes have to be transported and disposed.

Garbage collection and disposal is a routine function of any local

authority and is one of the most serious problems in any urban area. Hence,

it implies that at present day Cochin Corporation area alone, comprising of

87 km? , with a population of about 0.56 millions, about 270 tonne of garbage

is generated per day. Out of this, Corporation (by its own statistics) is able

to collect and dispose only 120 tonnes Iday (about 60 truckloads) cue to
inadequacy of necessary infrastructure. That is, about half of the "waste
generated is not collected, but get dumped into streets, open spaces and
drains creating serious environmental problems.

Out of the three major options of disposal, incineration is to be 2"-_iled

out (except for clinical wastes) as the waste has low calorific value and high

moisture content. Hence, sanitary land filling with due consideration to the

groundwater, supponed by composting plants, would be the ideal dis:-:.sal

solution with minimum pollution. Cochin Corporation has rmntly inszaf d (I)

biotechnologically managed compost plants in a few places on Ll) Fl

experimental basis. Installation of such small-scale plants in each neighb-tur­

hood seems to be the ultimate solution to the garbage disposal protein,

which will reduce the transportation cost also.
 Added to the above urban garbage load is the conir":~ution from the

other local bodies of the study area which is estimated to be about 380
tonnes / day. Hence. in the study area a total quantity of 650 tonnes of
garbage is generated daily (at the rate of 0.48 kg per head per day) by a
population of .13,53,040.

At present, in the eastern parts of the study area, there exists no

institutional system of waste collection and disposal. Thinly populated areas

in this region can resort to compost pits and in thickly populated pockets
covered type of land filling can be depended upon, because. in this region,

contamination of the deep—lying ground water is less likely, being protected

by the relatively impervious overlying laterite layer. However, this can only

be a temporary solution till the urbanisation spreads to these areas with

ensuing increase in population density and resultant increase in garbage.

7.3.5.. Liquid waste disposal.

The liquid waste in the city can be classified into sewage, sullage &
storm water and industrial effluents.

7.3.5.1. Sewage Disposal

A well planned sewerage system is absent in Cochin though efforts

were taken long back during the period 1967-70 by the then Public Health

Engineering Department (Water Authority) in which Cochin Ccporation and

its surroundings were brought under a sewerage scheme afte' dividing the

area into four zones (Mathew, 1995). They are

a. Emakulam Ncrth Scheme

Northern part of Emakulam town, Ecapally and a oortion of Vennala

b. Emakulam South Scheme

Southern part of Ernakulam town, remaining p:-:;on of Vennaia area

and a major portion of Vytila area.

c. Marad-Tripunithura Scheme

Remaining portion of Vytila, Marad and Tripunithura municipality.

d The Mattancherry, Fort—Cochin, Palluruthy Zone

Fort-Cochin. Mattancherry, Palluruthy

Even though schemes were prepared. very little was executed except

for a small portion of Emakulam south scheme in which at present, the

sewerage system is functioning only in about 3 Sq.kms out of the total 535

Sq.kms (Fig.7.9). Also, in many of the thickty populated housing colonies in

the central city area itself, anticipating theaplanned large-scale sewerage

system, cystern type of sewage disposal was resorted to as an interim

arrangement. Due to the delay in implemer.‘_=tion of the sewerage scheme,

these cystern pits often overflow, particularly in rainy season with the
ensuing health hazards. In other areas, cc-nservancy system (pits in the
ground) or septic tank system is followed wrfich was essentially evolved to
suit the niral houses. Their effectiveness is ’educed in the urban areas due

to the small size of the plots and conse:=_ient shortage of space for
dispersion of the efluent. In the r;=.::<~e of '..'.-’3 highly ;;.:._:-ulated low—lying
 $2
SCHEMATIC
(NOT TO SCALE)

IJ,§j3if*IIfi%II?;«I
I
A SEWER LAYING COMPLETED (COMMISSIONED)

B MAJOR PORTION COMPLETED (NOT COMMISSIONED)

C MAJOR PORTION INCOMPLETE (NOT COMMISSIONED)

FiG - 7 .9 . SEWERAGE IN COCHIN

 ‘western parts of ire study area. an elevated water tabie adds to the
problem. Hence, trese methods can be best adopted only in the eastern
upland areas of the szudy area vrizh a low population density. In all other

areas a well—orgar: ;e: sewerage is highly essential.

Considering ‘:75 flat nature of the city terrain, it may be necessary to

design the sewerage system by dividing the city into several zones
depending on the eevation of the area from sea level. The sewage
treatment plants may be suitably located for treating the load of each of
these zones. The treaied effluent can be either disposed in the backwaters
or for farming purposes.

7.3.5.2. Storm water & Sullage Disposal.

The disposal of st.orm water and sullage is a serious problem in

Cochin. in the western flatland portion of the study area, the storm water
and sullage flows through theroadside drains into the canal system and
finally to the backwaters. But in many places, the drains are absent or do
not function properly due to the flat nature of the terrain. Besides, Cochin

city is mostly a low-.ying area‘ with clayey soil and hence relatively
impervious to surface waters. These factors cause severe waterlogging in

Cochin during the monsoon season. During high tides, the problems are
further aggravated, since road-side drains are at or below sea level in
several places. So the foodwater cannot be discharged into the backwaters

by the existing system of gravitational drains. The storm water drainage is

dealt in the chapter or s_—.‘ace hydrology.

 Water-‘:;:ging in the western fiazfand, particularly in the Cochin city, is
due to the fcllowing reascns: —

. The difference in level between the highest and lowest area in the western

part of the study area is "roughly 1.5 meters (Fig.7.10). The difference
between high tide and low tide is about 1.2 meter. Since, the tide water level

is the deciding factor in the drain flow depth, flood water level will not recede

during torrential rains if the drains do not have adequate width, even if the
drains are deep enough. Also, the drains are often blocked by dumping of

building debns, garbage and other wastes, leading to the blocking of the
drains. Most of the drains are of inadequate size and frequently, the drains

are traversed by water supply pipes, electric cables, telephone conduits etc..

The floating matters get entrapped between the conduits and the flow is
blocked.

. Filling up of many of the thodus’ or natural drains in the last few decades

has diminished the drainage capacity of many of the areas in the central city.

M.G.Road, l‘=.-tullassery Canal Road and many other roads in”Cochin city

were ‘Thodus’ a few decades earlier, which were converted to roads by

filling up. these roads retain only small roadside drains. The flood
water from large areas, which were earlier relieved by such wide natural

drains, now find the road side drains grossly inadequate, thus causing water­

logging in the -33:31 even caring times of relatively weak rainstonns. Also,

rrany drainage channels 87% being encroached upon by individuals as well

ED. Nhters

ffl

IBC

(WESTERN FLAT LAND)

FiG - 7. 10 . OLD CONTOUR MAP OF ERNAKULAM TOWN

 as institutions resulting in the formation of bottlenecks that reduces the flow

considerably.

Formerly during heavy rains. the storm water drained into the natural pools

of marshes and paddy fields, which slowly emptied into the backwaters and

sea. So, in the old days, even when during torrential rains coinciding with

high tides, there was no flooding in these residential areas. But now, for
building purposes, many of these natural catch basins have been filled up
higher than the formerly high adjoining residential plots. Since there is no
outlet for the storm water and also because of water inflow from the newly

filled up areas, the old residential areas are now subject frequent floods.

. Reduction in seepage of rain water into the soil by the land being filled up

with laterite (the easily available one) which consolidates into an impervious

strata or cement concreting of courtyards results in the increased run off.

. Large natural drains and tidal canals are often blocked by a profuse growth
of Eichhornia (Wa.er hyacinth) due to eutrophication caused by domestic

, waste water and sullage inflow. Also, putting up of bunds in canals to

prevent the entry of saline water by various agencies blocks the fiow of
water and results in floods during monsoons.

The flooding of storm water along with sullage in low-lying areas

affects transportation, telecommunication, electric supply, water supply and

other public utility services besides causing innumerable human discomforts.

It also poses health hazards particularly by contaminating drinking water,

when taken from eireet taps in the low-lying areas.

 Many of the water-logging problems in the highly ur':anised western

flatland can be ameliorated by the following steps: ­

. Linking the drains of "all residential, commercial and indust-"Tal areas to the

main tidal canals, by a grid of drains along the roads which is possible since
all the areas in the western flatland are within 1 to 2 km of the north-south

running tidal canals. Also their proper maintenance has to be ensured.

. Deepening of the main canals may not be of much use since their bottoms
are already below the low tide level. Only widening can increase the
capacity of the canals considerably.
. Encroachers into the canals are to be evicted and the 'Thodu's are widened

to their original size, wherever possible.

In the eastern upland regions, comprising of 21 stream catchments, at

present there are no serious flood problems. This is because, there are
sufficient low—lying paddy fields in the flood zone of these streams, which act

as buffer containers to store the flood water. However, the recent trend in

filling up of those paddy fields, particularly those lying close to the outlets of

the streams, will reduce the discharge capacity of the streams. thus causing

frequent fioods in theupstream areas. Moreover, during torrential rains, the

surging water, particularly from the vast Kadambrayar and Puthencmz

catchments (81 and 58 square kms respectively), may demolish the ‘earthen

dam’ of land filling in the flood zone along with the buildings constructed
 there. Hence, filling up of padc'-_. fields in s;:1~. crucial areas must be
discouraged.

7.3.6. Traffic and Transport

The operational efficiency c‘ any urban system depends on the

adequacy of linkages between various activity areas by a system of traffic

network and goods transportation. Cochin is uniquely served with the

concentration of different modes of transportation on air water and land.

Goods traffic in any region, in general, is contributed by the factors like

population, which directly influenw the consumption requirement of
commodities, agricultural and industrial production and distributional or
commercial importance of the region.

However, the road transportation in Cochin is seriously affected by

the suburban spread of the city, which leads to excess pressure on the
arterial roads during peak hours, which were not adequately planned and
designed to meet the demand. When the roads do not have adequate width

to contain traffic and parking vehicles, the roadside trees are often cut down

to provide for carriagexuay. Also, in very narrow roads, traffic signals and
hoardings become visuaity very unsightly.

Traffic congestion results in burning of more fuel, particularly at peak

hours causing serious air pollution which will be more acute when the roads

are narrow with tall buildings on either side forming a canyon preventing air

circulation. When there is atmospheric inversion or isothermal condition the

atmosphere will be more stagnant resulting in "e production of
phototoxicants during daytime.

The land under transportation and communication {in the central city

area) constitutes 6.14% of the r.et dry land area (GCDA Structure Plan —
2001). This includes area under railway installations, road transport, dock
yards, jeirties etc. and airport. However, the roads are narrow and streets

are usually irregular lanes. The railway line divides the city into two in north­

south direction. The landing facilities for feny services and for inland
navigation are grossly inadequate.

Though the number of vehicles on the road has increased several

times, the road surface within the region in the past fifteen years has not
increased proportionately. The road congestion in the central business
district area of Ernakulam is the primary reason for the area being unable to

bear further commercialization. Another reason for over-congestion in the

region is that the potential of water transport has not been adequately
utilised.

The road transport in the study area is served by National Highways,

State highways and City level road network (Fig.7.11).

Three National Highways touch the city which facilitate fast movement

of peopfe and commodities from ‘is hinterland to Cochin and add to the

improvement of the emnomic environment of Cochin.

 ,..:N?:J<o_.uz_._ . .

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 (1). NH-47 running between Kanyakumari arid em passes '-.rgh
(1)

Cochin. Formerly this hi.ghwe'_.' passed through very congested e’-:-es of

Ernakulam, Thoppumpady an: Palluruthy. Now a Bi,-"pass has seen
constructed from Edappally passing through Vytila, Marad end Kumbe em to

join the highway at Aroor. It is iaid as a 4—lane roadway with service roads
on either side.

(2). A coastal highway NH-17 links Cochin direcfly to Parur and

beyond. to Mangalore.

(3). Another National Highway (NH-49) links Cochin to Madurai via

Muvattupuzha, Kothamangalam, Adimaliand Munnar.

The city is directly connected ‘.0 other urban centres of the region through

state rfghways and district roacis. These roads radiate from the city. The
most important roads in this group are: ­

1. Ernakuiem - Muvattupuzha road

2. Ernakulam - Piravom road
3. Ernakuiam - Perumbavoor road
4. Ernakulam - Parur road.
5. Fort Cochin - Chellanam road
6. Vypeen - Parur road
The operational efficiency of transportation along these radial roads is

very much hampered by poor eignment and road geometries, uncontrolled

ribbon development along the road sides. bottlenecks created by narrow

bridges; railway crossings etc E“.d insufficiency of roads connecting redial

roads with each other. These pads are linked to eeci other at se.eral
points by ring roads, which are the major link roads in the region and are the

following.

1) The inner ring road, of which the Elamkulam — Kaloor - Perandoor

road forms a major part, facilitate quick access to the central business
district comprising the trading centres around Ernakulam, Cochin Port and

Mattancherry.

2) The middle ring road is constituted by the existing Cochin Bypass and

the NH—17.

3) The outer ring road is the lrimpanam - Kalamassery industrial road

which links the industrial centres of Eloor, Ambalamugal as well as civil

station (office complex), the Cochin Export Processing Zone, the Naval
Physical and Oceanographic Laboratory at Thnkkekara and other
prospective work centres of the region.

The bulk of the hinterland of Cochin lies on its east and the rest on its

south and north. The regional roads from the hinterland have easy access to

the middle ring road of NH-47 Bypass on the periphery of the present highly

urbanised areas. From the middle ring road, at present there are only three
main roads to reach the inner ring road and the Central Business District

(CBD), which is the nerve centre of Cochin - Road via Thoppumpady ­

Wellington Island. Vytila - Pallimukku Sahodaran Ayyappan Road via
Kadavanthara junction and Banergi Road from Palarivattom - Medhava
Pharmacy via Kaloor. Besides, there is another road, Thammanam —
Pulleppady Roe: via Kathrukadavu which is very narrow. Now a new road
parallel to L'*.= Sahodaran Ayyappan road is nearfig comple: 3". All these

roads are at present very congested which make :16: entry of vehicles from

the hinterland to the CBD area very difficult. The ‘widening of the Sahodaran

Ayyappan road, which has now begun and the corpletion of its parallel road

(Ponnurunny — Gandhinagar) along with widehing of Thammanam ­

Pulleppady road may solve this problem to a great extent.

The rc/:d network in the city is a broken grid-iron pattern. The main

emphasis is on the north—south axis with minor rcads giving the east—west

connection. Vast portions of peripheral areas remain isolated from bus

services. This is due to the fact that most of the pefpheral roads are of poor

quality with narrow sections of the roadway, crossing of railway lines and
lack of continuity created by unbridged canals and streams.

The Clfiy has two bus terminals — the State—c‘-med KSRTC bus station

lying in the CBD which is about 4 kms away frcrn the second one, the
Private Bus Stand at Kaloor. No co-ordination exists between the operation

of buses from these two terminals. There is also cverlapping of suburban

and city servim within the city. The interchange from the suburban bus
system to dry bus system and vice versa is nc: defined. lf there are
separate but dose by temiinal facilities for inter-state, inter-city and city
sen/ice buses irrespective of whether they are opera:ed in the _cr-vate sector

or the government sector, can reduce considerat:_.' the number of buses

plying in the CBD area unnecessarily. Further, if ":er-state and inter city
buses are alfcwed to bypass the city through the ‘if-l-47, a ccésiderable
 amount of fuel, time as well as money can be saved in addition to reducing

traffic congestion in the city.

The lions share of the total goods traffic is handled by fast vehicles
consisiing of trucks and tempo vans. The special requirements of these
goods vehicles for parking, driver’s rest, petty repairs, transit of goods,
storage etc. are presently ill-organized and randomly distributed all over the

city.

Cochin is connected to the north and south by broad gauge lines.

The north line bifurcates at Shornur towards Mangelore and Madras.
Towards the south there are two lines - one going to Kanyakuman via
Kottayam and the other via Alapuzha The railway lines in the city serves

mainly for transportation of bulk goods for trade and commerce and the long

distance passengers. It also serves a section of the commuter traffic to the

city within a zone of about 75 kms from the city centre. The commuter traffic

has been steadily increasing. But, the restriction of the single line to the
south Kerala creates delay in the travel and inadequacies of trips to cater to

the increasing demand. Since railway is to be assessed on a regional scale,

it is not dealt with in detail.

Railways play a prominent part in the goods movement to and from

the dty especially catering to the finished petroleum products frcmthe

Cochin Refinery and Fertilizers from FACT unit at Ambalamugal. It also

carries a large bulk of the port traffic between the port and its hinterland,
which extends to the whole of Kerala, and Coimbatore arc‘ Salem diszffcts of
Tamélnadu. Considering the .;': of goods tra‘{.i-.: moverhent by rai}-.-.'ays in

the future decades, it is necessary to make provision for the expanscn of

goods shed, marshaling yards and allied needs of the raih-.=ay in Cochin.

Providing the entrance to the North and South railway stations from

the eastern side also will reduce the traffic congestion in me C.B.D.area due
to the reduction in criss cross traffic.

Water transport is the most energy efficient and economical transport

system. It includes sea routes, and inland waterways.

Sea routes links other ports of India as well as ports of foreign

nations. Cochin harbour, which is an a|l—weather protected harbour, lies in

the main ship routes in the Laotadives Sea. The entrance to the harbour is

450 m wide with the approach channel extending to about 5 kms into the
sea. The shipping channel on entering the harbour branches into
Mattancherry channel and Errakulam channel. There are mid-stream
moonng facilities in these channels and wharfs on either side of V\fillingdon

Island. facing these channels. The Cochin Shipyard and the oil tanker berth

are located on the Ernakulam foreshore facing Ernakulam channel. The

channel can accommodate org.‘ ships up to a maximum tonnage of 80,000

tonnes since the depth of the :'annel is only about 9 meters. This shows
that the potentialities of this net _'al harbour are not fully exploited. .

ln Cochin region, inlar: .vatervvays play an impcftant role in the

transportation of goods and pe:: e. The geographical set :13 of the regEcn is

such ‘set an alterfiative to wazeways would involve mc‘a cost and travel
time. Hence, waterways help to reduce expenditure and also to conserve

energy.

The inland waterwa‘-,-s of Cochin region comprise of the feeder canals to

Ambalamugal and Udyogamandal, the stretch of west coast canal and other

water areas of Vembanad lake in the region thus linking major areas of the

region with the city by water (Fig.7.12). Distance by waterways from Cochin

to important places along the west coast canal are given below which
indicates the possibility of having longer navigation services of regional and

interregional character.

Alapuzha - 70 kms
Quilon — 145 kms
Trivandrum - 205 kms
Munambam - 22 kms
Ponnani - 75 kms
Kadalundi — 135 kms
Badagara - 210 kms
Azhikkal - 255 kms
Hosdurg - 310 kms
On an average 70,000 daily passenger trips are being effected by
inland water transport services in the Cochin region excluding the passenger

trips by private boat operators. In the Ernakuiam-Vypeen route 20,00-3

passengers travel daily and this route serves as the main link for the Vypeen

based population for interacting with Cochin City.

The main boat jety at Shanmugham road is the busiest terminal in

the region. The main gs.-i.y handles on an average 40,000 passengers pe'
 %
0,
.‘ ­ I

: I I »_ v _, .­
.___ \\ .‘ ' -­

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’ .\__._--.'.'.- ""“—:._ A000 menu‘

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BENJAM|N_'P,V_

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I:
l
Ph.D. THESIS.

\ '- I o5\’J\L I
' soom oom 1000'“

PAF{T- TIME RESEARCH SCHOLAFL

SCHOOL OF ENVIRONMENTAL STUDIES.

/ REFER TABLE7 5 FOR NAMES OF LOCATIONS COCHIN UNIVERSITY or SCIENCE AND TECHNOLOGY

%zé”T:.
:. -’<‘\ .3‘-. ." " :":.
\r—­
WATERWAYS IN THE BACKWATERS OF THE‘
STUDY AREA - COCHIN .

4‘ I

Fig - 7‘. 12 . LOCATION OF IMPORTANT JETTIES ALONG THE

" ,»-' "“\'\ ,9.’ ”'‘‘''*'-"\"v ‘;‘-y :’ L‘ 5

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‘H93’ '» .\
"1 null:
‘TABLE - 7.5. NAMES OF IMPORTANT JETTIES ALONG THE
WATERWAYS OF COCHIN.

9-4
\./ TI-IANTHONNITHURUTI-IU 9) PONJIKKARA
HIGH COURT 20) PONNARIMANGALAM
ERNAKULAM 21) PONNARIMANGALAM HOSPITAL

PERUMANOOR 22) MULAVUKAD PANCHAYAT

ISLAND EMBARKATION 23) KORUNGOTA
ISLAND TERMINUS 24)KOTHADU
VYPEEN 25)VARAPUZHA
FORT—KOCHI TERMINAL 26) CHERANALLOR

99339321388
FORT-KOCHI CUSTOMS 27) ELOOR

10) MATTANCHERRY 28) MUTTINAKAM

1 1) THOPPUMPADY 29) ELOOR (N)

12) NADAKADAV 30)EDAYAR

13) KANNANGAD 31) KUMBALANGI(N)

14) THEVARA 32) NET'I‘OOR(S)

15) EDAKOCI-II 33) NETTOOR(N)

16) VADUTHALA(S) 34) KUNDANNOOR

17) PANAVALLI '35) CHAMPAKKARA

18) BOLGATTY 36) AMBALAMUGAL

 I

non
‘(II

Ion ma

4000 menu:

00 m 1000 m

Ph.D. THESIS. BEN.IAMIN.‘P.v.

SCHOOL OF ENVIRONMENTAL STUDIES.

PART- TIME RESEARCH SCHDLAR.

OCHIN UNIVERSITY OF SCIENCE AND TECHNDLOIW

2/fi\T.ll
wry)».T’T“‘Tr-1
.2 ' ‘T
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é7’T7 %Wwu;«wf GP.
E135
- DATA SOURCE ; INLAND WATERWAYS AUTHORITY OF INDIA
MAIN WATERWAYS

‘. I.
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Fig - 7 .13. DEPTH OF BACKWATER SYSTEM ALONG THE

I5

' ,1, N q_\.'

, 2/

“A,//J ' . -_'_:.'¥I(III'_;":la'l|-54‘-'

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day and nearly 320 boat trips. Other major boat termina 3 are Embarkation

jetty, Fort Cochin Jetty, Vypeen Jetty and High Court Jetty.

Movement of goods by waterways in the state is carried out generally

by country crafts. in the public sector, KINCO is moving raw materials like

sulphur and rock phosphate for FACT Cochin Division from port.

Lack of adequate boat services in the existing routes. absence of boat

services to some islands, lack of proper lenninal facilities, inadequate

intéi°ch'ange facilities in most of the boat jetties and inadequate canal‘
dredging are the main hindrances which affects the inland water navigation

in the Cochin region.

Inland water transport generates more employment compared to

other modes. There are also benefits like reduction in atmospheric pollution,

more effective maintenance of environmental and eccfogical balances,

reduction in congestion and acddents in the roads, savings due to reduction

of consumption of non-renewable energy resources and development of

tourism.

Cochin is having air traffic facility also. Cochin airport is located in the

Willingdon Island within an enciavecontrolled by the Eédian Navy. The

airport has two runways of 1620 m and 1440 m in length 5': a width of 45 m

each, suitable only for small aircraft, There is_ no scope :he expansion of
the aerodrome at the present location because of tlie ‘on-availability of
space.
 14.5

in order to provide facilities for big aircrafts, a rew airport is being

constructed at Nedumbassery near Angamaly, which is about 10 kms to the

north of the study area. The construction of the aerodrome is expected to be

complete by 1998.

7.3.7. Parks, Play grounds and open spaces

The percentage of land under parks, playgrounds and open spaces in

the city comes to only 0.78% of the net dry land (GCDA Structure Plan­
2001). Although water sheets and agricultural land provides the lung space

of the city and supplement the open space requirements, their use for
passive and active recreation is limited.

The minimum standard prescribed by TCPO (Town and Country

Planning Organisation - Government of India) is 0.5-hectares/1000
population. In Cochin, this mmes to only 0.145 hectares/1000 population,
which is much below Indian standard. Even this 0.145 hectares/1000
population is inclusive of marshlands and watersheets. In the near future
this land also is likely to be converted into built-up areas. (GCDA S‘:uoture

Plan-2001)

The open space requirement for the passive and active recreaticr. of the

city population is to be met by adequate provision of spaces catenng to

various levels of demands are as suggested below: ­

Provision for a major city park and development of a botanical garden as

central city facility.

 Provision is’ :he green sirip systems with specie. function such as open-air

theaters, refiy maidan etc. in specified parcels extending to 10-12 hectares

each.

iii. Parks, play grounds and the sports fields in different divisions of the city,

. Enough land should be assigned for social forestry to act as buffer zone
around the industrial areas.

v. Development of tourist villages on small islands in the back waters.

Acquisition of land for public open space is a non-remunerative

activity for the city development authorities. Hence, in order to make this
proposal economically viable, it is necessary to integrate other remunerative

schemes such as housing or commercial development with the development

of public open space.

VVith all the modes of transportation, an amiable climate, a long

tropical beech line, proximity to hill stations, relatively clean premises,
availability of hotels, boating & yachting facilities and a rich cultural heritage

etc, there is every potential for Cochin to become one of the important
tourism centres of the world. This resource is not yet exploited properly for

want of necessary awareness as well as exposure.

Meerwhile, even government lands such as coconut farm at Vytila.

extending several hectares, lying on the shores of Kaniampuzha river and

acting as a cuffer zone between industrial area at Ambalamugal and Cochin

Corporaticr has been converted inic industrial use by the Government itseif
 I-9)

in spite of public outcry against such a conversion. Only a collective effort of

various governmental agencies and local bodies with public participation can
achieve the necessary open space standards in Cochin.

7.4. Summary and conclusion.

Comfort in urban life lies in the condition of basic amenities and

services which in turn is linked to the socio-economic environment". Day by

day the urban limit of Cochin is increasing with consequent overload in the

available basic amenities and services. Proper assessment of the existing

condition of them is necessary to plan for the future. Water supply, drainage,

solid and liquid waste disposal, traffic and transport, park and recreational
facilities and housing problems are assessed. The observations are
summarized below: ­

The western flat land portion of the study area where the economic
and oommercial activities are centred - Central Business District (CBD) in

planning terms - has a considerably higher density of population than the

eastern upland. The population density decreases fast towards the east with

increasing distance from the CBD area. But there is no such remarkable
variation in the population density along the north—south direction. Hence,

eastern upland is having more potential for future urban expansion.

The ris_e in workers to population ratio also reflects a rapid economic

growth-induced increase in job opportunities. The "manufacturing,

processing and servicing sector are found to be the major contributor. thus
forming the economic base of tire area. Des_:Eie wides;‘::.: mechanisation

during the last decade, the percentage composition of czistruction workers

almost doubled indicating a healthy economic deve'::ment and rapid

construction boom, signs of fast urbanisation.

Even though. the housing shortage has decreased 2." the last decade,

still there exists a shortfall of about 21 houses per 1000 households. When

remedial measures for this deficit is envisaged for future panning, the trend

in family size vanation in the past has to be taken Er:-to consideration.

Between 1971 and 1991, the average family size has dec:eased from 6.33

to 5.08 persons, a result ofhigh literacy rate and high living standards - a
trend which is likely to continue - implying that future housing policies should
be oriented towards construction of small houses.

The slum dwellers account for about 21.27% of the city population; a

not-too—alarming figure when compared to other cities in India, however,

environmentally a very alarming one. Also, the number of slums is found to

increase with time. The availability of low—priced lands, as islands without

road connections, within the city or in close proximity. has so far been
successful in limiting the growth of slums to the present rates. However,
once these isolated land—strips are road-linked by construction of bridges,

land value may shoot up to heights beyond the reach of the urban poor.
This will accelerate the development of urban slums.

Hence, proper planning backed by a thcrough corsrehension of all

contributory factors leading to ‘be timely ir.*.:'ementaL:i:* of appropriate
 147

housing p: :ies, alone can prevent a degeneration in the urban

environmenze

Pota: I)- fresh water is naturally available in most of the eastern

upland pOl'7ilC’ of the study area, whereas, it is scarw in the western flatland

areas. The equirement is met by the public water supply syste rt drawing
water mostly from Periyar River at Alwaye and Muvattupuzha river at
Ramamangalam. In spite of recent augmentation, water supply in Cochin is

insufficient even by Indian Standards, which itself is far below the standards

of the developed countries. This is partly due to insufficient treatment &

pumping opacity and partly due to insufficient distritzutfon system as well as

wastages in zransit.

The river water, above the intake wells at Atwaye is contaminated

with municipal effluents from Perumbavoor and Alweye. Moreover, factory

effluents fror“ the Eloor industrial belt about 1 km downstream may reach

the pumping station during high tides when the river flow is very weak. The

contaminants from these factories, containing Mercury (TCC), Acids 8.

insecticides -\HlL) may reach the headwork area in large concentrations
along with tidal saline water in summer, if Periyar river flow is reduced
oonsiderably due to insufficient water being released from EdamaEayar Dam

or because of an intense drought.

At present, a major part of the study area is dependent upon water

supply from =eriyar River alone. in case of a serious contamination (either
c=_e to above-mentioned natural causes or due to man-made causes), the
whole water supply will have to be E‘-i down, with disastrous
consequences. So, as a precaution as well as 7'2? augmenting the present

insufficient water suppiy system, additional ir.:a7-<e facility with suitable

treatment system has to be added to the Ramarrangalam headworks in the

Muvattupuzffa River, .-riiclt at present meets mainly the industrial
requirements alone. Such a system can be connected to the existing water

supply grid so that the two systems together wiél meet the water demand in

normal times and in times of emergency, one system can be completely

closed while the other pumping system can prov?:e water to the whole area

at least partially.

The cistribution system is affected by ag:—old pipelines, which are

corroded at several places. In the western flatfand area where the water
table is high. has salty scit in several places, which: accelerates corrosion of

pipelines. .'»-loreover, tidal action corrodes expcsed pipelines by frequent

wetting & crying. In riany places, the pipelines which cross the drains
develop hcies by acceéerated corrosion resulting in leaks during times of

pressure and contaminafion of the water supply by sucking of sullage from

the drains -during low pessure. Timely replacement of the corroded and
damaged ppelines mace of corrosion-resistant and break-proof materials is

the only sciciion to this ;'co;em.

Solid waste dispcsai is becoming an increasingly serious problem in

Cochin pa.".':ularly in the densely populated v.-eszern flatland area where

there is h‘;* ‘.-/ater ta’: e and absence of probe’ : sposal sites. In the less
 I49

populated eastern uplands, the garbage disposal is not difficult due to

availabif :y of vacant lands. In the small townships of the eastern parts of the

study area, covered type of land filling can be depended upon, but in the

western flatland area. effective and environmentally sound garbage disposal

can be core by compost plants in appropriate places or sanitary land filling

outside the densely populated areas.

Sewage & sullage disposal also is a serious problem in the western

low land due to the high water table. Present system of septic tank or pit for

individual houses affects the environment adversely. Particularly during

heavy rains, waste levels in the tank rises to the level of flc-oo‘water causing

contamination by fecal matter. This intrusion may cause epidemic outbursts

any time and hence has to be viewed with sufficient seniousness. ne

sewerage system, covering only a very small portion of the city at present,
has to be extended to the whole flatland area. However. in the western

flatland area, due to the absence of gradient, it is rather very difficult to

convey the sewage from a vast area to a single or a few largescale sewage

treatment plants. Hence, it is more suitable to install mini treatment plants

sector wise or one in a colony of appropriate size.

In the eastern upland areas, not only there is sufficient space for
sewage and sullage disposal, but it is unlikely to contaminate the
groundwater which lies deep below a relatively impermeacie laterite layer.
Hence, a sewerage system may not be essential at present because septic
tank system is sufficient to meet the current requirements. Not only that.
since tre -cases are wide 8DE‘.~''. :. sewerage system will be very expensive
also.

Storm water and sullage dscosal is also a matter of serious concern

in the v.es‘.ern flatland area. Fi';:':'ing of storm water with sullage leads to

environreriial contarrfrzation and other human sufferings. in the western

flatland area the flood problem is iccal either due to the inadequacy of drains

or due to local depressions. This can be solved by properly linking the

roadside drains to the tidal canals, since, no place in the western flatland
area is more than about two kms away from a tidal canal. Also, the
encroachers into the canals and‘thodus’are to be evacuated along with
widening. Deepening cf the main canals may not be sufficient from drainage

point of view, since the bottom of many of these canals are already below

the low tide level. Hence, widening is necessary to increase the drain
capacity effectively.

However, the storm water drainage is bound to become a serious

threat in the near future in the valleys of the eastern upland. In these
regions. the flood zones of the streams, which drain, into the valleys are
being filled up for raising plantation crops and cnnstruction purposes, which

reduces the discharge capacity of the streams. This aspect is dealt with in

detail in the chapter on surface hydrology.

Cocwiia is served with all modes of transportation by air, water and

land. However, due ‘.0 improper location of ihe various transportation

services. the cotentiai 'emains grcssy unutilise-:'. The roads are narrow and
the railway line bifurcates the city, thereby -czsvucting "fie road lir-.7
between the two sides. The potential for inland navigaiécn remains L"Z~’.-'­

utilised. Cochin is having an all-weather protected harbour lying in the -"e 1

ship route but due to inadequate depth of the shipping channel the :2”;
remains inaccessible to large vessels. The existfng aerodrome at Willir;::1

Island has space restrictions, which preclude future expansions so as :3

accommodate international air traffic. However, the commissioning ::’
Neduml:-asserry airport on the outskirts of the study area will improve :1"
situation to a large extent.

Among the three ring roads - inner, middle and outer — the inner rig

road is too narrow to serve the existing passenger and goods traffic. (T718

GCDA has recently started widening). The radial road connections between

the inner and middle (NH-47 Bypass) ring roads. originating from the CED

area, are grossly inadequate both in number as well as width. Widening of

the existing roads, wherever pos.ible along virizjin construction of new roads

and flyovers can alone solve the present imbrogiio. The new roads shoeld
be constructed with enough strength to bear the heavy container traffic.

The important railway terminals in the city are Ernakulam Junciion

and Ernakulam Town. The entries to these szations are confined to me

western side only. In view of the fast deveicpment of the town on the

eastern side of the railway line. entries to the station from the east wiii ca
most desirable. This will also relieve the num':e' of the criss—cross traffi: fn

the central business district of "Ira city. The :’:posal for a Ring Rai?-.'.a_.
conne-::fng the majc' “ ;d-es of the metropolis, if implemented, will be a boon

to the city in not oniy ‘educing the traffic congestion but also in reducing the

pollution substantialiy

Inland watennays offer a cheap and eficient transportation of goods

and people. In the western part of the study area bestowed with tidal canals,

water transport it _:'operly designed, would reduce road congestion

considerably.

The interchanges between waterways and roadways are very

important in the city owing to the complementing roles of these two modes in

the transportation system. The facilities at these interchanges are noticeably

poor considering the character and volume of traffic. These are to be '
specially designed for efficient and comfortable transfer of goods and
passengers.

A properly planned water transport system utilising the tidal canals,

rivers and sea as well as limiting the inter-city and inter-state road transit to

the periphery of the highly urbanised area through NH-47 Bypass will greatly

reduce the urban roac’ congestion. Locating the terminals of the three trafic

systems — road, water and railways - in dose proximity will reduce

unnecessary criss-cross traffic within the city. The Vytila area where the

NH-47 Bypass, Kaniampuzha canal and railway line lie in close proximity

may be an ideal site for such a development. Vacant land is also available

in the locality at present. Since the area lies close to the middle ring road.

city leve‘; traffio can a so originate from there at: enter the city through the
road passage below the Vytila over bridge and enter the parallei ‘cad to
Sahodaran Ayyappan Road.

The area allotted for parks and open spaces corre to only 0.78% of

the net dry land even in the Cochin Corporation area whiie in other areas it is

almost absent although water sheets, paddy fields and plantation areas
provide lung space at present. But 0.5 hectaresl 1000 population need to be

earmarked and kept for the population projected to another 50 or hundred

years from now. Othen/vise, when full urbanization takes place, the area will

suffer from acute shortage of cpen spaces and parks. Planned buffer zones

between industrial and residential area are also lacking in Cochin, which
need immediate attention.

Tourism may play a major role in the socio—econornic improvement of

any region if judiciously managed. Cochin has a vast potential of natural

scenic areas and places of historic and architectural values. Such places
should be identified, maintained and managed so that it can become a good
resource.
 154

Chapter- 8

Summary and Conclusions

Population explosion and urbanization cause enormous stress on the

environment resulting in its rapid deterioration. Maximum human comfort in

the long run must be the objective of any human settlement planning. For
short—term benefits, this aspect is often neglected or left without giving
proper weightage resulting in irrecoverable damage to the environment,
which leads to unforeseen human sufferings. Hence it is necessary to
propose appropriate land uses which are complimentary and compatible with
various resources in the long run. Environmental planning is to allocate
appropriate land use pattern with optimisation of resource utilisation in such

a way that the quality of the environment is sustained.

The present study is aimed at assessing the various environmental

resources from a physical planning point of view so as to propose probable
and compatible urban developments in the various locations within the study
area. The Cochin basin - which is bounded by the ridgeline of Muvattu­
puzha river basin on the east and part of the south; and Periyar river basin
on part of the north side and Laccadives sea on the west. In the backwater
zone, there are interbasin linkages and hence there is no well-defined
boundary
 I55

Cochin is a coastal settlement interspersed with a large backwatc:r

system. The ridgeline of the eastern low laterite—capped hills provides a
we||—defined watershed delimiting Cochin basin, which help to confine the
environmental pzJr.:irriotcrs within a pliysical limit. This enables to arrive at

comprehensive conclusions regarding each of these parameters. The study

area — Cochin basin — covers an area of approximately 535 km? within 90 45’
N to 10° 14’ N and 760 10' E and 760 31' east in the southwestern coast of
India.

the bz.isi<: UllVltUlllllL.‘lllLIl resources are assessed under the tic‘-adsngs

1'. Physiography, 2. Geology Groundwater, 3. Surface hydrology

li;ir:|tw;ilt:i' :r.y:a.|«.,-in, rt tjliirmtt.-, 1). V(.‘.gct;.1li<)ii and (3. Eiwtio-—t.:corioniu:

environment & Basic amenities.

Physiography of the study area can be divided as follows­

_l-lills

Eastern Low hills

-Valleys

Cochin Basin

-Plain Land Area

Western flatland

Water Sheets
 All these areas are physiographically distinct. The eastern low hills
are laterite—capped with moderate slopes in most of the areas. Such a
terrain provides a generally stable land for any kinds of construction
activities, provided, care being taken while cutting and filling is done. The
valley floors of the midstream areas and the lower reaches of the streams

are vulnorablo to llood. At present the lloodwater is being drained through

the flood zones of the valleys and, in the case of heavy floods, the water
occupies the flood fringe zone also. But the current pace of urban sprawl
with filling up of the flood zone and flood fringe zone is sure to cause serious

damage to buildings and other constructions during floods leading to

trtznntiinit: |0:’.:s zintl lllllllilll stilleiing. llence it tlelziiletl IUVLJI stiivuy of tlit:

area is a pre—requisite for commencing developmental activities.

If physiography alone is considered, the western flatland is ideal for

urban development, being a level land linked by roads and railways and
also by commutable tidal canals and an extensive backwater system.
However, at present there is large scale filling up of shallow mangrove-~
fringed water sheets (paddy fields and estuary) by various private
individuals and government organisations, which may lead to serious
environmental crises. The decline in the fish catch seen in recent years is
indicative of such an environmental degradation since the shallow water is
the lm.-irrliitg gruunt.l tor lllillly estuarine and bratzkish water lnuna. lleiice

urban developments in such areas are to be regulated in the line of coastal

 I57

zone regulation notification which assumes added importance in view of the

predicted sea level rise resulting from global warming.

it is reported that there is a 2.2-mm annual rise in sea level in Cochin,

which will amount to 22 cms in the next 100 years. When it happens,
millions of people would be forced to relocate; human stress, anxiety and
discomfort would be severe. International Panel for Climatic change (IPCC)

in 1990 has predicted a 31-cm rise in sea level (lower scenario) induced by
greenhouse warming, by the year 2100. Such a rise in ocean levels would
cause the sea to move several meters farther inland thus pennanently
inundating a large area of the highly urbanised western flatlard region of the

study area.

The eastern low hills and western flatland are geologically also
distinct. The eastern low hills are eroding areas while the western flatland is
a dcpositioii area lorined by the sediments brought by various streams and
rivers. The eastern low hills are geomorphically an etched plain formed due
to differential erosion, the surface unprotected by laterite duricrust eroded
rapidly and formed the valleys while the comparatively stable laterite­
covered areas formed the hills. Lithostratigraphic study with the help of
bore—logs and historical evidences of seismic activity clearly indicates that

the western flatland is geologiclly unsuitable for urban development.

Also, in most of the areas of the western flatland potable groundwater

is absent, or if at all present, it is found either as perched aquifers (which is

easy to get contaminated by land pollutants like sewage, factory effluents

 158

etc.) or rarely as deep-seated (about 75 m below ground level) primeval non­

rechargeable aquifers, which, if extracted on a large scale, may cause not

only their extinction, but also the disastrous subsidence of overlying layers.

Hence it is recommended that future urban development in the western part

should be restricted or regulated taking into consideration the following

aspects: —

. Litho—stratigraphica| evidence indicates periodic sinking and upheaval and/or

ll:,'2llS[i'l't'3E_S':3lOll and it-2gi'e:ssioi'i ol the sea.

2 The area has a history of seismic activity

l._z.irgc scale lilting up ol Iowlying art;-.'_is can lead to r,‘,ru:.=.l2.il ii'iil.ml;_iiit:t:, \Nl!l(.‘ll

may induce tremors

The western llallzind being very close to sea level, any :~:<;-a |l,'Vi.‘l llllt,‘ r.,li.i«;: to

global warming can inundate the area in the foreseeable future.

. This area being of sedimentary origin, with clay as the major component.
which increases the building foundation costs

. Large—scale reclamation and dredging of backwater system will induce not

only geo—|ogical instability, but also increased wave action and intrusion of
tidal waters further inland

. In most of the areas, the groundwater in the upper strata is not potable and

unsuitable for construction purposes either due to salinity or high organic

content
 159

8. Excessive groundwater mining from recently discovered deep—seated

aqLnlui's may lead to land subsidence.

9 Being a flat terrain drainage is difficult.

‘l he eastern low hills are comparatively stable being forriied oi l£El'.t1!ilL.‘

or lateritic soil over a laterite layer forming a coping on the hills, which in turn

lies over crystalline parent rock. Hence this area is suitable for construcliori

activities and hence congenial for urbanisation due to the following reasons.

1. The substrate are geologically stable in most of the areas, and hence the
foundation cost will be less.

2. Also locally quarried laterite blocksl granite can be utilized thereby reducing
construction costs

3 Potable groundwater is available

4 ‘there is adequate slope lor ulliclcnt. drainage

However, developmental activities on steep slopes and flood zones of

streams should be discouraged or legally regulated.

Individual microcatchments (sub-basins) in the eastern low hill region

and drainage planning areas in the western flatland zone are identified with
the help of contour as well as land use maps supplemented with field
investigations. The study area (535 km? ) is divisible into 3 regions with
distinct surface hydrological characteristics.
 IOU

1. The eastern upland (291 km? ) with the highest point 115 m above lVl.S.L.
comprises of 21 sub-basins which drains into the backwater sy:-;tem lltrougli
streams

2. The western flat land (115 km? ) interspersed with tidal canals and the
islands in the backwater system (56.4 km?)

3. The backwater system (72.59 km? ).

The discharge efficiency of each stream and thereby the flood

probability in various catchments are studied. Based on calculations, the
flood—prone areas in the eastern hill valleys are identified. These areas
(existing mostly as paddy fields at present) are unsuitable for urban
development or for raising plantation crops, since such areas if reclaimed by
filling up are liable to be washed away by surging flood waters. Such areas

should be declared as filling—free zones where only regulated development

can be permitted.

Many of the environmental problems of Cochin are hydrologic in

origin because hydrologic cycle gets drastically modified during urbanisation.

The drainage basins, on which some modifications are done, often form a
portion of a larger drainage basin and hence these modifications may
inadvertently affect other areas of the drainage basin also, unless they are
carefully planned. Hence, drainage basin dynamics give a better under­
standing of hydrologic and geomorphic processes for analysing the spatial
linkages between different areas that can affect both regional and site
planning
 16]

In the land area of the western low-lying region, the main hydrologic

problem is waterlogging due to absence of slope. Hence water gets logged

in the depressions and the areas where there are no drains or where the
drains are blocked by various reasons. Waterlogging also occurs due to
inadequacy of drain size and/or clue to unnecessary meandering of dralnr.
through low-lying areas. Another serious problem is that land originally
above waterlogging levels becomes prone to frequent waterlogging due to
filling up of surrounding low lying areas to comparatively higher_ levels for
construction activities from where, during rains, water drains into the
originally flood—free areas.

The waterlogging problem in the western flatland can be easily

remedied by engineering solutions (linking the road-side drains to the nearby
tidal canals), since no part of the area is more than 2 or 3 km away from a
major tidal canal and the maximum extent of a catchment is only a few
hectares. Proper drainage planning with engineering solutions in all the
drainage planning areas will solve the problems if executed along with
proper maintenance system.

The islands in the backwater system are mostly rural in nature and
hence the abundant natural channels existing in these islands are sufficient
at present to meet the drainage requirements. In future when urbanisation
takes place, sufficient drains are to be laid with proper slopes and hierarchy.

These drains are to be linked to the backwaters at the nearest point.

 162

The Cochin backwater is a part of the Vembanad estuary, which has

a perennial fresh-water influx mainly from various rivers originating in the

Western Ghats. The width of the backwater extends from narrow channels

of a few meters to about 9 kms with a maximum depth of 9.3 m at the bar
mouth The backwntc-r system is mostly shallow, but along the main
waterways the depth varies from 1m to 9.3m. The backwater system is
open to sea at Cochin and at Azhikod (which lies towards north of the study
area). Through these guts seawater intrusion occurs during high tides. The
large fresh water inflow during the Southwest monsoon season (June­
September) drives out the entire saline water along ebb flow. This salinity
variation gives rise to a high primary productivity which nurtures an excellent

fish population. Also, the backwater system provides an easy navigational

system, which adds to the econorny of the area. The Ctlrrtznl ll"\..‘ll(| l7!
reclamation of the estuary and adjoining marshlands is ecologically
detrimental to the fish population and to biodiversity. Also, the increasing
pollution load from various industrial sources, urban sewage 8. drainage and

the residues of pesticide and fertilizers from agricultural sources has serious
repercussions on the productivity and biodiversity of the backwater system.

Cochin is a fast-developing industrial metropolis lying in central

Kerala, the southern state of India. Being a tropical coastal settlement, the
annual and diurnal variation in temperature and humidity is not very
significant. It can be said that the study area is free from winter season and
has only rainy season and summer season.
 I63

The study area enjoys a vigorous Southwest monsoon season and a

mild North-east monsoon with an yearly average rainfall of about 300 cm.

Since the rainy season extends to about 6 months, drainage is very

important particularly when urban settlements are developed. Not only that,
since there is continuous rain during rainy season any modification of the
land surface, without due consideration to the rainfall climatology, is likely to

cause denudation in the eastern sloped terrain due to erosion and

waterlogging in the flat areas.

Since Cochin lies at about 90 N, for about 8 months in a year, the sun

will be towards the south and hence, the southern slopes of hills receive
more concentrated solar rays for most part of the year and thereby
becoming warmer than flat terrain. Hence, south slopes in a hilly terrain as
in the eastern lowhills of the study area are less suitable for human
occupation. Northwest, north, northeast and east faclng slopes are the most

ideal for residential development in this region from the solar radiation point
of view.

Therelative humidity also is very high making it necessary to have

human settlements with appropriate orientation and ventilation. The
buildings are to be oriented so as to obtain maximum ventilation in relation to

wind direction during the most humid and hottest months. Also, buildings
are to be designed with minimum incidence of sunrays on the south side
walls or appropriate shade trees are to be planted on the southern side of
buildings.
 l 64

Cochin is the industrial capital of Kerala. The major industries are

located in 2 clusters in the study oree - one at Ambelemugol - Karimugel
area and the other at the Udyogamandal - Kalamasserry — Edayar area.
Some of these industries release large quantities of air pollutants and their
dispersion is a function of meteorological and physiographical aspects. An
important factor in the pollution climatology is the direction of the wind when

the speed is minimum i.e., during night and early morning hours particularly
during winter season. Rainfall also is a major determinant in the pollution
levels due to the scrubbing effect of rains resulting in reduced atmospheric
concentration of pollutants.

The winds are mostly from west (westerlies) during daytime and carry

pollutants towards east or southeast during daytime. The nighttime winds

are either absent or very weak north—easterlies and hence pollutants are not

transported to long distances resulting in the accumulation of pollutants in

the vicinity of source.

Pollution hazard will be maximum during inversions or isothermal

conditions, since such a condition blocks the dispersion of pollutants and

results in high ground level concentration. Inversion or isothermal conditions

are found to be maximum during December, January and February in
Cochin. Hence the areas in the direction of nightwind during these months

in relation to the major industrial zones will have considerable increase in

atmospheric pollution. Thus most of tho thickly populated areas in the
 l65

western flatland are high—risk areas both in the case of normal atmospheric
pollution or during a disaster (as happened in Bhopal).

As far as the location of the existing industries is concerned, the ideal

place would have been the extreme south west portion of the study area so
that the interior of the city and all the thickly populated areas would have
been relatively free from pollution. In such a case most of the spread of the
pollutants would have been over the ocean.

This study reveals that the places most safe from pollution is the
upper reaches of Kadambrayar, Puthencruz, Pallikkara, Kanjiramattom,
Pulikkamaly, Churnikkara and Thrikakkara East basins. Also, during
daytime, when strong winds blow towards east, these areas will have lesser
pollution, which is due to physiographical peculiarities. Besides these, some

areas far off from the pollution sources such as Udayamperoor, Kumbalam
and Chollunam Panchuyats and Cochin tuluk areas of Cochin Corporation
and the areas free from the night time wind direction such as
Nayarambalam, Kadamakkudy and Elamkunnapuzha panchayats may also
be free from air pollution from major industries within the study area.

Plants have an important role in the preservation as well as

improvement of environmental quality besides its fundamental role as the
only way of trapping solar energy to prepare food for all the biota.
Vegetation plays a pivotal role in the soil conservation, amelioration of
microclimate, reduction of urban noise, pollution reduction by active stomatal

absorption of polluting gases as well as providing vast areas of leaves for

 166

the settling of suspended particulate matter. Vegetation during

photosynthesis traps vast quantities of CO2 and releases 02 to the atmo­
sphere and it is an important source of fuel. Urban forests can be planted in
wastelands for timber and firewood.

The study of vegetation was carried out to identify the trees, shrubs
and climbers of aesthetic and /or economic value to provide information on

the germplasm. A detailed taxonomic survey was not attempted, instead an

ecologicall environmental planning approach was adopted in which trees,
perennial shrubs and perennial climbers, which have basic influence on the
environment, are considered.

A comprehensive study of the species diversity of vegetation is an

important pre-requisite for the assessment of environmental resource of any
area. The vegetation of any place is determined by edaphic, climatic and
biotic factors. Such a study will enable the authorities to propose
appropriate planting materials from the trees, shrubs and climbers of econo­
mic, aesthetic and. medicinal value which have proven capacity to grow
successfully in the various edaphic and microclimatic conditions of an area.

In the study area, due to its unique physiography, edaphic and

climatic zonation is clearly distinguishable with their own characteristic
vegetation types. However, this vegetation, originally tropical rain forest, is
drastically modified by biotic influence of urbanization and increased
agricultural activities. The vegetation in its original form exists only in a few

sacred groves and mangrove forest bits.

 I67

Alien species, which were once introduced for aesthetic planting or for
i.lglll.;l.lllLl|t_Il pulpusus, uiu lound Ill large numbers among the vegetation

cover of the western flatland area, whereas, alien plantation and agricultural
crops have significantly replaced the native vegetation in the eastern upland
area.

In Cochin altitude—based vegetation difference is negligible since the

altitude variation in the study area is less than 108 meters.

The western flatland shows a distinct edaphic condition of clayey or

sandy—clay or sandy soil with a very high water table. The land is less than

lmeter above MSL at Cochin. In this area, the predominant mesophytic

vegetation is Cocos nucifera, Areca catechu, Samadera ind/ca,
Dipterocarpus indicus, Hydnocarpus wightiana and bamboo thickets. Most
other native mesophytic trees, shrubs and climbers, though identified in the
study area, occur very rarely and that too mostly limited to individual plants.

Natural regeneration seems to be very low for the native plants

except for a few species like Samadera indica, Dipterocarpus indicus,
Thespesia populnea, Macranga ind/"ca, Alstonia scho/aris and a few species
of Eugenia (all of which regenerate naturally only in isolated pockets), while
alien species of Pithecolobium saman, Peltophorum inermi, Delonix regia,

Muntingia ca/abura and Lucaena /ucocepha/a show vigorous regeneration in

the western flatland area.

If this trend continues, the alien species are likely to replace the
native species from the scene as they now occur only as isolated patches or
 I68

individually with very low regeneration capacity. This is environmentally very

undesirable since birds and animals in the area are ecologically adapted to
the native vegetation and this kind of transformation to alien vegetation is

sure to upset the food chain and thereby the ecosystem, though the
quantification of the damage is not possible. Also, the pollens of these
species are likely to cause allergies. Hence, it is suggested that, as far as
possible, the planting of native species must be recommended in urban
aesthetic planting schemes instead of going for the ephemeral beautiful
flowers of the alien species with due consideration to aesthetic appeal.

The shore line vegetation shows pronounced zoning - the species

composition changes within a few meters from the shore line — both near the
sea as well as backwaters. In the case of backwater shores, the waterward
edge of intertidal zone is predominantly occupied by mangrove species of
Bruguiera roxburghiana, Rhizophora mucronata and Accanthus i/ic/‘fol/‘us.
Behind this, about 12 mangrove species occupy the landward edge of
intertidal zone. The land just above the intertidal zone has about 36 species
of trees and shrubs, which are the combination of mangrove and rnosophytic

vegetation.

This zoning is disturbed in many places either due to human

intervention or due to acute steepness of the shoreline. If the land suddenly

rises from the backwaters, only the second and/or the third zone will be
present. In the study area fifteen major locations of mangrove vegetation
 I 6‘)

are present besides the occasional existence of a few isolated mangrove

species here and there along the backwater shorelines.

For the prevention of backwater shore erosion and l|:>|l(_;‘l'lU1:}

protection, mangrove replanting should be done along with the conservation

of existing patches.

A similar zonation parallel to shorelines is observed in the vegetation

near the sea. The first layer of plants is that which can withstand the contact
with waves of the sea with its salt. Nineteen species of trees, shrubs and
other ground covers are found to grow in this zone. Protected either by the
above-mentioned vegetation or by the sea wall is the second zone, where,
46 species of trees, shrubs or climbers are found to thrive. These plants can

be ideally planted in this zone in future planting programmes. Behind the

second zone of beach vegetation, there exists a region, which is not
exposed to the direct impact of the sea, but with traces of salt in the soil. 66
species of trees, shrubs and climbers are idenlilied in this zone which can be
used for future planting schemes in the sand bars from Njarakal to
Chellanam where these plants occur in natural condition or cultivated
condition and found to survive.

Except the mangroves and beach vegetation in zones 1 and 2, almost

all the species survive in the eastern upland where they can be best utilized

for planting schemes depending upon the local edaphic and microclimatic
conditions.
 I’/tl

Comfort in urban life lies in the condition of basic amenities and

services which in turn is linked to the socio—economic environment. Day by

day the urban limit of Cochin is increasing with consequent overload in the

available basic amenities and services. Proper assessment of the existing

condition of them is necessary to plan for the future.

Water supply, drainage, solid and liquid waste disposal, traffic and
transport, park and recreational facilities and housing problems are
assessed in this chapter. The observations are summarized below: —

The western flat land portion of the study area where the economic and
commercial activities are centred - Central Business District (CBD) in
planning terms - has a considerably higher density of population than the
eastern upland. The population density decreases last townrd::. the L.‘.’.l::‘.l Wllll

increasing distance from the CBD area. But there is no such remarkable
variation in the population density along the north-south direction. Hence,
eastern upland is having more potential for future urban expansion.

The rise in workers to population ratio also reflects a rapid economic

growth—induced increase in job opportunities. The manufacturing, proce­
ssing and servicing sector are found to be the major contributor, thus
forming the economic base of the area. Despite widespread mechanisation
during the last decade, the percentage composition of construction workers

almost doubled indicating a healthy economic development and rapid

construction boom — signs of fast urbanisation.
 l7l

Even though, the housing shortage has decreased in the last decade,

still there exists a shortfall of about 21 houses per 1000 households. When
remedial measures for this deficit is envisaged for luture plannini_i, the tmiicl

in family size variation in the past has to be taken into consideration. During
the eighties, the average family size has decreased from 5.81 to 5.08
persons, a result of high literacy rate and high living standards - a trend
which is likely to continue — implying that future housing policies should be
oriented towards construction of small houses.

The slum dwellers account for about 21.27% of the city population; a
not—too—a|arming figure when compared to other cities in India, however,

environmentally a very significant one. Also, the number of slums is found to

increase with time. The availability of low-priced lands, as islands without

road connections, within the city or in close proximity, has so far been
successful in limiting the growth of slums to the present rates. However,
once these isolated land—strips are road—|inked by the construction of
bridges, land value may shoot up to heights beyond the reach of the urban
poor. This will accelerate the development of urban slums.

Hence, proper planning backed by a thorough comprehension of all

contributory factors leading to the timely implementation of appropriate hou­

sing policies, alone can prevent :1 degeneration of the urban environment.

Potable fresh water is naturally available inmost of the eastern

upland portion of the study area whereas, it is scarce in the western flatland
areas. The requirement is met by the public water supply system drawing
 172

WUlL.'l' mostly from l"()riyur Rivur [ll Alwuyu .:iiit| l\.(luv.iilliipii.-lm l-{ivm ill

Ramamangalam. In spite of recent augmentation, water supply in Cochin is

insufficient even by Indian Standards, which itself is far below the standards

of the developed countries. This is partly due to insufficient treatment &

pumping capacity and partly due to insufficient distribution system as well as
wastages in transit.

The river water, above the intake wells at Alwaye is contaminated

with municipal effluents from Perumbavoor and Alwaye. Moreover, factory
effluents from the Eloor industrial belt about 1 km downstream may reach

the pumping station during high tides when the river flow is weak. The
contaminants from these factories, containing Mercury (TCC), Acids 8.
insecticides (HIL) may reach the headwork area in large concentrations
along with tidal saline water during summer, if Periyar river flow is reduced
considerably due to insufficient water being released from Edamalayar Dam

or because of an intense drought. Already, the ldukki project has substan­

tially humbled the Periyar as water is diverted to the Muvattupuzha River.

At present, a major part of the study area is dependent upon water

supply from Periyar River. In case of a serious contamination (either due to

above-mentio_ned natural causes or due to man—made causes), the whole

water supply system will have to be shut down, with disastrous conseque­
nces. So, as a precaution as well as for augmenting the present insufficient
water supply system, additional intake facility with suitable treatment system
has to be added to the Ramamangalam headworks in the Muvattupuzha
River, whiz‘ at present r'2=‘w.3 mos:,' industriai requirements. Such a
system can be connected to he existi.-; water sL:_:-_o-Ey grid of the Cochin City

so that the ?.'.'O systems t:~i-;,:i—:tl1er ca* fleet the water demand in normal

times as we? as during S-FT‘.-?.Tg€'TlCl€S men one s;s':em can be completely

closed while the other purrspmg systerr can provide water to the whole area

at least partiafly.

The distribution system is affeczed by age—old pipelines, which are

corroded at several places. In the watern flatland area where the water­
table is high. has salty soil in several pieces, which accelerates corrosion of

‘pipelines. -.‘.creover, tidal action corrcdes exposed pipelines by frequent

wetting & drying. In many places, the i:-‘_o-elines which cross the drains even­

tually develop holes by accelerated corrosion resulting in leaks during times

of pressure and contamination of the waier supply by sucking of sullage from

the drains during low pressure. Timeiy replacement of the conoded and
damaged pipelines made of corrosion—resistant and break—proof materials is

the only solu:’on to this problem.

Solid waste disposal is becoming an increasingly serious problem in

Cochin partic'.far|y in the thickly populaied western flatland area where there

is high wate' table and absence of proper disposal sites. In the less
populated ea tern uplands, the garbage disposal is not difficult due to
(I)

availability of uacant lands. In the sma i iownships of the eastern parts of the

study area, c::vered type of land filling :an be decended upon. but in the
western flatie*:' area, effeczive and er. '3-nmentally sound garbage disposal
can be done by compost plants in appro_:'§ate places or sanitary land filling

outside the thickly populated areas.

Sewage Li sullage disposal also is a serious problem in the western

lowland due to the high water: ble. Present system of septic tank or pit for
U)

indiv?c'ual houses affects the environme-r.l: adversely. Particularly during

heavy rains, waste levels in the tank rises to the level of floodwater causing

contamination by fecal matter. This intrusion may cause epidemic outbursts

any time and hence has to be viewed with seriousness. The sewerage
system, covering only a very small portion of the city at present, has to be
extended to the whole flatland area. However, in the western flatland area,

due to the absence of gradient. it is rather very difficult to convey the sewage

from a vast area to a single or a few |arge—scale sewage treatment plants.

Hence, it is more suitable to install mini treatment plants sector wise or one

in a neighbourhood of appropriate size.

In the eastern upland areas, not only there is sufficient space for
sewage and sullage disposal but also it is unlikely to contaminate the
groundwater, which lies deep below a relatively impemieable laterite layer.

Hence, a sewerage system may not be essential at present because septic

tank system is sufficient to meet the current requirements.

Storm water and sullage disposal is also a matter of serious concern

in the western flatland area. Flooding of storm water with sullage leads to

environmental contamination and other '"r.'rnan sufferings. tn the western

flatfand area the flood problen‘. is local eiiisef due to the inadequacy of drains
 l75

or due to local depressions. This can be solved by propen‘; the

roadside drains to the tidal canals, since, no place in the wes1e'n fiatland
area is more than about two krns away from a tidal canal. Also, the
encroachers into the canals and 'thcc'-.s“are to be evacuated ejong with
widening. eepening ofthe main canais. may not be szzfiiciont fl'C.‘.“- -sir. image
5.1.]

point of view. since the bottom of these canals are mostly below the low tide

level. Hence, widening is necessary to increase the drain capacity.

However, the storm water drainage is bound to become a serious

threat in the near future in the valleys of the eastern upland. in these
regions, the flood zones of the streams. which drain, into the ‘valleys are
being filled up for raising plantation crops and construction purposes, which

reduces the discharge capacity of the streams. This aspect is oeeéz. with in
detail in the chapter on surface hydrology.

Cochin is served with all modes of transportation by air, water and

land. However, due to improper location of the various trarsoortation

services, the potential remains grossly unutilised. The roads are narrow, the

railway line biturcates the city, thereby obstructing the road linkage between

the two sides. The potential for inland navigation remains unc'e'-utilised.

Cochin is having an all—weather protected harbour lying in the “ain ship

route but due to inadequate depth of the shipping channel the pc~. emains
inaccessibleto large vessels. The existing aerodrorne at Willing-::-: island

has space restrictions, which preclude future expansions so as to a::ommo­

date international air traffic. However, the commissicnrg of Nedxtasserry
airp-~:'t on the outskirts of the study area will improve the situation to e §:;:‘-3-:3
extent.

Among the three ring rc-ads — inner, middle and :_ter — the liner ring

road is too narrow to serve ire existing passenger ar.:‘ tr The (ll

radfe road connections between the inner and middle :_i‘.'Z~!—'—‘..7 Bypass)

roads. originating from the CBD area, are grossly inadequate both in number

a v.-r width. Widening cf the existing roads, wherever possible along

with construction of new roads and flyovers can alone solve the present
imbrcglio. The new roads should be constructed with enough strength to
bear the container traffic.

The important railway szetions in the city are Ernaxulam Junczion and
Ernei-<ulam Town. The entries to these stations are ccrfned to the western

side only. In view of the fast cevelopment of the town c". the eastern side of

the railway line, entries to the station from the east will be most desirable.
This will also relieve the nurrber of the criss—cross ireitc in the central

business district of the city. The proposed Ring Rail‘-way connecting the
important nodes within the City will substantially reduce the traffic
congestion.

Inland waterways offer a cheap and efficient transportation of goods

and people. In the western pa: of the study area bestowed with tide? canals,

water transport if properly designed, would reduce road congestion

considerably.
 The interchanges bet.-.aen \.v\.“.ter—.-/ays and ".'.;?ways are very
important in the city owing to ‘tire complementing roles ‘.388 two modes in

the transportation system". The facilities at these intercha—.;.es are noticeably

poor considering the character and volume of traffic These are to be

specfally designed for efficiefi and corr.€ortable tr:-.;"s‘ar of goods and
passengers.

A properly planned water transport system utilisfig the tidal canals,

rivers and sea as well as limiting the inter-city and inter-state road transit to

the periphery of the highly urbanised area through NH-47 Bypass will greatly

reduce the urban road congestion. Locating the terminais of the three traffic

systems - road, water and railways — in close proximity will reduce unnece­

ssary criss-cross traffic within ihe city. The Vytila area where the NH-47

Bypass, Kaniampuzha canal arc? railway line lie in close proximity may be an

ideal site for such a develop-rrtent. Vacant land is also available in the
locality at present. Since the area lies close to the middle ring road, city
level traffic can also originate from there.

The area allotted for parks and open spaces come to only 0.78% of

the net dry land even in the Cochin Corporation area while in other areas it is

almost absent although water sheets, paddy fields and plantation areas
provide lung space at present. But 0.5 hectaresl 1000 population need to be

earmarked and kept for the pcoulation projected to anoiher 50 or hundred

years from now. Otherwise, when full urbanization takes place, the area will

suffer from acute shortage of ::en spaces and parks. P anned buffer zones
 I78

between Er-:'ustria| and residential area are also lacking in Cochin which
need immediate attention.

ToL"sm may play a major role in the socic—economic improvement or’

any region '7' judiciously managed. Cochin has a vast potential of naturai
scenic areas and places or’ historic and architectural values. Such places
should be identified maintained and managed so that it can become a good
resource.

Suggestions and Recommendations

This study has revealed the above—menticned aspects regarding the

limitations and possibilities of the environmental resources of the study area.

In view of the fast pace of urbanisation and hence alteration of the environ­

ment, the fcilowing basic recommendations are made which if taken into
consideration by the planners and decision-making authorities, will reduce
the adverse impact on the environment to a considerable extent.

In view of the physiographical peculiarities of the study area, land

modification will have serious impact on the environment, if cutting and
removal of hills in the eastern high lands for reclaiming the marshlands in the

western flat land and valleys of the eastern hills proceed unchecked at the
current rate. This has to be regulated after assessing the impact of such a

removal are / or filling up on (1) the opening c7‘ valleys to the pollution

sources of factories which are at present protected by the hills (ridgelines).

(2) changes in ground water regime where steed cuttings are done, (33
 I79

increased efosion and siltation, (4) modification of the floodways of strearfs

of the sub basins in the eastern lowhills, (5) impairment of hill—slope stabiti:'_.

‘due to outing of hills, (6) changes in geological stability of the wester‘

lowlands( ‘.-.‘hich are not immune to seismic activity )due to large—scale fillirg

and construction activities, (7) productivity changes of the bacl<‘.t-/ater syster

due to large scale reclamation and increased sedimentation etc.

VVit'r:in the limitations of the present study. the following suggestions

are made: —

Considering the sub-surface geological stability, availability of vacant lands

air and groundwater quality, construction costs. drainage and sewerage

facilities, flood and waterlogging possibilities and commutation facilities, the

eastern lowhill region is more suitable for future urban development

However, steep slopes. flood zones of streams (valley floors) and areas
close to industrial areas are to be avoided for residential purposes. Strict

regulations are required to preserve the flood zones of stream basins fro.‘
reclamation and human occupation which at present remains as paddy
fields. Based on the drainage efficiency and flood possibility assessments
extensive field level surveys are to be undertaken and flood zones ar.:
levels are to be permanently marked in the fields itself along with legs
enactments and empowering of suitable authorities so as to discourage lar-=:

development and human occupation.

Considering different aspects of the environment, the highly urbanise:

western flazfand is environmentally less suitable ‘Tc: urbanisation. Howeve'
this region already attained a high degree of urbanisation. The future
developme"3 and expansions have to be strictly regulated considering the

following as: :~:ts.(1) Lack of drainage facility due to soil condition as well as

fatness of "fie terrain which is close to the sea level, (2) Deficiency of
potable grc-3:.‘ water (3) seismic history (4) land shortage, (5) predicted sea

level rise d=_e Lzo global warming and (5; high construction costs. However,

the present stuation can be salvaged to a certain extent by (a) planning and

execution of an efficient water supply, drainage and sewerage system, (b)

reducing traffc congestions within the city by shifting inter-state and inter-city

bus terminaf. railway station and boat terminal in close proximity near
national highway at Vytila, a city level ring railway and promoting water

transport system to avoid road congest‘cn(c) maintenance of existing vacant

lands and marshes as lung space by suitable regulations (d) promoting tree

planting for pollution reduction and aesishetic appeal along road sides & other

vacant spaces and enforcing the establishment of greenbelts around

industrial areas.
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 Annex - 1.1

Regulatory Bodies of Various Environmental Resources

Natural Resources

Land Soil Minerals Forest Surface water Groundwater Fish 8. Marine

Air quality

State Bodies:­
I
KSPCB

Keral State Land Use Board

Kerala Land Dev.Corp.

Command Area Dev. Authority

Soil Survey Org.

Centre for Water Res. Dev. 8.
Man.

Ground Water Dept.

Dept. Of Forest

Central Bodies :­
Central Water Comm.

Central Ground Water Board

Dept. Of Ocean Dev.

NEERI

Geo. Survey of India

Central Inst. of Fish.. Nautiacal 8.
Engg. Trg
Central Inst. Of Fish. Tech.

Central Marine Fish. Res. Inst.

Fisheries Survey of India

 I8]

ANNEXURE-2.1

.Sub-basins in the eastern Iowhills

1, l<adaiiil)iayar Basin;

This is the area drained by Kadambrayar river and it includes Kizhakambalam,

Ktimarapiiram area covering an area of 81072 km2 . The highest peak in the study

area is, in this basin, and is near Arakkappady with a height of 115 m above sea
level. This basin drains westwards into a tidal canal east of Kakkanad. This basin

is the laigest drainage basin of Cochin major basin and it lies in the northeast
Corner.

l’ii|likl<.'ii;i liasiii:

This basin, covering an area of 21.325 kmz lies to the south of Kadambrayar basin

drains westwards into a tidal canal near the east of Kadambrayar basin. The
highest peak in the basin is /0 ineleis above MSL near Vembilli.

Brahmapuram basin:
llii:; I1; .i veiy IILIIIUW diaiiiagt; l.i;.isiii covering a total aiea 0| 3.880 kin‘) lying on the

south west of Pallikkara basin. This basin drains westward into a tidal canal near

Brahninpiiram. The highest peak in the basin is about 40 motor above MSl_.

Muttam Basin:

This basin, covering a total area of 6.037 kmz , lies on the south of Brahmapuram
basin. The highest peak in the area is only 40 m above MSL. The basin drains
westwards into a tidal canal, which extends to several kilometers on its western
edge.
 182

5. Vankkoli basin:

This basin covers an area of’ 14.496 km: and slopes down to the west. It is
sepa'ated by ridgelines from Muttam, Brahmapuram and Pallikkara basins on the
northern side and from the Puthencruz basin on its east and south side. The

highest peak in the basin is only 60 meter above MSL.

6. Puthencruz Basin:

This. the second largest basin in the Cochin major basin, covering an area 0''
57.753 kmz , originates in the eastern side of Kadambrayar and Varikkoli basins

and :s separated from them by a ridge line. It slopes towards south for about haft’
its way to backwater system and then slopes towards west on the southern side c‘

Varikkoli basin and Mamala basin and drains into the backwater system on the
south of Varikkoli basin. The highest peak in its ridgeline is 80m above MSL.

7. Pulikkamali - Amballur basin:

This basin covers an area of 22.4905 km2 and is bounded on the north by the ridge

line of Puthencruz and Kandanad basins, on the south by Kanjiramattom basin and

on the east by the ndge of Muvattupuzha valley and readies the backwater systerr

at the north of Parur. The highest peak in its ridgeline is 67 m above MSL nee’
Pembara.

8. Kanjiramattom basin:
This is the northernmost sub-basin of Cochin basin and it covers an area of 6.988 ‘I)

kmz. lt slopes towards west and joins the backwater system at Puthenkavu. It III

bounded on the south by the delta of Muvattupuzha River, o.n the east l:_.
 183

Muvaziuouzha Valle,‘ and on the north by Pulikkmali - Amballur basin. Its highest

point 5 only 20 m acove MSL.

9. Kanorad basin:

It lies .3 close proximity to the sackwater system with a maximum height of only
20m acove MSL and covers an area of 5.9524 km2 and is surrounded on its south

by Pulikkmali - Amballur basin, on its east by Puthencruz basin and on its north by

Udayamperoor basin. It slopes towards the west and drains into the tidal canal
which "sounds its western side.

10. Udayamperoor basin:

It cove's an area 0.54.617 km2 and is bounded by canal and Kandanadt:-asin on the
south. Puthencruz basin on the east and Thiruvankulam basin on the north. It

slopes westwards and joins the tidal canal which form its western boundary. Its
highest peak is only 20 m above MSL.

‘l1.Thiruvanku|am basin:

It covers an area of 3.861 km2 with its highest peak only 20 m above MSL. It is
bounded on its north and east by Puthencruz basin and on its south by
Udayamperoor basin. It slopes towards west and joins the tidal canal, which forms

its western boundary.

12. Mamala Basin:

It covers a total area of 0.9658 kmz only and is bounded on the east and south by

Puthercruz basin and on the north by Varikkoli basin. It slopes towards west and

dF8l.”:S r“.o a tidal canal, Chitrapuzha_ which forms its western boundary. The

higv exel in it is only 20m above MSL.

 184

13 Kukkzlilnd South l’$usin:

The basin covers an area of 3.8532 km2 and slopes down in the south-east
direction and drains into a tidal canal which forms its south-east boundary. The
highest level in the basin is only 20 m above MSL. It is bounded on its west and

north by Thudiyur basin and on its east by Kakkanad East basin.

14 Kakkanad East Basin:

This basin covers an area of 5.9474 km2 and slopes towards east. Four small
ELIIU-'l|ll1'. llnw lmni lliiz; Illlfllll one-;|w.'ir'rl and join lho tidnl (::1n.'1l, which lnrins; the

eastern and south boundary of the basin. Its ridgeline is only about 20 m above
MSL. It is bounded on the west by Kakkanad South basin, Thudiyur basin and
Cherumuttapuzha basin and on its north by Cherumuttapuzha basin and Trikkakara
East basin.

11). lliiikkukuia liust Basin.

This basin covers an area of 10,4581 km2 and drains southwards into Kandrakathu

thodu, which is a tidal canal. Its ridgeline is only about 20m above MSL. This
basin is bounded on its cast by Churnikara basin and Kadambrayar basin, and on

its north by Churnikara basin and on its west by Cherumuttapuzha basin, Edappilly
I u:;| l);l:'.Iii and Kzikkzmzltl I ;i:;| l)iI‘.';lll

16. Churnikara basin:

It covcis an area of 20 701 km2 and it drains westwards into Edappally Thodu.
which is a tidal canal. It is bounded on its west by lidappally lhodu, north by
Periyar valley, East by Kadambrayar basin and south by Thrikkakara east and
Kalainussery basins. lls lugliesl ridge is only about 40 Ill above MSL.
 I85

1/ K:il;iiii;i:;:;t.:iy hilfilll

This basin covers an area of 2.4813 km: and drains westwards into Edappally
thodu, which forms its western boundary. It is bounded on the south by Edappally
East and Edappally South basins, east by Thrikkakara East basin and north by
Churnikara basin. The highest point on its ridges is only about 20 m above MSL.

It ­ I ituppully N()l||l Iiusiii.

It drains northwards and westwards into Edappally thodu, which forms its northern
nnrt W(.'f;|(.'lll t>miii<t.'tiiu:; ll rtrivurs nit rimn of ? 1631 km? niirt If‘. tmiiiirlmt rm ilt:

east by Kalamassery basin and on its south by Edappally East basin. Its highest
ridge is only about 20 m above MSL.

19. Edappally East basin:

This has an area of 4.175 km2 and drains westward into the southern arm of
|*<t.'ipp.'il|y ttiodu. It is boundod on its wost by Edapp.'.1||y tliodu, on its east by
Thrikkakara East basin, south by Edappally North and north by Cherumuttapuzha

basin. Its highest level is only 20 m above MSL.

20. Cherumuttapuzha basin:

It has a total area of 5.475 km2 and drains westward into southern area of
Ldappally thodu. It is bounded on the west by the southern urm of Edappally
thodu, south by Thudiyur basin, east by Kakkanad East basin and north by Eda­
ppally East basin. The highest point in this basin is only about 20 m above MSL.
 I86

'/I Iluullynui l!.'1:;in

It has a total area of 6.327 km2' 3 smal| streams flowing in a southwestern direction
drains this basin into a tidal canal. It is bounded on the north by Cherumuttapuzha

basin, east by Kakkanad—East basin and souh by Kakkanad—South basin and west

by Iidnl canal. The highest point in this basin is about ?0 m above MSI .
 I87

ANNEXURE- 2.2

Drainage units in the western flatland

1). Thiruvankulam East
This unit covers an area of 4.165 km?‘ and is bounded by Chitrapuzha in the
east, Karingachira—|rumpanam road in the west, Thudiyur puzha in the north
and Tripunithura--Muvulliipu/Ira road in the south. Tlris has 21 small Ialcrilic
upland at Hill Palace

?) |flllll[):lll.'llll wr.>:;l:
This unit covers an area of 2.860 km2 and is bounded by Thidyur­
Thiruvamkulam road in the east, Eroor puzha in the west, Tripunithura­
MuvattupLizha road in the south and Thudiyur puzha in the north.

3) Eroor-Puthotta road East

This is a long stretch of land lying in a north-south direction. This strip
covers an arm: of 12 ?06 km? and is b0l|ll(l()d by Froor-Pirlhollzr Ilrodu on
the east, Eroor-Puthotta road in the west, Puthotta in the south and Eroor
bridge in the north. The general slope is towards east.

4) Eroor‘—Putliotta road west.

This is also a long stretch of land more or less parallel to Eroor-Puthotta
road and covers an area of 17.855 kmz. This is bounded on the east by
li_—‘roor--Puthotta road, west by Kandakadavu puzha and Kayal, Puthotta in the
south and Eroor bridge in the north. This has a general slope towards west.

5) Chathamma Fast.
This is a small strip of land covering an area of 0.571 kmz. Its boundaries
are Vembanad Kayal on the south, east and north, and a local road on the
west. It lies on the east of Panangad. The general slope is towards east.
 I88

6) Chathamma West
This lies on the west of Chathamma East with a road in between which
forms its eastern boundary. On its south side is Vembanad Lake and west
and north are tidal canals. The general slope is towards west. This has an
area of 0 326 klll? It is hoiindctl on its west, south and north by tidal Canals
and on its east by a road. The general slope is towards west.

/). Cheppanain l.-:asl.

This covers an area of 0.616 km2 and is bounded on the east by Vembanad
lake, south and north by tidal canals and west by a road. The general slope
is towards east.

8.) Panangad East

This covers an area of 2.965 kmz lying in a north—south direction. It is
bounded on its south by Vembanad Lake, east and noitli by lidal canals and
west by a local road and NH-47. The general slope is towards east.

fl) l‘an.'mg.'i<l West

It covers an area of 1.681 km2 and is separated from Panangad East by a
road and NH-47, which form its eastern boundary. It is bounded on its south
by Vembanad lake and north and west by tidal canals. The general slope is
towards west.

10) Kumbalam East

This covers an area or 0.857 klll? and is bounded on the south by Vembanad
Kayal, north and east by tidal canals and west by NH-47. The general slope
is towards east.
 I89

I1) Kumbalam Central"

I his covers an area or 0.801 kin" and hes between Alleppey railway line and
NH-47 Bypass at Kumbalam. Its east is NH-47, west Alleppey railway line,
south Vembanad Kayal and north a tidal canal.

12). Kumbalam West

It covers an area of 1.399 km2 and is bounded on the east and south by
railway linos and Vt.-rnbanad Iako, north by a tidal canal and west by
Vembanad Lake. The general slope is towards west.

13). Nettoor South

It covers an area of 1.271 km” and is bounded on all sides by tidal canals. A
road and NH-47 run in north-south direction through it and on the western
side of it. The slope is towards west and on the eastern side, the slope is
towards east whereas in the space between Nl-I-47 and old road, the slope
is towards north in the northern part.

14) Notloor North

This covers a total area of 1.900 km2 and bounded on all sides by tidal
canals. Two roads including NH-47 divide the area into 3 in north-south
direction. In the western part, the slope is towards west and in the eastern
part, the slope is towards east. In the central portion, slope is northwards on
the northern part and southwards in the southern part.

15) Kundannoor West

This covers an area of 1.614 kmz. Its boundaries are tidal canals on the
south and west, a local road on the north and NH-47 on the east. The
genoral slope is towards west.
I6) Kiindunn()()r lfast
It covers an area of 2.904 km2 and bounded by roads on the north, south
and west and by tidal canal on the east. The general slope is towards east.

17). Maradu
It covers an area of 2.669 kmz. It is bounded by a road on the northern side
and the other sides are bounded by tidal canals. The general slope is
towards north.

18). Vytila East

It covers an area of 1.125 km2 and is bounded by NH-47 on the west, a
railway line on the north, and Chantpakkara canal on the east and south.
The general slope is towards east.

19). Vytila West

It has an area of 1.777 km2 and bounded on the horth by Sahodaran
/\yynpp:in Rnml,mi:;l by Nil--/l7 Flyopnss, wosl nnd south by lirtnl cnnnls.
The general slope is towards west and south.

20). Chilavannoor
This has an area of 0.998 km2 and bounded on the east and south by tidal
canals, on the west by K.P.Vallon Road and on the north by Sahodaran
Ayyappan Road. The slope on the eastern side is towards east. The central
portion of the area is basically, paddy fields to which an arm of the

towards it. .
backwater extends northwards and on either side of it the land slopes

21). Kadavanthara
This has an area of 0.773 km2 and bounded on th% west by Thevara­
Perandore canal, east by K.P.Vallon Road, north by‘ Sahodaran Ayyappan
Road and south by a local road. The generalslope is towards east.
22). Konthuruthy
It has an area of 0.750 km2 and bounded by tidal canals all around except
for a small port in the northern boundary. The general slope is towards
south.

23). Panampilly Nagar

This has an area of 1.992 km: and bounded on tho wost by railway lino.
south and east by tidal canals and north by Sahodaran,Ayyappan road. This
land was originally low-lying paddy fields which was; recently filled up for
building construction. The slope of the land is not perceptible.

24). Thevara
It covers an area of 1.405 kmz. It is bounded on the east and south by tidal
canals, west by Vembanad lake and north by M.G.Road and a railway line.
The slope is towards east, west and south direction from the centre.

’/5;) |{z.ivipIu;iin
This has an area of 1.439 km2 and bounded on the west by Vembanad lake,
south and east by M.G.Road and north by Church Landing Road. The
general slope is towards west.

26) Ernakulam CBD Area

This has an area of 3.1 km2 and bounded by Ernakulam backwaters in the
wust,u iullwuy lino lll lliu oust, Uunurjl Rout] in tho noilli Lllld Cliurch l..un(ling
Road and Sahodaran Ayyappan Road in the south. The general slope is
towards west. However, ridges that run in north-south direction can be
identified at Chitloor Road and T.D. Road and have become insignificant
when the area was completely built up.
27) Gandhinagar west
This has an area of 0.617 kmz bounded in the west by a railway line, east by
Thevara—Perandoor canal, Sahodaran Ayyappan Road in the south and a
railway line in the north. This area is rather |ow—lying and hence the direction
of the slope is not perceptible.

28) Gandhinagar East

This covers an area of 0.971 kmz. It is bounded or; the west by Thevara­
Perandoor canal, Kaloor-Kadavanthara road on 2 the east Sahodaran
Ayyappan road on the south and a railway line on the north. The area was
originally low-lying marshlands except for localised elevated areas. Now,
most of this area has been filled up and built up extensively. Hence, definite
Sill luite slope rlimrzlion is not pmrteptihle.

29). Pulleppady East:

This covers a total area of 0.066 kmz. This area was originally low-lying but
now is mostly lulled up. It is bounded on tho |l()llll hy Klllllllll<l.l(l.‘.lVllv
Pulleppady Road, west by a railway line, east by Thevara—Perandoor canal
and south by a railway line. The general slope is towards east.

30). Kathrukadavu West

It covers an area of 0.162 kmz bounded by Ka|oor—Kadavanthara road on the
east, Thevara—Perandoor canal on the west, a railway line on the south and
Thammanam—Pu|leppady road on the north. The general slope is towards
west.

31). Kalhrukadavuliast
It has an area of 0.293 km2 and bounded by Thammanam-Pullepady road on
the north, a railway line on the south, a tidal canal on the east and Kaloor­
Kadavanthara road on the west. The general slope is towards east but not
perceptible since a lot of filling up has been done in it.
 193

32). Asan Nagar — Jawahar Nagar Area

this covers an area 0! 1.161 kin" and bounded on the west by Kaloor—
Kadavanthara road, east by tidal canal, south by Sahodaran Ayyappan Road
and north by a railway line. The general slope is towards east. However, it
is not fully perceptible since the |ow—lying areas have been filled up to a
great extent.

33) Ponnurunni
This covers an area of 1.666 km? and bounded on the west by tidal canal,
east by NH-47, south by Sahodaran Ayyappan road, and north by a railway
line. The general slope is towards west.

34) Thammanam:
This has an area of 1.286 km2 and is bounded on the east by NH-47, west a
by tidal canal, north by the Thammanam-Pullepady road and south by a
railway line. The general slope is towards west.

35) Chalikkavattom
This has an area of 2.339 km2 and is bounded on the north by the
Thammanam—Arkakadavu road, south by a railway line and tidal canals,
west by NH—47 Byepass, and east by a tidal canal. The general slope is
towards east and south. However, in the northern part, the slope is towards
west.

36). Arkakadavu
This covers an area of 1.190 km? and bounded on all sides by tidal canals.
The general slope is towards the west in the western half and towards the
(,‘.'ISI in tho onslnrn hnlf
 I94

37). Thrikkanarvatttom — Pachalam

This has an area of 2.897 km2 and bounded by Ernakulam Kayal on the
west, a railway line on the east, Banerji road on the south and a local road
on the north. "I he general slope is towards west.

38) Ka|oor- Indiranagar

This has an area of 0.319 km? and bounded on the east by the Thevara­
Perandoor Canal, on the west by a railway line, south by the Thammanam­
Pullepady road and north by the NH—47. This area was originally a
marshland, which has been filled up and hence the definite slope direction is
not perceptible.

39) Kathrukadavu — Kaloor west

T his has an area ol 0.5059 kin’ and is bounded by Kaloor Kathrukadavu
road on the east, Thevara Perandoor canal on the west, the Pullepady­
Thammanam road on the south and Nh 47 on the north. The general slope
is towards west.

40). Kathrukadavu - Kaloor East

This covers an area of 1436 km?‘ and bounded on the east by a tidal canal,
west by the Kaloor—Kathrukadavu road, NH-47 on the north and the
Thammanam-Pullepady road on the south. The general slope is towards
east through not clearly perceptible.

41). Palarivattom South

This has an area of 2.233 km2 and bounded o_n the south by the
lhammanarn—Pullepady road, north by the Palarivatttorn«Kaloor road west,
by a tidal canal and the east by NH-47 Bypass. The general slope is
towards west.
 195

42). Vennala
This covers an area of 2.907 km: and boundedon the south by the
Thammanam-Arkkakadavu road, west by the NH—47 Bypass, north by the
Pa|arivattom—Kakl<anad road and east by a tidal canal. The general slope is
towards east in the eastern parts and west in the western parts with a ridge
lying in the north—south direction.

43). Kaloor Sivaramamenon Road area

This has an area of 1.690 kmz and bounded by the Thevara-Perandoor
canal on the east, a railway line on the west, NH—47 on the south and a
railway line on the north. This area is more or less flat with a gentle slope
towards east.

44). Perandoor road West:

‘this covers an area of 0788 km’ and bounded by the Perandoor road on
the east, the Thevara-Perandoor canal on the west, NH-47' on the south and
a railway line on the north. The general slope is towards west.

45) Perandoor road East:

This has an area of 4.004 km: and bounded by a tidal canal and a railway
line on the north, Nl l- 47 in the south, the Perandoor road on the west and a
tidal canal on the east. The general slope is towards the east and the north.

46). Vaduthala
This covers an area of 3.2 km? and bounded by tidal canals on the north and
the east, backwaters on the west and a railway line in the south. This area
slopes towards east and west from a central northwest ridge.

47). Chittoor
It covers an area of 2.504 km: and bounded on all sides by tidal canals. The
land is flat.
 I96

48). Edappally South

This has an area of 2.685 km2 and bounded on the west by tidal canal, south
by the Palarivattom—Kaloor road, east by NH—47 Bypass and north by a local
road. The general slope is towards west.

49). Edappally North

It covers an area of 2.393 km2 and bounded on the west by tidal canal, east
by .11 lidul canal and 1) road, south by road and north by -‘.1 railway lino. Tho
central portion is slightly elevated and slopes towards east and west.

50). Cheranellur west

lliis has an area of 4.517 krn’ and bounded on the east by the Varapuzha
ferry road, west and north by tidal canals and south by a railway line. The
general slope is towards west.

51). Cheranellur east

It covers an area of 0.321 km2 and bounded by a local road on the west, a
lltlill c.'.m.'.1l on the north and east and a railway line on tho south. The
general slope is towards east.
 Annexure-6.1
List of common and in-:?;.-:a§iy growing plants identified in the study area

Botanical name Tree.-'3hrub/ Common name Family Uses

Climber
K
Acacia aun‘cu/iformis, Acunn . ex.3em h. Australian Wattle Legumlnosae Timber
u
K Ar:ac.Fa mangfum, Manjium Timber
Acacia fnls/a, Willd. lncha Medicinal
Ace,-"_v_.:."?a hisp;'da, Burm. Kuranguvalan Euphorbiaceae Ornamental
Ar:a.-’y__c:7a wr7r'<e.sr'ana, Muel|_ Ornamental
:4
Acl§'_p.'¢-3 marginaia, Ornamental
r-I!=DU*?'-¢~'N.­

. Aca.-‘_v_cI¢a namzflon/'ana. Ornamental

_c-> A»:s.'.*-mus r}’.l':-.r'r‘o/ius, L. Mnhala Chully Acanthaceae Soil Binder
Achras sapoia. L. Sapota Sapotaceae Fruit
. Adenanfnaa ‘cavonfa, L. Manjady Leguminosae Timber
. Aderclcalymma a/liaceum Veluthully Chedy Bignoniaceae Flowers
. Adfrafrcda vas/ca, Nees. Adalotakom Acanthaceae Medicinal
. Aengie .r:7arme,-"os, L. Corr. Koovalam Rutaceae Medicinal
. Agave amerfcana, L. Amerlcan aloe Amaryidaceae Flbre
. Agave amer/cane. ‘mart;/haia’ Omamenlal
. Agave v.-'1:-ior.v'a regfnawa Fibre
U
. Agave v"/c.*or.-"a reg/nae ’marg/nala‘ Ornamental
. Affanéhus excersa, Raxb. Pemmaram Simarubeae Sol wood
. A.i.fe..¢?.".;rs mafaberéca, DC. Pongafiam 80! wood
Vaka Leguminosae Sol! wood‘
. Am“: 2 _:rc.:era, Roxb. Benth. Vella Vaka Sat wood
. A//amarda cathartica. L. Manja I-(olambi Apocynaceae Ornamental
. Ax"/errrenda vzc.-‘acea Neela Kolambi Ornamental
Ezhilampala H Sol wood
Cashes-mm tree Anacardiaceae Nut

Pine apple Bromeliaceae Fruit

Seema Atha Anonaceae Fruit

Seethapazham Fruit
. /-1!‘.-'C."E :7‘?-LJFICE FE, lvluflan Alha -: ‘Fruit
. e»‘1..~.'5’-S .‘C,'A’r':CE.'.'r'3. Pers. Lesch. -l"“‘*"’-*“0O‘*-l-|"lcn0=¢ncn—roo-i—immcornmo4—i

Arayanjily l-vloraceae Timber

 31. Aphe/and.:'a .sr;ruarrosa Acanthaceae Ornamental
32. Aphe.’enc*ra letragona Acanthaceae Ornamental
33. Aporose =’:‘=d."e;-'ana. Wt. Baill. Vetty Euphorbiaceae Firewood
34. Ara;-‘ca-i 5 .:e;’sa, Br. Christmas tree Conilerae Ornamental
I‘
35. Araucara social. Br. Ornamental
-A» PAL- ,3 L
38. Ar-;~.c-.:.':C..’J, Kamuku Palmae Spme
37 Areca iu.‘escens Ornamental
38. Arislc.’:=:.I¢.r‘a ./ndica, L. Garudakodi Aristolochiaceae Medicinal
40. Artab-says o:loratis:'mu.ss, Br. Manoranjiny Anonaceae Ornamental
40. Artoca—xpus /‘noise. L .l.. Kataplavu Moraceae Fruit
41. Artocarpus /7/rsutus. Lamk. Anjily Timber
42. Artocajous /nt‘egn"fo//a, Li. Plavu yr Tmber/Fruit
43. A var/‘ma carambo/.9, L. lrimban Puly Geraniaceae Fruit
44. Averrhoa b/"I/rnbir", L. Chemmeen puly Fruit
45. Avbenma offl'cine/is, L. Kandal Verbenaceae Firewood
46. Azadfrachta ind/‘ca, AJuss_ Aryaveppu Mellaceae Medicinal
47. Bambusa vulgar/"s, Schrad. Manja liy Gramineae Industrial
43. Bambusa arundfnacea, l/‘Md. Kalan llly Industrial
49. Bar/er/a c/istata, L. Kanakambaram Acanthaceae Ornamental
50. Bauhinia variegata, L. Chuvanna mandaram Leguminosae Ornamental
51. Bauhin/a purpurea, L. Ornamental
52. Bauhinia tomentosa Manja Mandaram Ornamental
53. Bauhinia galp/‘ml’ Mandaram Ornamental
54. Bixa ore//ana, L. Maramyhnchi Bixaceae Ornamental
55. Bombax ma/abarfcum, DC. llavu Malvaceae Salt wood
56. Borassus flabel//fer, L. -4-I-low-|—1—l<n-4-1-I—l—l—I—i—i—ico<'>_._._,_,_.o-,m

Karimpana Painae Commercial

57. Bot/gs/nw'/Iaea g/abra. Chois S/C Bougain Vila Nyctaginaceae Ornamental
53. Bouga/nvi//aea spectabil/s,\NiId. S/C Ornamental
59. Bruguiera gymnorhiza, Lamk. T Kandal Rhizophoraceae Fiewood
60. Buchanan/a ax/'/tans. Derr. T Kulamavu Anacardeaceae Sotwood
61. Butea frondosa, Koen. ex Roth. T Palash Leguminosae Firewood
62.» Caesalpin/a pulcherr/‘ma, Swatz. S Rajamaly n Ornamental
/ea. Caesalp/n/‘a coriaria, Willd. T Divi Divi Ornamental
64., Ca/amus .rotan~g. L. S/C Chooral PaI'n_ae Commercial
85. C ax’.-’:’and.-'5 :=.'—.=<..'.iCes S Powder puff Leguminosae Ornamental
66. Camandre haernaroceprra.-=‘a S Red Powder puff ra Ornamental
.-.
V64. i.a.-".s.‘e.m.:.-<'a.‘::eo.‘iaius, ‘.3-meet. T Bottle brush lvlyrtaceae Ornamental
 '4)

68. Cafoph y‘./:'un'gl57o.:h y mm, L. T Punna Gultiferae Soft wood

69. Ca.—’ctr:,::'s, g.-"ga.¢.‘ea. Br.. S Vella Erukku Asclepiadaceae Medicinal
70. Ca/ctrc,:."s. p)'o:e.'a,Br.. S Chuvanna Erukku Asclepiadaceae Medicinal
71. Ca.-',«-‘c:_:.‘e.=r;'s h’o.r.‘t3mda, Lamk. S./C Pullanthi Combrelaceae Industrial
72. Cara.’:’a D _C. T Varangu Rmzophoraceae Firewood
73. C ar/ca papaya, L. T Papaya Passifloraceae Fruit
74. Carissa carandas, L. S Karavanda Apocynaceae Ornamental
75. C-‘aryota urens,L. T Choonda pana Palmae Commercial
78. Cass-‘a fistula, L. T Kanikonna Leguminosae Ornamental
77. Cassia renlgera, Wall. T Ornamental
73. Cassa nodosa. Han.ex.Roxb. T Omamenlal
79. Cass.-‘a javantba, L. T Ornamental
80. Cassia sr'amea__Lamk. T Ornamental
81. Cassie a./afa. L. S Puzhukkadi konna Medicinal
82. C assfa vlaevfg/"la S
83. Cassia blflora SIT Ornamental
84. Ca'suar/na equisetrfo//a, G.Forst. T Choola maram Casuarineae Firewood
35. Cefba rentandra. L.Gaertn. T Panji Malvaceae Commercial
86. Cer.‘;».=.'a odoilum. Gaertn. Othalam Apocynaceae Medicinal
87. Cestrum nocmrnt/m Nisha Gandhi Solanaeceae Ornamental
88. Cestrum diurnum I! Ornamental
89. C/‘nnamomum campfvora. (L).Ness.. Karpooram Lauraceae Medicinal
90. Cinnamomum zey./anicum, Breyn. Karuvappatta Spice
91. Citrus adda Cherunarakam Rutaceae Fmit
92. Citurs decumana, L. Babimas Frui
93. C/erodendron frag.-'ans, Vent . .(Br.) Verbenaceae Ornamental
94. C Ierodendron spfendens Ornamental
95. Cleradendron tr'7cmsonoe,Ba lt. Kadala Poovu Omamental
B6. C/erodendron tnclrotomum Ornamental
9?. C/era.‘-endron /'nfortunat‘um, Gaertn. Panrvalam Omamntal
93. C/erocendron ;'rrerme_. G aertn. wsha madari Medicinal
99. Cocos nucifera, L. Thengu Palmae Commercial
100 Cociaeum varxengatum Croton Euphorbiaceae Ornamental
101 C\::.r'r'ea arablca, L. Coffee Rubiaceae Commercial
102 Co.=';',: rs u'rnbl'acu.".ffe.r-5, L. -lw<D"cocnc/>:nm¢n.q¢°—i--i<ncn._,

Kudappana Paknae Commercial

103.. CC‘-D.'3C.= la gm-a.¢e.=7.s,-".5, Aubl T Nagalingam Myrlaceae Omamenlal
104. C ycas =:..-m/na;,s. L. T Eenlh Gymnosperm Ornamental
105.Cycas revo/uta, Thumb.Brandis 0rnams:nt;l
1 06 .Da/berg/a /atifolia, Roxb. Eetti Leguminosae Timber
107. Datura fastuosa. L. Neela Ummam Solanaceae Medicinal
108.Datura stramonfurn, L. Vella Ummam Solanaceae Medicinal
109.De/onix reg/a, Boj.Rafin. Gulmohur Leguminosae Ornamental
110.Dendroca/amus sir/"c-tus, Nees. Kallan iliy Crarnineae Commercial
1 1 1 .D.r'pterocarpus /ndfcus, Bedd. Kalpain Dipterocarpaceae Softwood
112. Dracaena fragrans Liliaceae Ornamental
1 13 Durante pIumr'en',Jacq. Golden dewdrop Verbenaceae Ornamental
114.Elaeis guineensis Ennappana Palmae Commercial
115. Ervatamia dicotoma. Blatter. Kuruttu Pala Apocynaceae .
1 18.Erythrina indfca, Lamk. Murikku Leguminosae Soft -.-.-cod

117. Erythr/ms 517/'c:.‘a_, Roxb_ Mullu Murikku Leguminosae Sofl Wood

1 18.Euca/yptus crtriodora, Hook. Eucatyptus Mynaceae Commercial
1 19.Euca!yptus g/obuius, Labil. Commercial
120.Euge/7/ajambo/ana, Lamk_ Njaval h Softwood
121 .Eupaton'um odoratum Communist Patcha Compositae ..
1 22. Euphcrbia t."ruca./!.r'x', L. Thirikalli Euphorbiacea Ornamental
123. Euphcrbfa ner/r'or’/a, L. Ornamental
1 24 .Euphorbr'a antiqorum, L. Chathurakkalfi Ornamental
1 25. Euphorb/‘a pu/cherr/ma,lMId m0'Jm—i<n_q'_4_4—l—tm—imw—i—i-It/3c0—t—i
Ornamental
12B.Euphorbfa splendans.Boj. S Christ's thorn Ornamental
127.Excoecan"a agattocha, L. Sff Kammatti Fire Wood
128.Excoecar/a bxco/or ,Hassk. S/T Ornamental
129. Ficus bengafensis, L. T Peral Moraceae Reigious
130. Ficus benjamina, L. T Vellal Ornamental
131 .F/cus elastica, Roxb. T India rubber Ornamental
132. Ficus asperina, Roxb. T Therakom
133.Fi'cus car/ca T Fig Frui
134. Ficus re/ig/osa. L. T Arayal

1 35 . Garc/"me mangostana. L. Mangosteen Frui

136. Gare/ma cambcgia, Gaenn.Desr. Kudampuly Spice
1 37_Gardenr'a ja.sminox‘des,Ellis. Gandharajan R.tj..'_-ccae Ornamental
138.6/or/osa superba, L. Menthonni Liiiaceae Medicinal
139.Gfycc:smfs pentaphy//a, Correa Panal Rutaceae Medicinal

140.G1'yn'c.Fdia macufata, H.B.K. Seemakonna L:-gut-rinosae

1 4 1 .GmeIina arbcria. R oxb. -I-lcncnr/1-1-i Kumbil Verbenacea Medicinal
 K}:

142 . Go.v'phimr'a gia uca S Ornamental

143.Grew'/lea robusfa, ACunn. T Si.!\-‘er oak Proteaceae Sofiwood
144.Hame./Ia pafens.Jacq. S Pavizha Malfy Rubiaccae 0r:...r.a:nta|
145. He.'ec.'ere.s /sora, L. S/T Edambin' Stercufiaceae M(..".a|
146.He'./ea brasrI.:'e.nsv's, Muell. T Para Rubber Euphorbiaceae In: 3|
147 .H/biscus mutab/'!zs,L. 8 Changeable rose Malvaceae Or ntal
143 .Hib/"sous rosa«s/'nens.v’s, L. 8 Shoeflower 0 ental
14 9 .Hr'b/sous shizopeta/ous S Kurunnila chemparathy ,, 0: ental
150. Hibiscus syr/"aces, L. S Neela chemparathy n 0:.._=':enta|
151 .H/biscus b"!/soau s T Atiu Parathy F1“.-30d
152.Hc!ygarna arno.*f/ana, Hook.f. T Chem Anacardiaceae N .nal
153.Hydnocarpus wxghfiana, Bl. T Maroiti Bixaceae Iv nal
154./xora oooc/nea, L. S Chetli Rubeaceae N nal
155.I'xo!a perw'f.I'ora . Vahl. S Vefla Chelti 0 ental
1 56 Jacaranda rzfimosaefo/.z'a. D .Don. T Neela gulrnohur Leguminosae Or anlal
157. Jacobfn/a cxomea S Acanthaceae 0- ental
1.58 .Jacqumontr'a pentamha C Convolvulaceae 0: enial
159.Jasm/'nium sambac, \/Vnght. C Malfika Oieaceae 0‘ tental
180.Jasm/n/um pubescens, Wild. C Kurukulhi mula C flental
161 .Jesm‘in/‘um roflananum, Wal. C Kattu muh C nental
1-62.Jafropha cumas, L. S Kammatfi Euphorbiaceae
163. Lagerstroemea f.-‘cs-regfna-3. Retz. T Poomaruthu Lylhraceae ( ._.nental
164.Lagersrroemea Indie-a , L. S May flower Crr‘-arnemal
165.Lagers.‘rrx-mea /ance/a-.‘a. Wall. T Vemhekku :1‘. s-. wood

166.Lantana camara, L. S I-(ongini Verbenaceae I’ memal

167.Lantana seiiow/ana S Neela kongini L-.5 rnental
1B8.Lanfana depressa S Manja kongini 0m..11enta|
189.Lawson/‘a a/ta, Lamk. S Mylangi Lythraceae Mecicinal
170.Let/caena /aucoc-epha.1-'5. Lamk.Bemh. T Subabul Leguminosae Frewood
171 Macranga ind/"ca. Wt. T Vatta Euphorbiaceae S;5:Vood
1 72 .Ma."p.r7gh/"a c:cc.rge.ra S Malpighiaceae Csrmsrnental
173.MaIvawiscL.s arboreus S Muiakuchemparaihy Maivaceae C.-namemal
u
174.Mar'vaw'scas moffis S H

175 .Ma.ngn‘e.ra :nc'/ca, L. T Mavu Anacardiaceae F";'r1

178. Man/"ho! utr'!'.-Ss:'ma, Pohl. S Maracheeni Eurphobiacea Tuber

177.Ma.m-‘ho! g.-*'azr'ow'i, Muell. S/T Cera-rubber -amental
178.Me;&"a aza=:’..ra-:n.‘a. L. T An/a Veppu Meliaceae icinal
179.MicheIia champaca, L. Chempakam Anonaceae Ornamental
1 80 .M/'/I/ngtonia hortensis, L .f. UfinjiPadiri Bignoniaceae Ornamental
181 .Mimusops a/enji. L. Elanji Sapotaceae Ornamental
182. Morinda tinctona, Roxb. Manjanatti Rubeaceae
183./llor/hga pterigosperma, Gaertn. Muringa Moringaceae Food
184 Muntin gia ca/abura, L. Vfild Cherry Elaeocarpaceae Ornamental
135. Murraya exotica. L. Rutaceae Omamemm
1 86 Murraya koen/"g//, Spre.. Kariveppu ., Spke
187 Mussaanda frondosa, L. Vellila Thali Rubiaceae
133 .Mussaenda Meofa Ornamental
189 .M ussaenda erythrophylla Ornamental
1 90 .11./Iynsbica fragrans, Houtt_ Jathy Myristicaceae Spbe
u
191.Myr/'sli'ca ma/abanba Kattu Jathy
192 .Na.r/um ind/"cum. Mill. Araly Apocynaceae Ornamental
1 93 .N_vclanthes arbor-ms lis, L. Parijatham Oleaceae Ornamental
194_OchIandra travancor/ca, Benth. Eetta Gramlneae Commercial
195.0cf7roma pyramfda/e, Cav.ex_La Baha Bombaceae Soll Wood‘
l9B.Odina wodier, Roxb. Kalasam Anacardiaceae Sell V\/ood
197.Oreodox.5 reg/a,H.B& K. Royal palm Palmae Ornamental
198. Oroxy/um ind/‘cum, Vent. Palaka payyani Bignoniaceae
1 99.Patchystachys-coccinea Acanthaceae Ornamental
200.F‘andanus odorat/es/mus. Roxb Kaflha Pandanaceae Commercial
201 ./-“and anus veitc.hr'i Ornamental
202.Pe/tophorum pterocarpum, D .C. Copper pod Leguminosae Ornamental
203.Petraea volub/'lis,Woodr. Purple wreath Verbenaceae Ornamental
204.Phy/Ianthus emb/Ea, L. Nelli Euphorbiaceae Medicinal
205.F’iper betel, L. Vettila Piperaceae Medicinal
208.Pipar nigrum, L. Kurumulaku Spice
207.Plthecolob/um duloe, Roxb. Benth Legumlnosae Flrewood
208.F’/umeria aculffo/fa, Polrst. Eezhachempakam Apocynaceae Ornamental
209.Plumer/a rubra, L. Ornamental
210.P/umer/a a/ba, L. Ornamental
211.Plumbago capens/'5, L. Neela koduvell Plumbaglnaceao Medlclnal
212.Po/ya/fh/a /ongifo/ia.Hk.l. Aranamarom Anonaceae Soft Wood
21,3.PoIya/this /ongifo//‘a 'pendula' Drooping asoka Soft Wood
2V14.Pongam/a g/abra, Vent. Mlnnarl Legumlnosae Medlcinal
215.Psid/‘um guajava, L. -l—l-l-lt/1-1-4-1-|0O_qO—|r/3-1U')_4-l-l-1-lU7U7-l—lWW¢/JUJU7-4-l-l-1-1-I Pera Myrtaceae Fruit
 21 B.Plerocarpus marsup/"um, Roxb. Venga Legumlnosae Medicinal
21 7 .Plarocarpus santalfnum, L. Raktha Chandanam Leguminosae Medicinal
21 8 Plerosparmum acerrfo/{um Sterculiaceae Ornamental
219.Pun/ca granatum, L. Mathalam Medicinal
220.Qu/squa/is ind/ca, L. Seema pulianthl Eiimbreta/cyeae Ornamental
221 flavana/a madagascar/ensr's,Sonn Traveller’-3 palm Musaceae Ornamental
222.Rhrzophora mucronala. Lamk. Panicha kandal Rhizophoreae Fire Wood
223_Rh/zophora conjugate, Lamk. Kaya kandal Flre Wood
224 _R/c/nus commums, L. Avanakku Euphorblaceae Medicinal
225.Samadera /ndica, Gaertn. K aringotla Simarubiaceae Medicinal
228 . Sap/nd us faurffo//"us. Vahl. Soap Maram
227.Saraca indies, L. Asokam Leguminosae Ornamental
228 . Sch/eichera tr/jugs, Willd. Poovam Sapindaceae Fire Wood
229.8/da refuse, L. Kurumthotty Malvaceae Medicinal
230 . S/da cordifo./1'5, L . Ooram
231 .S,c-athodea companu/ata, Beauw. Tulip tree Blgnoniaceae Ornamental
232_Spond»"as mang/"fora, Wild. Ambazham Anacardiaceae
233.Slercu/fa foetida, L. Pottakkavalam Sterculiaceae Ornamental
234.Slercu//5 urans, Roxb. Thondippazham
235.Strychnos nux—vomica, L Kanjlram Loganlaceae Medicinal
236.Sw/eton/a macrophy//a Mahogany Meliaceae Timber
237.Sw/alien/a mahogany
233. Tabernaemonlana dfchotoma. Roxb. Koonan Pala , Apocynaceae
239. Tabernaemontana coronar/‘a, Br.(iMlid) Nandyarvattom Medicinal
240_Tabernaemontana devaricala Ornamental
241.Tamarindus indioa. L. -l"’¢°<0-i—i—iw—-i-i—imc.o-i-I—i-4m_._.—lom—+..._¢

Valan Puly Leguminosae Spice

242.Tecoma slans, Juss. U: 3| Bignoniaceae Ornamental
243.Tecoma radicans, Juss. S Ornamental
244.Tectona grandis, L. T Teak Verbenaceae Timber
245. Term/'na/is catapa. L. T Thalli Thenga Combretaceae
24B.Term/nalia be//enba, Roxb. T Thanny Sofl Wood
247.Term/‘na//a chebula, Retz. T Kadukka 1| Medicinal
.r'248.Theobroma cacao T Coco Stercullaceae Beverage
24/9.Thespesia populnea, Soland.ex..Correa T Poovarasu Malvaceae Timber
‘2/'./i0.Thevel‘ra nerifo/Ia, Juss. Sfl' Manja Arai Apocynaceae Ornnamental
251.Trema orlentelis, Blume. T Pottarriy Ulmaceae Soft Wood
252.3’/nospora cord/To//‘a, Meers. C Amruthu Menispennaceae Medicinal
 Annexure-6.2
' Exotic trees identified in the study area

Botanical name Common name Family Origin

; Acacia auricu/iformis, A.cunn.ex.Benth. Australian Wattle Leguminosae Australia
. Acacia mangium, Manjium " Australia
Achras Sapota, L. Sapota Sapotaceae Mexico
. Adenanthera pavonia, L. Manjady Leguminosae Sri Lanka
. /leg/e marme/os, L. Corr. Koovalam Rutaceae Eastern India
.Anacardium occidentale, L. Cashewnut tree Anacardiaceae Tropical America
. Anona squamosa, L. Seema Atha Anonaceae Tropical America
-. Anona reticulata, L. Seethapazham ,, Tropical America
. Anona muricata, L. Mullan Atha ,, Tropical America
. Araucaria exce/sa. Br. Christmas tree Coniferae Australia
. Araucaria cookii, Br. " ,, Australia
. Averrhoa carambo/a, L. lrimban Puly Geraniaceae Indonesia
. Averrhoa bi/imbii, L. Chemmeen puly ,, Malaysia
. Azadirachta indica, A.Juss. Aryaveppu Meliaceae Eastern Ghats
. Bauhinia vanegata, L. Chuvanna mandaram Leguminosae North west lndia
. Bauhinia purpurea, L. North west lndia
. Butea frondosa, Koen. ex Roth. Palash Leguminosae Central India
. Caesa/pinia coriana, Willd. Divi Divi ,, South America
. Ca//istemon/anceo/atus, Sweet. Bottle brush Myrtaceae
. Canca papaya, L. Papaya Passifloraoeae South America
. Cassia renigera, Wall.
. Cassia nodosa, Han.ex.Roxb.
.. Cassia
Cassiasiamea.Lamk.
javariica, L.,,,,Burma
Java
. Casuarina equisetifo/ia, G.Forst. Choola maram Casuarineae Andamans—Polynesia
. Ceiba pentandra, L.Gaertn. Panji Malvaceae Tropical America
.Couropita guianensis, Aubl Nagalingam Myrtaceae South America
" .De/onix regia. Boj.Rafin. Gulmohur Leguminosae Madagascar
..E/aeis guineensis Ennappana Palmae Africa
Eucalyptus cimodora, Hook. Eucalyptus Myrtaceae Australia
Eucalyptus g/obu/us, Labill. Australia
 [J

Ficus benjamina, L. Vellal vi South East Asia

Ficus religiosa, L. Arayal :1 South East Asia
Garcinia mangostana, L. Mangosteen Guttiferae Malaysia
G/yricidia macu/ata, H. B. K. Seemakonna Leguminosae Tropical America
Grevil/ea robusta, A.Cunn. Silver oak Proteaceae Australia
Hevea brasiliensis, Muell. Para Rubber Euphorbiaceae South America
Jacaranda mimosaefo/ia. D.Don. Neela gulmohur Leguminosae South America
Leucaena /euoocepha/a, Lamk.Benth. Subabul Leguminosae Indonesia
Manihot glaziovii, Muell. Cera—rubber South America
Mi//ingtonia hortensis, L.f. U|injiPadiri Bignoniaceae Burma
Ochroma pyramidale, Cav.ex.La Balsa Bombaceae South America
Pe/tophorum pterocarpum, D.C. Copper pod Leguminosae South East Asia
P/umen'a acutifo/ia. Poirst. Eezhachempakam Apocynaceae Tropical America
P/umena rubra, L. ‘II Tropical America
P/umeria alba, L. n Tropical America
Po/ya/lhia /ongifo/ia,Hk.f. Aranamarom Anonaceae Tropical America
Po/yallhia /ongifo/ia 'pendu|a' Drooping Asoka Tropical America
Psidium guajava, L. Pera Myrtaceae Tropical America
Pterocarpus santa/inum, L. Raktha Chandanam Leguminosae Deccan
Ravenala madagascan'ensis,Scnn »O .
.Trave|ler‘s palm Musaceae Madagascar
Sparhodea companu/ara, Beauw. Tulip ireé Bignoniaceae Tropical America
Swietenia macrophy//a Mahogany Meliaceae Tropical America
Swietenia mahogany Tropical America
Tamarindus indica, L. Valan Puly Leguminosae Tropical Africa
Tecoma stans, Juss. Bignoniaceae Central America
Terminalia catapa, L. Thalli Thenga Combretaceae Andamans
Theobroma cacao Coco Sterculiaceae Tropical America
Zyzygium aromaticum, L. Mer Grampoo Myrtaceae Africa
 ANNEXURE — 7
ABBREVIATIONS AND SYMBOLS

PERCENT
°C DEGREE CENTIGRADE
A.D. ANNO DOMINI
ARKDV ARKKAKADAVU

Avg. AVERAGE
BP BEFORE PRESENT
BPCL BHARAT PETROLEUM CORPORATION LIMITED
BZL BINANI ZINC LIMITED
C.B.D. CENTRAL BUSINESS DISTRICT
C.E.P.Z.­ COCHIN ExPORT PROCESSING ZONE .
C.L.Rd CHURCH LANDING ROAD
C.P.T COCHIN PORT TRUST
C.R.L. COCHIN REFINERIES LIMITED
CGWB CENTRAL GROUND wATER BOARD

cm.
CENTIMETER
C0. COMPANY
C02 CARBON DI OXIDE
D.L.E!. DOCK LABOUR BOARD
dB DECIBELL
DDD DICHLORO DIPHENYL DICHLORO ETHANE
DDE DICHLORO DIPHENYL DICHLORO ETHYLENE
DDT DICHLORO DIPHENYL TRICHLOROETHANE
DIVN. DIVISION
EAST
E.|.A. ENVIRONMENTAL IMPACT ANALYSIS
E.S.|. EMPLOYEE'S STATE INSURANCE
BIC. ET CETERA
eg. EXAMPLE
EKM ERNAKULAM
F.A.C.T. FERTILIZERS AND CHEMICALS TRAVANCORE LIMITED
F.E.D.O. ­ FACT ENGINEERING AND DESIGN OEGANISATION
Fig. FIGURE
g. GRAM
G.C.D.A ­ GREATER COCHIN DEVELOPMENT AUTHORITY
G.House ­ GUEST HOUSE
H.l.L HINDUSTAN INSECTICIDES LIMITED
ha. HECTARE
HOC HINDUSTAN ORGANIC CHEMICALS
HPCL HINDUSTAN PETROLEUM CORPORATION LIMITED
 HOUR
Ht HEIGHT
Le. THAT Is
'_S.T_ INDIAN sTANDARD TIME
IAC INDIAN ALUMINIUM COMPANY
|D.B.| INDUsTRIAL DEVELOPMENT BANK OF INDIA
INS INDIAN NAVAL SHIP
IPCC INTERNATIONAL PANEL I=OR CLIMATIC CHANGE
IRPNM IRIMPANAM
K.S.P.C.B­ KEHALA sTATE POLLUTION CONTROL BOARD
kcal. KILO CALORIES
KDRA KADAVANTHARA

K9 KILOGRAM
KGCFIA KARINGACHIRA
K|NCO­ KERALA INLAND NAVIGATION CORPORATION
Km ­ KILOMETRE
KMPH ­ KILOMETER PER HOUR
KSIDC I<ERALA sTATE INDUsTRIAL DEVELOPMENT CORPORATION
KTKVD KATHRIKADAVU
KUDP KERALA URBAN DEVELOPMENT PROJECT
KWBSP I<UT_TANAD wATER BALANCE STUDY PROJECT
LAT. LATITUDE
LIC LIFE INSURANCE CORPORATION
LON .­ LONGITUDE
Ipcd LITREs PER CAPITA PER DAY
Ltd LIMITED
rn METRE
M.E,S MILITARY ENGINEERING sERvICE
M.G.FIOAD­ MAHATMA GANDHI ROAD
M.L.ArCh. ­ MASTER OF LANDSCAPE ARCHITECTURE
M.S.L MEAN SEA LEVEL
m.I CUBIC METRE
m°/s ­ CUBIC METRE PER sECOND
mb MILLI BARS
M9 MICROGRAM
mg. MILLIGRAM
min. MINUTE
mm MILLIMETRE
MVPA MUV_A1'rUPUzHA
MYEIP MILLION YEAFIS BEFORE PREsENT
NORTH
N.E.E.R.I­ NATIONAL ENVIRONMENTAL ENGINEERING RESEARCH INSTITUTE
N.H ­ NATIONAL HIGHWAY
N.|_O. ­ NATIONAL INSTITUTE OF OCEANOGRAPHY
N.W. ­ NORTHWEST
NEPA ­ NATIONAL ENVIRONMENTAL POLICY ACT
NH3 ­ AMMONIA

N02 ­ NITROUS OXIDE

N-o: ­ NUMBER
NPOL ­ NAVAL PHYSICAL AND OCEANOGRAPHIC LABORATORY
P&T ­ POST AND TELEGRAPH
P.M. ­ POST MERIDIAN
P_W.D. ­ PUBLIC WORKS DEPARTMENT
PH- ­ NEGATIVE LOGARITHM OF THE HYDROGEN ION CONCENTRATION
Ph.D. ­ DOCTOR OF PHILOSOPHY
PLPDY ­ PULLEPPADY
PLVTM ­ PALARIVATTOM
Qrts. — OUARTERS
R.C.C ­ REINFORCED CEMENT CONCRETE
Rd. ­ ROAD

Rlwy ­ RAILWAY
SOUTH
SECOND
S.A. Rd ­ SAHODARAN AYYAPPAN ROAD
S_B_| ­ STATE BANK OF INDIA
S.E. ­ SOUTHEAST
S_W. ­ SOUTHWEST
SAIL I STEEL AUTHORITY OF INDIA
SO2 ­ SULPHUR DIOXIDE
Sp. SPECIES
Sq km ­ SQUARE KILOMETRES
Sm ­ STATION
Sy. SURVEY
T.C.C ­ TRAVANCORE COCHIN CHEMICALS
T.C.P.O ­ TOWN AND COUNTRY PLANNING ORGANISATION
T.P. Canal­ THEVARA-PERANDOOR CANAL
TDYR ­ THUDIYUR
TE — TELEPHONE EXCHANGE
TMNM TI-IAMMANAM
TP RA ~ THRIPUNITHURA
TVKM ­ THIRUVAMKULAM
U.S.A ­ UNITED STATES OF AMERICA
Var. ­ VARIETY
Viz. ­ NAMELY
W_ WEST
W.ISLAND­ WILLINGDON ISLAND
253. Ty/ophora asthmalba, Wight. Valiippala Asclepladaceae Medicinal
254.Uvar/a narum, Dunne. Narumpanal
255. V/"fer/"a ind/"ca. L. Pine Dipterocarpaceae Soil Wood
256.V/'nca roses, L. Ushamalari Apocynaceae Medicinal
257.‘.//nca a/ba, L. Medicinal
258.V/tex negundo. L. Karunechi Verbenaceae Medicinal
259.Xy/Ia xy/ocarpa, Roxb.Taub. iru Muliu Timber
260.Zyz/phus jujuba, L. Ilianihapazham Rhamnaceae Fire Wood
261.Zyzygr'um aromaticum, L. Mer . -|—l-imU)</J-4070

Grampoo Myriaceae Spice

6 ?482.