Snow & Glacier Monitoring in Himalaya 2011

Snow and Glaciers of the Himalayas Study Carried out under the joint project of Ministry of Environment and Forests and Department of Space Government of India Space Applications Centre Ahmedabad - 380 015 May 2011 ISBN 13 978-81-909978-7-4 Vɪ É®ú É̈ É ®ú̈Éä ¶É ®ú ÉVª É ¨ ÉÆ j ÉÒ ( º ´Éi ÉÆ j É |ɦ ÉÉ®ú ) JAIRAM RAMESH {ɪ ÉÉḈÉ®ú hÉ B´ÉÆ´ÉxÉ ¦ ÉÉ®ú i É º É®ú EòÉ®ú xÉ<ÇÊnù ±±ÉÒ -110003 MINISTER OF STATE (INDEPENDENT CHARGE) ENVIRONMENT & FORESTS GOVERNMENT OF INDIA NEW DELHI - 110 003 FOREWORD Snow and glaciers are vital to human beings - they play a critical role in making our rivers perennial, controlling global climate and in view of our contemporary concerns, they serve as a sensitive indicator to change in our climate. However, we must remember that this source of water is not permanent as glacial dimensions change with climate. Therefore we need information that is deeply rooted in science, to understand future changes in the Himalayan snow and glacier covers and its influence on stream runoff. The inaccessible terrains and the harsh climate prevailing in the Himalayas makes the task of data collection extremely difficult, therefore, space based monitoring of these resources has been found to be an extremely viable and useful alternative. In view of the importance of the information on snow and glaciers, the Ministry of Environment and Forests has entrusted a study on inventory and monitoring of these natural resources in the Indian Himalaya to the Space Applications Centre (SAC), ISRO, Ahmedabad. This voluminous and important task has been successfully completed in four years by the Space Applications Centre along with 14 organizations of the country and the findings of the study is presented in this report. Snow cover has been monitored regularly for the- entire Indian Himalaya from 2004-05 to 2007-08. As per this inventory there are 32,392 glaciers in the Indus, Ganga and Brahmaputra basins draining into India. India alone, has 16,627 glaciers which covers an area of 40,563 sq. km. For the first time an inventory of such a magnitude has been accomplished using recently available satellite data. It is a task of great significance, that more than 2,500 glaciers have been monitored to estimate glacial advance and retreat. The snow line has been monitored for about one thousand Himalayan glaciers. I am delighted to introduce this Report to the scientific community, environmentalists and natural resources managers. I congratulate the team of scientists led by Dr. Ajai for successfully carrying out this important study covering entire Indian Himalaya. I am sure this report will be highly useful not only to scientific community but to the nation as a whole. 16th December, 2010 Snow and Glaciers of the Himalayas (Jairam Ramesh) .i. Space Applications Centre ISRO, Ahmedabad Government of India Department of Space SPACE APPLICATIONS CENTRE Ambawadi Vistar P.O. Ahmedabad - 380 015 (India) Telephone : 079-26761188, 26740256 Fax : 079-26765410, 26767708 ¦ ÉÉ®ú i É º É®ú EòÉ®ú + Æ i ÉÊ®ú I É Ếɦ ÉÉMÉ + Æ i ÉÊ®ú I É = {ɪ ÉÉä MÉ Eä òxpù + ÉÆ ¤ÉÉ́ÉÉb ÷ Ò Ếɺ i ÉÉ®úb ÷ ÉEò PÉ®ú , + ½þ̈Énù ɤÉÉnù : 380 015 ( ¦ ÉÉ®ú i É) nÚ ù ®ú ¦ ÉÉ¹É : 079-26761188, 26740256 ú ¡è òCº É : 079-26765410, 26767708 Rangnath R. Navalgund Director Preface Himalayan mountains contain important natural resources of frozen fresh water in the form of snow and glaciers. These glaciers are unique as they are located in tropics, high altitude regions, predominantly valley type and many are covered with debris. The great northern plains of India sustain on the perennial melt of snow and glaciers meeting the water requirements of agriculture, industries, domestic sector even in the months of summer when large tracts of the country go dry. Therefore, it is important to monitor and assess the state of snow and glaciers and to know the sustainability of glaciers in view of changing global scenarios of climate and water security of the nation. Any information pertaining to Himalayan glaciers is normally difficult to be obtained by conventional means due to its harsh weather and rugged terrains. Space Applications Centre (SAC) has been contributing to the development of methods/techniques for extraction and dissemination of reliable and quick information from remote sensing data pertaining to snow and glaciers of the Himalayas. The Centre has been instrumental in developing remote sensing based techniques, models and methods to generate a large amount of digital database and maps to understand the state of Himalayan cryosphere. This work has now assumed greater significance when the nation needs to address a large number of questions about the health and state of glaciers. There is no contemporary technique which provides this information to the nation in a very short span of time, and for a large number of glaciers occurring in inaccessible regions. A national project on “Snow and Glacier Studies” was taken up by the Space Applications Centre and executed in collaboration with 14 research organizations and academic institutions of the country, at the behest of the Ministry of Environment and Forests, Govt. of India. Snow cover for the entire Indian Himalaya has been monitored for four consecutive years starting from 2004 - 05. Inventory of the glaciers carried out on 1:50,000 scale reveals the total number of glaciers to be 32392 with a total glaciated area of 71182 sq. km. More than two thousand glaciers have been monitored to study the advance/retreat of their extent. Glacier mass balance, based on Accumulation Area Ratio method, as derived from satellite images, has also been studied. I compliment the entire team of scientists from both ISRO and other organizations for carrying out this task diligently. I do hope, the findings of the project presented in this document will be of interest and use to the researchers working in the field of environment, glaciology, hydrology and climate change. Ahmedabad July 9, 2010 Snow and Glaciers of the Himalayas (R. R. Navalgund) .ii. Space Applications Centre ISRO, Ahmedabad Government of India Department of Space SPACE APPLICATIONS CENTRE Ambawadi Vistar P.O. Ahmedabad - 380 015 (India) Telephone : 079-26761188, 26740256 Fax : 079-26765410, 26767708 ¦ ÉÉ®ú i É º É®ú EòÉ®ú + Æ i ÉÊ®ú I É Ếɦ ÉÉMÉ + Æ i ÉÊ®ú I É = {ɪ ÉÉä MÉ Eä òxpù + ÉÆ ¤ÉÉ́ÉÉb ÷ Ò Ếɺ i ÉÉ®úb ÷ ÉEò PÉ®ú , + ½þ̈Énù ɤÉÉnù : 380 015 ( ¦ ÉÉ®ú i É) nÚ ù ®ú ¦ ÉÉ¹É : 079-26761188, 26740256 ú ¡è òCº É : 079-26765410, 26767708 Dr. Ajai Group Director Marine Geo and Planetary Sciences Group Aknowledgement The Himalayas has one of the largest concentrations of glaciers outside the polar regions. Himalayan glaciers in the Indian subcontinent are broadly divided in to three river basins, namely, Indus, Ganga and Brahmaputra. These glaciers are important source of fresh water for northern Indian rivers and water reservoirs. For water resources planning and management in North-India, it is essential to study and monitor Himalayan glacier & snow cover. More ever the glaciers are important indicators of climate change. Space Applications Centre (SAC) has developed techniques for mapping and monitoring of Himalayan glaciers using satellite data. In view of the above, Ministry of Environment and Forests (MoEF), Govt. of India has identified mapping and monitoring of Himalayan glaciers and snow cover as one of the thrust area under standing committee on Bio-resources and environment (SC-B), NNRMS. Thus a project on “Snow and Glacier studies” was taken up by Space Applications Centre at the behest of MoEF with joint funding by DOS and MoEF. The present report is the final technical report of this project which has been executed by SAC in collaboration with 14 research organizations and academic institutions of the country. We would like to place on record our deep sense of gratitude to Dr. R.R. Navalgund, Director, SAC for his encouragement and guidance in carrying out this national project. We express our thanks to the Director’s and Scientific team of each of the collaborating agencies for their valuable contributions in carrying out the project. We are thankful to Dr. V.S. Hegde, Scientific Secretary ISRO and Director, EOS and Dr. J.S. Parihar, Dy. Director, RESA, SAC and Dr. K. Ganesh Raj, Dy. Director (Applications), ISRO H.Q., for their support and help. We are very much thankful to Dr. G.V. Subrahmanian, Advisor, Dr. Jag Ram, Director and Dr. Harendra Kharakwal, Scientist, MoEF for their continuous support in executing this project. Secretarial support provided by Mr. KDM Menon and Ms. Shweta Solanki, MESG, SAC is thankfully acknowledged. Ahmedabad May 25, 2010 Snow and Glaciers of the Himalayas (Ajai) .iii. Space Applications Centre ISRO, Ahmedabad May 258 Marine Geo and Planetary Sciences Group, EPSA Space Applications Centre (ISRO), Ahmedabad - 380015 fifteen General Snow and Glaciers of the Himalayas .v. Space Applications Centre ISRO, Ahmedabad Content............................................... Page No. 1. Introduction 1 2. Objectives and Study Area 3 3. Methodology 6 4. Snow cover monitoring 64 5. Glacier inventory 79 6. Monitoring changes in glacier extent 97 7. Glacier mass balance 122 8. References 137 Annexure I : Maps of snow cover 139 Annexure II : Maps of Glacier Inventory 203 Annexure III : Maps showing Retreat/Advance of Glacier 237 Annexure IV : Images showing Snow line fluctuations 253 Snow and Glaciers of the Himalayas .vi. Space Applications Centre ISRO, Ahmedabad 1. Introduction Today there are about 30 million cubic km of ice on our planet and cover an almost 10 percent of the World's land area. In addition, during northern hemispherical winter, snow covers almost 66 per cent of land cover. In the Himalayas, the glaciers cover approximately 33,000 sq km area and this is one of the largest concentrations of glacier-stored water outside the Polar Regions. Melt water from these glaciers forms an important source of run-off into the North Indian rivers during critical summer months. However, this source of water is not permanent as geological history of the earth indicates that glacial dimensions are constantly changing with changing climate. During Pleistocene the earth's surface has experienced repeated glaciation over a large landmass. The maximum area during the peak of glaciation was 46 Million sq km. This is three times more than the present ice cover of the earth. Available data indicates that during the Pleistocene the earth has experienced four or five glaciation periods separated by an interglacial periods. During an interglacial period climate was warmer and deglaciation occurred on a large scale. This suggests that glaciers are constantly changing with time and these changes can profoundly affect the runoff of Himalayan rivers. This change in glaciers can be further accelerated due to green house effect and due to man-made changes in the earth's environment. Therefore, a proper understanding of glaciers is necessary. In view of the above, a joint program of DOS and MoEF was undertaken for snow and glacial investigations. NNRMS Standing Committee on bio-resources in its meeting on Jan 21, 2003 has identified four major thrust areas namely 1) Forest type mapping on 1:12500 scale; (ii) Mapping of wildlife sanctuaries and national parks on 1:12500 scale; (iii) Coastal studies (including mangroves and coral reefs) and (iv) Snow and glaciers for taking up during the 10th five year plan in view of the recommendations of the peer review committee of remote sensing and GIS applications in the area of Environment and Forest. In view of above the Ministry of Environment and Forest, Government of India has constituted four task teams Snow and Glaciers of the Himalayas .1. Space Applications Centre ISRO, Ahmedabad for each of the above-mentioned themes. The task teams have been given the mandates to identify the priority areas for detailed investigations and also to prepare detailed documents / project proposals highlighting the methodology, data, manpower, equipment requirement, study areas, project execution plans, time frame, budget requirement, output result and expected end-use etc. Accordingly the task team on 'Snow and Glaciers' had a brainstorming meeting on May 7, 2003 at Space Applications Centre, Ahmedabad. Subsequently, detail project proposal was prepared and submitted to Ministry of Environment and Forests. This proposal was discussed in detail during National level one-day workshop on August 6, 2004 at Space Applications Centre, Ahmedabad. Based on this, the project was sanctioned by Ministry of Environment and Forests on March 28, 2005. Details of the findings of the above study on ‘snow and glaciers of the Himalayas’ carried out under the joint project of Ministry of Environment and Forests and Department of Space are given in this volume. Snow and Glaciers of the Himalayas .2. Space Applications Centre ISRO, Ahmedabad 2. Objectives and Study Area Snow Cover Monitoring: To map and monitor seasonal snow cover of the Himalayas from year 2004-05 to 2007-08. Snow cover maps at an interval of 5 and 10 days were prepared for 33 sub-basins of Himalayas. The sub-basins identified for snow cover monitoring are given in Table 1. Table 1: Sub-basins for snow cover monitoring S. No. Basin Sub-basins 1 Ganga Alaknanda, Bhagirathi, Yamuna 2 Satluj Spiti, Pin, Baspa, Jiwa, Parbati, Beas 3 Chenab 4 Indus Ravi, Chandra, Bhaga, Miyar, Bhut, Warwan Jhelum, Kishanganga, Astor, Suru, Dras, Shigo, Zaskar Nubra, Shyok, Hanza, Gilgit, Shasgan, Shigar 5 Brahmaputra Tista, Rangit, Tawang, Dibang and Subansiri Glacier Inventory: To carry out systematic inventory of the glaciers occurring in the Indus, Ganga and the Brahmaputra basins and draining into India by using Indian Remote Sensing Satellite data for the period 2004-2007. The area covered under glacier inventory is shown in figure 1. STUDY AREA N Figure 1: Study area for Glacier Inventory Snow and Glaciers of the Himalayas .3. Space Applications Centre ISRO, Ahmedabad The study area comprises of glaciated sub-basins of Indus, Ganga and Brahmaputra river basins. The three rivers are mighty rivers that are originating from the glaciated Himalayan region where these rivers are fed by seasonal snow and glacier melt water. The Indus river originates in the Tibetan plateau near Lake Mansarovar and Mount Kailash and flow westward, south of Karakoram range and north of the Great Himalayas to Mt. Naga Parbat where it turns sharply to the south flowing through Pakistan into the Arabian sea near Karachi after traveling for 2880 km. In India the length of Indus river is 1114 km. The Ganga river originates from the Gangotri Glacier where it is known as Bhagirathi which is joined by Alaknanda at Deoprayag and combined together it is called as Ganga. The total length of the river is about 2525 km. The Brahmaputra river (Yalu Zangbu or Tsang po) rises in the glacier of the Kailash range, just south of the Lake Konggyu Tsho in Tibet. The Brahmaputra with a length of 2880 km ranks amongst the longest rivers of the world. It traverses its first 1625 km in Tibet, 918 km in India and the remaining 337 km in Bangladesh before it drains into the Bay of Bengal. The average width of Brahmaputra valley is about 86 km of which the river itself occupies 15-19 km. The Brahmaputra river system drains almost the entire eastern Himalaya. Middle and lower Himalayan hills account for the central part of this basin. In the Indian part very heavy rainfall is received in the entire Brahmaputra basin from early June to early September. Winters are very cold and snowfall occurs in the higher reaches. Dense evergreen and semi-evergreen forests are found along the Brahmaputra river in its course through Indian territory. Glacier Monitoring: To monitor advance/retreat of Himalayan glaciers in selected sub-basins in Jammu and Kashmir, Himachal Pradesh, Uttarakhand and Sikkim. The list of basins for monitoring glacial advance/retreat is given in Table 2. Table 2: List of basins used for glacial monitoring Basins Chandra Bhaga Warwan Bhut Miyar Alaknanda Bhagirathi Dhauliganga Suru Zaskar Parbati Baspa Sptiti Nubra Snow and Glaciers of the Himalayas .4. Space Applications Centre ISRO, Ahmedabad Mass Balance Estimation: To estimate mass balance based on accumulation area ratio method for glaciers of selected sub-basins and mass balance using glaciological method for selected glaciers. List of basins is given in Table 3. Table 3 List of basins used for glacier mass balance Basins Chandra Bhaga Warwan Bhut Miyar Alaknanda Bhagirathi Dhauliganga Suru Zaskar Snow and Glaciers of the Himalayas .5. Space Applications Centre ISRO, Ahmedabad 3. Methodolgy 3.1 Snow Cover Monitoring The AWiFS data of Resourcesat satellite was analyzed to estimate snow extent. The snow cover was monitored for a period between October and June for 4 years from year 2004-05. A total 1500 AWiFS scenes were analyzed. Snow cover was not monitored during June-September due to cloud cover. To generate snow cover products, initially master template was prepared using control points from 1:250,000 scale maps and then basin boundaries were delineated using drainage map. The master template was used for registration of all satellite data. Then algorithm based on Normalized Difference Snow Index (NDSI) was used to map snow cover (Kulkarni et al, 2006). NDSI was calculated using the ratio of green (band 2) and SWIR (band 5) channel of AWiFS sensor. NDSI is established using following method as given in equation 1. Normalized Difference Snow Index( NDSI ) = (band 2 − band 5) /(band 2 + band 5) ...(1) To estimate NDSI, DN numbers were converted into top-of-atmosphere (TOA) reflectance. This involves conversion of digital numbers into the radiance values, known as sensor calibration, and then reflectance was estimated. The various parameters as maximum and minimum radiances, mean solar exo-atmospheric spectral irradiances in the satellite sensor bands, satellite data acquisition time, solar declination, solar zenith and solar azimuth angles, mean Earth-Sun distance was used to estimate reflectance (Markham and Barker, 1987; Srinivasulu and Kulkarni, 2004). Sensitivity analysis has shown that a NDSI value of 0.4 can be taken as a threshold to differentiate between snow and non-snow pixels. Exoatmospheric reflectance of band 2 and band 5 of AWiFS sensor were used to compute the NDSI and no atmospheric correction has been applied at present. Field investigations have suggested that NDSI values are independent of illumination conditions i.e. snow/non-snow pixels can be identified under Snow and Glaciers of the Himalayas .6. Space Applications Centre ISRO, Ahmedabad different slopes and orientations, even under mountain shadow region (Kulkarni et. al., 2006). The flow diagram of NDSI based algorithm is given in Figure 2. Validation of snow cover mapping algorithm was carried out in Beas basin. Three locations were selected in Beas basin and respective GPS locations were taken. Total 69 AWiFS scenes were processed from December 2003 to October 2005. Each pixel was classified as completely snow covered or snow free. Out of 207 points, 73 points were excluded due to presence of ice cloud which gives similar signature of snow and removed from final validation exercise. 132 out of 134 points were correctly classified as snow/non-snow pixels (Table 4). Table 4: Validation of NDSI to detect snow pixels Sr. No. Validation points Nos. 1 Match 132 2 Unmatched 2 3 Excluded due to cloud 73 Total 207 Snow and Glaciers of the Himalayas .7. Space Applications Centre ISRO, Ahmedabad AWiFS B2 AND B5 Reflectance image NDSI IMAGE > 0.4 Snow + Water < 0.4 >0 Cloud Pixel <0 Other Pixel N-5 days AWiFS B2 and B5 AWiFS B4 NDSI IMAGE Reflectance Image AWiFS B4 Snow NonSnow Water pixel N+5 days Snow AWiFS B4 SNOW AND CLOUD MAP Snow NDSI IMAGE Basin Mask 10-DAILY BASIN -WISE MAXIMUM SNOW Non - snow COVER Figure 2: Algorithm for snow cover mapping using AWiFS data Snow and Glaciers of the Himalayas .8. Space Applications Centre ISRO, Ahmedabad In second method for validation of snow products, an area around Beas basin was selected. AWiFS data of 1 September 2005 was used to classify the region into 3 classes as snow or ice, barren land or soil and vegetation, when most of the area was snow free. ISODATA technique was used for classification. Then to estimate accuracy of snow products, satellite imagery of 26 February 2006 was selected, when region was completely snow covered. This assessment was made based on field observations on snow fall. The snow product suggests an error less than 1% for all three classes. However, this error will significantly increase, if region is covered by ice clouds. Many times ice clouds have similar signature as snow and corresponding pixels can be misclassified. This can significantly add error to final results. For example, in Parbati river basin in Himachal Pradesh in the year 2004-05 in 18 out of 58 scenes, clouds were misclassified as snow. The present algorithm, due to lack of thermal band in AWiFS, has little potential to correct this problem. Therefore, satellite data were checked manually after geocoding and scenes were rejected if ice clouds were observed in the basin area. Manual separation between snow and ice cloud is possible due to textural differences (Kulkarni and Rathore, 2003). Another possible source of error in snow areal extent is identification and mapping of snow under mixed pixel category. To understand influence of mixed pixels due to vegetation and soil, spectral reflectance studies were carried out in the Himalaya. The studies were carried out at Dhundi observatory of Snow and Avalanche study Establishment, Manali. A field photograph taken during observations is given in Figure 3. Snow and Glaciers of the Himalayas .9. Space Applications Centre ISRO, Ahmedabad Figure 3: A field photograph showing spectral reflectance observations Snow extent is estimated at an interval of 5 and 10 days, depending upon availability of AWiFS data. Cloud over snow covered region is a critical issue and it can introduce significant errors. In 10-daily product, three scenes are analyzed depending on its availability. For example, for 10 March product data of 5, 10 and 15 March were used. If any pixel is identified as snow on any one date then it was classified as snow on final product. If three consecutive scenes are not available, then all available scenes in the 10-day window were used in the analysis. This will be used to generate basin-wise 10-daily product information and is expected to have at least one scene under cloud free condition for each pixel. In the present algorithm, water bodies are marked in pre-winter season and masked in the final products during winter, as discrimination of snow and water is difficult using reflectance due to mountain shadow. This procedure was modified in Sikkim, due to extensive cloud cover. Cloud free images was difficult to get, therefore, two consecutive images were used to make composite product. Snow and Glaciers of the Himalayas .10. Space Applications Centre ISRO, Ahmedabad 3.2 Glacier Inventory The main aim of this work is to generate a glacier morphological map using multi temporal IRS LISS III and ancillary data. Specific measurements of mapped glacier features are the inputs for generating the glacier inventory data sheet (Annexure-1) with 37 parameters as per the UNESCO/TTS format and 11 additional parameters associated with the de-glaciated valley. The data sheet provides glacier wise details for each glacier on the significant glacier parameters like morphology, dimensions, orientation, elevation, etc. for both the active glacier component as well as the associated de-glaciated valley features. Mainly these comprise glacier identification in terms of number and name, glacier location in terms of coordinate details, information on the elevation above mean sea level, measurements of dimensions like length width of ablation and orientation etc. of glacier. A table showing statistics summarizing the essential glacier features is then generated. The sub-basin wise glacier inventory summary statistics provides a means to compare the glacier characteristics among the glaciated sub-basins. Analysis of inventory data is carried out to understand the broad distribution of glaciers across various sub-basins. Critically analyzed glacier inventory data can provide an insight to the behavior as well as the overall health of glaciers and the glaciated basins. For this each of the glacier features is studied independently as well as in conjunction with other associated glacier features. The glacier features of significance that are studied and analyzed are the accumulation area, ablation area (both ice exposed and debris covered), supra-glacier lakes, snout or terminus, deglaciated valley and moraine dam lake. The analysis is carried out mainly in terms the glacier dimension, elevation, orientation, association, etc. The accumulation and ablation areas of glaciers are susceptible to subtle changes in atmospheric variability. These changes can put glaciers in changed environment which results in retreat/advance or thinning/thickening of glacier. This will depend on the response time of glacier which is a function of glacier geometry and other factors. Snow and Glaciers of the Himalayas .11. Space Applications Centre ISRO, Ahmedabad The relative size of various glacier features is significant as it indicates the characteristics of glacier in a given basin. As compared to large glaciers the smaller glaciers are relatively more prone to rapid melting depending on position and orientation of the glacier valley. The number and size of lakes particularly the moraine dam lakes and supra-glacier lakes indicate the glacier melt pattern in the glacier sub-basins. The information on such lakes is important as it indicates the possible hazard due to sudden breach or bursting of such lake dams. Similarly the de-glaciated valley number and size are also indicators of past glacier melt patterns among the sub-basins. Description of each of these glacial features and its significance in glacial studies is given below; Accumulation area The region where snow falls on a glacier more commonly on a snowfield or cirque and where the glacier ice accumulates by the precipitation of snow and other forms of ice at the glacier surface is the accumulation area. The most important primary source of ice on most glaciers is snowfall, although amounts vary a great deal from place to place and throughout the year. On a more local scale, accumulation rates are strongly influenced by redistribution processes such as wind-blowing or avalanching. In accumulation area winter snowfall is more than summer ablation and is characterized by snow with high reflectance in visible and NIR region of electromagnetic spectrum. The accumulation area is significant glacier feature that indicates that the snow feed received is accumulated over a period of time and is not getting melted across seasons. The variation of accumulation area over time indicates the melt pattern of glaciers. The ratio of accumulation area and total area of a glacier when measured over a period of time is useful for estimating the variation in mass balance of glacier. Ablation area The region of a glacier where more glacier mass is lost by melting or sublimation than is gained is called as the ablation area. In ablation area the loss from a glacier ice could be due to wind ablation, avalanching, calving into water, melting, etc. Snow and Glaciers of the Himalayas .12. Space Applications Centre ISRO, Ahmedabad Melting is the dominant process of ablation on many glaciers specially if the temperature exceeds 0 degree C for a part of year. This process looses winter snow accumulation, therefore, glacier ice gets exposed and has lower reflectance in visible and NIR region giving green-white tone on False Colour Composite (FCC) which can easily be differentiated from the accumulation area. The information on ablation area is significant as it indicates the area that is exposed to active seasonal ablation effect. The glacier ice in the ablation area is believed to be relatively protected from effective melting if it is covered by a layer of debris. The exposed ice on glacier in ablation area is prone to more rapid melting as compared to glacier ice in debris covered ablation area. De-glaciated valley The de-glaciated valley is one of the indicators of retreat of valley glaciers by vacating the valleys in lower reaches beyond the snout region. The dimensions of the de-glaciated valley and the elevation at which these occur along with the various types of moraines are significant in glacial studies related to the glacier retreat pattern. Moraine dam lakes The water bodies or glacial lakes are formed due to accumulation of glacier melt water at the lower elevation of the glaciers in the de-glaciated valleys and are still associated with the glacier. In majority of the cases the water bodies are resultant from the dam effect due to moraines. The moraine dam lakes are prone to dam bursts and sudden breaches leading to flooding in downstream areas. Glacieret and snow fields The small glaciers that cannot be morphologically further divided and the snow fields that occur in two consecutive years of satellite data are classified as glacieret and snow fields. Snow cover throughout the year and perennially under the snow covers these areas. Such areas can be mapped at the end of hydrologic year, when seasonal snow cover is fully melted. However, some confusion can arise if amount of seasonal snowfall is abnormally higher for a year. Then it can lead to mapping of seasonal snow cover into this category. To avoid this confusion, multi-year satellite images to be used for permanent snow mapping. Snow and Glaciers of the Himalayas .13. Space Applications Centre ISRO, Ahmedabad 3.2.1 Methodology for generation of Glacier Inventory Maps and datasheets Geocoded IRS LISS III data on 1:50,000 scale, from period July to end of September for the glacier inventory seasons is procured in the form of FCC paper prints and digital format. The hard copy geocoded FCC's of standard band combination such as 2 (0.52-0.59 µ), 3 (0.62-0.68 µ) and 4 (0.77-0.86 µ) and in digital data the standard bands with additional SWIR band (1.55-1.70 µ) is procured from National Data Centre (NDC), National Remote Sensing Centre (NRSC), Hyderabad. IRS AWiFS data with five day repeativity has also been used for glacier inventory as the possibilities of obtaining good quality cloud free data with less snow cover is high. In general satellite data for the period 20042007 has been used. For few map sheets where 2004-07 IRS satellite data were not available, other satellite data as well as the data for period 2002-03 were also used. In addition, collateral data as Drainage maps from Irrigation Atlas of India, basin Boundary maps from Watershed Atlas of All India Soil and Land Use Survey (AIS&LUS), available Snow and Glacier maps (at 1:250,000) and other scales from internet. (Bahuguna et. al. 2001, Kulkarni et. al. 1999 and 2005, Kulkarni and Buch. 1991), elevation information from DEM generated from SRTM data, road, trekking routes and guide maps, Political and Physiographic maps and Published literatures on Himalayan glaciers are used. The glacier inventory map with details of the glacier features is prepared by visual on screen interpretation by using soft copy of multi-temporal IRS LISS III satellite data and ancillary data. Earlier field studies and results derived using satellite data suggest that spectral reflectance's of the accumulation area are high in bands 2, 3 and 4 of IRS LISS II and TM data. On the other hand, reflectance in band 2 and 3 are higher than the surrounding terrain but lower than vegetation in band 4. These spectral characteristics are useful to differentiate between glacial and non-glacial features (Dozier, 1984). The broad approach for the preparation of glacier inventory map, data sheet and digital data base is given in flow chart below in Figure 4 (Sharma et al, 2006). Snow and Glaciers of the Himalayas .14. Space Applications Centre ISRO, Ahmedabad Browse, identify select procure from NRSA-NDC Web Site Wshed Satellite data set - I Post field corrections DEM Study area limits Interpretation Preliminary glacier map Satellite data set - II SOI Grid Interpret key & Legend Interpretation Pre-field glacier map Limited field verification Final glacier map Digital database standards Digitization, edit, codification Measurements Digital map layers Natural Resources Data Base Parameters UNESCO/TTS/ Other Data sheet Final glacier map and inventory data sheet Himalayan Glacier Information System Figure 4: Broad approach for glacier inventory map and data sheet preparation In practice the preparation of glacier inventory map involves preparation and integration in GIS of primary theme layers. The primary theme layers are grouped into three categories i) Base information ii) Hydrological information iii) Glacier and De-glaciated valley features as shown in Table 5 (Sharma et al, 2008). Snow and Glaciers of the Himalayas .15. Space Applications Centre ISRO, Ahmedabad Table 5: Theme layers for glacier inventory map and data sheet creation Sr. No. Theme Remarks/ Contents A] Base Map 1 Frame work 5' * 5' latitude-longitude tic points (background for all layers) 2 SOI map reference 15'*15' latitude-longitude grid and SOI reference no. 3 Country Boundaries Country (not authenticated) 4 Roads Metalled/unmetalled road, foot-path, treks, etc. 5 Settlement extent Extent of habitation 6 Settlement location Location of habitation 7 Elevation DEM* Image grid B] Hydrology 8 Drainage lines Streams with nomenclature 9 Drainage poly Water body, river boundary with nomenclature 10 Watershed Boundary Watershed boundary and alphanumeric codes C] Glacier 11 Glacier boundary Ablation, accumulation, snow cover areas, supra-glacial lake, de-glaciated valley, moraine dammed lake, etc 12 Glacier lines Ice divide, transient snow line, centre line, etc. Glacier point Point locations representing coordinates for glacier, glacier terminus/snout, moraine dam lake, supra-glacier lakes, etc. 13 Glacier elevation Glacier elevation point locations. point locations Highest/lowest values for glacier, moraine dam lake, supra-glacier lakes. Snow and Glaciers of the Himalayas .16. Space Applications Centre ISRO, Ahmedabad Initially the small scale ancillary data (drainage, watershed, roads, settlements, etc.) is used to prepare preliminary digital maps corresponding to the base and hydrology themes. These preliminary theme layers are modified and finalized by using multi-temporal satellite data. Preliminary glacier inventory maps have been prepared using the first set of satellite data. Subsequently, they are modified as pre-field glacier inventory maps using second set of satellite data to include all the essential glacier features. Limited field visits are carried out to verify the pre-field glacier inventory map. Corrections, if any, are incorporated to prepare the final glacier inventory map. Measurements carried out on the glacier inventory map result in generating the glacier data sheet. Preparation of theme layers The published Irrigation Atlas, Watershed Atlas, small and large scale maps like political/ physical maps from reliable source have been identified for utilization for base map and hydrology theme layers. The information like administrative boundary, transportation features and settlement locations, drainage, watershed, etc., are identified on these maps. The maps are then scanned as raster images and registered / projected with the satellite data based on common control features. These scanned images are used in the background for extracting the base information on separate vector layers. The information content of each of the primary theme layers and the procedure for their preparation is discussed below:Base map layers The base map comprises of the four types of layers like the administrative boundary layer, transportation network, settlement locations and elevation information (DEM) layer. Snow and Glaciers of the Himalayas .17. Space Applications Centre ISRO, Ahmedabad Administrative boundary layer Major administrative boundaries like the national is obtained from published Political maps (or SOI open series maps). In digital data base these boundaries are identified, delineated, codified and are stored as separate layers with corresponding look-up tables (Table 6 and Table 7). The country codes as identified by UNESCO/TTS /Muller are followed. The satellite data does not have any role in creating these administrative layers. However, these are significant reference layers essential for understanding the distribution of glaciers within the political boundaries. The layers are directly procured from SOI as open series digital maps. The administrative maps are directly incorporated in the data base at SAC. Table 6: Attribute tables for Country: COUNTRY.LUT COUNTRY-CODE COUNTRY-NAME IN India CH China / Tibet NP Nepal BH Bhutan TB Tibet Table 7: Structure of table-COUNTRY.LUT Field Name Field Type Key Field- Y/N COUNTRY-CODE 2,2,C Y COUNTRY-NAME 10,10,C N Snow and Glaciers of the Himalayas .18. Space Applications Centre ISRO, Ahmedabad Transportation network As majority of the glaciated areas in the Himalayas are not easily assessable, the meager transportation features that are available become all the more significant for any glacier related study. The information on the transportation features occurring in the area is represented in a separate layer called the Roads layer. The road maps published by the state or other transportation network maps like road atlas, tourist/track maps, etc., containing the required information on various types of roads are used. The road network comprising of various types of metalled, un-metalled roads, foot paths, cart tracks, track on glacier, etc. leading to the glacier or across the glacier, if any, are identified and delineated on to the vector layer. This information is then compared and updated based on satellite data and field visit. The layer is digitized and appropriately codified to create a final ROADS layers. The corresponding look up tables (ROADS.LUT) and structure of the table are as given in Tables 8 and 9 given below. Table 8: Attribute Table for Roads: ROADS.LUT (Anonymous, 2000) RD- CODE ROAD TYPE SUB-TYPE 01-00 Metalled Black Topped (BT) or Bitumen Roads 01-01 National Highway 01-02 State Highway 01-03 District Road 01-04 Village Road 02-00 Unmetalled Water Bound Macadam (WBM) or Concrete/ Cement Roads 02-01 National Highway 02-02 State Highway 02-03 District Road 02-04 Village Road Snow and Glaciers of the Himalayas .19. Space Applications Centre ISRO, Ahmedabad 03-00 Tracks 03-01 Pack Track in Plains 03-02 Pack Track in hills 03-03 Track follows stream 03-04 Cart Track in plains 03-05 Cart track in desert/ wooded/ hilly area 03-06 Footpath 03-07 Footpath in hill 04-00 Route Over glacier 05-00 Pass 06-00 Pass in permanent snow 07-00 Road on dry river bed 08-00 Road under construction 08-01 National Highway 08-02 State Highway 08-03 District Road 08-04 Village Road 09-00 Others Earthen/Gravel, Flyover etc. Table 9: Structure of the table - ROADS.LUT (Anonymous, 2000) Field Name Field Type Key Field - Y/N Remarks RD-CODE 4, 4, C Y Feature Code TYPE 30,30, C N Road Type SUB-TYPE 30,30, C N Sub-Type Snow and Glaciers of the Himalayas .20. Space Applications Centre ISRO, Ahmedabad Settlement location The lower reaches of the basins are inhabited and presence of small settlements common. The extents of such village/town are first delineated based on available published maps and stored as a polygon (SETTLEA) layer or the habitation mask. The village/town settlement extent (polygon) is updated using multi-date satellite data and corresponding codification is done as per look-up table SETTLEA.LUT (Table 10 and Table 11). The centeroid of the delineated polygon for settlement is marked as the settlement location point (SETTLEP) and all relevant information is attached with this point in the look-up table SETTLEP.LUT (Table 12). The SETTLEP codification for each of the village is as per the codes given in Census (2001). The settlement layers is used as habitation location mask that are overlaid on the glacier inventory map while generation of the hardcopy output during the preparation of the A3 size Atlases for each of the three basins. Table 10: Attribute Table for Settlement (Polygons): SETTLEA.LUT (Anonymous, 2000) SETA-CODE SET-TYPE 01 Towns/ Cities (Urban) 02 Villages (Rural) Table 11: Structure of the Table DRAINL.LUT (NRIS) Field Name Key (Y/N) Remarks SETA-CODE 4,4, C Y Feature Code SET-TYPE N Code Description Snow and Glaciers of the Himalayas Field Type 30,30,C .21. Space Applications Centre ISRO, Ahmedabad Table 12: Attribute Table for Settlements (Points): SETTLEP.LUT (Anonymous, 2000) Field Name Field Type Key Field Y/N SCODE 8,8,C Y LOCATION 25,25,C N V TYPE 25,25,C N Remarks Village Name SCODE is the system link CODE SCODE V -TYPE 00009000 Village 00009001 Forest 00009002 Town 9004 Others Elevation information (DEM) layer The DEM generated based on Shuttle Radar Terrain Mapping (SRTM) Mission with vertical resolution of 30 m is used for collecting the elevation information. The point location layer is overlaid on the DEM and significant elevation measurements required as input for the data sheet is obtained. Hydrology The hydrology layer with information on all the minor, major drainage, water bodies and watershed with their corresponding identification numbers and names is created. The published small scale Irrigation Atlas of India is used as input for generating the preliminary drainage line and water bodies layers. The watershed Atlas of India is used as input for generating the preliminary watershed (Basin/ Sub-basin) layer. The drainage layer is generated as two separate layers the drainage line layer (DRAINL) and the drainage polygon layer (DRAINP). Snow and Glaciers of the Himalayas .22. Space Applications Centre ISRO, Ahmedabad Drainage line layer The drainage line layer is prepared to represent all the streams arising from the snow and glacier feed area and which is represented only as single line due to mapping scale (DRAINL.LUT) as given in Table 13 and Table 14. Table 13: Attribute Table for Water Body Polygons: DRAINL.LUT (Anonymous, 2000) DRNL-CODE DISCR 01 Perennial 02 Dry 03 Tidal* 04 Undefined/ Unreliable 05 Perennial - Unreliable 06 Tidal creek* 07 Water channel in dry river 08 Broken Ground/ ravines *may not exist in glacier areas. Table 14: Structure of the Table DRAINL.LUT (Anonymous, 2000) Field Name Field Type Key (Y/N) Remarks DRNL-CODE 2,2,C Y Feature Code DISCR 30,30,C N Code Description STREAM ORDER 2,2,I N Stream Order Drainage poly layer This layer provides information on all the major streams and the water bodies which are mapped as polygons at this scale. The dry and wet parts of the Snow and Glaciers of the Himalayas .23. Space Applications Centre ISRO, Ahmedabad drainage are identified and delineated with appropriate codification. The sand area, which is seasonally under water during occasional flooding caused by snow melt, should also be appropriately identified and mapped. The moraine dammed lakes and the supra-glacial lakes are delineated and appropriately classified (DRAINP.LUT) (Table 15 and Table 16). Names of large water bodies and rivers are identified from published maps and stored in the associated record in look-up table. Both the preliminary drainage line and polygon layers prepared using small scale maps as input are updated using multi-date satellite data. All changes in stream/river courses and presence of new water bodies are incorporated in the final drainage layers. Table 15: Attribute Table for Water Body Polygons: DRAINP.LUT (Anonymous, 2000) DRNL-CODE 01 02 03 04 05 06 07 08 09 10 11 DISCR River Canal* Lakes/ Ponds Reservoirs Tanks Cooling Pond/ Cooling Reservoir* Abandoned quarries with water* Bay* Cut-off Meander* Supra-glacial lake Moraine dammed lake *may not exist in glacier areas. Table 16: Structure of the Table DRAINP.LUT (Anonymous, 2000) Field Name Field Type Key (Y/N) Remarks DRNL-CODE 2,2,C Y Feature Code DISCR 30,30,C N Code Description Snow and Glaciers of the Himalayas .24. Space Applications Centre ISRO, Ahmedabad Watershed (Basin / Sub-basin) boundary layer The hierarchical (preliminary) watershed boundary information as delineated from the small scale watershed maps as available in the Watershed Atlas. The delineated boundaries in the preliminary map are modified using multi-date satellite data. The ridges, ice divide and stream/river features representing the watershed boundaries as seen on the image are carefully interpreted and are refined at 1:50,000 scale to prepare the final watershed (Basin / Sub-basin) map layer. Glacier The glaciers in the Himalayas are mainly of the Mountain and valley glacier type. The available archive information on glaciers in the form of glacier maps / Atlas on the Himalayan Glacier Inventory at 1:250,000 scale (Kulkarni and Buch, 1991) is referred before the mapping is initiated to get an idea of the glacier occurrences and distribution in the past. Using multi-date satellite data the required glacier morphological features are mapped. However, for convenience of generating statistics from digital layers, these morphological features are stored separately as line point and polygon layers. The glacier inventory map is prepared in two steps; first the preliminary glacier inventory map is prepared using the first set of satellite data and all glacier features (Figure 5) are mapped. Later, the dynamic features like snow line, permanent snow covered area, moraine extent, etc., are modified and new glacier features, if any, are appended based on the subsequent year satellite data to prepare the pre-field glacier inventory map. The pre-field glacier inventory map is then verified in the field wherever possible and final glacier inventory map is prepared after including the modifications if any. Snow and Glaciers of the Himalayas .25. Space Applications Centre ISRO, Ahmedabad The mapped glacier features comprise of the permanent (for 2 or more glacial inventory season) snow covered areas/snow fields, the boundary of smaller glacieret, the Glacier boundary for accumulation and ablation area with the transient snow line separating the two areas. Accumulation area Lateral moraine De glaciated valley Ablation area - exposed Ablation area - debris covered Snout Figure 5: Glacier Features as seen on IRS LISS III FCC (Sep. 2005) The ice divides line at the margin of glaciers and other features like cirque, horn the glacial outwash plain areas, the glacier terminus / snout, etc. are delineated. The ablation area is further classified as ice exposed or debris covered. The lateral and medial moraine features associated with the ablation areas are delineated. The supra-glacier lakes if any are delineated. Snow and Glaciers of the Himalayas .26. Space Applications Centre ISRO, Ahmedabad The extent of the de-glaciated valley and the associated various types of moraines and moraine dammed lake features are delineated. These features are appropriately stored in GIS as point line and polygon layers. Glacier features layers Using multi-date satellite data, the extent of the perennial snow covered areas, the glacieret, the glacier accumulation and ablation area, etc., associated with the glacier are delineated as polygon features (GLACIER) and appropriately codified (GLACIER.LUT). The transient snow line which separates the accumulation and ablation areas and the ice divide line at the margins of two or more glaciers are identified and delineated as line features in a separate cover. The centre line running along the maximum length/longitudinal axis of the glacier and dividing it into two equal halves is delineated and stored as line feature (GLACIERL). The position of the glacier terminus or snout is delineated as point feature in a separate cover (GLACIERP). The associated look-up tables for the glacier poly, line and point features are created as GLACIER.LUT, GLACIERL.LUT and GLACIERP.LUT along with corresponding structure for each of these are respectively given in Tables 17, 18, 19, 20, 21 and 22. As per the TTS format the glacier positions as represented by the latitude /longitude and coordinate system are essential. Similarly, various point locations representing the coordinate point for de-glaciated valley, supra-glacier lake, snout, moraine dam lake, etc. are essential for tabular representation and future reference. The layer GLACIERP with point location (coordinates in latitude /longitude) is created for this purpose. Snow and Glaciers of the Himalayas .27. Space Applications Centre ISRO, Ahmedabad De-glaciated valley feature The de-glaciated valley and associated features are significant to determine the health of the glacier. The dimensions of the valley and the type of moraines deposits reflect upon the retreat pattern of the glacier. The multi-date satellite data is used to identify and delineate the extent of the de-glaciated valley features. Mainly the de-glaciated valley and associated features that are mapped include the glacial valley, moraines like the terminal, medial, lateral moraine, outwash plain, moraine dammed lake, etc. (Figure 6). The moraines can occur both as polygon as well as line features depending upon their width at the mapping scale. The information is stored in polygon vector (GLACIER) layer. Some of the lateral and terminal moraines which are delineated only as the lines are separately kept in a line vector layer the de-glaciated valley line (GLACIERL) layer. Ablation area - exposed Lateral moraine Ablation area - debris covered Terminus/ Snout De-glaciated valley Medial moraine Moraine-dammed lake Terminal moraines Cloud cover / shadow Figure 6: Glacier and De-glaciated valley features on IRS LISS III FCC (Samudra Tapu Glacier, Indus Basin) Snow and Glaciers of the Himalayas .28. Space Applications Centre ISRO, Ahmedabad The elevation information, particularly the highest and lowest elevation of glaciers, de-glaciated valley, the supra-glacial and moraine dam lakes are significant as these are incorporated in the TTS format. A point layer (ELEVP) is created to store all the locations of these elevation points and their elevation values. The attribute table and the structure of the ELEVP is given in Table-23. The elevation information for these locations is obtained by intersecting this layer with the DEM layer created using SRTM data. Table 17: Attribute Code Table for Glacier Polygon Layer: GLACIER.LUT GL-Code Discr-L1 01-00-00 Glacier Discr-L2 Discr-L3 01-01-00 Accumulation area 01-02-00 Ablation area 01-02-01 Ablation area: debris cover 01-02-02 Ablation area: exposed 01-03-00 Moraine 01-03-01 Terminal moraine 01-03-02 Medial moraine 01-03-03 Lateral moraine 01-04-00 02-00-00 Supra glacier lakes De glaciated valley 02-01-00 Moraine 02-01-01 Terminal moraine 02-01-02 Lateral moraine 02-02-00 Outwash plain 02-03-00 Moraine dammed lake 03-00-00 Glacieret & Snow field 88-88-88 Non glaciated area Snow and Glaciers of the Himalayas .29. Space Applications Centre ISRO, Ahmedabad Table 18: Structure of the Table GLACIER.LUT Field Name Field Type Key Field (Y/N) Remarks GL-Code 6, 6, C Y Feature Code GLAC_ID 15, 15, C Y Glacier identification number Discr-L1 50,50, C N Glacier Unit at very small scale Discr-L2 50,50, C N Glacier Unit at large (1:50k ) scale Discr-L3 50,50, C N Glacier Unit at large (1:50k ) scale with next level of (hierarchy) details Table 19: Attribute Code Table for Glacier Line Layer: GLACIERL.LUT GLL-Code Discr-L1 01 Ice divide line 02 Lateral Moraine glaciated area (trace) 03 Median Moraine in glaciated area (trace) 04 Terminal Moraine in glaciated area (trace) 05 Lateral Moraine in de-glaciated area (trace) 06 Terminal Moraine in de-glaciated area (trace) 07 Transient snow line 08 Centre line of total glacier (max. length) 09 Centre line of glacier (2) smallest (min. length) 10 Centre line of total de-glaciated valley (max. length) 11 Centre line of exposed glacier (max. length-exposed) 12 Centre line of ablation area (max. length) 13 Mean width line for ablation area maximum length 14 Mean width line for ablation area minimum length Snow and Glaciers of the Himalayas .30. Space Applications Centre ISRO, Ahmedabad Table 20: Structure of the Table GLACIERL.LUT Field Name Field Type Key Field Remarks (Y/N) GLL-Code 2, 2, C Y Feature Code GLAC_ID 15, 15, C Y Glacier identification number Discr 50,50, C N Glacier line feature at large (1:50k ) scale Table 21: Attribute Code Table for Glacier Point Layer: GLACIERP.LUT GLP-Code DESCRIPTION 01 Terminus / snout 02 Glacier coordinate point 03 Supra-glacial lake coordinate point 04 De-glaciated valley coordinate point 05 Moraine dam lake coordinate point 06 Snowline coordinate point Table 22: Structure of the Table - GLACIERP.LUT Remarks GLP-Code Field Type Key Field (Y/N) 2, 2, C Y GLAC_ID 15, 15, C Y Glacier identification number Discr 50,50, C N Glacier co-ordinate point location Field Name Snow and Glaciers of the Himalayas .31. Feature Code Space Applications Centre ISRO, Ahmedabad Glacier elevation point layer (ELEVP) The elevation information, particularly the highest and lowest elevation of glaciers, de-glaciated valley, the supra-glacial and moraine dam lakes are significant as these are incorporated in the TTS format. A point layer (ELEVP) is created to store all the locations of these elevation points and their elevation values. The attribute table and the structure of the ELEVP are given in Table 23 and Table 24. The elevation information for these locations is obtained by intersecting this layer with the DEM layer created using SRTM data. Table 23: Attribute Code Table for Elevation Point Layer: ELEVP.LUT GLP-Code DESCRIPTION 01 Highest glacier elevation point 02 Lowest glacier elevation point (same as snout location) 03 Lowest supra-glacial lake elevation point 04 Lowest moraine dam lake elevation point 05 Snowline elevation point / high elevation ablation area / low elevation of accumulation area 06 Lowest De-glaciated valley elevation point Table 24: Structure of the Table - ELEVP.LUT Field Name Field Type Key Field Remarks (Y/N) ELEV-CODE 2, 2, C Y Feature Code GLAC_ID 15, 15, C Y Glacier identification number ELEV-VAL 5,5,I N Glacier elevation value in meters Discr 50,50, C N Various glacier elevation point Snow and Glaciers of the Himalayas .32. Space Applications Centre ISRO, Ahmedabad Preparation of glacier inventory map and data sheet: For preparing the glacier inventory map and data sheet, onscreen analysis of satellite data is carried out using FCC digital image. Along with the satellite data following thematic layers prepared earlier are also used. l Frame work (FRAME) comprising of tic marks at interval of 5' x 5' representing the latitude and longitude for the study area with WGS 84 and projection in WGS84 corresponding to open series maps (OSM) is created and provided. The codification for the tic ids is DDMMSSDDMMSS (12 digits) corresponding to the longitude and latitude for the tic location. l SOI layer comprising of polygons Grid obtained by joining the tics located at interval of 15' x 15' and representing the boundary of 1:50,000 scale map sheet. The information of the map sheet number the minimum and maximum values of latitude and longitude associated with the sheet is stored in the associated look-up table (SOI.LUT) Table 25. l Watershed (Basin / Sub-basin) boundary (WSHED) based on small scale maps and codification as per AIS&LUS procedure. l DEM based on SRTM data. Raster image with elevation information. Snow and Glaciers of the Himalayas .33. Space Applications Centre ISRO, Ahmedabad Table 25 : Attribute Table for Survey of India Toposheets: SOI.LUT Field Name Field Type Key Field- Y/N SOI-CODE 6,6,C (Y) SOI-NAME 8,8,C N LAT-MIN 10,10,C N LONG-MIN 10,10,C N LAT-MAX 10,10,C N LONG-MAX 10,10,C N Explantation for SOI-CODE (nn-qq-ss) Nn Toposheet Number at 1:1million level i.e. 01, 02..... Qq Quadrant number Ss 01 A 02 B ---------- ----------- 16 P Segment Numbers from 01 to 16 For Example SOI-CODE for Toposheet 56/E/2 is 56-05-02 l The administrative boundary of COUNTRY is generated and is finally integrated with the data base. The corresponding look-up tables is prepared for these layers COUNTRY.LUT l The details of steps involved in the preparation of the glacier inventory map given in Figure 7 and data sheet in Annexure-2. The geocoded satellite data and the vector layers are appropriately loaded on to the computer system. Snow and Glaciers of the Himalayas .34. Space Applications Centre ISRO, Ahmedabad A new vector layer is created with the projection and datum system standards. Copies of this layer are made and appropriately renamed as DRAINL, DRAINP, WSHED, GLACIER, GLACIERL, GLACIERP, etc. The coverage topology is built as poly, line or point as required. DRAINL The available scanned small scale drainage map is used and all the drainage features as seen on the map are delineated as a line. The courses of drainage are modified as seen on the satellite data to finalize the drainage line layer. The lines are suitably codified as given in DRAINL.LUT. DRAINP The boundary of streams /rivers and water body features as seen on the map are delineated as double line. Modifications based on satellite data are carried to include the changed courses of drainage features. The extent of dry sections of channel / water body is also appropriately delineated and all features are codified. WSHED The small scale preliminary watershed map is used and correlated with the features on satellite data like the ridges or courses of major stream, ice divide, etc. which represents watershed / basin limits. The refinement is done to follow distinctly seen watershed (Basin) features on the satellite data. ROADS The preliminary small scale ROADS layer is superimposed on the satellite data and the road features on map and satellite data are correlated. The new road features are delineated and any other changes with respect to road features as seen on the satellite data are incorporated on to the map. The delineated road features are codified as per the codification scheme. All map sheets do not have roads layer. Snow and Glaciers of the Himalayas .35. Space Applications Centre ISRO, Ahmedabad Snow and Glaciers of the Himalayas .36. Space Applications Centre ISRO, Ahmedabad Figure 7: Glacier Inventory Map GLACIER : The glacier inventory map is prepared in two stages using two set of satellite data. The preliminary layers which are intermediate layers are stored in the database. First the preliminary glacier inventory map is prepared using the first set of satellite data by superimposing the glacier poly layer on the satellite data and delineating the area features like the extent of the snow fields and glacierets. The glacier boundary with separate accumulation and ablation area are delineated as polygon features and appropriately codified (GLACIER.LUT) and stored. The line vector layer for glacier (GLACIERL) contains the line features like the transient snow line which separates the accumulation and ablation areas and the ice divide line at the margins of two or more glaciers are identified and delineated as line features. The centre line running along the maximum length/longitudinal axis of the glacier and dividing it into two approximately equal halves is identified, delineated, codified and stored as line feature in the database. Besides these, other line features are also delineated as required to fill the standard TTS glacier inventory data sheet. These lines mostly are drawn to represent width of the glacier (mean width line) for ablation and accumulation areas. In practice, two lines are drawn for width estimation, one representing the maximum width and other representing the minimum width of the feature (viz. ablation area / accumulation area). These lines are only meant for recording the measurements for the purpose of the TTS data sheet. Similarly the point vector glacier layer GLACIERP is created by delineating the glacier terminus or snout as point feature. The coordinate point for glacier features such as glacier, de-glaciated valley, supra-glacier lake, moraine dam lake, etc. are delineated. The corresponding latitude and longitude values are obtained against these locations for further use in TTS form and others. These points are appropriately codified and stored as GLACIERP layer in the database. Snow and Glaciers of the Himalayas .37. Space Applications Centre ISRO, Ahmedabad The various elevation points like the lowest/highest glacier elevation are identified using the SRTM - DEM within the glacier boundaries (ELEVP). It is important to note that some of the point features as required for the TTS form may be common during digitization. Like the lowest glacier elevation point may be lowest elevation point for ablation area and may also represent the location for the snout position. The same point representing more than one feature may also occur in both the GLACIERP as well as the ELEVP layers. But these are essential for the analysis purpose and hence are repeated in more than one layer. To finalize the glacier layer the second date (subsequent year) satellite data is used to verify and, if necessary, modify the previously delineated boundaries of glacier features. The snout position is taken as in the latest data set. The snow extent and snow line is taken as the minimum extent of the two set of data. The associated look-up tables for the glacier poly, line and point features are created as GLACIER.LUT, GLACIERL.LUT and GLACIERP.LUT respectively. The maps are edge matched/ mosaicked and stored in database. The final outputs are prepared basin-wise. Field verification The final glacier inventory map layer is prepared only after limited field verification exercise is carried out for few specific glaciers that are approachable. The specific glaciers are selected judiciously from among a set of basins geographically well distributed and showing definite variation of observed geomorphological parameters. The accessibility to the regions is ascertained while identifying the glaciers for field validation. Based on the field expeditions to different glaciers, the glacier inventory map is verified and corrections, if any, are incorporated. Snow and Glaciers of the Himalayas .38. Space Applications Centre ISRO, Ahmedabad ELEVP The elevation locations mainly represent the highest glacier elevation, lowest glacier elevation, lowest supra-glacial lake elevation, lowest moraine dam lake elevation, snowline elevation, etc. All elevations measurements (as applicable) are taken along the centre line of the glacier. The point locations are provided codes/attributed as given in ELEVP.lut. The actual elevation values are obtained by overlaying the ELEVP on the DEM layer in GIS using identity function for the points. Integration of Layers and Preparation of Final Glacier Inventory Map The various layers prepared by interpretation of multi-date satellite data are digitized, appropriately codified and stored in the digital database in GIS environment. These layers are then systematically integrated in GIS to prepare the final glacier inventory map (pre-field). Limited field verification is carried out to verify the delineated features. The post-field modifications, if any, are incorporated in the map to prepare the final glacier inventory map. Cartographic maps are composed by overlaying the various layers in GIS and by using appropriate symbology for each of the features related to the base map, hydrology and glacier features layers. The Index map showing India and environs comprising of parts of major basins Indus, Ganga and Brahmaputra that flow into India are given in Figure 8. The Basin maps for Indus, Ganga and Brahmaputra basin showing the locations of Sub-basins are given in Figure 9, Figure 10 and Figure 11. Sub-basin wise sample glacier inventory maps one each for Indus, Ganga and Brahmaputra represented by Chenab, Alaknanda and Tista respectively are given in Figure 12 to 14. The remaining sub-basin wise maps are given in Annexure-2. Snow and Glaciers of the Himalayas .39. Space Applications Centre ISRO, Ahmedabad HIMALAYAN GLACIER INVENTORY INDIA AND ENVIORNS N Figure 8: Index map - India and Environs (Indus, Ganga and Brahmaputra basins) Figure 9: Index map showing Indus sub-basins Snow and Glaciers of the Himalayas .40. Space Applications Centre ISRO, Ahmedabad Figure 10: Index map showing Ganga sub-basins Figure 11: Index map showing Brahmaputra sub-basins Snow and Glaciers of the Himalayas .41. Space Applications Centre ISRO, Ahmedabad HIMALAYAN GLACIER INVENTORY INDUS BASIN (INDUS, GANGA AND BRAHMPUTRA BASINS) CHENAB SUB-BASIN N Figure 12: Glaciated area of Chenab Sub-basin (Indus Basin) HIMALAYAN GLACIER INVENTORY GANGA BASIN (INDUS, GANGA AND BRAHMPUTRA BASINS) ALAKNANDA SUB-BASIN N Figure 13: Glaciated area of Alaknanda Sub-basin (Ganga Basin) Snow and Glaciers of the Himalayas .42. Space Applications Centre ISRO, Ahmedabad HIMALAYAN GLACIER INVENTORY BRAHMAPUTRA BASIN (INDUS, GANGA AND BRAHMPUTRA BASINS) TISTA SUB-BASIN N Figure 14: Glaciated area of Tista Sub-basin (Brahmaputra Basin) Generation of glacier inventory data sheet Inventory data (Annexure-2) is generated for individual glaciers in a well-defined format as suggested by UNESCO/TTS and later modified. It is divided into two parts. First part comprises of all 37 parameters recommended by UNESCO/TTS. Second part contains additional information on 15 parameters related to remote sensing and de-glaciated valleys and glacier lakes. These parameters are not recommended by UNESCO/TTS. However, by considering usefulness of this information in glaciological studies, these are also included in the present investigation. By using the glacier inventory map layers in GIS environment, systematic observations and measurements are made on the glacial feature and recorded in tabular form in the Inventory data sheet The observations and features measured and recorded are mainly related to the data (age / year) used, location, dimensions, Snow and Glaciers of the Himalayas .43. Space Applications Centre ISRO, Ahmedabad elevations and directions, etc. for the glacier. Majority of the measurements are directly obtained through GIS functions. The table thus generated is linked to corresponding glacier inventory map feature in GIS through the unique glacier identification number. Data fields description The World Glacier Inventory data sheet contains the following data fields. Not all glaciers have entries in every field. Explanations for various Data fields in the standard Data Sheets are as below 1. Glacier identification number : The glacier identification number as defined by the World Glacier monitoring Service's convention is based upon inverse STRAHLER ordering of the stream. To achieve uniform classification, a base map of 1:20,000 scale was used. On this map the smallest river gets, by definition, order five and when two rivers of the same order meet together; they make a lower order river. Each order is assigned a fixed position in the numbering scheme, which has a total of 12 positions. First three positions are reserved for apolitical and continent identification; fourth position for first order basin and code Q and O is assigned for Indus and Ganga rivers, respectively. Next three positions are reserved for 2nd, 3rd and 4th order basins, respectively. In order to identify every single glacier, remaining five positions from 8 to 12 are kept at the disposal of local investigators. In the local system of identification, glaciers are first identified with map number and then numbered in the individual basins. In the present investigation the identification of major basin is done by using map supplied by UNESCO/TTS. Present investigation is done on large scale maps; therefore, to make full utilization of inventory information it would be necessary to further subdivide major basin into smaller sub basins. This will make it possible to provide glacier inventory information for small stream and thus improving utility in water resources management. To facilitate this, smallest stream is given, by definition, order eight, instead of four as given by UNESCO/ TTS. This can cause change in number from order five to eight and no change is necessary for positions between four and one. This makes data completely Snow and Glaciers of the Himalayas .44. Space Applications Centre ISRO, Ahmedabad compatible with UNESCO/ TTS data base. To get number for stream order between eight and five; the map of watersheds is taken from Watershed Atlas of India (Anon., 1990). 2. Glacier name: Every glacier does not have a name within the database. Often the name is the glacier's numerical position within its particular drainage subregion. 3. Latitude: The latitude of the glacier, in decimal degrees North. 4. Longitude: The longitude of the glacier, in decimal degrees East. 5. Coordinates: Local coordinates in UTM (or other nationally determined format) 6. Number of drainage basins: Number of drainage basins 7. Number of independent states: The number of independent states 8. Topographic scale: The scale of the topographic map used for measurements of glacier parameters. 9. Topographic year: The year of the topographic map used for measurements of glacier parameters. 10 Photo / image type: The year of the photograph/image used for measurements of glacier parameters. 11. Photo year: The year of the photograph/image used. 12. Total area: The total surface area of the glacier, in square kilometers. 13. Area accuracy: The accuracy of the area measurements on a percentile basis. 14. Area in state: The total area in the political state reporting. 15. Area exposed: The area of open ice, in square kilometers. 16. Area of ablation (total): The total surface ablation area of the glacier, in square kilometers. 17. Mean width of glacier: The mean width of the glacier, in kilometers. 18. Mean length (total): The mean glacier length, in kilometers Snow and Glaciers of the Himalayas .45. Space Applications Centre ISRO, Ahmedabad 19. Max length: The maximum glacier length, in kilometers. 20. Max length exposed: The maximum length of exposed ice, in kilometers. 21. Max length ablation: The maximum length of ablation area, in kilometers 22. Orientation of the accumulation area: The aspect of the accumulation area in degrees in direction of flow. The value -360 indicates an ice cap. 23. Orientation of the ablation area: The aspect of the ablation area in degrees in direction of flow. The value -360 indicates an ice cap. 24. Max / highest glacier elevation: The maximum glacier elevation, in meters. 25. Mean elevation: The mean glacier elevation, in meters. 26. Min / lowest elevation: The minimum glacier elevation, in meters. 27. Min / lowest elevation exposed: The minimum elevation of exposed ice, in meters. 28. Mean elevation-accumulation: The mean elevation of accumulation area, in meters (along the centre line mean of max. elevation and min. elevation) 29. Mean elevation ablation: The mean elevation of the ablation area, in meters. (Along the centre line mean of max_elevation_ablation and min. elevation_ablation) 30. Classification: Is the six digit form morphological classification of individual glaciers (UNESCO/IASH guidelines) as detailed in Table 26. Snow and Glaciers of the Himalayas .46. Space Applications Centre ISRO, Ahmedabad Table 26: Classification System for Glaciers Descriptions of each of the above classification are given below Digit 1 Primary classification 0 Uncertain or Misc. - Any not listed 1 Continental ice sheet - Inundates areas of continental size 2 Ice field - Ice masses of sheet or blanket type of a thickness not sufficient to obscure the surface topography Snow and Glaciers of the Himalayas .47. Space Applications Centre ISRO, Ahmedabad 3 Ice cap - Dome shaped ice mass with radial flow 4 Outlet glacier - Drains ice sheet or ice cap, usually of valley glacier form; the catchment area may not be clearly delineated 5 Valley glacier - Flows down a valley; the catchment area is well defined 6 Mountain glacier - Cirque, niche or crater type; includes ice aprons and groups of small units 7 Glacieret and snow field - Glacieret is a small ice mass of indefinite shape in hollows, river beds and on protected slopes developed from snow drifting, avalanching and / or especially heavy accumulation in certain years; usually no marked flow pattern is visible and therefore no clear distinction from snow fields is possible. Exists for at least two consecutive summers. 8 Ice shelf - A floating ice sheet of considerable thickness attached to a coast, nourished by glaciers (s); snow accumulation on its surface or bottom freezing 9 Rock glacier - A glacier-shaped mass of angular rock in a cirique or valley either with inertial ice, firn and snow or covering the remnants of a glacier, moving slowly down slope Digit 2 Form 1 Compound basins - Two or more individual valley glaciers issuing from tributary valleys and coalescing (Figure 15a and Figure 17). 2 Compound basin -Two or more individual accumulation basins feeding one glacier system (Figure 15b and Figure 18). 3 Simple basin - Single accumulation area (Figure 15c and Figure 19a). 4 Cirque - Occupies a separate, rounded, steep walled recess which it has formed on a mountain-side (Figure 15d and Figure 19b). 5 Niche - Small glacier formed in initially V-shaped gulley or depression on mountain slope; generally more common than the genetically further developed cirque glacier (Figure 15e). Snow and Glaciers of the Himalayas .48. Space Applications Centre ISRO, Ahmedabad 6 Crater - Occurring in extinct or dormant volcanic craters which rise above the regional snow line. 7 Ice apron - An irregular, usually thin, ice mass plastered along a mountain slope or ridge. 8 Group - A number of similar small ice masses occurring in close proximity and too small is assessed individually. 9 Remnant -An inactive, usually small ice mass left by a receding glacier. Figure 15: Glacier Classification- Form a) Compound basins, b) Compound basin c) Simple basin d) Cirque e) Niche (After Muller, 1977) Digit 3 Frontal characteristics (Figure 16) 1 Piedmont (glacier) -Ice-field formed on lowland by the lateral expansion of one or the coalescence of several glaciers. (Figure 16a and 16b) 2 Expanded foot - Lobe or fan of ice formed where the tower portion of the glacier leaves the confining wall of a valley and extends on to a less restricted and more level surface (Figure 16c and Figure 20). 3 Lobed - Part of an ice sheet or ice cap, disqualified as outlet or valley glacier. 4 Calving - Terminus of glacier sufficiently extending into sea or occasionally lake water to produce icebergs; includes-fot his inventory-dry land calving, which would be recognizable from the 'lowest glacier elevation. 5 Coalescing - non contributing (Figure 16d). Snow and Glaciers of the Himalayas .49. Space Applications Centre ISRO, Ahmedabad a b c d Figure 16: Glacier Classification - Frontal characteristics Digit 4 Longitudinal profile 1 Even -Includes the regular or slightly irregular and stepped longitudinal profile. 2 Hanging (glacier) - Perched on a steep mountain-side or issuing from a hanging valley. 3 Cascading - Descending in a series of marked steps with some crevasses and seracs. 4 Ice-fall - Break above a cliff, with reconstitution to a cohering ice mass below. Digit 5 Nourishment Source of nourishment for glacier mostly comprises of seasonal snow and avalanche snow & ice. Digit 6 Tongue activity A simple-point qualitative statement regarding advance or retreat of the glacier tongue in recent years, if made for all the glaciers on earth, would provide most useful information. The assessment for an individual glacier (strongly or slightly advancing or retreating, etc.) should be made in the context of the region and not just that of the local area; however, it seems very difficult to establish an objective, i.e. quantitative basis for the assessment of the tongue activity. A change of frontal position of up to 20 m per year might be classed as a 'advance or retreat. If the frontal change takes place at a greater rate it would be called 'marked'. Very strong advances or surges might shift the glacier front by more than 500 m per year. It is important to specify whether the information on the tongue activity is documented or estimated. As data used is for short duration of two years only assessment of tongue activity is not taken in to consideration in the current study. Snow and Glaciers of the Himalayas .50. Space Applications Centre ISRO, Ahmedabad Figure 17: Glacier Classification Compound Basins as seen on satellite data Figure 18: Glacier Classification Compound Basin as seen on satellite data Snow and Glaciers of the Himalayas .51. Space Applications Centre ISRO, Ahmedabad a a b Figure 19: Glacier Classification – a) Simple Basin and b) Cirque as seen on satellite data Figure 20: Glacier Classification - Frontal Characteristics-Expanded Foot as seen on satellite data Snow and Glaciers of the Himalayas .52. Space Applications Centre ISRO, Ahmedabad 31. Period for which tongue activity assessed: Period of activity for which the tongue activity was assessed. 32. Moraine code: 1st digit refers to moraines in contact with present-day glacier. The 2nd digit refers to moraines farther downstream. Both the above digits use the same coding system Table 27. Table 27: Coding Scheme for Moraine Code Description Code Description 0 No moraines 5 Combinations of 1 and 3 1 Terminal moraine 6 Combinations of 2 and 3 2 Lateral and/or medial moraine 7 Combinations of 1, 2, and 3 3 Push moraine 8 Debris, uncertain if morainic 4 Combinations of 1 and 2 9 Moraines, type uncertain or not listed 33. Snow line elevation: The observed or calculated location of the snow line for the total glacier in meters above mean sea level (masl). 34. Snow line accuracy: The snow line accuracy rating is high as snow line based on the two set of satellite data (SAT_DATA) are entered in the Proforma. 35. Snow Line Date: The date of observation of the snow line or the method of calculation of the snow line. The date of observation can range from a precise day (e.g. 1/7/06) to an individual year (e.g. 2006). 36. Mean Depth: The physical depth of the glacier, in meters. This is estimated based on Table 28. Snow and Glaciers of the Himalayas .53. Space Applications Centre ISRO, Ahmedabad Table 28: Mean glacier depth estimates (after Muller, 1970) Glacier Type Compound basins Valley glaciers Compound basin Simple basins Mountain glacier, cirque Glacieret and snow fields Area km2 Depth (m) 1-10 10-20 20-50 50-100 50 70 100 100 1-5 5-10 10-20 20-50 50-100 1-5 5-10 10-20 0-1 1-2 2-5 5-10 10-20 0-0.5 .05-1 1-2 30 60 80 120 120 40 75 100 20 30 50 90 120 10 15 20 37. Depth Accuracy rating: The accuracy rating of the depth measurement on a percentile basis is given as shown in Table 29. Table 29: Accuracy rating of the depth measurement Index [A] Area, length % [B] Altitude (m) 1 0-5 0-25 2 5-10 25-50 3 10-15 50-100 4 15-25 100-200 5 > 25 > 200 Snow and Glaciers of the Himalayas .54. Space Applications Centre ISRO, Ahmedabad Derivation of dimensions (length / width / area), altitude and azimuth information of glacier features in GIS The glacier polygon, line and point layers are designed for providing easy access to important information for filling the glacier inventory data sheet. The glacier inventory map layers are used to obtain various details for filling the datasheet as per modified UNESCO/TTS format and additional parameters. Using standard GIS tools, area is found out for the polygon features like total glacier, the ablation zone, accumulation zone, de-glaciated valley, moraine-dammed lakes, etc. By measurement in GIS of various stored line features information for length and width is obtained. By using GIS function the altitude information is derived from DEM generated by SRTM data of corresponding scale. The data thus generated is stored in a structured digital data sheet (GLACIER.DAT) with 65 entries corresponding to the modified UNESCO/TTS format. A sample data sheet with the defined database structure (GLACIER.DAT) is given in Annexure-2. 3.3 Estimation of changes in glacier extent There is a pertinent relationship between retreat and advance of glaciers and variations in the mass balance of glaciers. It is the climate which is the driving forces controlling the mass balance of glacier in space and time and resulting in recession and advancement of glacier. Climatic ice fluctuations cause variation in the amount of snow and ice lost by melting. Such changes in the mass initiate a complex series of change in the flow of glacier that ultimately results in a change of the position of terminus. As glaciers descend from the mountain or plateaus, a part of the matter composing them is expended for melting and evaporation, which become more intense as they descend into the region of higher temperatures. Finally, they reach a level at which the amount of ice arriving from the accumulation area is balanced completely by ablation. In case of equilibrium between replenishment and ablation, the position of the lower boundary of a glacier is stationary and the dimensions of the glacier remain more or less constant. If the supply by the accumulation increases, while Snow and Glaciers of the Himalayas .55. Space Applications Centre ISRO, Ahmedabad melting and evaporation remain unchanged, the glacier advances and its dimensions increase. Such glacier is said to be advancing. The picture is reversed when replenishment diminishes and wastage increases. In that case, the glacier will grow shorter until the snout (the front end of glacier) reaches a stationary position, corresponding to new equilibrium of replenishment and ablation. This is known as retreat of glacier. Thus advancement and retreat of glacier closely depend on the conditions of replenishment of an accumulation area and the intensity of ablation i.e. faster melting due to climatic changes. The retreat/advance of glaciers is therefore determined by mapping glacier boundaries of different time frame. In this project, satellite images have been used to map glacier boundaries in different basins to find out the status of retreat/advance of glaciers. Following two major steps have been followed while carrying out this study. (i) Georeferencing of the satellite data The IRS LISS III data (band 1, band 2, band 3 and band 4) is georeferenced with Survey of India (SOI) topographical maps covering the study area. Prior to this the data had already being processed for radiometric and first order geocorrections. First order geocorrections are usually carried out using five corner coordinates given along with IRS scene in leader file. The georeferencing with topographical maps is carried out by identifying a set of ground control points on the maps and images. The topographical maps used for this georeferencing is at 1:50,000 scale. Normally, the GCPs are those locations where either drainages intersect or there is sharp bends of drainages. The point accuracy of topographical map is 12.5 m. Ideally GCPs are normally, collected in the field using high precision GPS in differential mode. But due to remote locations of glaciers in the Himalayan region this method cannot be employed therefore topographical maps with fairly good amount of accuracy are considered to be the best alternative as a source of GCPs. One of the other purposes of using topographical map is that the glaciers extent in a given basin in toposheets are required to be compared with the extent mapped from IRS images. A comparison of glacial extent of two different time period can be done when the two source of glacial boundaries are properly registered. In the Snow and Glaciers of the Himalayas .56. Space Applications Centre ISRO, Ahmedabad present case approximately 100 points are used to georeference the satellite dataset of two basins. The registration is based on polynomial model. The ERDAS imagine version 9.1 has been used for this work. (ii) Delineation of glacial boundaries from SOI maps and satellite data Monitoring changes in glacial extent and advance/retreat is carried out using satellite images/maps of two or more time frame. In the present work, monitoring of glacier extent and retreat/advances has been done by extracting glacier boundaries using the recent satellite images (year 2001, 2004) as well as the topographical sheets of 1962. It has been observed while taking boundaries from maps that sometimes the boundary of the accumulation zone matches with the ridge boundary but in many other instances glacier boundary at the head is a few meters lower than the ridge boundary. This point is matched with glacial extent is interpreted and extracted on screen from any satellite image. To extract glacial boundary from satellite image false color composite (FCCs) are interpreted in different combination of band 1 to band 4. The SWIR band is used to discriminate cloud and snow because clouds are often observed on the upper region of the glaciers. The distinction of non-glaciated and glaciated region is sharper in SWIR band. The unique reflectance of snow-ice, shape of the valley occupied by the glacier, the flow lines of ice movement of glaciers, the rough texture of the debris on the ablation zone of the glaciers, the shadow of the steep mountain peaks and presence of vegetated parts of the mountains help in clear identification of a glacier on the satellite image. The understanding of reflectance curve of various glacier features helps to delineate the glacial boundary on satellite data. The snout of the glacier is a vital element of interpretation of glacial extracts. The glacier terminus is identified on satellite data using multiple criterions such as: a) Sometimes the river originates from the snout and river can be easily identified on the image. b) The peri-glacier area downstream of the snout has distinct geomorphologic set up then the glacier surface. Snow and Glaciers of the Himalayas .57. Space Applications Centre ISRO, Ahmedabad In many instances the frontal portion of the glaciers which are retreating has convex shape therefore it helps identification of the terminus. d) When interpretation becomes more complex sometimes DEM is used in the background to confirm the snout as there is a chance of change in the slope of glacier profile near the snout and 3d view help to identify the lateral and terminal boundary of glacial extent. e) Extreme care is taken while delineating glacier boundary that boundaries are marked in the inner side of the lateral moraines. c) (iii) Estimating loss in area of glaciers To estimate change in glacial area, the glacier boundaries of two time frame data of glacier extent are overlaid on each other. The two time frame data/glacier boundaries are brought to common scale. While matching the boundary, the scale of the map and image is kept at 1:50,000 because the mapping depends on the scale. Increase or decrease in the evacuated area from glaciers can be measured. (iv) Validation on ground In order to validate the retreat in the field one glacier in each basin has been visited and snout reading has been taken using GPS. 3.4 Monitoring snowline at the end of ablation season for mass balance The mass balance of the glacier is usually referred as the total loss or gain in glacier mass at the end of the hydrological year. It is estimated by measuring the total accumulation of seasonal snow and ablation of snow and ice. Mass balance has two components, accumulation and ablation. The accumulation (input) includes all forms of deposition, precipitation mainly and ablation (output) means loss of snow and ice in the form of melting, evaporation and calving etc from the glacier. The boundary between accumulation and ablation is the Equilibrium line. The difference between net accumulation and net ablation for the whole glacier over a period of one year is Net balance. The net balance for each glacier is different in amount and depends upon the size/shape of the glacier and climatic condition of the area. The net balance per unit area of glacier is specific mass balance, expressed in mm of water equivalent. There is wide variation in mass changes from time to time and place to place on the glacier due to the various Snow and Glaciers of the Himalayas .58. Space Applications Centre ISRO, Ahmedabad factors. The process of mass balance of the glaciers over an entire region is complex, as it is irregular in amount, rate and time of occurrence. Therefore the ultimate aim to monitor mass balance is to match it with the changes in various parameters of the glaciers. These changed directly affect the flow of the glacier and its terminus position. i.e. advancement and recession of the frontal position of the glaciers. There are several methods for carrying out the mass balance studies of a glacier, which has been used worldwide. Generally mass balance studies are carried out mainly by following methods. Geodetic Method A volume change can be estimated by subtracting the surface elevation of a glacier and the glacier extent at two different times. By measuring the density of snow at different parts of the glacier, the volume change can be converted into mass change. This method can be applied using topographic maps, digital elevation models obtained by aircraft, satellite imagery and by airborne laser scanning. The satellite imageries must be analysed for average mass balance of a glacier over a period of 5 - 10 years. This method has some limitations; the geodetic method must be applied over the entire glacier surface, which is a difficult task. Surveying the surface by field methods require that all parts of glacier is covered, including highly crevassed and steep regions. In addition the density of the firn and/or ice body must be approximated. This is rather easy for the ice portions but not easy for the firn areas. These major changes in the accumulation areas are difficult to determine accurately. Also this method does not yield point values of mass balance, such as its variation with elevation. For example, a glacier in steady state will yield a zero volume (mass) change over time, yet field measurement point values will yield positive values in the accumulation zone and negative values in the ablation zone. Snow and Glaciers of the Himalayas .59. Space Applications Centre ISRO, Ahmedabad This is a convenient method and time saving and this has been used worldwide. This method is simple and easy for monitoring of glacier mass balance and only applicable to determine the average mass balance of the entire glacier. Glaciological Method Glaciological method is the only method that includes in-situ measurements. Glaciological method is a traditional method, which is accepted and used worldwide. This method includes accurate determination of mass balance by monitoring the stake network .The net accumulation/ablation data from each stake measurement within a time interval is taken. The difference in level (accumulation/ablation), when multiplied by the near surface density yields an estimate of the mass balance of that point. Changes in the levels are measured in a variety of ways, including stakes drilled into the glacier and snow depth relative to a known stratigraphic surface (e.g. previous summer surface). Density value for the ice is assumed constant at 900 kg m-3. Snow density is measured in snow pits, which are dug down to a reference surface. Density can also be measured from cores taken with a drill or a cylinder of known volume. In this method, net balance is measured representative points on the glacier. The mass of snow and ice accumulated during the current balance year that remains during end of the year. This is the net balance at points in the accumulation area. There are several ways to calculate total mass balance of a glacier. One way is to construct a plot of mass balance as a function of elevation and a plot of area of glacier with elevation. A regression equation can be applied to each plot. Multiplying the values of many mass balance and area for specific intervals of elevation and summing the product over all the intervals gives the mass balance. This method is considered to be the most accurate method till date and it provides the most detailed information on the spatial variation of mass balance magnitudes. Furthermore, confidence in the results increases after independent checking by the geodic method. However, although the glaciological method may achieve the greatest accuracy and provide the investigator with a feel for the field conditions, it is based on repeated field measurements, which have to be carried out every year. Snow and Glaciers of the Himalayas .60. Space Applications Centre ISRO, Ahmedabad Hydrological Method When hydrology is concerned, the glacier acts as a reservoir with seasonal gains and losses. Thus mass balance of a glacier can also be calculated by estimating the annual accumulation and ablation from snow-accumulation and discharge data. This is generally used for confined drainage basin. Estimation of mass balance of a glacier by this method is extremely unreliable, as the adequate sampling of precipitation, runoff and evaporation of the glacier is difficult to record throughout the year. It takes lot of effort for unattended operation in high alpine basins. Maintaining a good gauging station for water discharge can be expensive and also time consuming. Accumulation Area Ratio Method It is not feasible to study all the mountain glaciers in the field for every year, therefore it is important to replace the conventional method by some cost effective, fast and reliable techniques so that a quick assessment of mass balance of individual glaciers could be done. The method based on computing Accumulation Area Ratio (AAR) is an alternate method to assess mass balance at reconnaissance level. Delineation of Accumulation and ablation zone on highresolution satellite images of ablation period is a well-established procedure. Accumulation and ablation zone are defined as zones of glacier above and below equilibrium line or snow line at the end of ablation season (melting season). The snow line can be defined as the location where there is enough snowfall and energy available to balance accumulation and ablation. On temperate glaciers, this is typically taken as the boundary between snow and ice. The snow line at the end of ablation season, which roughly corresponds to the equilibrium line on glaciers in mountainous region glaciers, can be identified on satellite images. A relationship between AAR and mass balance is developed using field mass balance data of Shaune Garang and Gor Garang glaciers (Figure 21). The model has shown AAR representing zero mass balance as 0.5 in comparison to 0.7 in the Alps and Rocky Mountains. On the basis of accumulation area ratio (area of accumulation divided by whole area of glacier) mass balance in terms of gain or loss can be estimated. Snow and Glaciers of the Himalayas .61. Space Applications Centre ISRO, Ahmedabad Figure 21: Relationship of AAR and Specific mass balance (Kulkarni et al., 2004) A snow line separated from bare ice by an area of old firn indicates a more negative balance than the preceding few years. AWiFS data from IRS P-6 (Resourcesat-1) satellite is the main source of information in the present study. Its repeativity of 5 days has been exploited for monitoring of snow line. This method of estimating mass balance has been employed in this project. The steps which are followed to extract AAR for each glacier under study have been enumerated as below. 1) AWiFS images of the year 2005, 2006 and 2007 for the period from July to October were georeferenced with Survey of India maps (SOI). 2) Basin boundary was digitized and overlayed on the images. Image to map registration was carried out to match basin boundary. 3) All the glaciers boundaries were digitized on screen using IRS LISS III image to get area of glaciers. The LISS III scenes are used in order to ascertain the boundary of glaciers using higher resolution of the data. These boundaries are further confirmed using SOI maps. To match the boundary of glaciers from maps and satellite data part of accumulation zone is matched Snow and Glaciers of the Himalayas .62. Space Applications Centre ISRO, Ahmedabad which is further matched with boundary created using shadow. The boundaries of retreating glaciers do not match with SOI maps near the snout of glaciers. 4) Glacier boundaries are overlaid on all AWiFS scenes sequentially. Band 4 is essentially used to discriminate snow and cloud on the image. Snowline of the date is created on the glacier. AWiFS data has 10 bit radiometry therefore while delineating snowline the part of the glacier having fresh snow is identified based on highest reflectance. 5) The accumulation area is the area of glacier above equilibrium line or snow line at end of ablation season. Thus AAR is derived for each glacier based on location of snow line at the end of ablation season. 6) A table is generated for AAR of each glacier corresponding to each scene. The least AAR is considered for estimation mass balance. 7) The mass balance for each glacier is estimated using relationship between AAR and mass balance. 8) Glaciers with no accumulation zone are confirmed using LISS III data. Snow and Glaciers of the Himalayas .63. Space Applications Centre ISRO, Ahmedabad 4. Snow Cover Monitoring NDSI Algorithm was used to generate snow cover products for all the 33 basins. Ten daily products along with satellite images for 5 basins are shown in Fig. 22 to 31. These basins are selected on the basis of different climatic zones and distributed from Jammu and Kashmir to Sikkim. For the remaining basins images and products are given in Annexure 1. For the same five basins snow accumulation and ablation curves are given in Figure 32 to 36 and for remaining basins curves are given in annexure 1. The snow accumulation and ablations curves are different for each basin, depending upon climatologically sensitive zones and altitude distribution of the basin. The Himalayan region is classified into three regions namely Lower, Middle and Upper Himalayan Zones with average snow fall (1990-2004) of 1178 cm, 537 cm and 511 cm, respectively (Sharma et al, 2000; Gusain et al, 2004). For comparative analysis Ravi and Bhaga basins are selected, as located in south and north of Pir Panjal Range, respectively. The area altitude distributions of these basins has shown that Ravi basin is located in lower altitude zone. For example, 90% of Ravi is located at an altitude below 4000 m, whereas this portion is only 20% for the Bhaga basin. Altitudes of the Ravi and Bhaga basins range from 630 m to 5860 m, and from 2860 m to 6352 m, respectively. In Ravi basin, snow accumulation and ablation are continuous processes throughout the winter. Even in the middle of winter melting of large snow area was observed. In January 2005, snow area was observed to be reduced from 90% to 55%. Similar trends were observed for the year 2005-06 and 2007-08 (Figure 33). This is a significant reduction in snow extent in the winter season. In summer, snow ablation was fast and almost 50% of the snow cover was melted within a period of one month and by the end of June almost 80% of the snow cover was melted. Snow and Glaciers of the Himalayas .64. Space Applications Centre ISRO, Ahmedabad In the Bhaga basin, snow melting was observed in the early part of the winter i.e. in the month of December. Snowpack was stable from the middle of January to the end of April (Annexure 1). This observation is consistent with earlier observations made in Baspa basin (Kulkarni and Rathore, 2003). Baspa is a high altitude basin and located on the Northern side of the Pir Panjal range. In this basin, significant melting of snow was observed in December influencing stream runoff. These observations suggest that river basins are responding to climate change depending on geographical location and altitude distribution. Snow and Glaciers of the Himalayas .65. Space Applications Centre ISRO, Ahmedabad AWIFFS IMAGE : ALAKNANDA BASIN DATA USED 02 MARCH 2008 DATA USED 16 MARCH 2008 DATA USED 21 MARCH 2008 0 25 50 100 150 200 Kilometers Figure 22: AWIFS Image of Alkananda Basin Snow and Glaciers of the Himalayas .66. Space Applications Centre ISRO, Ahmedabad Figure 23: 10 Daily Snow cover maps of Alkananda Basin Snow and Glaciers of the Himalayas .67. Space Applications Centre ISRO, Ahmedabad Figure 24: AWIFS Image of Ravi Basin Snow and Glaciers of the Himalayas .68. Space Applications Centre ISRO, Ahmedabad Figure 25: 10 Daily Snow cover maps of Ravi Basin Snow and Glaciers of the Himalayas .69. Space Applications Centre ISRO, Ahmedabad Figure 26: AWIFS Image of Astor Basin Snow and Glaciers of the Himalayas .70. Space Applications Centre ISRO, Ahmedabad Figure 27: 10 Daily Snow cover maps of Astor Basin Snow and Glaciers of the Himalayas .71. Space Applications Centre ISRO, Ahmedabad Figure 28: AWIFS Image of Zasker Basin Snow and Glaciers of the Himalayas .72. Space Applications Centre ISRO, Ahmedabad Figure 29: 10 Daily Snow cover maps of Zasker Basin Snow and Glaciers of the Himalayas .73. Space Applications Centre ISRO, Ahmedabad Figure 30: AWIFS Image of Tista Basin Snow and Glaciers of the Himalayas .74. Space Applications Centre ISRO, Ahmedabad Figure 31: 10 Daily Snow cover maps of Tista Basin Snow and Glaciers of the Himalayas .75. Space Applications Centre ISRO, Ahmedabad Figure 32: 10 Daily Snow Extent of Alaknanda Sub-Basin Figure 33: 10 Daily Snow Extent of Ravi Sub-Basin Snow and Glaciers of the Himalayas .76. Space Applications Centre ISRO, Ahmedabad Figure 34: 10 Daily Snow Extent of Zasker Sub-Basin Figure 35: 10 Daily Snow Extent of Astor Sub-Basin Snow and Glaciers of the Himalayas .77. Space Applications Centre ISRO, Ahmedabad Figure 36: 10 Daily Snow Extent of Tista Sub-Basin Snow and Glaciers of the Himalayas .78. Space Applications Centre ISRO, Ahmedabad 5. Glacier Inventory For the three basins 1152 glacier inventory map sheets are prepared at 1:50,000 scale for the glaciated area of the Himalayas (index map is shown in annexure-2). The Indus, Ganga and Brahmaputra basins are covered in 483, 203 and 544 number of map sheets respectively with an overlap in 78 map sheets. The inventory maps and datasheets are prepared to cover all glaciers in these three basins located within India or located outside but draining into India. The glacier inventory map depicts the presence of glaciers and their distribution in space. The significant glacier morphological features for each of the glaciers are mapped and appropriately represented on the map by a pre-defined colour scheme. The mapped glacier features comprise of glacier boundary with separate accumulation area and ablation area. The ablation area is further divided into ablation area ice exposed and ablation area debris covered. The Moraines like median, lateral and terminal moraines present on the glacier are separately mapped and delineated. The supra-glacier lakes occurring on the glaciers are also delineated. The snout is marked as a point location depicting the end of the glacier tongue. The de-glaciated valley associated with the glacier is also delineated along with the associated moraines both lateral and terminal moraines and the moraine dam lakes. The glacier inventory datasheet with 37 parameters is prepared for each glacier. The three basins put together have 71182.08 sq km of glaciated area with 32392 numbers of glaciers. The Indus basin has 16049 glaciers occupying 32246.43 sq km of glaciated area. The 18 glaciated sub-basins in Indus basin are mapped. The Ganga basin has 6237glaciers occupying 18392.90 sq km of glaciated area. There are 7 glaciated sub-basins in Ganga basin. The Brahmaputra basin has 10106 glaciers occupying 20542.75 sq km of glaciated area. The 27 glaciated sub-basins in Brahmaputra basin are mapped. Basin wise glacier summary for Indus, Ganga and Brahmaputra basin is provided in Table 30. Snow and Glaciers of the Himalayas .79. Space Applications Centre ISRO, Ahmedabad Table: 30 Summary of glacier inventory results for Indus, Ganga and Brahmaputra basins Basin Sr. Characteristics Indus Brahma- All basin putra total Nos./ Nos./ Nos./ Nos./ Area km2 Area km2 Area km2 Area km2 Vol km3 Vol km3 Vol km3 Vol km3 1 Sub-basins (Nos.) 18 2 Accumulation area 3 Ablation area debris 6650.95 4 Ablation area ice exposed 5 Total no. of glaciers 6 Total glaciated area 7 No. of Permanent Snow fields and Glacierets 8 Area under Permanent Snow fields and Glacierets 9 No. of Supra-glacier lakes 10 Area of Supra-glacier lakes 11 No. of Moraine dam / Glacial lakes 12 Area of Moraine dam / Glacial lakes Ganga 7 27 52 19265.98 10884.60 12126.36 42276.94 4844.70 5264.90 16760.55 6310.58 2663.50 3081.48 12055.56 16049 6237 10106 32392 32246.43 18392.90 20542.75 71182.08 5117 641 3651 9409 991.68 198.70 1282.92 2473.30 411 87 474 972 18.92 15.20 70.01 104.13 469 194 226 889 33.82 64.10 70.15 168.07 Broad statistical analysis of data for the three basins is carried out to understand the distribution of the glaciated area in each basin. The related bar chart showing the ablation and accumulation area distributions are given in Figure 37. It is observed that the percent accumulation area is highest in the Indus basin as compared to the other two basins. The percent accumulation area is almost similar among Ganga and Brahmaputra basin. The ratio of accumulation to ablation area is also high in Indus basin. The ratio of accumulation to ablation area is almost similar among Ganga and Brahmaputra basins. This indicates that the glaciers of the Indus basin are having larger feed area and hence are relatively more stable as Snow and Glaciers of the Himalayas .80. Space Applications Centre ISRO, Ahmedabad compared to the other two basins. The percent ablation area debris cover is almost similar among Ganga and Brahmaputra basin and is low in the Indus basin. The ablation area ice exposed is highest in Indus basin. The ablation area ice exposed is almost equal among Ganga and Brahmaputra basin. For the Brahmaputra and Ganga basin the accumulation - ablation area ratios are low and most of the glaciated areas are having varying amounts of debris cover. The thick debris cover plays an important role by stopping the heat from sun rays in reducing the melting of glacier ice. However, the status of these glacier features depends on its altitude and latitudinal distribution. 100.0 90.0 80.0 70.0 60.0 ablat ion area ice exposed 50.0 ablat ion area debris cover accumulat ion area 40.0 30.0 20.0 10.0 0.0 1 basin Indus 2 basin Ganga 3 Brahmaput ra basin Figure: 37 Distribution of percent glaciated area in three basins The mean area under various glacier classes like accumulation area, ablation area, glacieret and snow fields, Supra-glacier lakes and moraine dam lakes area are studied for the three glaciated basins and shown in Figure 38. It is observed that the mean accumulation areas and the mean supra-glacier lake area are relatively larger in the Ganga basin as compared to the other two basins. The mean ablation area is high in Brahmaputra basin whereas mean areas for glacieret and snow field are highest in Brahmaputra and low in Indus basin. Moraine dam mean areas are higher for Brahmaputra and Ganga basin as compared to Indus basin. Indus basin has high mean accumulation, low mean ablation area along with low mean supra glacial lake and mean moraine damned lake area which shows this basin to be Snow and Glaciers of the Himalayas .81. Space Applications Centre ISRO, Ahmedabad more stable as compared to Ganga and Brahmaputra basins. It is observed that low mean accumulation area of Brahmaputra basin along with relatively higher mean area for supra glacial lake and moraine damned lake could be serious for glacier health and stability rather than Ganga basin which has relatively high mean accumulation area and high mean ablation area. Mean distribution of glacier classes of major river basin 2.00 Indus Ganga Brahmaputra Mean area (km^2) 1.50 1.00 0.50 0.00 Figure: 38 Mean distributions of glacier classes of major river basin. The detailed discussions and analysis for each of the basin and their sub-basins are given below Indus Basin The Indus basin has 16049 glaciers occupying 32246.43 sq km of glaciated area. The total area under permanent snowfields and glacieret is 991.68 sq km distributed in 5117 number of distinct occurrences. The glaciated part of Indus basin is further divided into eighteen sub-basins namely Gilgit, Hanza, Indus, Astor, Shingo, Shigar, Drass, Suru, Nubra, Zaskar, Pangong Tso, Shyok, Chenab, Beas, Ravi, Sutlej, Spiti and Jhelum. The sub-basin wise maps depicting the distribution of glaciers are given in Annexure-3. The glaciated area is further differentiated as Accumulation area comprising of 19265.98 sq km area and Ablation area comprising of 12961.53 sq km area. Depending upon the presence or absence of debris on glaciers the Ablation area is further divided as Ablation area ice exposed comprising 6310.58 sq km area and Ablation area debris covered comprising 6650.95 sq km area. The summarized glacier inventory data is given in Table 31. Snow and Glaciers of the Himalayas .82. Space Applications Centre ISRO, Ahmedabad Table 31 Summarized glacier inventory data for Indus Basin Snow and Glaciers of the Himalayas .83. Space Applications Centre ISRO, Ahmedabad Statistical distributions of significant glacier features are studied for entire basin as well as for each sub-basin and relevant graphs are prepared. The Percent glaciated area under major morphological classes is given in figure 39 and figure 40. 0.06 19.57 accumulat ion area ablat ion area debris cover ablat ion area ice exposed 20.63 59.75 supraglcier lake Figure: 39 Indus Basin - Percent glaciated area under various classes 12 10 2 8 1.5 6 1 4 0.5 Glacier area (km^2) Permanent snow, Supraglacial lake, Deglaciated valley and Moraine damned lake area (km^2) 2.5 2 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 sub-basins (as per sr. No.) permanent snow supraglacier lake moraine damned lake glacier area deglaciated valley Figure: 40. Mean distribution of different classes of Indus sub-basins. Snow and Glaciers of the Himalayas .84. Space Applications Centre ISRO, Ahmedabad Accumulation area It is evident that the accumulation area is dominant in the Indus basin and covers 59.75% of the total glaciated area. The Ablation area debris covered is 20.63% and the Ablation area ice exposed is 19.57%. Supra-glacier lakes There are 411 supra-glacier lakes occupying 18.92 sq km area of the Indus basin which is about 0.05% of the total glaciated area. The highest numbers of supra-glacier lakes about 172 in number occur in Indus sub-basin and occupy an area of 6.27 sq km. Supra-glacier lakes are not found over any of the glaciers in Hanza and Drass sub-basins. De-glaciated valley The de-glaciated valley is one of the indicators of retreat of valley glaciers by vacating the valleys in lower reaches beyond the snout region. There are 761 number of de-glaciated valleys in the Indus basin and occupy a total of 356.76 sq km area. There highest number of 160 de-glaciated valleys occur in Shyok subbasin and encompass a total area of 69.27 sq km. Other sub-basins like Shigar, Indus, and Gilgit have 155, 90 and 108 numbers of de-glaciated valleys respectively. The four Suru, Nubra, Beas and Ravi do not show the presence of any de-glaciated valleys. Moraine dam lakes There are 469 number of Moraine dam lakes in the Indus basin and occupy a total of 33.82 sq km area. The Gilgit sub-basin has the highest number of moraine dam lakes numbering 215 followed by 81 in Indus and 71 number of moraine dam lakes in Jhelum sub-basins. Although the Jhelum sub-basin has only 71 moraine dam lakes but it has the largest area of 11.79 sq km under moraine dam lakes. The five sub-basins viz. Hanza, Shigar, Nubra, Beas and Ravi do not show the presence of any moraine dam lakes. The mean area under moraine dam lakes is highest for Jhelum sub-basin. Snow and Glaciers of the Himalayas .85. Space Applications Centre ISRO, Ahmedabad Glacieret and permanent snow fields The total area under permanent snowfields and glacieret is 991.68 sq km distributed in 5117 number of distinct occurrences in all the sub-basins. The highest number of occurrences of glacieret and snow fields is in the Indus subbasin which has 1080 number of such glacieret and snow field areas occupying about 108.7 sq km area. The Shigar sub-basin has 566 number of glacieret and snow fields and occupy a much larger area of 299.53 sq km. Ganga Basin The inventoried Ganga basin has 6237glaciers occupying 18392.89 sq km of glaciated area. The total area under permanent snowfields and glacieret is 198.7 sq km distributed in 641 numbers of distinct occurrences. The glaciated part of Ganga basin is further divided into seven sub-basins namely Yamuna, Bhagirathi, Alaknanda, Ghagara, Karnali, Narayani and Kosi as per their location from west to east. While the Karnali sub-basin is the largest sub-basin, the Bhagirathi sub-basin is the smallest in the Ganga Basin. The glaciers in the Ganga basin are located from lower elevation of approx. 2564 m a.s.l. in Ghagra basin to as high as approx. 6312 m a.s.l. in Kosi sub-basin. The sub-basin wise maps depicting the distribution of glaciers are given in Annexure-3. The summarized glacier inventory data for all the seven sub-basins are given in Table 32. The glacierised area is further differentiated as Accumulation area comprising of 10884.63 sq km area and total Ablation area comprising of 7508.27 sq km area. Depending upon the presence or absence of debris on glaciers the Ablation area is further divisible as Ablation area ice exposed comprising 2663.54 sq km and Ablation area debris covered comprising 4844.73 sq km. The largest glaciers in Ganga basin were observed of length of 252, 130, 96 and 93 sq km whereas the altitude positions were found to vary from 3000-6300 m a.s.l. Snow and Glaciers of the Himalayas .86. Space Applications Centre ISRO, Ahmedabad Table 32 Sub-basin wise summarized Glacier Inventory data for Ganga Basin 0.08 59.13 Accumulat ion area Ablat ion area debris cover 14.47 Ablat ion area ice exposed Supraglacier lake 23.32 Figure: 41 Ganga Basin Percent glaciated area under various morphological classes Snow and Glaciers of the Himalayas .87. Space Applications Centre ISRO, Ahmedabad Statistical distributions of significant glacier features are studied for entire basin as well as for each sub-basin and relevant graphs are prepared. Percentage of glaciated areas under major morphological classes is given in figure 41. The graph representing the mean of glacier area, accumulation area, ablation area ice exposed, ablation area debris covered, supra-glacier lakes, de-glaciated valley, and moraine dam lakes is given in figure 42. S u p ra g la c ia l la ke , Mo ra ine d a m n e d la ke a re a (km ^2 ) 6 4 0.5 2 0 Gla c ie r a re a , De g la c ia te d va lle y a nd P e rm a n e nt s no w (km ^2 ) Mean dsitrbution of Ganga sub-basins 1 0 1 2 Supraglacier lake Permanent snow 1.Yamuna, 2.Bhag 3 4 sub-basins 5 Moraine damned lake Deglaciated valley 6 7 Glacier area irathi, 3.Alaknanda, 4.Ghaghara, 5.Karnali, 6.Narayani and 7. Kosi Figure: 42 Graph showing sub-basin wise mean distribution of various glacier features (numbers on x-axis represent the seven sub-basins as given in table above) Snow and Glaciers of the Himalayas .88. Space Applications Centre ISRO, Ahmedabad Accumulation area The accumulation area is significant glacier feature that indicates the total snow feed received which is accumulated over a period of time. The variation of accumulation area over time indicates the melt pattern of glaciers. It is evident that the accumulation area is dominant in the Ganga basin and covers 59.13% of the total glaciated area. Among the sub-basins the Narayani sub-basin has the largest cumulative accumulation area comprising of 3397.42 sq km area. The least cumulative accumulation area of 87.11 sq km occurs in Yamuna sub-basin. Ablation Area The glaciers are relatively more protected in Ganga basin as the ablation area debris covered is about 26.32 percent as compared to ablation area ice exposed which is 14.47 percent of the total glaciated area. The Kosi sub-basin has highest ablation area having 1635.28 sq km and 1007.97 sq km area respectively under ablation area debris covered and ablation area ice exposed. The Yamuna sub-basin has the least ablation area having 37.67 sq km and 41.85 sq km area respectively under ablation area debris covered and ablation area ice exposed. Supra-glacier lakes There are 87 supra-glacier lakes occupying 15.24 sq km area in the Ganga basin which is about 0.08% of the total glaciated area. The highest numbers of supraglacier lakes, 27 in number occur in Karnali sub-basin and occupy an area of 3.27 sq km. Supra-glacier lakes are not found over any glaciers of Yamuna sub-basins. De-glaciated valley There are 84 numbers of de-glaciated valleys in the Ganga basin occupying a total of 211.75 sq km area. The highest numbers of de-glaciated valleys, about 48 numbers, occur in Kosi sub-basin and occupy a total area of 167.73 sq km. The Yamuna and Bhagirathi sub-basins do not show the presence of any de-glaciated valleys. Snow and Glaciers of the Himalayas .89. Space Applications Centre ISRO, Ahmedabad Moraine dam lakes There are 194 number of Moraine dam lakes in the Ganga basin occupying a total of 64.19 sq km area. The Kosi sub-basin has the highest number of moraine dam lakes numbering 168 covering an area of 59.33 sq km under moraine dam lakes. The four sub-basins viz. Yamuna, Bhagirathi, Alaknanda and Ghaghara do not show the presence of any moraine dam lakes. The mean area under moraine dam lakes is highest for Jhelum sub-basin (Figure 40). Glacieret and snow fields The total area under permanent snowfields and glacieret is 198.7 sq km distributed in 641 numbers of distinct occurrences in all the sub-basins. The highest number of occurrences of glacieret and snow fields (GS) is in the Alaknanda sub-basin which has 186 numbers of glacieret and snow fields occupying 24.51 sq km area. All the sub-basins of Ganga basin show the presence of GS. The Ghagra sub-basin has 113 number of glacieret and snow fields occupying a much larger area of 44.35 sq km. Brahmaputra Basin The glaciated part of Brahmaputra basin is covered in 544 map sheets and is further divided into twenty seven sub-basins namely Chorta Tsangpo, Dharia, Dihang/Siang, Dibang, Dukukhu, Gangadhara, Giamda Chhu, Hya Chhu, Kamba Sumdo, Kameng, Kyi Chhu, Lohit, Manas, Manchu, Matsang Tsangpo, Matszyan, Nuang Chhu, Ooitszun, Padrok Chhu, Raga Tsangpo, Sakya Tam, Shang Chhu, Shote Tsangpo, Subansiri, Tista, Tsachu and Yamdrog Tsho. Snow and Glaciers of the Himalayas .90. Space Applications Centre ISRO, Ahmedabad Snow and Glaciers of the Himalayas .91. Space Applications Centre ISRO, Ahmedabad Table 33 Sub-basin wise summarised Glacier Inventory data for Brahmaputra Basin Snow and Glaciers of the Himalayas .92. Space Applications Centre ISRO, Ahmedabad There are 10106 numbers of glaciers in the Brahmaputra basin together occupying of 20542.75 sq km of glaciated area. The total area under permanent snowfields and glacieret is 1282.92 sq km distributed in 3651 number of distinct occurrences 0.34 15.00 accumulat ion area ablat ion area debris cover ablat ion area ice exposed 25.63 59.03 supraglcier lake Figure: 43. Brahmaputra Basin Percent glaciated area under various classes. The glaciated area is further categorized as Accumulation area comprising of 12126.36 sq km area and Ablation area comprising of 8346.38 sq km area (Figure 43). Depending upon the presence or absence of debris on glaciers the Ablation area is further divisible as Ablation area ice exposed comprising 3081.48 sq km area and Ablation area debris covered comprising 5264.9 sq km area. Some of the larger glaciers in Brahmaputra basin were observed having lengths of 141, 126, 98, 55 sq km whereas the lowest altitude position was at 3000 m a.s.l. Accumulation area It can be observed that the accumulation area in the Brahmaputra basin covers 59.16% of the total glaciated area. The Ablation area debris covered is 25.63% more than accumulation area along with a small amount of Ablation area ice exposed of 15%. Snow and Glaciers of the Himalayas .93. Space Applications Centre ISRO, Ahmedabad Ablation area: Brahmaputra has shown area covered under debris which acts as a protection layer against direct sunlight if sufficiently thick. A total of 5264.9 sq km ablation area is under debris whereas ablation area exposed ice exposed is 3081.48 sq km. Few sub-basins like Manas and Gangadhara have shown significant debris cover of 32.05 and 33.81 percent respectively over the glaciated area. Large areas of ablation zone ice exposed could be more susceptible to faster melting considering their altitudinal and geographical positions, however, large debris cover can act as a shield to reduce the effect. Supra-glacier lakes There are 474 supra-glacier lakes occupying 70.02 sq km area of the Brahmaputra basin which is about 0.3 % of the total glaciated area. Brahmaputra sub-basins have significant supra-glacial lakes like Manas, Dihang/Siang, Tista and Giamda Chhu having 88, 133, 61, and 58 numbers respectively. However, the highest mean area of supra-glacial lake was found in Yamdrog Tsho sub-basin. The presence of supra-glacial lakes could be hazardous and cause loss to human life and property. However, the presence of supra-glacial lakes is indicator providing vital information linked with climatic fluctuations. Moraine dam lakes There are 226 number of Moraine dam lakes in the Brahmaputra basin and occupy a total of 70.16 sq km area. The highest moraine damned lake area was found in Dukukhu, Dihang and Kameng 14.56, 12.18 and 12.22 sq km respectively. The highest mean area of Moraine damned lake was also found in Nuang Chhu subbasin. De-glaciated valley There are 127 glaciers associated with de-glaciated valley formation and cover almost 141.4 sq. km. area in this category. Matsang Tsangpo, Dukukhu and Snow and Glaciers of the Himalayas .94. Space Applications Centre ISRO, Ahmedabad Dihang/Siang sub-basins contains most of the de-glaciated valley covering 69.3, 26.1 and 13.6 sq km respectively. However, the mean area was found to be more in Matsang Tsangpo, Padrok Chhu, Dukukhu, Manas and Shote Tsangpo covering 4.08, 3.15, 2.90, 2.05, 1.56 sq km respectively. Permanent snow field: In Brahmaputra valley, approximately 1282.92 sq km area was covered with permanent snow having 3651 number of distinct occurrences. The sub-basins of Giamda Chhu, Lohit and Dihang/Siang are covering 430, 195 and 160 sq km respectively. However, Kameng and Gangadhara have shown the highest mean distribution of 5.76 and 1.55 respectively in Brahmaputra basin. Mean Distribution of different glacier classes: The mean distribution of each category like total glaciated area, permanent snow, supra-glacial lake, de-glaciated valley area and moraine dam lake area has been estimated for all the 27 sub-basins (Figure 44). The sub-basins of Dukukhu, Tista, Yamdrog Tsho and Lohit were found having higher glaciated areas. The Matsang Tsangpo sub-basin has shown highest de-glaciated area along with significant moraine damned lake and de-glaciated valley. The Nuang Chhu sub-basin has shown highest mean moraine damned lake area. It can be observed that Yamdrog Tsho sub-basin has shown a consistently high glaciated area, high supra-glacial lake and moraine damned lake area. Nuang Chhu has shown a high glaciated area with high moraine damned lake. Dukukhu and Matsang Tsangpo have shown a high de-glaciated valley along with high moraine damned lake. Gangadhara has shown a high area under de-glaciated valley along with significant area under supra-glacier lake which could be critical for a glacier system. This mean variability of different glacier features will be helpful to understand the overall glacier condition. Snow and Glaciers of the Himalayas .95. Space Applications Centre ISRO, Ahmedabad 3.5 6 3 5 2.5 4 2 3 1.5 2 1 1 0.5 0 Glacier area (km^2) Mean Permanent snow, Supraglacial lake, Deglaciated valley and Moraine dam lake area (km^2) 7 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 sub-basins (as per sr. No.) permanent snow supraglacier lake moraine damned lake glacier area deglaciated valley Figure: 44 Mean distribution of different classes of Brahmaputra sub-basins (X-axis represents sub-basins 1- Chorta Tsangpo; 2-Dharia; 3-Dibang; 4Dihang/Siang;5- Dukukhu; 6- Gangadhara; 7- Giamda Chhu; 8- Hya Chhu; 9Kamba Sumdo; 10- Kameng; 11- Kyi Chhu; 12- Lohit; 13- Manas; 14-Manchu; 15- Matsang Tsangpo; 16- Matszyan; 17- Nuang Chhu; 18- Ooitszun; 19- Padrok Chhu; 20- Raga Tsangpo; 21- Sakya Tam; 22- Shang Chhu; 23- Shote Tsangpo; 24- Subansiri; 25- Tista; 26- Tsachu; 27-Yamdrog Tsho). Snow and Glaciers of the Himalayas .96. Space Applications Centre ISRO, Ahmedabad 6. Monitoring Changes in Glacier Extent The retreat or advance what is normally observed on the surface is the response of glaciers to adjust to change in its mass balance. The most conspicuous effect is seen on the movement of snout or terminus. The retreat can be measured in following three ways: 1. Linear or one dimensional based on movement of snout 2. Aerial or two dimensional based on change in glacier area 3. Volumetric or three dimensional based on change in volume The third category is covered under glacier mass balance studies. The approach adopted here is based on the areal extent measurements using topographical maps and satellite images. As discussed in methodology the work has been carried out in two parts. (i) Measurements of changes in extent using topographical maps as reference and comparing the extent interpreted from IRS LISS III images covering the specific basin: The topographical maps of 1962 are used except in case of Suru and Nubra basin where maps are of 1969. The satellite data used is of year 2001 or 2004 or 2005 and 2007. The surveys of India maps were also checked in the field for a few glaciers to ascertain the accuracy of glacier extents. (ii) Measurements of changes in extent of glaciers interpreted using satellite images only: The satellite images used as reference are Landsat TM images of 1989/1990 and recent IRS images pertaining to 2004-07 time frame. Glaciers of fifteen basins were monitored. The work has been carried out in collaboration with twelve other organizations. The organizations include University departments, State remote Sensing centers and government organizations. The list of these agencies is separately given in the report. Snow and Glaciers of the Himalayas .97. Space Applications Centre ISRO, Ahmedabad Digital database for the areal extent of individual glaciers of each basin has been created in a GIS environment. These basins are located in different geographic, geologic and climatic conditions. The glaciers include valley glaciers and small permanent snow/ice fields. For example Chandra, Bhaga, Miyar, Warwan and Bhut basins are located in Himachal Pradesh or at the border of Jammu and Kashmir and Himachal Pradesh. They all are part of Chenab basin and occur in the region where wet precipitation is poor. Alaknanda, Bhagirathi, Dhauliganga and Goriganga basins are located in Garhwal and Kumaon Himalayas and lie at a lower latitude than Chenab basin. Suru and Zanskar basins belong to Zanskar range of Ladakh and lie across northwards of Chenab basin. Parbati basin belongs to Beas and Beas is tributary of Satluj basin. This basin lies in relatively wet zones of Himachal Pradesh. Baspa is a part of Satluj basin and lies in wet zones of Himachal Pradesh. The Spiti basin is also a part of Satluj basin and bears a dry climatic condition. Within each basin also glaciers behave differently because the local inherent characters of valleys play important role in accumulation and ablation. The geologic geomorphic and climatic conditions control the accumulation and ablation pattern of glaciers. These external forcing also has implication on debris cover on glaciers. The results of retreat/advance have been presented in four tables. The results show the total gain or loss for an individual basin. The loss or gain is expressed as percentage of total initial area of glaciers. Table 34 shows the total loss in area of glaciers for each basin. The number of glaciers given in table 34 is based on the number of glaciers mapped from topographical maps. Small permanent snow fields and ice fields are also included as glaciers. Table 35 shows the change in glaciers extents as mapped from satellite data of different periods for the same basins. Table 36 and 37 shows the statistics of number of glaciers showing retreat, advance or no change. Based on the data shown on these tables we discuss the results of each basin. Snow and Glaciers of the Himalayas .98. Space Applications Centre ISRO, Ahmedabad Chandra basin: Bara Shigri, Chota Shigri, Hamta and Samudra Tapu glaciers are some of the large glaciers of this basin. Glacier boundaries of 116 glaciers were taken from topographical maps. The total area of these glaciers in 1962 and 2001 were 696 and 554 sq km respectively. This gives a loss of 20% in glacier area. Number of glaciers which show retreat are 113 and the glaciers which do not show any change is 3. This shows that most of the glaciers in this basin show retreat. Landsat images available of 1990 covering this basin show that most of the glaciers are snow covered. Therefore the comparison could not be done for most of the glaciers. The snouts of three glaciers could be identified and mapped on 1999 data. The three glaciers having an area of 107 sq km show a decline of about 3 % during a period of 12 years. Figure 45 shows IRS LISS III FCC covering Samudra Tapu glacier in Chandra basin. Figure 46 is the map showing retreat of this glacier and figure 47 shows the snout position on ground. Miyar Basin One hundred and sixty five glaciers of Miyar basin were monitored for the period 1962-2001. Out of these glaciers 80 have shown retreat, 78 glaciers have advanced whereas 7 glaciers show no change in the glacier area. Detailed investigations have been carried out for 13 glaciers in this basin using satellite data of years 1989, 2000 and 2007, supported by field verifications. Twelve glaciers have shown retreat during 1989-2000 period. Whereas all the thirteen glaciers have shown retreat of the snout during 2000-2007. Bhaga basin Most of the glaciers of this basin are located on Manali Leh road along the river Bhaga. Glacier boundaries of 111 glaciers were adopted from topographical maps of this basin. The total area of 111 glaciers in 1962 and 2001 has been found to be 363 sq km and 254 sq km respectively. There is loss of 30 % during 1962-2001. Among these 108 glaciers show retreat and 3 glaciers do not show any change. Bhaga basin is located in similar climatic conditions as Chandra basin but glaciers of this basin show higher rate of retreat. This is possibly due to the fact that glaciers of this basin are mostly debris free. Glaciers with or without debris cover can be discriminated on FCCs. Another reason for this much retreat could be the size of the glaciers. Mean glacier area of this basin suggests that glaciers are smaller in size. Smaller size indicates the smaller depth of glaciers and short response time. Therefore retreat or advance is faster in smaller glaciers. Snow and Glaciers of the Himalayas .99. Space Applications Centre ISRO, Ahmedabad Landsat images of ablation season in 1990 covering this basin show that glaciers are mostly snow covered. However ten glaciers were observed to be exposed at their snouts in images of 1990. Glacier extents of these glaciers were compared using satellite images. The ten glaciers having an area of 90 sq km show a decline of about 2 % during a period of 12 years. This rate is relatively smaller than what has been found for duration of 1962-2001. A glacier named after Panchinala stream originating from it was also visited on ground. Its snout is shown in figure 48. figure 49 shows accumulation zone of Panchinala glacier in Bhaga basin. figure 50 shows a glaciated region in Bhaga basin at its origin. Another glacier near Patsio village called patsio glacier has been visited for its snout position verification (figure 51). Warwan basin The number of glaciers mapped from topographical maps for this basin is 230. The total area of these glaciers is 740 sq km in 1962 and 608 sq km in 2001 respectively. This gives a loss of 18 %. No. of glaciers which show retreat is 180 and which do not show any change is 15. Number of glacier shows advance is 35. This shows that about 78 % of the glaciers of this basin show retreat. Glacier extents were also compared using satellite images available for 2001 and 2007. One hundred eighty glaciers could be compared using the satellite images of the above time frames. The total area declined from 513 to 510 sq km. this gives 1 percent loss during 2001-2007. This loss of 1 percent in 6 years is much less than 18 % loss during 1962-2001. This shows that there is decline in the trend of glacier retreat after 2001. Bhut basin The number of glaciers mapped from topographical maps for this basin is 143. The total area of glaciers is 450 sq km in 1962 and 417 sq km in 2001 respectively. This gives a loss of 7 %. Number of glaciers which show retreat is 74 and 29 glaciers do not show any change. Among these, 40 glaciers show advance. This shows that 51.7 % of the glaciers show retreat. Snow and Glaciers of the Himalayas .100. Space Applications Centre ISRO, Ahmedabad Glacier extents were compared using satellite images available for 2001 and 2007. Twenty eight glaciers could be compared using the images. The total area declined from 217 to 203sq km this gives 6 percent loss during 2001-2007. This loss of 6 percent is much higher than loss during 1962-2001. This shows that the glacier retreat after 2001 for this basin is much rapid than previous years. Though Bhut basin and Warwan basin are adjacent basins the rate of retreat during 19622001 and 2001-2007 show a contrasting trend. Alaknanda basin Satopanth and Bhagirath Kharak glaciers are some of the large glaciers of this basin. 274 glaciers were mapped from topographical maps. The total area of glaciers is 1047 sq km in 1962 and 905 sq km in 2004 respectively. This gives a loss of 14 %. Number of glaciers which show retreat is 243 and 4 glaciers do not show any change. Among these, 27 glaciers show even advance. When glacier extents were compared using satellite images available for years 1990 and 2005 we find that there is a loss of 10 % in glacier area. The glacier area in 1990 and 2005 are 393 sq km and 355 sq km respectively for 119 glaciers. The loss after 1990 is 10 percent as compared to 14 percent during 1962-2005. This shows that the glacier retreat after 1990 for this basin is much rapid than previous years. Figure 52 shows validation of snout of Satopanth glacier in Alaknanda basin. Bhagirathi basin Gangotri group of glaciers is largest glacier of this basin. One hundred eighty three glaciers were mapped for this basin. The total area of glaciers is 1218 sq km in 1962 and 1074 sq km in 2004 respectively. This gives a loss of 11 %. No. of glaciers which show retreat is 117 and 39 glaciers do not show any change. Among these, 27 glaciers show even advance. Figure 53 shows IRS LISS III FCC covering Gangotri glacier and its tributaries. Figure 54 shows map corresponding to this image. Snow and Glaciers of the Himalayas .101. Space Applications Centre ISRO, Ahmedabad When glacier extents were compared using satellite images available for 1990 and 2005 we find that there is a loss of 1.8 % in glacier area. The glacier area in 1990 and 2005 are 867 sq km. and 851 sq km. respectively for 153 glaciers. The loss after 1990 is 1.8 percent than 11 percent during 1962-2005. Among 153 glaciers only 44 show retreat, 6 show advance and 103 glaciers show no change. This shows that the glacier retreat after 1990 for this basin is much slower than in adjacent basins and also in comparison to period of 1962-2005. Though Alaknanda and Bhagirathi basin are adjacent basins the rate of retreat during 1962-2001 and 2001-2007 show a contrasting trend. Gauri Ganga basin Milam glacier is one of the largest glaciers of Kumaon Himalayas. The satellite images and corresponding map covering this glacier are shown in figure 55 and figure 56. The retreat was estimated for selected glaciers subject to the availability of topographical maps of this region. The comparison between satellite images of year 1990 and 2005 has been carried out. Twenty nine glaciers with area of 272 sq km in 1990 and 261 sq km in 2005 indicating a loss of 4 percent were mapped. Most of the glaciers of this basin show retreat. Dhauliganga basin Extents of a few glaciers of this basin have been taken from topographical maps. There are 104 glaciers shown in topographical maps. Among 104 glaciers 65 glaciers show retreat whereas 39 glaciers show no change. The loss found during 1962-2005 is 16 %. This loss is quite comparable to retreat of glaciers in other basin. Suru basin 215 glaciers were mapped for this basin. The total area of glaciers is 568 sq km in 1969 and 474 sq km in 2001 respectively. This gives a loss of 17%. All glaciers show retreat in this basin. 17 % loss matches well with similar loss shown by many other basins though the duration of monitoring is smaller than with respect to monitoring carried out using topographical maps of 1962. Snow and Glaciers of the Himalayas .102. Space Applications Centre ISRO, Ahmedabad When glacier extents were compared using satellite images available for 1990 and 2001 we find that there is a loss of 9 % in glacier area. The glacier area in 1990 and 2001 are 506 sq km and 459 sq km respectively for 355 glaciers. All the 355 glaciers show retreat. The loss after 1990 is 9 %. This shows that there glacier retreat after 1990 for this basin is much rapid than in comparison to period of 1969-2001. Zanskar basin The number of glaciers monitored in this basin is highest among all. 631 glaciers were mapped for this basin. The total area of glaciers is 1107 sq km in 1962 and 940 sq km in 2001 respectively. This gives a loss of 15%. Number of glaciers which shows retreat is 578. Rest of glacier either show no change or advance. 15 % loss in glacier area matches well with similar loss shown by many other basins. When glacier extents were compared using satellite images available for 2001 and 2006 we find that there is a loss of 9 % in glacier area. The glacier area in 1990 and 2001 is 775 sq km and 709 sq km respectively for 463 glaciers. Among these, 422 glaciers show retreat. The loss after 2001 is 9 %. This shows that glacier retreat after 2001 for this basin is much rapid than in comparison to period of 19622001. The 9 percent loss after 2001 in Zanskar basin is comparable to Spiti basin. Spiti basin 337 glaciers were monitored for this basin. The total area of glaciers is 474 sq.km in 1962 and 396 sq. km. in 2001 respectively. This gives a loss of 16 %. Number of glaciers which shows retreat is 169. Rest of glacier either show no change or advance. 16 % loss matches well with similar loss shown by many other basins. When glacier extents were compared using satellite images available for 2001 and 2007 we find that there is a loss of 13.4 % in glacier area. The glacier area in 2001 and 2007 is 718 and 622 sq. km respectively for 722 glaciers. Among all, 648 glaciers show retreat. This shows that there glacier retreat after 2001 for this basin is much rapid than in comparison to period of 1962-2001. This rate is highest among all basins for a period after 2001. Snow and Glaciers of the Himalayas .103. Space Applications Centre ISRO, Ahmedabad Parbati The number of glaciers monitored during 1962- 2001 are 90. Eighty eight glaciers show loss in area. The loss for the basin comes out to be 20 %. Based on satellite images the loss is 5 percent during 1998-2004. This rate is also higher than what has been found during 1962-2001. Figure 57 shows snout of Parbati glacier which is debris covered. Figure shows a field photograph of snout of Parbati glacier. The snout is covered with thick debris. Tista Since the topographical maps were not available for this basin the glaciers were only monitored using satellite images. Thirty Four glaciers mapped from data of 1990. The total area of these glaciers in 1990 was 305 sq. km. and decreased to 301 sq km in 2004. This gives only 1 percent loss. Tista basin is located in much lower latitudes than other basins. Most of the glaciers are covered with debris. There is almost no retreat in this basin. It shows that basins of eastern Himalaya show no or very less retreat than western Himalayas. Among 34 glaciers 23 glaciers show retreat and rest of them show either no change or advance. Figure58 and 59 shows IRS LISS III image covering Zemu glacier of Tista basin and figure is the map showing glacier extent covering this glacier. Nubra The number of glaciers monitored during 1962- 2001 are 31. 17 glaciers show loss in area. The loss for the basin comes out to be 6 %. The total area of glaciers in 1969 was 2150 sq km and 2026 sq. km. in 2001. This data shows that the glaciers of this basin are very large. The number of glaciers mapped in 1989 is 84 and cover 3159 sq km area. The area increases to 3163 sq km. in 2001. The data indicates almost no change in glaciers after 1989. As we see that the number of glaciers of this basin occupy a very large area the response time is slow and retreat is very loss. The Kichik Kumdam glacier which is not part of the identified basins has also been added in this investigation. This glacier has shown an increase in area using satellite data of 1989 and 2001 (figure 60). Snow and Glaciers of the Himalayas .104. Space Applications Centre ISRO, Ahmedabad Table: 34 Loss/gain in area of glaciers in different basins based on Survey of India (SOI) maps and satellite images Snow and Glaciers of the Himalayas .105. Space Applications Centre ISRO, Ahmedabad Table 35: Loss/gain in area of glaciers in different basins based on satellite images Snow and Glaciers of the Himalayas .106. Space Applications Centre ISRO, Ahmedabad Table 36: Overview of number of glacier fluctuations in different basins based on SOI maps and satellite images Total Snow and Glaciers of the Himalayas 90 88 2630 2047 .107. - 435 2 148 Space Applications Centre ISRO, Ahmedabad Table: 37 Overview of number of glacier fluctuations in different basins based on Satellite images. Total Snow and Glaciers of the Himalayas 2190 1673 .108. 158 359 Space Applications Centre ISRO, Ahmedabad Figure 45: IRS 1C LISS III Image of August 23, 2005 showing the glaciers of part of the Chandra Sub-Basin Snow and Glaciers of the Himalayas .109. Space Applications Centre ISRO, Ahmedabad Figure 46: Map showing loss in area of the Glaciers of a part of the Chandra sub-basin between 1962 and 2005 Snow and Glaciers of the Himalayas .110. Space Applications Centre ISRO, Ahmedabad Figure 47: Snout of Samudra Tapu glacier Figure 48: Snout of Panchinala glacier. Snow and Glaciers of the Himalayas .111. Space Applications Centre ISRO, Ahmedabad Figure 49: Accumulation zone of Panchinala glacier near Patseo in Bhaga basin. Figure 50: Glacier with fresh snow on its ablation zone in Bhaga basin near Bara-La Cha pass. Snow and Glaciers of the Himalayas .112. Space Applications Centre ISRO, Ahmedabad Figure 51: Snout of Patsio glacier. Figure 52: GPS reading at the snout of Satopanth glacier. Snow and Glaciers of the Himalayas .113. Space Applications Centre ISRO, Ahmedabad Figure 53: IRS LISS III FCC showing Gangotri glaciers (Bhagirathi basin) Snow and Glaciers of the Himalayas .114. Space Applications Centre ISRO, Ahmedabad Figure 54: Map showing loss in area of the Glaciers of a part of the Bhagirathi sub-basin between 1989 and 2005 Snow and Glaciers of the Himalayas .115. Space Applications Centre ISRO, Ahmedabad Figure 55: IRS 1C LISS III Image of September 7, 2005 showing the glaciers of part of the Gauriganga Sub-Basin Snow and Glaciers of the Himalayas .116. Space Applications Centre ISRO, Ahmedabad Figure 56: Map showing loss in area of the Glaciers of a part of the Gauriganga sub-basin between 1962 and 2005 Snow and Glaciers of the Himalayas .117. Space Applications Centre ISRO, Ahmedabad Figure 57: Field Photograph Showing the Snout Area of Parbati Glacier in Himachal Pradesh Snow and Glaciers of the Himalayas .118. Space Applications Centre ISRO, Ahmedabad Figure 58: LANSAT TM Images of Zemu and Changsang Glaciers, 1990 Snow and Glaciers of the Himalayas .119. Space Applications Centre ISRO, Ahmedabad Figure 59: Map showing loss in area of the Glaciers of a part of the Zemu sub-basin between 1990 and 2004 Snow and Glaciers of the Himalayas .120. Space Applications Centre ISRO, Ahmedabad Figure 60: Image showing increase in area of Kichik Kumdam glacier between 1989 and 2001. Snow and Glaciers of the Himalayas .121. Space Applications Centre ISRO, Ahmedabad 7. Glacier Mass Balance Glacier mass balance estimation is based on monitoring of snow line at the end of ablation season. The snow line is treated equivalent to equilibrium line. The zone above equilibrium line is accumulation zone and below that is ablation zone. The ratio of accumulation area and total area of glaciers is used for estimation of mass balance. A mathematical relationship is developed for AAR and field mass balance which is used to estimate mass balance if AAR is known. The ratio has pertinent relationship with -vemass balance which is used here to estimate the mass balance of other glaciers. AWIFS data from IRS P6 has been used to delineate snow line at the end of ablation season for each glacier of identified basins. Ten basins were taken up based on their diversity in geographically and climatically. The mass balance was estimated for mainly valley glaciers and not small glaciers /permanent snow fields. This has been carried out for three years 2005, 2006 and 2007. The salient results of mass balance are given for each basin in table no. 37 to 52. Each table shows the number of glaciers showing positive or negative mass. This method gives an approximate estimate of increase or decrease of mass of the glacier. This method is also useful for inter and intra comparison of trend in mass balance among all the basins. The data indicates upward movement of snowline for more number of glaciers. The glaciers showing negative mass balance have larger area than showing positive mass balance. In figure 61 AWiFS data shows variation of snow line on glaciers. Warwan basin Table 38 shows highlights of mass balance of Warwan basin for 2005. 43 glaciers were monitored. The basin shows both glaciers showing positive mass balance and negative mass balance. But the total area of glaciers with negative mass balance is much more than having positive mass balance in 2005 (table 38). In 2006 the number of glaciers with negative mass balance is 28 with total area more than those having + mass balance showing in table 39. In 2007 (table 40) the number of glaciers with mass balance is less than number having +vemass balance but its total area is much higher than the those having + mass balance. It Snow and Glaciers of the Himalayas .122. Space Applications Centre ISRO, Ahmedabad indicates an upward trend in number of glaciers having negative mass balance. Figure 62 shows an example of snow line variations in one of the glacier of Warwan basin for 2005. Bhut basin Table 41 shows highlights of mass balance of Bhut basin for 2005. 43 glaciers were monitored in 2005. The basin shows both glaciers showing positive mass balance and negative mass balance. Number of glaciers with + mass balance is less than those having - mass balance. Total area is much higher for glaciers with mass balance. In 2006 the number of glaciers with negative mass balance is 17 with area of 230 sq km showing in table 42. In 2007 (table 43) number of glaciers with vemass balance is 20. It indicates an upward trend in number of glaciers having negative mass balance. Chandra basin Table 44 shows highlights of mass balance of Chandra basin for 2005. 106 glaciers were monitored. The basin has glaciers showing positive mass balance and negative mass balance too. Though the number of glaciers with mass balance is different than those having + mass balance but the total area is almost similar in 2005. Table 45 and table 46 shows that the number of glaciers with negative mass balance is 37 in 2006 and 90 in 2007. The total area of glaciers with negative mass balance remains more than for + mass balance. It indicates an upward trend in number of glaciers having negative mass balance. Bhaga basin Table 47 shows highlights of mass balance of Bhaga basin for 2005. 72 glaciers were monitored. 67 glaciers indicate +vemass balance and 5 glaciers show mass balance. The total area of 67 glaciers is 255.60 sq km. In 2006 the number of glaciers having mass balance is 20 (table 48) and 37 in 2007 (table 49). Dhauliganga basin Table 50 shows highlights of mass balance of Dhauliganga basin for 2006. 59 glaciers were monitored. The results show both glaciers showing positive mass balance and negative mass balance also. The number of glaciers with mass Snow and Glaciers of the Himalayas .123. Space Applications Centre ISRO, Ahmedabad balance is more than those having + mass balances (15) and the total area is also higher for glaciers with mass balance in 2005. In 2007 (table 51) the number of glaciers with negative mass balance is 38 but its total area is much higher than in 2006. Goriganga basin Table 52 shows highlights of mass balance of Goriganga basin. 42 glaciers were monitored in 2006. The basin shows both glaciers showing positive mass balance and negative mass balance. The number of glaciers with mass balance is less than those having + mass balances (26) and the total area is also less for glaciers with mass balance. In 2007 (table 53) the number of glaciers with negative mass balance is 23 and its total area is also higher. Miyar Basin: In Miyar basin, 114 glaciers were monitored. The glaciers of basin have shown positive mass balance and negative mass balance. The number of glaciers with negative mass balance and positive mass balance are 87 and 26 respectively in year 2005 (table 54). Miyar basin shows the number of glaciers with negative mass balance 110 in 2006 (table 55) and 91 in 2007(table 58). Total area of glaciers with negative mass balance remains more than for positive misbalance. It indicates an upward trend in number of glaciers with negative mass balance. Alaknanda, Bhagirathi and Mandakini basins: The AAR of glaciers of Bhagirathi, Alaknanda and Mandakini basins were estimated for the years 2005, 2006 and 2007. One hundred glaciers were monitored for this study. But the mass balance was estimated from AAR only for the year 2007 as the data corresponding to end of ablation season was covered with clouds. For mass balance determination the essential requirement of data is that data should be of end of ablation. In the year 2007, 56 glaciers of Alaknanda and Mandakini basins were observed to have negative mass balance. 34 glaciers have shown positive mass balance. The data of 10 glaciers were found cloudy. The mass balance of glaciers of Bhagirathi basin was estimated for year 2007. 120 glaciers were monitored in this study. 87 glaciers have shown negative mass balance and 33 glaciers have shown positive mass balance. Snow and Glaciers of the Himalayas .124. Space Applications Centre ISRO, Ahmedabad Figures 63, 64 and 65 show the variation of snow line for a glacier of Chandra, Miyar and Bhaga basin respectively. Figure 61: Snow line variation on glaciers for estimation of AAR. Snow and Glaciers of the Himalayas .125. Space Applications Centre ISRO, Ahmedabad Table 38: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2005 ablation period for Warwan basin. Characteristics 2005 No. Area(km2) 1 Glaciers 43 414.6 2 Glaciers with no accumulation area 3 3.57 3 Glaciers with +vemass balance 16 122.27 4 Glaciers with -vemass balance 24 288.76 S.N. Table 39: Salient results of mass balance estimation based on AAR Approach using AWiFS data of 2006 ablation period for Warwan basin. S.N. Characteristics 2006 No. Area(km2) 1 Glaciers 43 414.6 2 Glaciers with no accumulation area 2 2.58 3 Glaciers with +vemass balance 11 88.94 4 Glaciers with -vemass balance 28 319.04 Table 40: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2007 ablation period Warwan basin. S.N. Characteristics 2007 No. Area(km2) 1 Glaciers 43 413.33 2 Glaciers with no accumulation area 1 2.18 3 Glaciers with +vemass balance 13 119.13 4 Glaciers with -vemass balance 29 294.2 Snow and Glaciers of the Himalayas .126. Space Applications Centre ISRO, Ahmedabad Table 41: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2005 ablation period for Bhut basin S.N. Characteristics 2005 No. Area(km2) 1 Glaciers 38 343.78 2 Glaciers with no accumulation area 0 0 4 Glaciers with +vemass balance 24 139.68 5 Glaciers with -vemass balance 14 204.10 Table 42: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2006 ablation period for Bhut basin S.N. Characteristics 2006 No. Area(km2) 1 Glaciers 38 343.78 2 Glaciers with no accumulation area 0 0 4 Glaciers with +vemass balance 19 107.56 5 Glaciers with -vemass balance 17 230.07 Table 43: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2007 ablation period for Bhut basin. S.N. Characteristics 2007 No. Area(km2) 1 Glaciers 38 343.78 2 Glaciers with no accumulation area 2 2.78 4 Glaciers with +vemass balance 16 91.88 5 Glaciers with -vemass balance 20 249.12 Snow and Glaciers of the Himalayas .127. Space Applications Centre ISRO, Ahmedabad Table 44: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2005 ablation period for Chandra basin. S.N. Characteristics 2005 No. Area(km2) 1 Glaciers 106 586.109 2 Glaciers with +vemass balance 67 293.639 3 Glaciers with -vemass balance 37 292.470 4 Cloudy 2 Table 45: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2006 ablation period for Chandra basin. S.N. Characteristics 2006 No. Area(km2) 1 Glaciers 106 586.109 2 Glaciers with +vemass balance 30 182.709 3 Glaciers with -vemass balance 37 308.926 4 Cloudy 39 Table 46: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2007 ablation period for Chandra basin. S.N. Characteristics 2007 No. Area(km2) 1 Glaciers 106 586.11 2 Glaciers with +vemass balance 15 133.85 3 Glaciers with -vemass balance 90 447.79 4 Cloudy 1 Snow and Glaciers of the Himalayas .128. Space Applications Centre ISRO, Ahmedabad Table 47: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2005 ablation period for Bhaga basin. S.N. Characteristics 2005 No. Area(km2) 1 Glaciers 72 278.41 2 Glaciers with +vemass balance 67 255.60 3 Glaciers with -vemass balance 5 22.81 4 Cloudy - Table 48: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2006 ablation period for Bhaga basin. S.N. Characteristics 2006 No. Area(km2) 1 Glaciers 72 278.41 2 Glaciers with +vemass balance 24 107.40 3 Glaciers with -vemass balance 20 121.54 4 Cloudy 28 Table 49: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2007 ablation period for Bhaga basin. S.N. Characteristics 2007 No. Area(km2) 1 Glaciers 72 278.41 2 Glaciers with +vemass balance 34 172.73 3 Glaciers with -vemass balance 37 103.66 4 Cloudy 1 Snow and Glaciers of the Himalayas .129. Space Applications Centre ISRO, Ahmedabad Table 50: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2006 ablation period for Dhauliganga basin. S.N. Characteristics 2006 No. Area(km2) 1 Glaciers 59 206.62 2 Glaciers with +vemass balance 15 76.98 3 Glaciers with -vemass balance 32 102.90 4 Cloudy 12 Table 51: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2007 ablation period Dhauliganga basin. S.N. Characteristics 2007 No. Area(km2) 1 Glaciers 59 206.62 2 Glaciers with +vemass balance 3 23.21 3 Glaciers with -vemass balance 38 168.34 4 Cloudy 18 Snow and Glaciers of the Himalayas .130. Space Applications Centre ISRO, Ahmedabad Table 52: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2006 ablation period for Gauriganga basin. S.N. Characteristics 2006 No. Area(km2) 1 Glaciers 42 318.85 2 Glaciers with +vemass balance 26 236.83 3 Glaciers with -vemass balance 5 65.48 4 Cloudy 11 Table 53: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2007 ablation period for Gauriganga basin. S.N. Characteristics 2007 No. Area(km2) 1 Glaciers 42 318.85 2 Glaciers with +vemass balance 14 135.72 3 Glaciers with -vemass balance 23 176.81 4 Cloudy 5 Snow and Glaciers of the Himalayas .131. Space Applications Centre ISRO, Ahmedabad Table 54: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2005 ablation period for Miyar basin. S.N. Characteristics 2005 No. Area(km2) 114 504 1 Glaciers 2 Glaciers with no accumulation area - 3 Glaciers with +vemass balance 26 79 4 Glaciers with -vemass balance 87 423 Table 55: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2006 ablation period for Miyar basin. S.N. Characteristics 2006 No. Area(km2) 114 504 1 Glaciers 2 Glaciers with no accumulation area - - 3 Glaciers with +vemass balance 2 2 4 Glaciers with -vemass balance 110 495 Table 56: Salient results of mass balance estimation based on AAR approach using AWiFS data of 2007 ablation period Miyar basin. S.N. Characteristics 2007 No. Area(km2) 114 504 1 Glaciers 2 Glaciers with no accumulation area - - 3 Glaciers with +vemass balance 3 62 4 Glaciers with -vemass balance 91 432 Snow and Glaciers of the Himalayas .132. Space Applications Centre ISRO, Ahmedabad Figure 62: IRS P6 Images showing fluctuation of snow line for 2005 Glacier of Warwan Basin Snow and Glaciers of the Himalayas .133. Space Applications Centre ISRO, Ahmedabad Figure 63: IRS P6 Images showing fluctuation of snow line for 2007 Glacier of Chandra Basin Snow and Glaciers of the Himalayas .134. Space Applications Centre ISRO, Ahmedabad Figure: 64 IRS P6 Images showing fluctuation of snow line for 2007 Glacier of Miyar Basin Snow and Glaciers of the Himalayas .135. Space Applications Centre ISRO, Ahmedabad Figure 65: IRS P6 Images showing fluctuation of snow line for 2007 Glacier of Bhaga Basin Snow and Glaciers of the Himalayas .136. Space Applications Centre ISRO, Ahmedabad 8. References 1 Anonymous, National (Natural) Resources Information System (NRIS)-Node design and standards ISRO-NNRMS-SP-2000, Bangalore 2000. 2 Bahuguna I. M., and Kulkarni A.V., 2001, Application of Digital Elevation Model and Ortho images derived from IRS PAN stereo data in Monitoring variations in Glacial Dimensions, Proc. of National Symposium in Advances in Remote Sensing Technology with Special Emphasis on High Resolution Imagery, Ahmedabad 3 Dozier J. 1984. Snow reflectance from Landsat-4 Thematic Mapper. IEEE Transactions on Geosciences and Remote Sensing GE-22, 323 328 4 Gusain H.S., A. Singh, A. Ganju and D. Singh, 2004. Characteristics of the Seasonal Snow Cover of Pir Panjal and Great Himalayan Ranges in India Himalaya, In Proceedings of the International Symposium Snow Monitoring and Avalanches, 12-16 April 2004, Manali, India. Manali, Snow and Avalanche Study Establishment, 97-102. 5 Kulkarni A. V., B. P. Rathore, Suresh Mahajan and P. Mathur, 2005, Alarming retreat of Parbati Glacier, Beas basin, Himachal Pradesh, Current Science 88(11), 1844-1850. 6 Kulkarni A. V., S. K. Singh, P. Mathur and V. D. Mishra, 2006, Algorithm to monitor snow cover using AWiFS data of RESOURCESAT for the Himalayan region, International Journal of Remote Sensing, Vol. 27, No. 12, 2449-2457. 7 Kulkarni A.V., P. Basak, S.S. Randhawa and R.K. Sood, 1999, Estimation of seasonal snow cover contributing into snow melt runoff models in winter season, Proceedings of National Snow Science Workshop 1999 (NSSW-99) organized by Snow and Avalanche Study Establishment, Manali, pp. 151-155. 8 Kulkarni A.V and Buch, A.M., 1991, Glacier Atlas of Indian Himalaya, SAC/RSA/ RSAG- MWRD/SN/05/91, pages 62. Snow and Glaciers of the Himalayas .137. Space Applications Centre ISRO, Ahmedabad 9 Kulkarni A.V. and B. P. Rathore, 2003, Snow covers monitoring in Basapa basin using IRS WiFS data, Mausam 54(1), 335-34. 10 Kulkarni A.V., B. P. Rathore and Suja Alex, 2004, Monitoring of glacial mass balance in the Basapa basin using Accumulation Area Ratio method, Current science 86(1), 101-106. 11 Markham B.L. and J.L. Barker. 1987. Thematic mapper bandpass solar exoatmospheric irradiances. Int. J. Remote Sens., 8(3), 517523 12 Muller F., Cafflisch, T and Muller, G., 1977. Instruction for compilation and assemblage of data for a world glacier inventory, Dept. of Geography, Swiss Federal Institute of Technology, Zurich 13 Sharma S.S. and A. Ganju, 2000. Complexities of Avalanche Forecasting in Western-Himalayas-An Overview. Cold Reg. Science Technologies, 31 (2), 95-102. 14 Sharma A.K., Singh S.K. and Kulkarni A.V., 2008, Approach for Himalayan glacier inventory using remote sensing and GIS techniques, Proceedings of International workshop on snow, ice, glacier and avalanches (January 7-9, 2008, IIT Mumbai), pp 177-188. 15 Sharma A.K., Singh S.K. and Kulkarni A.V., 2006, Technical guidelines for Himalayan glacier inventory (Indus, Ganga and Brahmaputra basin), SAC/RESIPA/MESG-SGP/TN 27/2006. 16 Srinivasulu J. and Kulkarni A.V., 2004, A Satellite based Spectral Reflectance Model for Snow and Glacier Studies in the Himalayan Terrain, Proc. of the Indian Acad. Sci. (Earth and Planet. Sci.) 113 (1), 117-128. Snow and Glaciers of the Himalayas .138. Space Applications Centre ISRO, Ahmedabad An n e x u r e I Maps of Snow Cover Snow and Glaciers of the Himalayas .139. Space Applications Centre ISRO, Ahmedabad Figure 66 : AWiFS image of Bhagirathi basin Snow and Glaciers of the Himalayas .140. Space Applications Centre ISRO, Ahmedabad Figure 67: 10 daily snow cover map of Bhagirathi basin Snow and Glaciers of the Himalayas .141. Space Applications Centre ISRO, Ahmedabad Figure 68: AWiFS image of Yamuna basin Snow and Glaciers of the Himalayas .142. Space Applications Centre ISRO, Ahmedabad Figure 69 : 10 daily snow cover map of Yamuna basin Snow and Glaciers of the Himalayas .143. Space Applications Centre ISRO, Ahmedabad Figure 70: AWiFS image of Baspa basin Snow and Glaciers of the Himalayas .144. Space Applications Centre ISRO, Ahmedabad Figure 71: 10 daily snow cover map of Baspa basin Snow and Glaciers of the Himalayas .145. Space Applications Centre ISRO, Ahmedabad Figure 72: AWiFS image of Beas basin Snow and Glaciers of the Himalayas .146. Space Applications Centre ISRO, Ahmedabad Figure 73: 10 daily snow cover map of Beas basin Snow and Glaciers of the Himalayas .147. Space Applications Centre ISRO, Ahmedabad Figure 74: AWiFS image of Jiwa basin Snow and Glaciers of the Himalayas .148. Space Applications Centre ISRO, Ahmedabad Figure 75: 10 daily snow cover map of Jiwa basin Snow and Glaciers of the Himalayas .149. Space Applications Centre ISRO, Ahmedabad Figure 76: AWiFS image of Parbati basin Snow and Glaciers of the Himalayas .150. Space Applications Centre ISRO, Ahmedabad Figure 77 : 10 daily snow cover map of Parbati basin Snow and Glaciers of the Himalayas .151. Space Applications Centre ISRO, Ahmedabad Figure 78 : AWiFS image of Pin basin Snow and Glaciers of the Himalayas .152. Space Applications Centre ISRO, Ahmedabad Figure 79 : 10 daily snow cover map of Pin basin Snow and Glaciers of the Himalayas .153. Space Applications Centre ISRO, Ahmedabad Figure 80: AWiFS image of Spiti basin Snow and Glaciers of the Himalayas .154. Space Applications Centre ISRO, Ahmedabad Figure 81: 10 daily snow cover map of Spiti basin Snow and Glaciers of the Himalayas .155. Space Applications Centre ISRO, Ahmedabad Figure 82: AWiFS image of Chandra basin Snow and Glaciers of the Himalayas .156. Space Applications Centre ISRO, Ahmedabad Figure 83: 10 daily snow cover map of Chandra basin Snow and Glaciers of the Himalayas .157. Space Applications Centre ISRO, Ahmedabad Figure 84: AWiFS image of Bhaga basin Snow and Glaciers of the Himalayas .158. Space Applications Centre ISRO, Ahmedabad Figure 85: 10 daily snow cover map of Bhaga basin Snow and Glaciers of the Himalayas .159. Space Applications Centre ISRO, Ahmedabad Figure 86: AWiFS image of Miyar basin Snow and Glaciers of the Himalayas .160. Space Applications Centre ISRO, Ahmedabad Figure 87: 10 daily snow cover map of Miyar basin Snow and Glaciers of the Himalayas .161. Space Applications Centre ISRO, Ahmedabad Figure 88: AWiFS image of Bhut basin Snow and Glaciers of the Himalayas .162. Space Applications Centre ISRO, Ahmedabad Figure 89: 10 daily snow cover map of Bhut basin Snow and Glaciers of the Himalayas .163. Space Applications Centre ISRO, Ahmedabad Figure 90: AWiFS image of Warwan basin Snow and Glaciers of the Himalayas .164. Space Applications Centre ISRO, Ahmedabad Figure 91 : 10 daily snow cover map of Warwan basin Snow and Glaciers of the Himalayas .165. Space Applications Centre ISRO, Ahmedabad Figure 92 : AWiFS image of Drass basin Snow and Glaciers of the Himalayas .166. Space Applications Centre ISRO, Ahmedabad Figure 93: 10 daily snow cover map of Drass basin Snow and Glaciers of the Himalayas .167. Space Applications Centre ISRO, Ahmedabad Figure 94: AWiFS image of Jhelum basin Snow and Glaciers of the Himalayas .168. Space Applications Centre ISRO, Ahmedabad Figure 95: 10 daily snow cover map of Jhelum basin Snow and Glaciers of the Himalayas .169. Space Applications Centre ISRO, Ahmedabad Figure 96: 10 daily snow cover map of Kishanganga basin Snow and Glaciers of the Himalayas .170. Space Applications Centre ISRO, Ahmedabad Figure 97: 10 daily snow cover map of Kishanganga basin Snow and Glaciers of the Himalayas .171. Space Applications Centre ISRO, Ahmedabad Figure 98: AWiFS image of Shingo basin Snow and Glaciers of the Himalayas .172. Space Applications Centre ISRO, Ahmedabad Figure 99: 10 daily snow cover map of Shingo basin Snow and Glaciers of the Himalayas .173. Space Applications Centre ISRO, Ahmedabad Figure 100: AWiFS image of Suru basin Snow and Glaciers of the Himalayas .174. Space Applications Centre ISRO, Ahmedabad Figure 101: 10 daily snow cover map of Suru basin Snow and Glaciers of the Himalayas .175. Space Applications Centre ISRO, Ahmedabad Figure 102: AWiFS image of Gilgit basin Snow and Glaciers of the Himalayas .176. Space Applications Centre ISRO, Ahmedabad Figure 103: 10 daily snow cover map of Gilgit basin Snow and Glaciers of the Himalayas .177. Space Applications Centre ISRO, Ahmedabad Figure 104: AWiFS image of Hanza basin Snow and Glaciers of the Himalayas .178. Space Applications Centre ISRO, Ahmedabad Figure 105 : 10 daily snow cover map of Hanza basin Snow and Glaciers of the Himalayas .179. Space Applications Centre ISRO, Ahmedabad Figure 106: AWiFS image of Nubra basin Snow and Glaciers of the Himalayas .180. Space Applications Centre ISRO, Ahmedabad Figure 107: 10 daily snow cover map of Nubra basin Snow and Glaciers of the Himalayas .181. Space Applications Centre ISRO, Ahmedabad Figure 108: AWiFS image of Shasgan basin Snow and Glaciers of the Himalayas .182. Space Applications Centre ISRO, Ahmedabad Figure 109: 10 daily snow cover map of Shasgan basin Snow and Glaciers of the Himalayas .183. Space Applications Centre ISRO, Ahmedabad Figure 110: 10 daily snow cover map of Shigar basin Snow and Glaciers of the Himalayas .184. Space Applications Centre ISRO, Ahmedabad Figure 111: 10 daily snow cover map of Shigar basin Snow and Glaciers of the Himalayas .185. Space Applications Centre ISRO, Ahmedabad Figure 112: AWiFS image of Shyok basin Snow and Glaciers of the Himalayas .186. Space Applications Centre ISRO, Ahmedabad Figure 113: 10 daily snow cover map of Shyok basin Snow and Glaciers of the Himalayas .187. Space Applications Centre ISRO, Ahmedabad Figure 114: Composite snow cover image of Rangit basin Snow and Glaciers of the Himalayas .188. Space Applications Centre ISRO, Ahmedabad Figure115: Composite snow cover map of Rangit basin Snow and Glaciers of the Himalayas .189. Space Applications Centre ISRO, Ahmedabad Bhagirathi sub-basin (10 daily) % Ar e a l e x te n t o f s n o w 80 60 40 20 0 1-Oct 1-Dec 1-Feb 1-Apr 1-Jun Days year 04-05 year 05-06 year 06-07 year 07-08 Figure 116 : 10 daily snow product Bhagirathi sub-basin Yamuna sub-basin (10 daily) % Ar e a l e x te n t o f s n o w 80 60 40 20 0 1-Oct 1-Dec 1-Feb 1-Apr 1-Jun Days year 04-05 year 05-06 year 06-07 year 07-08 Figure 117 : 10 daily snow product Yamuna sub - basin Snow and Glaciers of the Himalayas .190. Space Applications Centre ISRO, Ahmedabad Spiti sub-basin (10daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb 1-Apr Days year05-06 year 06-07 1-Jun year 07-08 Figure 118: 10 daily snow product of Spiti sub-basin Pin sub-basin (10 daily) % Are a l e xte n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 119 : 10 daily snow product of Pin sub - basin Snow and Glaciers of the Himalayas .191. Space Applications Centre ISRO, Ahmedabad Baspa sub-basin (10 daily) % Are a l e xte n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb 1-Apr Days year05-06 year 06-07 1-Jun year 07-08 Figure 120 : 10 daily snow product of Baspa sub - basin Jiwa sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 121 : 10 daily snow product of Jiwa sub - basin Snow and Glaciers of the Himalayas .192. Space Applications Centre ISRO, Ahmedabad Parbati sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 122 : 10 daily snow product of Parbati sub - basin Beas sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 123 : 10 daily snow product of Beas sub - basin Snow and Glaciers of the Himalayas .193. Space Applications Centre ISRO, Ahmedabad Chandra sub-basin ( 10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 124 : 10 daily snow product of Chandra sub - basin B h a g a s u b -b a s in ( 1 0 d a i ly ) 100 80 w o n s f o6 0 tn e tx e la4 0 re A % 20 0 1 - O ct 1- D e c y e a r 0 4 -0 5 1 -F e b y e a r0 5 -0 6 D a ys 1 -A pr y e a r 06 -0 7 1 -J u n y ea r 0 7 -0 8 Figure 125 : 10 daily snow product of Bhaga sub - basin Snow and Glaciers of the Himalayas .194. Space Applications Centre ISRO, Ahmedabad Miyar sub-basin ( 10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 126 : 10 daily snow product of Miyar sub - basin Bhut sub-bain (10 Daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 127 : 10 daily snow product of Bhut sub - basin Snow and Glaciers of the Himalayas .195. Space Applications Centre ISRO, Ahmedabad Warwan sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 128 : 10 daily snow product of Warwan sub - basin Dras sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 129 : 10 daily snow product of Dras sub - basin Snow and Glaciers of the Himalayas .196. Space Applications Centre ISRO, Ahmedabad Kisanganga sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec 1-Feb 1-Apr -20 year 04-05 Days year05-06 year 06-07 1-Jun year 07-08 Figure 130 : 10 daily snow product of Kisanganga sub - basin Shigo sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 131 : 10 daily snow product of S higo sub - basin Snow and Glaciers of the Himalayas .197. Space Applications Centre ISRO, Ahmedabad Jhelum sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec 1-Feb 1-Apr -20 1-Jun Days year 04-05 year05-06 year 06-07 year 07-08 Figure 132 : 10 daily snow product of Jhelum sub - basin Suru sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb year05-06 Days 1-Apr year 06-07 1-Jun year 07-08 Figure 133 : 10 daily snow product of Suru sub - basin Snow and Glaciers of the Himalayas .198. Space Applications Centre ISRO, Ahmedabad Gilgit sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 134 : 10 daily snow product of Gilgit sub - basin Hanza sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 135 : 10 daily snow product of Hanza sub - basin Snow and Glaciers of the Himalayas .199. Space Applications Centre ISRO, Ahmedabad Nubra sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 136 : 10 daily snow product of Nubra sub - basin Shahgan sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 137 : 10 daily snow product of Shahgan sub - basin Snow and Glaciers of the Himalayas .200. Space Applications Centre ISRO, Ahmedabad Shyok sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 138 : 10 daily snow product of Shyok sub - basin Shigar sub-basin (10 daily) % A re a l e x t e n t o f s n o w 100 80 60 40 20 0 1-Oct 1-Dec year 04-05 1-Feb Days year05-06 1-Apr year 06-07 1-Jun year 07-08 Figure 139 : 10 daily snow product of Shigar sub - basin Snow and Glaciers of the Himalayas .201. Space Applications Centre ISRO, Ahmedabad % AREAL E XTE NT OF S NO W RANGIT BASIN (COMPOSITE) 2004-2008 40 30 20 10 0 O N D J F M A M J MONTHS 2004-2005 2005-2006 2006-2007 2007-2008 Figure 140 : Composite snow product of Rangit sub-basin Snow and Glaciers of the Himalayas .202. Space Applications Centre ISRO, Ahmedabad An n e x u r e I I Maps of Glacier Inventory Snow and Glaciers of the Himalayas .203. Space Applications Centre ISRO, Ahmedabad Table 57 : UNESCO/TTS PARAMETERS Snow and Glaciers of the Himalayas .204. Space Applications Centre ISRO, Ahmedabad Snow and Glaciers of the Himalayas .205. Space Applications Centre ISRO, Ahmedabad Table 58 : REMOTE SENSING PARAMETERS / ADDITIONAL PARAMETERS Snow and Glaciers of the Himalayas .206. Space Applications Centre ISRO, Ahmedabad Table 59 : STRUCTURE OF GLACIER.DAT WITH SAMPLE DATA (MODIFIED TTS FORMAT) Snow and Glaciers of the Himalayas .207. Space Applications Centre ISRO, Ahmedabad Snow and Glaciers of the Himalayas .208. Space Applications Centre ISRO, Ahmedabad Inventory Maps of Indus Basin Snow and Glaciers of the Himalayas .209. Space Applications Centre ISRO, Ahmedabad Figure 141: Inventory maps of Beas Sub -basin Figure 142: Inventory maps of Astor Sub -basin Snow and Glaciers of the Himalayas .210. Space Applications Centre ISRO, Ahmedabad Figure 143: Inventory maps of Zanskar Sub -basin Figure 144: Inventory maps of DrassSub -basin Snow and Glaciers of the Himalayas .211. Space Applications Centre ISRO, Ahmedabad Figure 145: Inventory maps of Gilgit Sub -basin Figure 146: Inventory maps of Hanza Sub -basin Snow and Glaciers of the Himalayas .212. Space Applications Centre ISRO, Ahmedabad Figure 147: Inventory maps of Indus Sub -basin Figure 148: Inventory maps of Jhelum Sub -basin Snow and Glaciers of the Himalayas .213. Space Applications Centre ISRO, Ahmedabad Figure 149: Inventory maps of Nubra Sub -basin Figure 150: Inventory maps of Pangong Sub -basin Snow and Glaciers of the Himalayas .214. Space Applications Centre ISRO, Ahmedabad Figure 151: Inventory maps of Ravi Sub -basin Figure 152: Inventory maps of Shigar Sub -basin Snow and Glaciers of the Himalayas .215. Space Applications Centre ISRO, Ahmedabad Figure 153: Inventory maps of Shingo Sub -basin Figure 154: Inventory maps of Shyok Sub -basin Snow and Glaciers of the Himalayas .216. Space Applications Centre ISRO, Ahmedabad Figure 155: Inventory maps of Spiti Sub -basin Figure 156: Inventory maps of Sutluj Sub -basin Snow and Glaciers of the Himalayas .217. Space Applications Centre ISRO, Ahmedabad Figure 157: Inventory maps of Suru Sub -basin Snow and Glaciers of the Himalayas .218. Space Applications Centre ISRO, Ahmedabad Inventory Maps of Ganga Basin Snow and Glaciers of the Himalayas .219. Space Applications Centre ISRO, Ahmedabad Figure 158: Inventory maps of Ghaghra Sub -basin Figure 159: Inventory maps of Karnali Sub -basin Snow and Glaciers of the Himalayas .220. Space Applications Centre ISRO, Ahmedabad Figure 160: Inventory maps of Kosi Sub -basin Figure 161: Inventory maps of Narayani Sub -basin Snow and Glaciers of the Himalayas .221. Space Applications Centre ISRO, Ahmedabad Figure 162: Inventory maps of Yamuna Sub -basin Figure 163: Inventory maps of Bhagirathi Sub -basin Snow and Glaciers of the Himalayas .222. Space Applications Centre ISRO, Ahmedabad Inventory Maps of Brahmaputra Basin Snow and Glaciers of the Himalayas .223. Space Applications Centre ISRO, Ahmedabad Figure 164: Inventory maps of Chorta Tsangpo Sub-basin Figure 165: Inventory maps of Dharia Sub-basin Snow and Glaciers of the Himalayas .224. Space Applications Centre ISRO, Ahmedabad Figure 166: Inventory maps of Dibang Sub-basin Figure 167: Inventory maps of Dihang Sub-basin Snow and Glaciers of the Himalayas .225. Space Applications Centre ISRO, Ahmedabad Figure 168: Inventory maps of Dukukhu Sub-basin Figure 169: Inventory maps of Gangadhara Sub-basin Snow and Glaciers of the Himalayas .226. Space Applications Centre ISRO, Ahmedabad Figure 170: Inventory maps of Giamda Chhu Sub-basin Figure 171: Inventory maps of Hya Chhu Sub-basin Snow and Glaciers of the Himalayas .227. Space Applications Centre ISRO, Ahmedabad Figure 172: Inventory maps of Kamba Sumdo Sub-basin Figure 173: Inventory maps of Kameng Sub-basin Snow and Glaciers of the Himalayas .228. Space Applications Centre ISRO, Ahmedabad Figure 174: Inventory maps of Kyi Chhu Sub-basin Figure 175: Inventory maps of Lohit Sub-basin Snow and Glaciers of the Himalayas .229. Space Applications Centre ISRO, Ahmedabad Figure 176: Inventory maps of Manas Sub-basin Figure 177: Inventory maps of Manchu Sub-basin Snow and Glaciers of the Himalayas .230. Space Applications Centre ISRO, Ahmedabad Figure 178: Inventory maps of Matsang Tsangpo Sub-basin Figure 179: Inventory maps of Matszyan Sub-basin Snow and Glaciers of the Himalayas .231. Space Applications Centre ISRO, Ahmedabad Figure 180: Inventory maps of Nuang Chhu Sub-basin Figure 181: Inventory maps of Ooitszun Sub-basin Snow and Glaciers of the Himalayas .232. Space Applications Centre ISRO, Ahmedabad Figure 182: Inventory maps of Pardrok Chhu Sub-basin Figure 183: Inventory maps of Raga Tsangpo Sub-basin Snow and Glaciers of the Himalayas .233. Space Applications Centre ISRO, Ahmedabad Figure 184: Inventory maps of Sakya Tam Sub-basin Figure 185: Inventory maps of Shang Chhu Sub-basin Snow and Glaciers of the Himalayas .234. Space Applications Centre ISRO, Ahmedabad Figure 186: Inventory maps of Shote Tsangpo Sub-basin Figure 187: Inventory maps of Subansiris Sub-basin Snow and Glaciers of the Himalayas .235. Space Applications Centre ISRO, Ahmedabad Figure 188: Inventory maps of Tsachu Sub-basin Figure 189: Inventory maps of Yamdrog Tsho Sub-basin Snow and Glaciers of the Himalayas .236. Space Applications Centre ISRO, Ahmedabad An n e x u r e I I I Maps showing Retreat/Advance of Glaciers Snow and Glaciers of the Himalayas .237. Space Applications Centre ISRO, Ahmedabad Figure 190: IRS 1C LISS III image of August 27, 2001 showing the glaciers of part of the Bhaga sub basin Snow and Glaciers of the Himalayas .238. Space Applications Centre ISRO, Ahmedabad Figure191: Map showing loss in area of the glaciers of a part of the Bhaga sub-basin between 1962 and 2005 Snow and Glaciers of the Himalayas .239. Space Applications Centre ISRO, Ahmedabad Figure 192: Map showing loss in area of the glaciers of a part of the Bhaga sub-basin between 1989 and 2005 Snow and Glaciers of the Himalayas .240. Space Applications Centre ISRO, Ahmedabad Figure 193: Map showing loss in area of the glaciers of a part of the Bhagirathi sub-basin between 1962 and 2005 Snow and Glaciers of the Himalayas .241. Space Applications Centre ISRO, Ahmedabad Figure 194: Map showing loss in area of the glaciers of a part of the Chandra sub-basin between 1989and 2005 Snow and Glaciers of the Himalayas .242. Space Applications Centre ISRO, Ahmedabad Figure 195 : IRS 1C LISS III image of September 7, 2005 showing the glaciers of part of the Dhauliganga sub basin Snow and Glaciers of the Himalayas .243. Space Applications Centre ISRO, Ahmedabad Figure 196: Map showing loss in area of the glaciers of a part of the Dhauliganga sub-basin between 1962 and 2005 Snow and Glaciers of the Himalayas .244. Space Applications Centre ISRO, Ahmedabad Figure 197: Map showing loss in area of the glaciers of a part of the Dhauliganga sub-basin between 1990 and 2005 Snow and Glaciers of the Himalayas .245. Space Applications Centre ISRO, Ahmedabad Figure198: Map showing loss in area of the glaciers of a part of the Goriganga sub-basin between 1990 and 2005 Snow and Glaciers of the Himalayas .246. Space Applications Centre ISRO, Ahmedabad Figure 199: Map showing loss in area of the glaciers of a part of the Bhaga sub-basin between 1962 and 2005 Snow and Glaciers of the Himalayas .247. Space Applications Centre ISRO, Ahmedabad Figure 200: Map showing loss in area of the glaciers of a part of the Alaknanda sub-basin between 1962 and 2005 Snow and Glaciers of the Himalayas .248. Space Applications Centre ISRO, Ahmedabad Figure 201: Map showing loss in area of the glaciers of a part of the Alaknanda sub-basin between 1990 and 2005 Snow and Glaciers of the Himalayas .249. Space Applications Centre ISRO, Ahmedabad Figure 202: Map showing gain in area in North Remo glacier of Shyok sub-basin between 1989 and 2001 Snow and Glaciers of the Himalayas .250. Space Applications Centre ISRO, Ahmedabad Figure 203 : Map showing gain in area in Kichik Kumdan Glacier between 1989 and 2001 Snow and Glaciers of the Himalayas .251. Space Applications Centre ISRO, Ahmedabad Figure 204: Map showing gain in area in North Remo Glacier between 1989 and 2001 Snow and Glaciers of the Himalayas .252. Space Applications Centre ISRO, Ahmedabad An n e x u r e I V Images showing Snow Line Fluctuations Snow and Glaciers of the Himalayas .253. Space Applications Centre ISRO, Ahmedabad 13 August ‘06 6 September ‘06 Cloudy 25 September ‘06 30 September ‘06 Legen d Glacier Boundary Snow Line Accu. Accumulat ion Area Ablan. Ablat ion Area Figure 205: IRS P6 Images showing fluctuation of snow line for 2006 glacier of Miyar Basin Snow and Glaciers of the Himalayas .254. Space Applications Centre ISRO, Ahmedabad 16 July ‘06 9 August ‘06 Accu. Ablan.. 18 August ‘06 26 September ‘06 Legend Glacier Boundary Snow Line Accu. Accumulat ion Area Ablan. Ablat ion Area Figure 206: IRS P6 Images showing fluctuation of snow line for 2006 glacier of Bhaga Basin Snow and Glaciers of the Himalayas .255. Space Applications Centre ISRO, Ahmedabad 15 July ‘06 9 August ‘06 18 August ‘06 6 September ‘06 Ablan.. Accu. Legend Glacier Boundary Snow Line Accu. Accumulat ion Area Ablan. Ablat ion Area Figure 207 : IRS P6 Images showing fluctuation of snow line for 2006 glacier of Chandra basin Snow and Glaciers of the Himalayas .256. Space Applications Centre ISRO, Ahmedabad 1 September ‘05 30 July ‘05 ‘05 Accu. Ablan.. 16 September ‘05 21 September ‘05 Legend Glacier Boundary Snow Line Accu. Accumulat ion Area Ablan. Ablat ion Area Figure 208: IRS P6 Images showing fluctuation of snow line for 2005 glacier of Miyar basin Snow and Glaciers of the Himalayas .257. Space Applications Centre ISRO, Ahmedabad Legend Glacier Boundary Snow Line Accu. Accumulat ion Area Ablan. Ablat ion Area Figure 209 : IRS P6 Images showing fluctuation of snow line for 2005 glacier of Bhaga Basin Snow and Glaciers of the Himalayas .258. Space Applications Centre ISRO, Ahmedabad