Review presentation on

The performance of hydrological models for evaluating

hydrological responses in relation to climate change

By
Yilak Taye (Student)

Seminar Advisors
Bogale Gebremariam Neka (Dr.Ing)
Tarun Kumar Lohani (Professor)

December| 2023
Presentation outline

 Introduction

 Future hydrological responses due to climate

 Types of hydrological model

 Performances of some models (single)

 Comparisons of performances some models

 Conclusion
 INTRODUCTION

 Water is essential, limited, recycled, spatial and temporal varied

resources, and subject to change with external factors

 Planners, policymakers, and managers need to know the amount of

hydrological components

 Hydrological model is needed to estimate the water availability at

the relevant location and at the necessary time

 The ideal model is one that uses the fewest parameters and the least
amount of model complexity while producing results that are very
similar to reality
 Effect of climate on the catchments Hydrology response

 The stream flow at current and at the future time is the cumulative and
complex interlinking effect of different factors
Population size
LULC
Climate change Watershed management

Water Abstraction
Policy of the country
Others
Awareness of people
 High Evaporation
Cont…
 Climate change is one of the hydrological cycle affecting factor,
which has gained attention in recent years

 Significant effects of climate change will be felt, especially in Dry season flow
decrease
developing nations where agriculture plays a major economic role

 Currently, there are many climate effects based studies on

hydrological study including Ethiopia.

 Most of the findings of the future hydrology due to climate is rise

of temperature; high evaporation and evapotranspiration,
decreasing of dry season flow, and High flood.
High flood
Annual maximum temperature change

 Temperatures will change by almost zero in the Dhidessa watershed in the upper Blue
Nile river basin up to 8.2 °C in the Wabishebele River basin.

 Though the magnitude of variation varied with authors, the trend is nearly consistence
(Tekeze and Omo-Gibe)
9 8.2
Change in Tmax(℃)

0.3
0

b ay bay bay bay ash eze awa aro a sh m

2 ele an a
eze i be i b e
aro lley lley lley
awa
/ A a/A l A / A Aw ek -D B
Aw 2 K h eb ak ek o-G o-G B va t va t va e D
a e h T e / 3 s T t
ch hes
s
i lg g ec na
l
et a
1 ,0 a b i a W
Om Om
Ri f
Rif Rif n al
i n e e l 6 elk e/ o/ o/ e/ e
F i d G
M G Ke sh/ r W b b b t i / G
D h a pe M
W
a
i da i da Bila d ot
w p
Watershed/Basin A U G G Ya
RCP4.5/Near Future RCP8.5/Near future RCP4.5/Mid future RCP8.5/Mid future
 Annual precipitation/rainfall

 The yearly rainfall indicate an inconsistent pattern going forward such as the increase in
Awash River basin, while they will drop in other areas, such as the Gidabo and Bilate
rivers of the Rift Valley Lake Basin. 56
Change in rain fall(%)

60

40

20

b a y
b a y
ba y
ba y
a sh eze wa aro ash m2 ele ana eze ibe ibe aro lley lley lley wa
-20 A A lA A Aw e k a B w 2K he b a k e k - G - G B va a a a
/ / / - D A T mo mo v v D
h a ssa lge ech T
a l e t a /
,0 3
b is W i f t i f t i f t
a le
i nc-40 dhe Gi e g e n e l e / 61 a l ka O
e / O
o / R
o / R
e / R e n
F hi M G K ash er W e b b b ti /G
M a a a l a t
D
-60 w pp W G
id
G
i d Bi a do
A U Y
-80 Watershed
RCP4.5/Near Future RCP8.5/Near future RCP4.5/Mid future RCP8.5/Mid future
-86.3
-100
Annual stream flow

 The same trend with precipitation, annual stream also show different trends.

 The Awash River basin may see a 191% rise in stream flow and will cause flooding
problems, whereas the Gidabo River may see a 43%
250
200 191
Change in stream flow(%)

150
100
50
0
y y y y h e a ro h 2 ele na ze be be ro ey ey ey a
-50 ba ba ba ba as k ez aw a as m b a k e i i a ll ll ll aw
/A a/A l A ch/A w
Te D B w 2K ishe ak e -G -G B va va va eD
-100 h a ss g e A
ale- ta/A
0 3 b W T
m
o
m
o
ift ift ift
al
il e 1, a
inc d he G eg en ele /6 W
a
elk O e /O o /R o /R i e/R en
F i M G K ab ab ab t t/G
D
h as
h
p er M id id ila o
w p W G G B a d
A U Y
Watershed/ Area
RCP4.5/Near Future RCP8.5/Near future RCP4.5/Mid future RCP8.5/Mid future
Reviews summary regarding to climate impact
 The hydrological response due to climate is a complex, and also certainty is difficult.

 The variation in the estimation could be caused by various factors, including different
hydrological model types, different amounts of input data, different global climate
models, different calibration approaches used by different authors, and other factors this
review has not observed.

 Therefore, before any planning, policy-making, or development of water resources for

any given watershed, a climate impact assessment for future hydrology should be
conducted
 ! ! !
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