Document: MESSAGE
Section: Annexure - IV: Glossary
Type: text

**Ablation:** The process that reduce the mass of the glacier (Cogley et al., 2011).

**Ablation area/zone:** The part of the glacier where ablation exceeds accumulation in magnitude, that is, where the cumulative mass balance relative to the start of the mass-balance year is negative. The extent of the ablation zone can vary strongly from year to year (Cogley et al., 2011).

**Accumulation:** The process that add to the mass of the glacier (Cogley et al., 2011).

**Accumulation area/zone:** The part of the glacier where accumulation exceeds ablation in magnitude, that is, where the cumulative mass balance relative to the start of the mass-balance year is positive. The extent of the accumulation zone can vary strongly from year to year. The accumulation zone is not the same as the firn area (Cogley et al., 2011).

**Altitude:** The vertical distance of a point above a datum, which is usually an estimate of mean sea level. Altitude and elevation are synonyms in common usage (Cogley et al., 2011).

**Aspect:** The compass direction towards which a slope faces; measured clockwise in degrees from the North.

**Attribute:** Non-spatial descriptive characteristics of a real-world phenomenon, often a measurement or value associated with spatial locations.

**Avalanche:** A slide or flow of a mass of snow, firn or ice that becomes detached abruptly, often entraining additional material such as snow, debris and vegetation as it descends. The duration of an avalanche is typically seconds to minutes (Cogley et al., 2011).

**Band:** One layer of multispectral image representing data values for a specific range of the electromagnetic spectrum of reflected light or heat.

**Climate:** Climate is usually defined as the average weather or as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. The classical period for averaging these variables is 30 years. The relevant quantities are most often surface variables such as temperature, precipitation and wind (Pandey, 2019).

**Climate change:** Climate change refers to a change in the state of the climate that can be identified by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer. UNFCCC defines climate change as: ‘a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods’. (Pandey, 2019).

**Climate variability:** Climate variability refers to variations in the mean state and other statistics (such as standard deviations, the occurrence of extremes, etc.) of the climate on all spatial and temporal scales beyond that of individual weather events. Variability may be due to natural internal processes within the climate system (internal variability), or to variations in natural or anthropogenic external forcing (external variability) (Pandey, 2019).

**Cryosphere:** The cryosphere is the part of the Earth system that contains ice, for example snow on the ground, glaciers, ice sheets, lake ice, river ice, sea ice, seasonally and perennially frozen ground (GCW 2016).

**Database:** An organized, integrated collection of data related by a common fact or purpose.

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Document: MESSAGE
Section: Annexure - IV: Glossary
Type: text

and temporal scales beyond that of individual weather events . Variability may be due to natural internal processes within the climate system ( internal variability ) , or to variations in natural or anthropogenic external forcing ( external variability ) ( Pandey , 2019 ) . * * Cryosphere : * * The cryosphere is the part of the Earth system that contains ice , for example snow on the ground , glaciers , ice sheets , lake ice , river ice , sea ice , seasonally and perennially frozen ground ( GCW 2016 ) . * * Database : * * An organized , integrated collection of data related by a common fact or purpose . * * *

GLACIAL LAKE ATLAS OF GANGA RIVER BASIN

**Debris-covered glacier:** A glacier that is covered at its tongue with supra-glacial debris across its full width (Kirkbride, 2011). In the accumulation zone any deposited debris is buried by later snowfalls, but in the ablation zone debris remains at the surface and englacial debris is added to the surface layer from beneath as ice ablates away. The debris cover affects the rate of ablation, with very thin debris resulting in accelerated melt and debris thicker than a few tens of millimetres reducing the melting rate (Cogley et al., 2011).

**Digital Elevation Model (DEM):** An array of numbers representing the elevation of part or all of the Earth’s surface as samples or averages at fixed spacing in two horizontal coordinate directions (Cogley et al., 2011).

**Disaster:** A serious disruption of the functioning of a community or a society at any scale due to hazardous events interacting with conditions of exposure, vulnerability and capacity, leading to one or more of the following: human, material, economic and environmental losses and impacts (UNISDR 2017).

**Disaster risk:** The potential loss of life, injury, or destroyed or damaged assets which could occur to a system, society or a community in a specific period of time, determined probabilistically as a function of hazard, exposure, vulnerability and capacity (UNISDR 2017).

**Early warning system:** The set of capacities needed to generate and disseminate timely and meaningful warning information to enable individuals, communities and organizations threatened by a hazard to prepare to act promptly and appropriately to reduce the possibility of harm or loss (Pandey, 2019).

**Electromagnetic spectrum:** The spectrum of wavelengths of electromagnetic radiation.

**Englacial:** Pertaining to the interior of the glacier, between the summer surface and the bed (Cogley et al., 2011).

**Exposure:** The presence or situation of people, livelihoods, species, ecosystems, environmental functions, services, and resources, infrastructure, or economic, social, or cultural assets in places and settings, and other tangible human assets located in hazard-prone areas that could be adversely affected (UNISDR, 2017; Pandey, 2019).

**Feature:** A real-world phenomenon, often used in cartography to name classes of elements shown on a map.

**Firn:** Snow (in which the pore space is at least partially interconnected, allowing air and water to circulate) that has survived at least one ablation season but has not been transformed to glacier ice (Cogley et al., 2011).


Document: MESSAGE
Section: Annexure - IV: Glossary
Type: text

resources , infrastructure , or economic , social , or cultural assets in places and settings , and other tangible human assets located in hazard - prone areas that could be adversely affected ( UNISDR , 2017 ; Pandey , 2019 ) . * * Feature : * * A real - world phenomenon , often used in cartography to name classes of elements shown on a map . * * Firn : * * Snow ( in which the pore space is at least partially interconnected , allowing air and water to circulate ) that has survived at least one ablation season but has not been transformed to glacier ice ( Cogley et al . , 2011 ) .

**Flood:** The overflowing of the normal confines of a stream or other body of water, or the accumulation of water over areas not normally submerged. Floods include river (fluvial) floods, flash floods, urban floods, pluvial floods, sewer floods, coastal floods and glacial lake outburst floods (Pandey, 2019).

**Format:** The pattern into which data are systematically arranged for use on a computer.

**Geographic Information System (GIS):** A set of tools for collecting, storing, retrieving, transforming, and displaying spatial data from the real world for a particular set of circumstances.

**Glacial Lake Outburst Flood (GLOF):** Flood caused by the outburst of a glacial lake due to rapid accumulation of water in it, resulting to extreme damage in loss of lives and infrastructure in the downstream area.

**Glacial Lake:** As a result of glacier thinning and retreating, melt water gets accumulated at terminal moraines or on it covered by glacier ice, is known as glacial lake.

**Glacier Erosion Lake:** These are the water bodies formed in a depression after the glacier has retreated in a form of cirque or trough valley, might be isolated and far away from the present glaciated area, and mostly stable in nature.

Prepared under: National Hydrology Project

National Remote Sensing Centre
Indian Space Research Organisation
Department of Space, Government of India
Hyderabad - 500 037

NHP
इसरो isro


Document: IHR GlacialLake Atlas (1)
Section: SUMMARY
Type: text

National Remote Sensing Centre (NRSC), Indian Space Research Organisation (ISRO), Hyderabad as one of the Implementing Agency under the National Hydrology Project (NHP), is carrying out hydrological studies using satellite data and geospatial techniques. As part of this, detailed glacial lake inventory, prioritization for Glacial Lake Outburst Flood (GLOF) risk, and simulation of GLOF for selected lakes are taken up for entire catchment of Indian Himalayan Rivers covering Indus, Ganga, and Brahmaputra River Basins. Under this activity, an updated inventory of glacial lakes using high resolution satellite data was prepared for the Indus, Ganga and Brahmaputra River basins and published in December 2020 (NRSC-RSAA-WRG-WRAD-Nov2020-TR-0001702-V1.0), June 2021 (NRSC-RSAA-WRG-WRAD-Mar2021-TR-0001818-V1.0), and July 2022 (NRSC-RSAA-WRG-WRAD-May2022-TR-0002026-V1.0) respectively, and currently an updated inventory of glacial lakes has been prepared for the Indian Himalayan River basins. The present glacial lake atlas is based on the inventoried glacial lakes in part of Indus, Ganga and Brahmaputra River basins from its origin to foothills of Himalayas covering a total catchment area of 9,89,784 Km².

The study portion of all the three river basins covers part of India and transboundary region. Elevation in the river basin varies from the minimum 45 m to the maximum 8,848 m above mean sea level (amsl). In India, the study area falls in four states viz., Himachal Pradesh, Uttarakhand, Sikkim and Arunachal Pradesh and 2 Union-Territories namely Jammu & Kashmir and Ladakh.

In the present study, glacial lakes with water spread area ≥ 0.25 ha have been mapped using Resourcesat-2 (RS-2) Linear Imaging Self Scanning Sensor-IV (LISS-IV) satellite data using visual interpretation techniques. Based on its process of lake formation, location, and type of damming material, glacial lakes are identified in all ten different types, majorly grouped into four categories viz., Moraine-dammed, Ice-dammed, Glacier Erosion, and Other glacial lakes.

A total of 28,043 glacial lakes have been mapped in the Indian Himalayan River basins using a total of 397 high resolution multispectral RS-2 LISS-IV images, with a total lake water spread area of 1,31,070.90 ha. Each glacial lake has been given a 12 alpha-numeric unique glacial lake ID, along with several attributes that include hydrological, geometrical, geographical, and topographical characteristics. About 23,167 (82.61%) lakes are with < 5 ha lake area contributing to 23.72% of total lake area. The remaining lakes with > 5 ha in size are 4,876 (17.39%) contributing to 76.28% of total lake area in the Indian Himalayan River Basins. There are only 299 glacial lakes in the Indian Himalayan River basins having an area of greater than 50 ha. Other Glacial Erosion Lake type are found to be the maximum with 16,106 (57.43%) occupying a total lake extent of 61,228.37 ha at 46.71% in the basin. Majority (i.e. 93.08%) of the lakes are situated above the high altitude range of greater than 4,000 m amsl and dominated by Other Glacial Erosion lake type i.e., 57.32%.


Document: IHR GlacialLake Atlas (1)
Section: SUMMARY
Type: text

total lake area in the Indian Himalayan River Basins . There are only 299 glacial lakes in the Indian Himalayan River basins having an area of greater than 50 ha . Other Glacial Erosion Lake type are found to be the maximum with 16 , 106 ( 57 . 43 % ) occupying a total lake extent of 61 , 228 . 37 ha at 46 . 71 % in the basin . Majority ( i . e . 93 . 08 % ) of the lakes are situated above the high altitude range of greater than 4 , 000 m amsl and dominated by Other Glacial Erosion lake type i . e . , 57 . 32 % .

Glacial lakes are predominantly distributed in Brahmaputra basin (64.19%) followed by Indus basin (19.02%) and Ganga basin (16.78%), with a total lake extent of 92,990.74 ha, 17,395.03 ha and 20,685.13 ha at 70.95%, 13.27% and 15.78% respectively in the entire basins. In terms of very large size lakes i.e. ≥ 50 ha, Brahmaputra basin has majority i.e. 207 out of 299 large lakes within it. Other Glacial Erosion lakes, which are dominant lake type in Indian Himalayan River basins are distributed in all basins, and found maximum in count in Brahmaputra basin (73.55%) and minimum in Ganga basin (10.83%). However, Glacier Ice-dammed lakes are only five in

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS

the entire Indian Himalayan River basins and is located two each in Brahmaputra & Indus and one in Ganga basin. Indus basin consists of higher number of Supra-Glacial Lakes in the entire Indian Himalayan River basins, whereas Brahmaputra basin contains highest number of Other Moraine Dammed lakes.

A total of 7,570 (i.e. 26.99%) glacial lakes lies within Indian region covering 23.00% of the total lake area, whereas remaining 73.01% of lakes are located in transboundary region with a 77.00% of the total lake area. In Indian region, majority of glacial lakes are of Other Glacial Erosion Lake type (56.64%), followed by Other Moraine Dammed lakes (12.85%). Arunachal Pradesh, Sikkim, Himachal Pradesh, and Uttarakhand share 28.90%, 9.68%, 7.09%, and 4.58% of lake count with a total area of 41.43%, 10.84%, 3.26%, and 1.86% respectively. A total of 24 (i.e., 41.38%) glacial lakes with lake area > 50 ha are situated in the Union-Territories of Jammu & Kashmir and Ladakh. Sikkim state has 288 (20.67%) number of glacial lakes lying above 5,000 m elevation.


Document: IHR GlacialLake Atlas (1)
Section: SUMMARY
Type: text

Arunachal Pradesh , Sikkim , Himachal Pradesh , and Uttarakhand share 28 . 90 % , 9 . 68 % , 7 . 09 % , and 4 . 58 % of lake count with a total area of 41 . 43 % , 10 . 84 % , 3 . 26 % , and 1 . 86 % respectively . A total of 24 ( i . e . , 41 . 38 % ) glacial lakes with lake area > 50 ha are situated in the Union - Territories of Jammu & Kashmir and Ladakh . Sikkim state has 288 ( 20 . 67 % ) number of glacial lakes lying above 5 , 000 m elevation .

In this atlas, map sheets (plates) are prepared on the basis of 2° X 2° grids which are 42 in number covering the entire Indian Himalayan River basins. Out of 42 plates, only 39 plates have glacial lakes and corresponding plates are incorporated in atlas. The map sheets are arranged in such a way that glacial lake map is on the right page and its corresponding satellite image is on the left page. At the end of the atlas, an annexure is provided containing list of glacial lakes of size ≥ 10 ha inventoried in the Indian Himalayan River basins with their unique glacial lake ID, latitude, longitude, subbasin, glacial lake type, area (ha), and elevation (m). Glacial Lake ID number of 12 alpha-numeric character has 3 characters bold with dark red colour depicting the corresponding toposheet number of the SOI of 1:250,000 scale.

***

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 1. INTRODUCTION > 1.1 About Project
Type: text

The National Hydrology Project (NHP) sponsored by Department of Water Resources, River Development and Ganga Rejuvenation (DoWR, RD&GR), Ministry of Jal Shakti, Government of India (GOI) with financial aid from the World Bank. The objective of the project is to improve the extent and accessibility of water resources information and strengthen institutional capacity to enable improved water resources planning and management across India. The mission is to establish an effective and sound hydrologic database and Hydrological Information System (HIS), together with the development of consistent and scientifically based tools and design aids, to assist in the effective water resources planning and management of the implementing agencies.

NHP is intended for setting up of a system for timely and reliable water resources data acquisition, storage, collation and management. It will also provide tools/systems for informed decision making through Decision Support Systems (DSS) for water resources assessment, flood management, reservoir operations, drought management, etc. NHP also seeks to build capacity of the State and Central sector organisations in water resources management through the use of Information Systems and adoption of State-of-the-art technologies like Remote Sensing. NHP will improve and expand hydrology data and information systems, strengthen water resources operation and planning systems, and enhance institutional capacity for water resources management. NHP will contribute to the GOI Digital India initiative by integrating water resources information across State and Central agencies.

National Remote Sensing Centre (NRSC), as one of the Implementing Agency under NHP, is engaged with generation of geo-spatial products & services pertaining to water resources sector, generation of high-resolution Digital Elevation Models (DEM), development of flood early warning systems, decision support system development for irrigation water management, modelling & dissemination of hydrological products to support water resources management and capacity building to NHP stakeholders. The satellite data based geo-spatial products & services, mainly encompassing the following:

* Satellite Data/Geo-Spatial Data Hosting & Services through Bhuvan Web Portal
* Water Resources Information Products & Services (Satellite/Model derived – Bhuvan/India- Water Resources Information System (India-WRIS)/National Water Informatics Centre (NWIC))
* Customized Applications Development (Flood Forecasting, Irrigation Water Management)
* Hydro-conditioned Digital Elevation Model (Satellite & Aerial)
* Capacity Building (Customized Training & Hand Holding)

As part of various NHP technical studies carried out, NRSC has taken up “Glacial Lake Outburst Flood (GLOF) Risk Assessment of Glacial Lakes in the Himalayan Region of Indian River Basins”. In this activity, it was proposed to prepare an updated inventory of glacial lakes, prioritization and selection of critical glacial lakes based on certain characteristics (such as glacial lake, glacier, topography and others), GLOF modelling and flood inundation simulation for selected few lakes using high resolution Digital Elevation Model (DEM) for downstream of the lakes along their river reach, and to assess GLOF risk.

As a result of initial outcome of this activity, an updated inventory of glacial lakes in Indus, Ganga and Brahmaputra


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > 2.1 Overview
Type: text

The IHR consists of three major river systems of Indus, Ganga, and Brahmaputra stretches over five countries viz., India, China, Nepal, Pakistan and Bhutan, and on the basis of physiography it has been divided into four mountain regions viz., Eastern Himalayas, Central Himalayas, Western Himalayas, and the Karakoram Mountain range. The Indian Himalayan River Basins cover a total drainage area of 9,89,784 Sq.Km. In India it has a share of about 38.78% which is 3,83,880 Sq.Km cutting across the states of Arunachal Pradesh, Assam, Himachal Pradesh, Uttarakhand, West Bengal, Meghalaya, Nagaland and Sikkim and union territories of Jammu & Kashmir, and Ladakh. Figure 1 shows the origin of the Ganga, and the Brahmaputra river of the Indian Himalayan River Basins.


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > 2.1 Overview > Brahmaputra Basin
Type: text

Topographically River Brahmaputra is unique in terms of its diverse environment as it has cold plateau in Tibet, rainy Himalayan region, alluvial lands of Assam and the large deltaic plains of Bangladesh. The Brahmaputra River also known as Yarlung Tsangpo (in Tibet) originates in the glacier mass from the Kailash ranges of Himalayas at an altitude of 5,150 m south of the lake ’Konggyu Tsho’. The higher elevation zones in the basin causes snow fall mostly over the northern region. The river flows through a length of 2,900 Km out of which 916 Km in the Indian Territory and joins finally in the Bay of Bengal. The catchment area receives number of tributaries at its north and south banks especially in Indian region. The catchment receives heavy rainfall with significant spatial variability. The land use/cover of the basin consist extensive forest cover, plantations, crop fields and swampy water lands, the northern part of the basin (outside India) covers mostly snow. There are number of hydraulic structures constructed across the tributaries in terms of weirs, barrages for the purpose of Irrigation and Dams for the hydro power utilization. The Brahmaputra River basin from its origin to foothills of Himalayas with a catchment area of 3,99,833 Sq.Km which extends from latitude 26.70° N to 32.70° N and from longitude 82.00° E to 97.77° E.

2. STUDY AREA
2.1 Overview
Brahmaputra Basin


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > 2.1 Overview > Ganga Basin
Type: text

The Ganga River basin is unique in the sense that it contains 9 of the 14 highest peaks in the world over 8,000 m in height, including Mt. Everest which is the high peak of Ganga River basin. The other peaks over 8,000 m in the basin are Kanchenjunga, Lhotse, Makalu, Cho Oyu, Dhaulagiri, Manaslu, Annapurna, and Shishapangma. The Ganga River basin extends over Central Himalayas in India, Nepal, Tibet (China), and Bangladesh.

The Ganga River originates as the Bhagirathi from the Gangotri group of glaciers in the Himalayas at an elevation of about 7,010 m amsl, in the Uttarkashi district of Uttarakhand, which has been joined by the Alaknanda at Devprayag, and the combined stream assumes the name ‘Ganga’. River flows through the highly terrain mountain region and debouches into the plains at Sukhi (near Rishikesh). It is joined by a large number of tributaries on both the banks in the course of its total run of about 2,525 km before its outfall into the Bay of Bengal. The delta of the Ganga River is said to begin at the Farakka barrage in West Bengal, where the river divides into two arms namely the Padma which flows to Bangladesh and the Ganga which flows through West Bengal. Ganga River basin from its origin to the foothills of Himalayas with a catchment area of 2,47,110 Km² which extends from latitude 26.35° N to 31.46° N and from longitude 77.05° E to 88.95° E.

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > Indus Basin
Type: text

The Indus River basin is unique in the sense that it contains seven of the world’s highest peaks after Mt. Everest, among these are K2 (8,557 m), Nanga Parbat (8,100 m) and Rakaposhi (7,800 m). The Indus basin extends over Western Himalayas and Karakoram Mountain range in India, China, and Nepal.

Indus River originates from Bokhar Chu (glacier) in northern slopes of Mt. Kailash (6,714 m) from the Tibet Autonomous Region of China (Husain, 2012; CWC, 2019). The Indus River follows a long and straight course in Ladakh region (flowing in northwest direction in India), running between the Ladakh and the Zaskar ranges. The gradient of the river is also gentle here. It forms a spectacular gorge near Gilgit (at Bunzi, north of Nanga Parbat Glacier) in Jammu & Kashmir. Downstream, the river passes by the Nanga Parbat Glacier, crossing the Himalayas, it turns into south-west and enters Pakistan near Chillar in the Dardistan region. Finally, the Indus River drains into the Arabian Sea near the port city of Karachi, Pakistan after forming a huge delta. It has a total length of 2,880 Km, of which 709 Km lies in India. The Indus River basin from its origin to foothills of Himalayas has a catchment area of 3,42,841 Km² which extends from latitude 30.32° N to 37.09° N and from longitude 72.50° E to 82.45° E.


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > 2.2 Hydrological Divide > Brahmaputra Basin
Type: text

The entire Brahmaputra River basin is sub divided into three reaches namely upper, middle and lower. In the upper reach the river is fed by glaciers. In the lower and middle reaches, it is joined by number of tributaries. The principal tributaries of the Brahmaputra River joining from right are the Lohit, the Dibang, the Subansiri, the Jiabharali, the Dhansiri, the Manas, the Torsa, the Sankosh and the Teesta whereas the Burhidihing, the Desang, the Dikhow, the Dhansiri and the Kopili joins it from left.

2. STUDY AREA
2.2 Hydrological Divide
Brahmaputra Basin


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > 2.2 Hydrological Divide > Ganga Basin
Type: text

Major rivers flowing in the Ganga River basin is Yamuna, joining the main river on the right, whereas rivers like Sarda, Ghaghara, Gandak, and Kosi joining on the left.

2. STUDY AREA
2.2 Hydrological Divide
Ganga Basin


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > Indus Basin
Type: text

Major rivers flowing in the Indus River basin are Satluj, Beas, Ravi, Chenab, Jhelum, and Zaskar joining the main river on the left, whereas rivers like Sengee Tsangpo, Shyok, and Gilgit joining on the right.

Beas Chenab Gilgit Jhelum Ravi Satluj Shyok


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > Indus Basin
Type: figure
Figure: Figure 2 shows the location of the study area with Resourcesat-2 (RS-2) Linear Imaging Self Scanner (LISS-IV) satellite images. Table 1 shows the catchment area of each of the above basins.

Figure 2 shows the location of the study area with Resourcesat-2 (RS-2) Linear Imaging Self Scanner (LISS-IV) satellite images. Table 1 shows the catchment area of each of the above basins.


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > Indus Basin
Type: table
Table: Table 1: Basin Details of Indian Himalayan River Basins

| S. No. | Basin | Area (Km²) | Area (%) |
| :--- | :--- | :--- | :--- |
| 1 | Brahmaputra | 3,99,833 | 40.40 |
| 2 | Ganga | 2,47,110 | 24.96 |
| 3 | Indus | 3,42,841 | 34.64 |
| | **Total** | **9,89,784** | **100.00** |


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > 2.3 Hydrology > Brahmaputra Basin
Type: text

The Upper reach of the River Brahmaputra flows through 1,625 Km from the source of origination point to the Indo-China border through Tibetan plateau and enters India at Kobo, Arunachal Pradesh, Upper reach of the river is mostly fed by snow and glaciers. In the middle reach between India and Bangladesh border it flows through a length of 916 Km where it has numerous riverine islands because of its low gradient. The entire lower reach falls within the Bangladesh flows about a length of 337 Km and drains into Bay of Bengal. The river flows are at low in winter season, gradually increases in summer season (due to melting of snow and glaciers in upper reaches) and reaches peak in monsoon season. The average water resources potential (In India) of the basin is 537.24 BCM out of which utilizable surface water resource is 24 BCM (Brahmaputra Basin Report, 2014).

2. STUDY AREA
2.3 Hydrology
Brahmaputra Basin


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > 2.3 Hydrology > Ganga Basin
Type: text

All the principal tributaries of the Ganga River system are fed by snow and glaciers in the upper parts of their mountainous catchments. The snow accumulation in their upper catchments usually starts from October to March months reaching peak in January/February. The river flows are at minimum during the winter months of December to March. When snow and glaciers start melting during summer months of April to June, river flows gradually increase and accelerated further by rainy season of July to September. The Ganga River basin carries average annual water potential of about 525 Billion Cubic Metre (BCM), of which total utilizable surface water resource in the basin is 250 BCM. The Ghaghara, Kosi, and Gandak combined carry almost half, and the Yamuna, Ramganga, and other major and minor tributaries combined constitute the remainder of the total supply of the system (Ganga Basin Report, 2014).


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > 2.3 Hydrology > Indus Basin
Type: text

All the principal tributaries of the Indus River system are fed by snow and glaciers in the upper parts of their mountainous catchments. The snow accumulation in their upper catchments usually starts from October to March months reaching peak in January/February. The river flows are at minimum during the winter months of December to March. When snow and glaciers start melting during summer months of April to June, river flows gradually increase and accelerated further by rainy season of July to September. Annually, the upper Indus carries about 110 Billion Cubic Metre (BCM) slightly less than half the total supply of water in the Indus River system. The Jhelum and Chenab combined carry roughly one-fourth, and the Ravi, Beas, and Satluj combined constitute the remainder of the total supply of the system.


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > 2.4 Topography > Brahmaputra Basin
Type: text

The Brahmaputra basin mainly resides in the middle and eastern Himalayan region, which is also known as one of the main topographic divisions of the Indian subcontinent. The Himalayas comprises the Himalayan ranges including their numerous snow peaks and each of these peaks is surrounded by snow fields and glaciers. The elevation ranges between 450 m and 8,352 m amsl, where glaciers and glacial lakes are mostly distributed in the higher altitude region. The mean elevation of the study area is about 4,048 m amsl.

2. STUDY AREA
2.4 Topography
Brahmaputra Basin


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > 2.4 Topography > Ganga Basin
Type: text

The Ganga basin mainly resides in the Central Himalayan region, which is also known as one of the main topographic divisions of the Indian subcontinent (Ganga Basin Report, 2014). The Central Himalayas comprises the Himalayan ranges including their numerous snow peaks rising above 7,000 m and each of these peaks is surrounded by snow fields and glaciers. All the tributaries are characterized by well regulated flows and assured supply of water throughout the year by these glaciers. The elevation ranges between 45 m and 8,848 m amsl, where glaciers and glacial lakes are mostly distributed in the higher altitude region. The mean elevation of the study area is 4,374 m amsl. Slope in the Ganga basin varies up to a maximum of 86.60°, while the mean slope in the Ganga River basin is 22.31°.

2. STUDY AREA
2.4 Topography
Ganga Basin


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > 2.4 Topography > Indus Basin
Type: text

The elevation of the Indus basin ranges between 153 m and 8,557 m above mean sea level (amsl), where glaciers and glacial lakes are mostly distributed in the higher altitude region. The mean elevation of the study area is 4,355 m amsl. The transverse glaciers present in the basin at different locations and occasional landslides may also dam the river resulting in formation of temporary lakes. Downwards, the Indus crosses the Central Himalayan Range through a huge synclinal gorge. The Indus makes several deep gorges, amongst which the deepest of all is at Gilgit, which is 5,200 m in height amsl. Slope in the entire study area varies up to a maximum of 87.76°, while the mean slope in the Indus River basin is 22.23°.

Hypsometric curve shown in figure 3 depicts the proportion of land area that exists at various elevations by plotting relative area against relative height for the Indian Himalayan River basins.

2. STUDY AREA
2.4 Topography
Indus Basin


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > 2.5 Climate > Brahmaputra Basin
Type: text

The climate of the Brahmaputra River basin varies from the harsh cold, and dry conditions found in Tibet to the generally hot and humid conditions prevailing in Assam state. Tibetan winters are severely cold, with average

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS

temperatures below 0°C, while summers are mild and sunny. The upper river valley lies in the rain shadow of the Himalayas, and precipitation there is relatively light (Lhasa receives about 400 mm annually). Climate over the Brahmaputra River basin mainly comprises of four seasons in a year namely winter, summer, and monsoon and post monsoon. The winter season begins in December and continues to the end of February. From March onwards, the hot weather starts and continues up to the last week of May. The monsoon begins in the last week of May or in early June and the basin receives heavy rainfall spatially distributed over the basin.

2. STUDY AREA
2.5 Climate
Brahmaputra Basin


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > 2.5 Climate > Ganga Basin
Type: text

Climate over the Ganga River basin is mainly tropical and subtropical to temperate subhumid on the plains. The higher elevation zones in the Himalayan ranges especially in parts of Uttarakhand and Himachal Pradesh, experience lower temperatures than the other parts of the basin within India. Lowest annual precipitation < 500 mm is observed in the lowlands to a maximum of > 2,200 mm in upper region. The study area receives total average annual precipitation of approximately 1,200 mm. The average temperature in the basin ranges between 9°C to 40°C, where the minimum temperature is usually high mainly because of the lower plains of the basin.


Document: IHR GlacialLake Atlas (1)
Section: 2. STUDY AREA > 2.5 Climate > Indus Basin
Type: text

Climate over the Indus River basin varies from subtropical arid and semiarid to temperate subhumid on the plains of Sindh and Punjab provinces to alpine in the mountainous highlands of the north. Annual precipitation ranges between 100 and 500 mm in the lowlands to a maximum of 2,000 mm on mountain slopes. In the lower plains, December to February is the cold season and mean monthly temperatures vary from 14°C to 20°C. Mean monthly temperatures during March to June vary from 42°C to 44°C. Whereas, in the upper plains mean temperature ranges from 23°C to 49°C during summer and from 2°C to 23°C during winter.

***

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 3. DATA USED
Type: text

Earth observation satellites capture the data repeatedly in various spectral ranges and at different spatial and radiometric resolutions. For inventorying glacial lakes, high to medium resolution datasets are proved to be useful by many research studies (Bolch et al., 2010; Mergili et al., 2013; Wang et al., 2013; Zhang et al., 2015; Gupta et al., 2019, Guru et al., 2019). Data captured between September and December were mostly used because the presence of snow or cloud cover during this period is minimum. USGS satellite data of Landsat 5 and 7 (TM and ETM+) has been used widely for mapping glacial lakes due to free accessibility. Whereas, IRS satellite data from sensors of AWiFS, LISS-III, LISS-IV has also been used for such inventory.

In the present study, high resolution Resourcesat-2 LISS-IV satellite images with spatial resolution of 5.8 m covering a swath of 70 × 70 Km have been used for inventorying glacial lakes. Maximum of the images used for inventorying were of 2016-2021 (71.54%) and remaining images procured were of previous years due to non-availability of cloud-free and snow-free images for the recent years. Majority of images were of September and December months (76.32%) due to less snow and cloud cover, and rest 23.68% images of other months. Figure 4 shows the layout of the RS-2 LISS-IV scenes (path-wise) procured for the Indian Himalayan River basins along with its details in Table 2. The layout of satellite scenes is divided into paths (shown in separate colours) and rows (row numbers shown in the layout).

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 3. DATA USED
Type: table
Table: Table 2: Details of satellite scenes used for inventory

| | Other Months | Sep - Dec | Total |
| :--- | :---: | :---: | :---: |
| Prior to 2016 | 33 | 80 | 113 |
| 2016-21 | 61 | 223 | 284 |
| **Total** | **94** | **303** | **397** |


Document: IHR GlacialLake Atlas (1)
Section: 3. DATA USED
Type: text

Digital Elevation Model (DEM) of Cartosat satellite with 10 m spatial resolution has been used for topographic information and watershed boundary generation. Figure 5 shows elevation range map of the study area i.e. Indian Himalayan River basins. Other information like names of lakes and rivers has been gathered from digital toposheets available from University of Texas - Toposheet Library at 1:250,000 scale and Tibet Map Institute at 1:100,000 scale (U.S. Army Map Service 1955; Andre 2017).

***

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 4. METHODOLOGY > 4.1 Satellite Data Interpretation
Type: text

The spectral reflectance curve of water in the visible spectrum starts with a low in Blue region (0.4 to 0.5 μm), reaches peak in Green region (0.5 to 0.6 μm), decreases in Red region (0.6 to 0.7 μm) and probably the most distinctive characteristic is the energy absorption at Near InfraRed (NIR) wavelengths. Identifying and delineating water bodies with remote sensing data are carried out easily in near infrared wavelengths because of this absorption property in IR region. However, various physical conditions of water bodies (water depth, turbidity, chlorophyll content, etc.) manifest spectral changes. As a result of various conditions of lakes, the water in satellite images in False Colour Composite (FCC) ranges in appearance from light to dark blue to black. In the case of frozen lakes, it appears white.

Glacial lake sizes are generally small, having circular, semi-circular, or elongated shapes with very fine texture and are generally associated with glaciers in high altitude areas. Certain types of glacial lakes, like erosion and cirque lakes are not necessarily associated with glaciers. Knowledge of the physical characteristics of the glacial lakes, and their associated features is always essential for the interpretation of the images.

Satellite data interpretation can be done using visual image interpretation keys such as colour, size, tone, texture, pattern, association, shape, shadow, and orientation. A number of remote sensing methods had been developed for glacial lake detection and mapping or development of inventory (Kääb 2000; Mool et al., 2001a; Huggel et al., 2002; Huggel et al., 2006; Ives et al., 2010). Manual or automated lake mapping methods have certain difficulties in identifying the lakes, which are described in the following section. An attempt was made to study the accuracy of mapping of glacial lakes using multiple automated methods along with visual interpretation, the details of which are given in Annexure-1. From this study, it was concluded that visual interpretation method was best accurate method. Hence, in the present study glacial lakes and their different types are identified and mapped using RS-2 LISS-IV multispectral images using visual interpretation method.

4. METHODOLOGY
4.1 Satellite Data Interpretation


Document: IHR GlacialLake Atlas (1)
Section: 4. METHODOLOGY > 4.1 Satellite Data Interpretation > Difficulties in Lake Identification:
Type: text

Glacial lake identification can be done either using visual interpretation or automatic mapping methods. The automatic mapping procedures have limitations due to varying terrain conditions like lakes situated in the shadow portions of mountains, presence of snow cover, cloud cover, and partly frozen lakes, etc. In the presence of snow cover on the glacier tongue or glacier’s ablation area where many Supra-glacial lakes may be present, both methods have limitations and difficulties.

As lake water absorbs the incident radiation making it appear in darker tone and colour in the standard FCC of satellite data, similar response also prevails over shadow region of clouds or mountains on surface, which may lead to incorrect mapping. In fact, a mountain shadow covering a lake partly/completely within its vicinity, making it difficult to accurately map the lake boundary.

Many lakes due to inclement terrain condition, can be under shadow of high peaks and will get missed in both ways of mapping. On the contrary, a lake can also present in white colour while it is in frozen form due to cold

weather conditions over the area, then definitely it will not get classified while automatic mapping. Whereas, frozen lakes can be identified and mapped using visual interpretation to some extent.

**Challenges in Automatic Mapping:**

In the IHR, due to high and inclement terrain surface and due to near vertical acquisition of satellite images, some lakes get covered with shadows of mountains, which create problems in identifying glacial lakes. Also, identification of lakes with high turbidity, partial ice-covered lakes and the lakes in shadow areas are misclassified by automatic methods. Glacial lake mapping is always a semi-automatic approach because even after applying any of those methods, it should always be followed by the post processing i.e. correcting the errors using visual interpretation. Even in all cases, automatic mapping will never give the exact and accurate boundary of the lake, leading to necessary manual corrections.

**Reasoning for Visual Interpretation:**

Although automatic mapping methods can speed up the detection of glacial lakes, but these methods could not be applied to the entire Himalayan region due to lot of variations in satellite scenes (seasons/years) and problems mentioned above. For example, if lakes are frozen or covered with snow or cloud and lies in a shadow area, they cannot be detected using these automatic methods. In such cases, the manual interpretation method will be helpful to map these lakes. Thus, any mapping of glacial lakes can be automated up to a certain extent only. So, visual image interpretation keys and technique will give accurate results and avoids misclassification. Therefore, in this present study, glacial lakes and its type identification, and its mapping for the entire Indian Himalayan River Basins has been done manually using visual interpretation. High resolution satellite data available on Bhuvan/Google Earth has been used on need basis in finalizing various features of glacial lake database.

**Limitations:**

The RS-2 LISS-IV MX data used for glacial lake database preparation sporadically covered with cloud and seasonal/permanent snow. Also, the Himalayan region being highly varying topography with steep slopes, the satellite data has hill shadows. Thus, few glacial lakes would not have been mapped owing to the following constraints:
* Presence of snow or cloud over the glacial lakes
* Glacial lakes under frozen condition
* Glacial lakes under mountain shadow

4. METHODOLOGY
4.1 Satellite Data Interpretation
Difficulties in Lake Identification:


Document: IHR GlacialLake Atlas (1)
Section: 4. METHODOLOGY > 4.2 Types of Glacial Lake
Type: text

Various researchers have proposed glacial lakes classification schemes based on dam type, process of lake formation, topographic feature, and geographical position (Hewitt 1982; Liu and Sharma 1988; Clague and Evans 2000; Mool et al., 2001a, 2001b). Lakes located on the glacier surface can be mapped using satellite data, but there are englacial and subglacial lakes that may also exist, but cannot be mapped from aerial/optical satellite images, requires ground-based instrument (Yao et al., 2018). Majorly surface glacial lakes are classified in 4 classes and 10 subclasses, i.e. Moraine-dammed lake, Ice-dammed lake, Glacier Erosion lake (also known as Bed-rock lake), and Other Glacial lake. Two-character symbol has been used for glacial lake classification, in which first letter (uppercase) represents lake type and second letter (lowercase) within brackets represents lake subtype, for example, M(e) for End-moraine dammed lake. Details of types of lakes are given in Table 3 and their appearance in satellite images are shown in Figure 6.

4. METHODOLOGY
4.2 Types of Glacial Lake


Document: IHR GlacialLake Atlas (1)
Section: 4. METHODOLOGY > 4.2 Types of Glacial Lake
Type: table
Table: Table 3: Glacial lake types and their identification keys

| S. No. | Lake Type | Lake Subtype | Code | Identification Keys |
|---|---|---|---|---|
| 1 | Moraine-dammed Lake | End-moraine Dammed Lake | M(e) | Lake dammed by end (terminal) moraines |
| 2 | Moraine-dammed Lake | Lateral Moraine Dammed Lake | M(l) | Lake dammed by lateral moraine(s) not in contact with glacial ice |
| 3 | Moraine-dammed Lake | Lateral Moraine Dammed Lake (with Ice) | M(lg) | Lake dammed by lateral moraine(s) in contact with glacial ice |
| 4 | Moraine-dammed Lake | Other Moraine Dammed Lake | M(o) | Lake dammed by other moraines |
| 5 | Ice-dammed Lake | Supra-glacial Lake | I(s) | Pond or lake on the surface of a glacier |
| 6 | Ice-dammed Lake | Glacier Ice-dammed Lake | I(d) | Lake dammed by glacier ice with no lateral moraines |
| 7 | Glacier Erosion Lake | Cirque Erosion Lake | E(c) | A small pond occupying a cirque |
| 8 | Glacier Erosion Lake | Glacier Trough Valley Erosion Lake | E(v) | Lakes formed in the glacier trough as a result of the glacier erosion process |
| 9 | Glacier Erosion Lake | Other Glacial Erosion Lake | E(o) | Bodies of water occupying depressions formed by the glacial erosion process |
| 10 | Other Glacial Lake | Other Glacial Lake | O | Lakes formed in a glaciated valley, and fed by glacial melt, but damming material not directly part of the glacial process |

S. No.
Lake Type
Lake Subtype
Code
Identification Keys


Document: IHR GlacialLake Atlas (1)
Section: 4.3 Lake Attribute Information
Type: text

A total of 22 attributes has been given to all mapped lake features in the geodatabase, which are broadly consisting information grouped in five different categories as shows in Table 4.


Document: IHR GlacialLake Atlas (1)
Section: 4.3 Lake Attribute Information
Type: table
Table: Table 4: Details of glacial lake attributes

| S.No. | Category | Attribute |
|---|---|---|
| 1 | Hydrological | Basin, subbasin, river, lake name |
| 2 | Geometrical | Maximum length, mean width, surface area |
| 3 | Geographical | Latitude, longitude, region, state, district, toposheet 250k, toposheet 50k |
| 4 | Topographical | Elevation, aspect |
| 5 | Lake Information | Feature types, glacial lake type, lake ID |
| 6 | Data Source Information | Source of database, source of elevation, date of pass |


Document: IHR GlacialLake Atlas (1)
Section: 4.3 Lake Attribute Information
Type: text

Typically, lake ID is given in 12 alpha-numeric character format like “0378A1303118”, where first two digits ‘03’ refers to Basin code which is Brahmaputra (01-Indus and 02- Ganga), next five characters ‘78A13’ refers to the 1:250,000 (78A) and 1:50,000 (78A13) scale SOI Toposheet number, and the last five digits refers to the sequential number of each lake sorted from top left to bottom right. A typical example of the glacial lake database generated is given below in Table 5 along with fields and format.


Document: IHR GlacialLake Atlas (1)
Section: 4.3 Lake Attribute Information
Type: table
Table: Table 5: Typical example of glacial lake attribute database

| S. No. | Database Fields | Type | Format / Unit | Lake Attribute |
|---|---|---|---|---|
| 1 | ID No | String | Text | 0378A1303118 |
| 2 | Toposheet 250K | String | Text | 78A |
| 3 | Toposheet 50K | String | Text | 78A13 |
| 4 | Latitude* | Float | Decimal Degree | 27.990 |
| 5 | Longitude* | Float | Decimal Degree | 88.816 |
| 6 | Basin | String | Text | Brahmaputra |
| 7 | Subbasin | String | Text | Teesta |
| 8 | River | String | Text | Teesta River |
| 9 | Type (GL/WB) | String | Text | Glacial Lake |
| 10 | Name | String | Text | Khangchung Tso |
| 11 | Glacial Lake Type | String | Text | M(e): End-moraine Dammed Lake |
| 12 | Surface Area | Float | ha | 174.29 |
| 13 | Length | Float | Km | 3.13 |
| 14 | Mean Width | Float | Km | 0.75 |
| 15 | Elevation | Integer | m (amsl) | 5303 |
| 16 | Aspect | String | Text | NW |
| 17 | Source of Database | String | Text | RS-2 LISS-IV |
| 18 | Date of Pass | Date | DDMMYYYY | 17112016 |
| 19 | Source of Elevation | String | Text | Cartosat DEM |
| 20 | Region | String | Text | India |
| 21 | State | String | Text | Sikkim |
| 22 | District | String | Text | North Sikkim |

S. No.
Database Fields
Type
Format / Unit
Lake Attribute


Document: IHR GlacialLake Atlas (1)
Section: 4.3 Lake Attribute Information
Type: text

\* Latitude and longitude has been taken at the centroid of the lake


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS
Type: text

The mapped glacial lakes are analyzed for their distribution in terms of area, type, and elevation, at catchment, basin, administrative and transboundary level. Area of mapped glacial lakes is ranging from a minimum of 0.25 ha to a maximum of 2,658.49 ha in Brahmaputra basin, 540.55 ha in Ganga basin, and 262.56 ha in Indus basin. Details of glacial lakes of size ≥ 10 ha inventoried for the Himalayan River catchment is given in Annexure-II. The results are discussed in subsequent sections:


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Area range-wise Distribution
Type: text

A total of 28,043 glacial lakes (≥ 0.25 ha) were identified and mapped using RS-2 LISS-IV images for the entire Himalayan River catchment, with a total lake water spread area of 1,31,070.90 ha. Table 6 and Figure 7 shows the area range-wise distribution of glacial lakes for the entire catchment. About 23,167 (82.61%) lakes are with < 5 ha lake area contributing to 23.72% of total lake area. The remaining lakes with > 5 ha in size are 4,876 (17.39%) contributing to 76.28% of total lake area in the basin. Details of lakes ≥ 50 ha is given in Annexure-III.


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Area range-wise Distribution
Type: table
Table: Table 6: Area range-wise distribution of Glacial Lakes (GL) in Indian Himalayan River Basins

| S. No. | Lake Area Range (ha) | No. of Lakes | Total Lake Area (ha) | Total Lake Area (%) |
|---|---|---|---|---|
| 1 | 0.25 - 0.5 | 6,284 | 2,244.06 | 1.71 |
| 2 | 0.5 - 1 | 6,252 | 4,473.30 | 3.41 |
| 3 | 1 - 5 | 10,631 | 24,370.94 | 18.59 |
| 4 | 5 - 10 | 2,445 | 17,180.97 | 13.11 |
| 5 | 10 - 50 | 2,132 | 41,281.30 | 31.50 |
| 6 | > 50 | 299 | 41,520.33 | 31.68 |
| | **Total** | **28,043** | **1,31,070.90** | **100.00** |

S. No.
Lake Area Range (ha)
No. of Lakes
Total Lake Area (ha)
Total Lake Area (%)


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Area range-wise Distribution
Type: text

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Type-wise Distribution
Type: text

Distribution of different types of glacial lakes in the entire Indian Himalayan River Basins is given in Table 7 and Figure 8. Out of 10 types of lakes described above, all types of lakes are present in the catchment. Out of 10 types of glacial lakes, Other Glacial Erosion lakes are found to be the maximum with 16,106 (57.43%) occupying a total lake extent of 61,228.37 ha at 46.71% in the Indian Himalayan River basins. Two other types of lake, namely, Other Moraine Dammed and Other Glacial lakes are 5,664 (20.20%) and 1,798 (6.41%), extend over an area of 15,159.27 ha (11.57%) and 15,331.89 ha (11.70%) respectively.


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Type-wise Distribution
Type: table
Table: Table 7: Type-wise distribution of GL in Indian Himalayan River basins

| S. No. | Code | Types of Glacial Lake | No. of Lakes | Total Lake Area (ha) | Total Lake Area (%) |
|---|---|---|---|---|---|
| 1 | M(e) | End-moraine Dammed Lake | 1,058 | 21,479.58 | 16.39 |
| 2 | M(l) | Lateral Moraine Dammed Lake | 363 | 1,145.38 | 0.87 |
| 3 | M(lg) | Lateral Moraine Dammed Lake with Ice | 56 | 118.33 | 0.09 |
| 4 | M(o) | Other Moraine Dammed Lake | 5,664 | 15,159.27 | 11.57 |
| 5 | I(s) | Supra-glacial Lake | 1,698 | 1,438.32 | 1.10 |
| 6 | I(d) | Glacier Ice-dammed Lake | 5 | 239.48 | 0.18 |
| 7 | E(c) | Cirque Erosion Lake | 1,286 | 11,467.10 | 8.75 |
| 8 | E(v) | Glacier Trough Valley Erosion Lake | 9 | 3,463.16 | 2.64 |
| 9 | E(o) | Other Glacial Erosion Lake | 16,106 | 61,228.37 | 46.71 |
| 10 | O | Other Glacial Lake | 1,798 | 15,331.89 | 11.70 |
| | | **Total** | **28,043** | **1,31,070.90** | **100.00** |

S. No.
Code
Types of Glacial Lake
No. of Lakes
Total Lake Area (ha)
Total Lake Area (%)


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Type-wise Distribution
Type: text

***

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Area range-Type-wise Distribution
Type: text

Glacial lake distribution by area range vs. type-wise is given in Table 8 and Figure 9. The lakes with < 5 ha in size (82.61%) are dominant with Other Glacial Erosion Lake type (58.25%) followed by Other Moraine Dammed (21.78%) and Other Glacial Lake (6.46%). The lakes with > 5 ha (17.39%) are dominated by Other Glacial Erosion lakes (53.57%) followed by Cirque Erosion Lake (13.97%) and Other Moraine Dammed Lake (12.69%). All types of Moraine-dammed glacial lakes, which constitute about 25.46% are predominantly with < 5 ha in water spread.


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Area range-Type-wise Distribution
Type: table
Table: Table 8: Area range-wise vs. Type-wise distribution of GL in Indian Himalayan River Basins

| S. No. | Lake Area Range (ha) | M(e) | M(l) | M(lg) | M(o) | I(s) | I(d) | E(c) | E(v) | E(o) | O | Total |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 0.25 - 0.5 | 60 | 102 | 18 | 1,513 | 939 | 0 | 24 | 0 | 3,155 | 473 | 6,284 |
| 2 | 0.5 - 1 | 68 | 99 | 10 | 1,488 | 504 | 1 | 65 | 0 | 3,597 | 420 | 6,252 |
| 3 | 1 - 5 | 353 | 123 | 23 | 2,044 | 223 | 3 | 516 | 1 | 6,742 | 603 | 10,631 |
| 4 | 5 - 10 | 179 | 15 | 3 | 369 | 20 | 0 | 331 | 0 | 1,422 | 106 | 2,445 |
| 5 | 10 - 50 | 301 | 19 | 2 | 231 | 12 | 0 | 337 | 1 | 1,089 | 140 | 2,132 |
| 6 | > 50 | 97 | 5 | 0 | 19 | 0 | 1 | 13 | 7 | 101 | 56 | 299 |
| | **Total** | **1,058** | **363** | **56** | **5,664** | **1,698** | **5** | **1,286** | **9** | **16,106** | **1,798** | **28,043** |

S. No.
Lake Area Range (ha)
M(e)
M(l)
M(lg)
M(o)
I(s)
I(d)
E(c)
E(v)
E(o)
O
Total


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Area range-Type-wise Distribution
Type: text

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS

**Elevation range-wise Distribution**

Elevation ranges over the entire study area has been classified into four different categories viz., low altitude (up to 3,000 m), medium altitude (3,001 - 4,000 m), high altitude (4,001 - 5,000 m), and very high altitude (> 5,000 m). Table 9 and Figure 10 shows the distribution of the glacial lakes in the Himalayan River Catchment as per elevation range-wise. Majority of glacial lakes are situated above 4,000 m elevation i.e. 26,103 (93.08%) with total lake area of 1,15,750.40 ha (88.31%) and remaining 6.92% glacial lakes are below 4,000 m elevation.


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Area range-Type-wise Distribution
Type: table
Table: Table 9: Elevation range-wise distribution of GL in Indian Himalayan River Basins

| S. No. | Elevation Range (m) | No. of Lakes | Total Lake Area (ha) | Total Lake Area (%) |
|---|---|---|---|---|
| 1 | up to 3,000 | 33 | 209.78 | 0.16 |
| 2 | 3,001 - 4,000 | 1,907 | 15,110.70 | 11.53 |
| 3 | 4,001 - 5,000 | 14,322 | 68,201.49 | 52.03 |
| 4 | > 5,000 | 11,781 | 47,548.91 | 36.28 |
| | **Total** | **28,043** | **1,31,070.90** | **100.00** |

S. No.
Elevation Range (m)
No. of Lakes
Total Lake Area (ha)
Total Lake Area (%)


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Area range-Type-wise Distribution
Type: text

***

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS

**Area-Elevation range-wise Distribution**

Glacial lake distribution has been analyzed as per area range vs. elevation range-wise, given in Table 10 and Figure 11. It is noted that, about 42.01% of glacial lakes (11,781) are situated in very high-altitude range i.e. > 5,000 m amsl, which also constitutes total lake area within that range i.e. 36.28%. However, very few glacial lakes (33) lie below 3,000 m amsl, has maximum of its lakes with 0.25 - 5 ha lake area range. Figure 11 shows that maximum of lakes lying in very high-altitude range is of size ranging 1 - 5 ha (i.e. 4,333), followed by lakes in high altitude range within in 0.25 – 0.5 ha (i.e. 2,978).


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Area range-Type-wise Distribution
Type: table
Table: Table 10: Area range vs. Elevation range-wise distribution of GL in Indian Himalayan River Basins

| S. No. | Lake Area Range (ha) | Elevation Range (m) up to 3,000: No. of lakes | Elevation Range (m) up to 3,000: Total Lake Area (ha) | Elevation Range (m) 3,001 - 4,000: No. of lakes | Elevation Range (m) 3,001 - 4,000: Total Lake Area (ha) | Elevation Range (m) 4,001 - 5,000: No. of lakes | Elevation Range (m) 4,001 - 5,000: Total Lake Area (ha) | Elevation Range (m) > 5,000: No. of lakes | Elevation Range (m) > 5,000: Total Lake Area (ha) | Total: No. of lakes | Total: Lake Area (ha) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 0.25 - 0.5 | 10 | 3.48 | 338 | 122.49 | 2,958 | 1,061.35 | 2,978 | 1,056.75 | 6,284 | 2,244.06 |
| 2 | 0.5 - 1 | 5 | 3.26 | 282 | 200.37 | 3,032 | 2,178.56 | 2,933 | 2,091.14 | 6,252 | 4,473.30 |
| 3 | 1 - 5 | 8 | 22.25 | 703 | 1,729.26 | 5,587 | 12,977.12 | 4,333 | 9,642.23 | 10,631 | 24,370.94 |
| 4 | 5 - 10 | 2 | 15.64 | 263 | 1,885.54 | 1,378 | 9,713.04 | 802 | 5,566.77 | 2,445 | 17,180.97 |
| 5 | 10 - 50 | 8 | 165.17 | 286 | 5,875.04 | 1,215 | 23,137.02 | 623 | 12,104.00 | 2,132 | 41,281.30 |
| 6 | > 50 | 0 | 0.00 | 35 | 5,297.95 | 152 | 19,134.18 | 112 | 17,087.95 | 299 | 41,520.33 |
| | **Total** | **33** | **209.78** | **1,907** | **15,110.70** | **14,322** | **68,201.49** | **11,781** | **47,548.91** | **28,043** | **1,31,070.90** |


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Area range-Type-wise Distribution
Type: text

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Type-Elevation range-wise Distribution
Type: text

Glacial lake distribution has been analyzed as per type-wise vs. elevation range-wise, given in Table 11 and Figure 12. The dominant lake type in the Indian Himalayan River basin i.e., Other Glacial Erosion lakes (57.43%) are predominantly located in the elevation range of 4,001 - 5,000 m (60.03%). The two other dominant lake types, namely, Other Moraine Dammed and Other Glacial lakes are mostly distributed in both 4,001 - 5,000 m and > 5,000 m elevation ranges. 70.12% of Moraine-dammed glacial lakes, which constitute 25.46% of the total lakes, lies in the very high-altitude range of > 5,000 m amsl. Elevation range-type-wise distribution of glacial lakes has been represented in Figure 13.


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Type-Elevation range-wise Distribution
Type: table
Table: Table 11: Type-wise vs. Elevation range-wise distribution of GL in Indian Himalayan River Basins

| S.No. | Elevation Range (m) | Types of Glacial Lake M(e) | Types of Glacial Lake M(l) | Types of Glacial Lake M(lg) | Types of Glacial Lake M(o) | Types of Glacial Lake I(s) | Types of Glacial Lake I(d) | Types of Glacial Lake E(c) | Types of Glacial Lake E(v) | Types of Glacial Lake E(o) | Types of Glacial Lake O | Total |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | up to 3,000 | 2 | 1 | 0 | 10 | 11 | 0 | 0 | 0 | 5 | 4 | 33 |
| 2 | 3,001 - 4,000 | 34 | 35 | 0 | 75 | 270 | 0 | 207 | 3 | 1,138 | 145 | 1,907 |
| 3 | 4,001 - 5,000 | 326 | 207 | 15 | 1,429 | 841 | 0 | 905 | 5 | 9,668 | 926 | 14,322 |
| 4 | > 5,000 | 696 | 120 | 41 | 4,150 | 576 | 5 | 174 | 1 | 5,295 | 723 | 11,781 |
| | **Total** | **1,058** | **363** | **56** | **5,664** | **1,698** | **5** | **1,286** | **9** | **16,106** | **1,798** | **28,043** |

S.No.
Elevation Range (m)
Types of Glacial Lake M(e)
Types of Glacial Lake M(l)
Types of Glacial Lake M(lg)
Types of Glacial Lake M(o)
Types of Glacial Lake I(s)
Types of Glacial Lake I(d)
Types of Glacial Lake E(c)
Types of Glacial Lake E(v)
Types of Glacial Lake E(o)
Types of Glacial Lake O
Total


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.1 Indian Himalayan River Basins Statistics > Type-Elevation range-wise Distribution
Type: text

***

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > 5.2.1 Brahmaputra Basin
Type: text

Topographically River Brahmaputra is unique in terms of its diverse environment as it has cold plateau in Tibet, rainy Himalayan region, alluvial lands of Assam and the large deltaic plains of Bangladesh. The Brahmaputra River also known as Yarlung Tsangpo (in Tibet) originates in the glacier mass from the Kailash ranges of Himalayas at an altitude of 5,150 m south of the lake 'Konggyu Tsho'. The river flows through a length of 2,900 Km out of which 916 Km in the Indian Territory and joins finally in the Bay of Bengal. The catchment area receives number of tributaries at its north and south banks especially in Indian region. The Brahmaputra River basin from its origin to foothills of Himalayas with a catchment area of 3,99,833 Sq.Km is considered in the present study, which extends from latitude 26.70º N to 32.70º N and from longitude 82.00º E to 97.77º E. A total of 18,001 glacial lakes has been mapped, covering a total area of 92,990.74 ha (Figure 14).

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS

5. RESULTS
5.2 Basin-Wise Statistics
5.2.1 Brahmaputra Basin


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-wise Distribution
Type: text

A total of 18,001 glacial lakes (≥ 0.25 ha) were identified and mapped using RS-2 LISS-IV images for the entire Brahmaputra River basin, with a total lake water spread area of 92,990.74 ha. Table 12 and Figure 15 shows the area range-wise distribution of glacial lakes for the entire basin. About 14,499 (80.55%) lakes are with < 5 ha lake area contributing to 21.92% of total lake area. The remaining lakes with > 5 ha in size are 3,502 (19.45%) contributing to 78.08% of total lake area in the basin.

5. RESULTS
5.2 Basin-Wise Statistics
Area range-wise Distribution


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-wise Distribution
Type: table
Table: Table 12: Area range-wise distribution of Glacial Lakes (GL) in Brahmaputra River basin

| S. No. | Lake Area Range (ha) | No. of Lakes | Total Lake Area (ha) | Total Lake Area (%) |
|---|---|---|---|---|
| 1 | 0.25 - 0.5 | 3,627 | 1,294.83 | 1.39 |
| 2 | 0.5 - 1 | 3,856 | 2,771.84 | 2.98 |
| 3 | 1 - 5 | 7,016 | 16,315.71 | 17.55 |
| 4 | 5 - 10 | 1,749 | 12,348.79 | 13.28 |
| 5 | 10 - 50 | 1,546 | 30,040.25 | 32.31 |
| 6 | > 50 | 207 | 30,219.32 | 32.50 |
| | **Total** | **18,001** | **92,990.74** | **100.00** |


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-wise Distribution
Type: text

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Type-wise Distribution
Type: text

Distribution of different types of glacial lakes in the entire Brahmaputra River basin is given in Table 13 and Figure 16. Out of 10 types of lakes described above, all types of lakes are present in the basin. Out of 10 types of glacial lakes, Other Glacial Erosion lakes are found to be the maximum with 11,846 (65.81%) occupying a total lake extent of 48,368.91 ha at 52.01% in the basin. Two other types of lake, namely, Other Moraine Dammed and Other Glacial lakes are 3,019 (16.77%) and 1,481 (8.23%), extend over an area of 9,457.52 ha (10.17%) and 12,049.76 ha (12.96%) respectively.

5. RESULTS
5.2 Basin-Wise Statistics
Type-wise Distribution


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Type-wise Distribution
Type: table
Table: Table 13: Type-wise distribution of GL in Brahmaputra River basin

| S.No. | Code | Types of Glacial Lake | No. of Lakes | Total Lake Area (ha) | Total Lake Area (%) |
|---|---|---|---|---|---|
| 1 | M(e) | End-moraine Dammed Lake | 391 | 10,620.51 | 11.42 |
| 2 | M(l) | Lateral Moraine Dammed Lake | 38 | 259.67 | 0.28 |
| 3 | M(lg) | Lateral Moraine Dammed Lake with Ice | 2 | 0.93 | 0.00 |
| 4 | M(o) | Other Moraine Dammed Lake | 3,019 | 9,457.52 | 10.17 |
| 5 | I(s) | Supra-glacial Lake | 272 | 263.13 | 0.28 |
| 6 | I(d) | Glacier Ice-dammed Lake | 2 | 2.50 | 0.00 |
| 7 | E(c) | Cirque Erosion Lake | 943 | 8,521.90 | 9.16 |
| 8 | E(v) | Glacier Trough Valley Erosion Lake | 7 | 3,445.91 | 3.71 |
| 9 | E(o) | Other Glacial Erosion Lake | 11,846 | 48,368.91 | 52.01 |
| 10 | O | Other Glacial Lake | 1,481 | 12,049.76 | 12.96 |
| | | **Total** | **18,001** | **92,990.74** | **100.00** |

S.No.
Code
Types of Glacial Lake
No. of Lakes
Total Lake Area (ha)
Total Lake Area (%)


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Type-wise Distribution
Type: text

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-Type-wise Distribution
Type: text

Glacial lake distribution by area range vs. type-wise is given in Table 14 and Figure 17. The lakes with < 5 ha in size (80.55%) are dominant with Other Glacial Erosion Lake type (67.58%) followed by Other Moraine Dammed (18.02%) and Other Glacial Lake (8.66%). The lakes with > 5 ha (19.45%) are dominated by Other Glacial Erosion lakes (58.45%) followed by Cirque Erosion Lake (14.85%) and Other Moraine Dammed Lake (11.62%). All types of Moraine-dammed glacial lakes, which constitute about 18.99% are predominantly with < 5 ha in water spread.

5. RESULTS
5.2 Basin-Wise Statistics
Area range-Type-wise Distribution


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-Type-wise Distribution
Type: table
Table: Table 14: Area range-wise vs. Type-wise distribution of GL in Brahmaputra River basin

| S.No. | Lake Area Range (ha) | M(e) | M(l) | M(lg) | M(o) | I(s) | I(d) | E(c) | E(v) | E(o) | O | Total |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 0.25 - 0.5 | 6 | 6 | 1 | 718 | 153 | 0 | 13 | 0 | 2,324 | 406 | 3,627 |
| 2 | 0.5 - 1 | 12 | 6 | 1 | 743 | 75 | 1 | 46 | 0 | 2,636 | 336 | 3,856 |
| 3 | 1 - 5 | 93 | 17 | 0 | 1,151 | 38 | 1 | 364 | 0 | 4,839 | 513 | 7,016 |
| 4 | 5 - 10 | 78 | 3 | 0 | 236 | 4 | 0 | 250 | 0 | 1,092 | 86 | 1,749 |
| 5 | 10 - 50 | 152 | 5 | 0 | 156 | 2 | 0 | 262 | 0 | 868 | 101 | 1,546 |
| 6 | > 50 | 50 | 1 | 0 | 15 | 0 | 0 | 8 | 7 | 87 | 39 | 207 |
| | **Total** | **391** | **38** | **2** | **3,019** | **272** | **2** | **943** | **7** | **11,846** | **1,481** | **18,001** |

S.No.
Lake Area Range (ha)
M(e)
M(l)
M(lg)
M(o)
I(s)
I(d)
E(c)
E(v)
E(o)
O
Total


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-Type-wise Distribution
Type: text

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Elevation range-wise Distribution
Type: text

Elevation ranges over the entire study area has been classified into four different categories viz., low altitude (up to 3,000 m), medium altitude (3,001 - 4,000 m), high altitude (4,001 - 5,000 m), and very high altitude (> 5,000 m). Table 15 and Figure 18 shows the distribution of the glacial lakes in the Brahmaputra basin as per elevation range-wise. Majority of glacial lakes are situated above 4,000 m elevation i.e. 16,802 (93.34%) with total lake area of 81,290.89 ha (87.41%) and remaining 6.66% glacial lakes are below 4,000 m elevation.

5. RESULTS
5.2 Basin-Wise Statistics
Elevation range-wise Distribution


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Elevation range-wise Distribution
Type: table
Table: Table 15: Elevation range-wise distribution of GL in Brahmaputra River basin

| S. No. | Elevation Range (m) | No. of Lakes | Total Lake Area (ha) | Total Lake Area (%) |
|---|---|---|---|---|
| 1 | up to 3,000 | 11 | 152.21 | 0.16 |
| 2 | 3,001 - 4,000 | 1,188 | 11,547.28 | 12.42 |
| 3 | 4,001 - 5,000 | 9,670 | 52,525.25 | 56.48 |
| 4 | > 5,000 | 7,132 | 28,765.99 | 30.93 |
| | **Total** | **18,001** | **92,990.74** | **100.00** |


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Elevation range-wise Distribution
Type: text

***

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area-Elevation range-wise Distribution
Type: text

Glacial lake distribution has been analyzed as per area range vs. elevation range-wise, given in Table 16 and Figure 19. It is noted that, about 39.62% of glacial lakes (7,132) are situated in very high-altitude range i.e. > 5,000 m amsl, which also constitutes total lake area within that range i.e. 30.93%. However, very few glacial lakes (11) lie below 3,000 m amsl, has maximum of its lakes with 10 - 50 ha lake area range. Figure 19 shows that maximum of lakes lying in very high-altitude range is of size ranging 1 - 5 ha (i.e. 2,728), followed by lakes in high altitude range within in 1 - 5 ha (i.e. 3,772).

5. RESULTS
5.2 Basin-Wise Statistics
Area-Elevation range-wise Distribution


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area-Elevation range-wise Distribution
Type: table
Table: Table 16: Area range-wise vs. Elevation range-wise distribution of GL in Brahmaputra River basin

| S. No. | Lake Area Range (ha) | Elevation Range: up to 3,000 (m) - No. of lakes | Elevation Range: up to 3,000 (m) - Total Lake Area (ha) | Elevation Range: 3,001 - 4,000 (m) - No. of lakes | Elevation Range: 3,001 - 4,000 (m) - Total Lake Area (ha) | Elevation Range: 4,001 - 5,000 (m) - No. of lakes | Elevation Range: 4,001 - 5,000 (m) - Total Lake Area (ha) | Elevation Range: > 5,000 (m) - No. of lakes | Elevation Range: > 5,000 (m) - Total Lake Area (ha) | Total - No. of lakes | Total - Lake Area (ha) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 0.25 - 0.5 | 0 | 0.00 | 98 | 36.60 | 1,824 | 655.23 | 1,705 | 603.00 | 3,627 | 1,294.83 |
| 2 | 0.5 - 1 | 1 | 0.64 | 124 | 90.74 | 1,966 | 1,417.19 | 1,765 | 1,263.30 | 3,856 | 2,771.84 |
| 3 | 1 - 5 | 3 | 10.07 | 513 | 1,299.91 | 3,772 | 8,855.14 | 2,728 | 6,150.52 | 7,016 | 16,315.71 |
| 4 | 5 - 10 | 1 | 5.77 | 219 | 1,576.08 | 1,035 | 7,306.45 | 494 | 3,460.51 | 1,749 | 12,348.79 |
| 5 | 10 - 50 | 6 | 135.75 | 209 | 4,288.89 | 952 | 18,351.30 | 379 | 7,264.24 | 1,546 | 30,040.25 |
| 6 | > 50 | 0 | 0.00 | 25 | 4,255.00 | 121 | 15,939.70 | 61 | 10,024.36 | 207 | 30,219.32 |
| **Total** | | **11** | **152.21** | **1,188** | **11,547.28** | **9,670** | **52,525.25** | **7,132** | **28,765.99** | **18,001** | **92,990.74** |


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area-Elevation range-wise Distribution
Type: text

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > 5.2.2 Ganga Basin
Type: text

The Ganga River originates as the Bhagirathi from the Gangotri group of glaciers in the Himalayas at an elevation of about 7,010 m amsl, in the Uttarkashi district of Uttarakhand, which has been joined by the Alaknanda at Devprayag, and the combined stream assumes the name ‘Ganga’. River flows through the highly terrain mountain region and debouches into the plains at Sukhi (near Rishikesh). It is joined by a large number of tributaries on both the banks in the course of its total run of about 2,525 km before its outfall into the Bay of Bengal. The delta of the Ganga River is said to begin at the Farakka barrage in West Bengal, where the river divides into two arms namely the Padma which flows to Bangladesh and the Ganga which flows through West Bengal. Ganga River basin from its origin to the foothills of Himalayas with a catchment area of 2,47,110 Km² is considered in the present study, which extends from latitude 26.35° N to 31.46° N and from longitude 77.05° E to 88.95° E (Figure 22).

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS

5. RESULTS
5.2 Basin-Wise Statistics
5.2.2 Ganga Basin


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-wise Distribution
Type: text

A total of 4,707 glacial lakes ≥ 0.25 ha were identified and mapped using RS-2 LISS-IV images for the entire Ganga River basin, with a total lake water spread area of 20,685.12 ha. Table 18 and Figure 23 shows the area range-wise distribution of glacial lakes for the entire basin. About 4,035 (85.72%) lakes are with < 5 ha lake area contributing to 23.13% of total lake area. The remaining lakes with > 5 ha in size are 672 (14.28%) contributing to 76.87% of total lake area in the basin.


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-wise Distribution
Type: table
Table: Table 18: Area range-wise distribution of Glacial Lakes (GL) in Ganga River basin

| S. No. | Lake Area Range (ha) | No. of Lakes | Total Lake Area (ha) | Total Lake Area (%) |
|---|---|---|---|---|
| 1 | 0.25 - 0.5 | 1,279 | 452.30 | 2.19 |
| 2 | 0.5 - 1 | 1,157 | 824.04 | 3.98 |
| 3 | 1 - 5 | 1,599 | 3,508.94 | 16.96 |
| 4 | 5 - 10 | 315 | 2,184.89 | 10.56 |
| 5 | 10 - 50 | 299 | 5,938.21 | 28.71 |
| 6 | > 50 | 58 | 7,776.74 | 37.60 |
| | **Total** | **4,707** | **20,685.12** | **100.00** |

S. No.
Lake Area Range (ha)
No. of Lakes
Total Lake Area (ha)
Total Lake Area (%)


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-wise Distribution
Type: text

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS

**Type-wise Distribution**

Distribution of different types of glacial lakes in the entire Ganga River basin is given in Table 19 and Figure 24. Out of 10 types of lakes described above, 9 types of lakes are present in the basin except Glacier Trough Valley Erosion Lake. Out of 9 types of glacial lakes, Other Glacial Erosion lakes are found to be the maximum with 1,744 (37.05%) occupying a total lake extent of 4,612.02 ha at 22.30% in the basin. Two other types of lake, namely, Other Moraine Dammed and Supra-glacial lake are 1,740 (36.97%) and 617 (13.11%), extend over an area of 4,489.35 ha (21.70%) and 566.14 ha (2.74%) respectively.


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-wise Distribution
Type: table
Table: Table 19: Type-wise distribution of GL in Ganga River basin

| S. No. | Code | Types of Glacial Lake | No. of Lakes | Total Lake Area (ha) | Total Lake Area (%) |
| :--- | :--- | :--- | :--- | :--- | :--- |
| 1 | M(e) | End-moraine Dammed Lake | 260 | 8,591.78 | 41.53 |
| 2 | M(l) | Lateral Moraine Dammed Lake | 100 | 568.12 | 2.75 |
| 3 | M(lg) | Lateral Moraine Dammed Lake with Ice | 9 | 5.48 | 0.03 |
| 4 | M(o) | Other Moraine Dammed Lake | 1,740 | 4,489.35 | 21.70 |
| 5 | I(s) | Supra-glacial Lake | 617 | 566.14 | 2.74 |
| 6 | I(d) | Glacier Ice-dammed Lake | 1 | 2.45 | 0.01 |
| 7 | E(c) | Cirque Erosion Lake | 123 | 973.77 | 4.71 |
| 8 | E(o) | Other Glacial Erosion Lake | 1,744 | 4,612.02 | 22.30 |
| 9 | O | Other Glacial Lake | 113 | 876.01 | 4.23 |
| | | **Total** | **4,707** | **20,685.12** | **100.00** |

S. No.
Code
Types of Glacial Lake
No. of Lakes
Total Lake Area (ha)
Total Lake Area (%)


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-wise Distribution
Type: text

***

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS

**Area range-Type-wise Distribution**

Glacial lake distribution by area range vs. type-wise is given in Table 20 and Figure 25. The lakes with < 5 ha in size (85.72%) are dominant with Other Moraine Dammed Lake type (38.74%) followed by Other Glacial Erosion (38.64%) and Supra-glacial lake (14.94%). The lakes with > 5 ha (14.28%) are dominated by Other Glacial Erosion lakes (27.53%) followed by End Moraine Dammed Lake (27.23%) and Other Moraine Dammed Lake (26.34%). All types of Moraine-dammed glacial lakes, which constitute about 44.81% are predominantly with < 5 ha in water spread.


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-wise Distribution
Type: table
Table: Table 20: Area range-wise vs. Type-wise distribution of GL in Ganga River basin

| S. No. | Lake Area Range (ha) | M(e) | M(l) | M(lg) | M(o) | I(s) | I(d) | E(c) | E(o) | O | Total |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| 1 | 0.25 - 0.5 | 5 | 22 | 4 | 462 | 354 | 0 | 4 | 400 | 28 | 1,279 |
| 2 | 0.5 - 1 | 12 | 24 | 4 | 484 | 166 | 0 | 5 | 433 | 29 | 1,157 |
| 3 | 1 - 5 | 60 | 35 | 1 | 617 | 83 | 1 | 49 | 726 | 27 | 1,599 |
| 4 | 5 - 10 | 41 | 6 | 0 | 106 | 6 | 0 | 34 | 115 | 7 | 315 |
| 5 | 10 - 50 | 100 | 9 | 0 | 68 | 8 | 0 | 31 | 65 | 18 | 299 |
| 6 | > 50 | 42 | 4 | 0 | 3 | 0 | 0 | 0 | 5 | 4 | 58 |
| | **Total** | **260** | **100** | **9** | **1,740** | **617** | **1** | **123** | **1,744** | **113** | **4,707** |

S. No.
Lake Area Range (ha)
M(e)
M(l)
M(lg)
M(o)
I(s)
I(d)
E(c)
E(o)
O
Total


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-wise Distribution
Type: text

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Elevation range-wise Distribution
Type: text

Elevation ranges over the entire study area has been classified into four different categories viz., low altitude (up to 3,000 m), medium altitude (3,001 - 4,000 m), high altitude (4,001 - 5,000 m), and very high altitude (> 5,000 m). Table 21 and Figure 26 shows the distribution of the glacial lakes in the Ganga basin as per elevation range-wise. Majority of glacial lakes are situated above 4,000 m elevation i.e. 4,644 (98.66%) with total lake area of 20,451.70 ha (98.87%) and remaining 1.34% glacial lakes are below 4,000 m elevation.


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Elevation range-wise Distribution
Type: table
Table: Table 21: Elevation range-wise distribution of GL in Ganga River basin

| S. No. | Elevation Range (m) | No. of Lakes | Total Lake Area (ha) | Total Lake Area (%) |
|---|---|---|---|---|
| 1 | up to 3,000 | 1 | 9.87 | 0.05 |
| 2 | 3,001 - 4,000 | 62 | 223.55 | 1.08 |
| 3 | 4,001 - 5,000 | 1,855 | 7,374.89 | 35.65 |
| 4 | > 5,000 | 2,789 | 13,076.81 | 63.22 |
| **Total** | | **4,707** | **20,685.12** | **100.00** |

S. No.
Elevation Range (m)
No. of Lakes
Total Lake Area (ha)
Total Lake Area (%)


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Elevation range-wise Distribution
Type: text

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area-Elevation range-wise Distribution
Type: text

Glacial lake distribution has been analyzed as per area range vs. elevation range-wise, given in Table 22 and Figure 27. It is noted that, about 59.25% of glacial lakes (2,789) are situated in very high-altitude range i.e. > 5,000 m amsl, which also constitutes maximum total lake area within that range i.e. 63.22%. However, very few glacial lakes (63) lie up to 4,000 m amsl, has maximum of its lakes with 0.25 - 0.5 ha lake area range. Figure 27 shows that maximum of lakes lying in very high-altitude range is of size ranging 1 - 5 ha (i.e. 928), followed by lakes in high altitude range within in 1 - 5 ha (i.e. 659).


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area-Elevation range-wise Distribution
Type: table
Table: Table 22: Area range-wise vs. Elevation range-wise distribution of GL in Ganga River basin

| S. No. | Lake Area Range (ha) | Elevation Range up to 3,000 (m) - No. of Lakes | Elevation Range up to 3,000 (m) - Total Lake Area (ha) | Elevation Range 3,001 - 4,000 (m) - No. of Lakes | Elevation Range 3,001 - 4,000 (m) - Total Lake Area (ha) | Elevation Range 4,001 - 5,000 (m) - No. of Lakes | Elevation Range 4,001 - 5,000 (m) - Total Lake Area (ha) | Elevation Range > 5,000 (m) - No. of Lakes | Elevation Range > 5,000 (m) - Total Lake Area (ha) | Total - No. of Lakes | Total - Lake Area (ha) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 0.25 - 0.5 | 0 | 0.00 | 21 | 6.90 | 486 | 173.33 | 772 | 272.07 | 1,279 | 452.30 |
| 2 | 0.5 - 1 | 0 | 0.00 | 17 | 12.44 | 426 | 305.22 | 714 | 506.38 | 1,157 | 824.04 |
| 3 | 1 - 5 | 0 | 0.00 | 12 | 33.16 | 659 | 1,465.56 | 928 | 2,010.22 | 1,599 | 3,508.94 |
| 4 | 5 - 10 | 1 | 9.87 | 5 | 34.15 | 137 | 967.00 | 172 | 1,173.87 | 315 | 2,184.89 |
| 5 | 10 - 50 | 0 | 0.00 | 7 | 136.90 | 128 | 2,392.37 | 164 | 3,408.94 | 299 | 5,938.21 |
| 6 | > 50 | 0 | 0.00 | 0 | 0.00 | 19 | 2,071.42 | 39 | 5,705.32 | 58 | 7,776.74 |
| **Total** | | **1** | **9.87** | **62** | **223.55** | **1,855** | **7,374.90** | **2,789** | **13,076.80** | **4,707** | **20,685.12** |


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Type-Elevation range-wise Distribution
Type: text

Glacial lake distribution has been analyzed as per type-wise vs. elevation range-wise, given in Table 23 and Figure 28. The dominant lake type in the Ganga River basin i.e., Other Glacial Erosion lakes (37.05%) are predominantly located in the elevation range of 4,001 - 5,000 m (52.18%). The two other dominant lake types, namely, Other Moraine Dammed and Supra-glacial lake are mostly distributed in both 4,001 - 5,000 m and > 5,000 m elevation ranges. 75.82% of Moraine-dammed glacial lakes, which constitute 44.81% of the total lakes, lies in the very high-altitude range of > 5,000 m amsl. Elevation range-type-wise distribution of glacial lakes has been represented in Figure 29.

5. RESULTS
5.2 Basin-Wise Statistics
Type-Elevation range-wise Distribution


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Type-Elevation range-wise Distribution
Type: table
Table: Table 23: Type-wise vs. Elevation range-wise distribution of GL in Ganga River basin

| S. No. | Elevation Range (m) | M(e) | M(l) | M(lg) | M(o) | I(s) | I(d) | E(c) | E(o) | O | Total |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | up to 3,000 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 |
| 2 | 3,001 - 4,000 | 3 | 1 | 0 | 8 | 14 | 0 | 1 | 23 | 12 | 62 |
| 3 | 4,001 - 5,000 | 77 | 54 | 1 | 366 | 286 | 0 | 93 | 910 | 68 | 1,855 |
| 4 | > 5,000 | 180 | 45 | 8 | 1,366 | 317 | 1 | 29 | 810 | 33 | 2,789 |
| | **Total** | **260** | **100** | **9** | **1,740** | **617** | **1** | **123** | **1,744** | **113** | **4,707** |

S. No.
Elevation Range (m)
M(e)
M(l)
M(lg)
M(o)
I(s)
I(d)
E(c)
E(o)
O
Total


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > 5.2.3 Indus Basin
Type: text

Indus River originates from Bokhar Chu (glacier) in northern slopes of Mt. Kailash (6,714 m) from the Tibet Autonomous Region of China (Husain, 2012; CWC, 2019). The Indus River follows a long and straight course in Ladakh region (flowing in northwest direction in India), running between the Ladakh and the Zaskar ranges. The gradient of the river is also gentle here. It forms a spectacular gorge near Gilgit (at Bunzi, north of Nanga Parbat Glacier) in Jammu & Kashmir. Downstream, the river passes by the Nanga Parbat Glacier, crossing the Himalayas, it turns into south-west and enters Pakistan near Chillar in the Dardistan region. Finally, the Indus River drains into the Arabian Sea near the port city of Karachi, Pakistan after forming a huge delta. It has a total length of 2,880 Km, of which 709 Km lies in India. The present study area extends from latitude 30.32° N to 37.09° N and from longitude 72.50° E to 82.45° E (Figure 30).

5. RESULTS
5.2 Basin-Wise Statistics
5.2.3 Indus Basin


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-wise Distribution
Type: text

A total of 5,335 glacial lakes (≥ 0.25 ha) were identified and mapped using RS-2 LISS-IV images for the entire Indus River basin, with a total lake water spread area of 17,395.03 ha. Table 24 and Figure 31 shows the area range-wise distribution of glacial lakes for the entire basin. About 4,633 (86.84%) lakes are with < 5 ha lake area contributing to 34.04% of total lake area. The remaining lakes with > 5 ha in size are 702 (13.16%) contributing to 65.96% of total lake area in the basin.


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-wise Distribution
Type: table
Table: Table 24: Area range-wise distribution of Glacial Lakes (GL) in Indus River basin

| S. No. | Lake Area Range (ha) | No. of Lakes | Total Lake Area (ha) | Total Lake Area (%) |
| :--- | :--- | :--- | :--- | :--- |
| 1 | 0.25 - 0.5 | 1,378 | 496.93 | 2.86 |
| 2 | 0.5 - 1 | 1,239 | 877.42 | 5.04 |
| 3 | 1 - 5 | 2,016 | 4,546.28 | 26.14 |
| 4 | 5 - 10 | 381 | 2,647.29 | 15.22 |
| 5 | 10 - 50 | 287 | 5,302.84 | 30.48 |
| 6 | > 50 | 34 | 3,524.27 | 20.26 |
| | **Total** | **5,335** | **17,395.03** | **100.00** |


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Type-wise Distribution
Type: text

Distribution of different types of glacial lakes in the entire Indus River basin is given in Table 25 and Figure 32. Out of 10 types of glacial lakes, Other Glacial Erosion lakes are found to be the maximum with 2,516 (47.16%) occupying a total lake extent of 8,247.44 ha at 47.42% in the basin. Two other types of lake, namely, Other Moraine Dammed and Supra-glacial lake are 905 (16.96%) and 809 (15.16%), extend over an area of 1,212.40 ha (6.97%) and 609.05 ha (3.50%) respectively.


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Type-wise Distribution
Type: table
Table: Table 25: Type-wise distribution of GL in Indus River basin

| S. No. | Code | Types of Glacial Lake | No. of Lakes | Total Lake Area (ha) | Total Lake Area (%) |
|---|---|---|---|---|---|
| 1 | M(e) | End-moraine Dammed Lake | 407 | 2,267.29 | 13.03 |
| 2 | M(l) | Lateral Moraine Dammed Lake | 225 | 317.59 | 1.83 |
| 3 | M(lg) | Lateral Moraine Dammed Lake with Ice | 45 | 111.92 | 0.64 |
| 4 | M(o) | Other Moraine Dammed Lake | 905 | 1,212.40 | 6.97 |
| 5 | I(s) | Supra-glacial Lake | 809 | 609.05 | 3.50 |
| 6 | I(d) | Glacier Ice-dammed Lake | 2 | 234.53 | 1.35 |
| 7 | E(c) | Cirque Erosion Lake | 220 | 1,971.43 | 11.33 |
| 8 | E(v) | Glacier Trough Valley Erosion Lake | 2 | 17.25 | 0.10 |
| 9 | E(o) | Other Glacial Erosion Lake | 2,516 | 8,247.44 | 47.42 |
| 10 | O | Other Glacial Lake | 204 | 2,406.12 | 13.83 |
| | | **Total** | **5,335** | **17,395.03** | **100.00** |


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Type-wise Distribution
Type: text

***

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-Type-wise Distribution
Type: text

Glacial lake distribution by area range vs. type-wise is given in Table 26 and Figure 33. The lakes with < 5 ha in size (86.84%) are dominant with Other Glacial Erosion Lake type (46.10%) followed by Other Moraine Dammed (18.80%) and Supra-glacial lake (17.20%). The lakes with > 5 ha (13.16%) are also dominated by Other Glacial Erosion lakes (54.10%) with remaining 9 types together contributing to 45.90%. All types of Moraine-dammed glacial lakes, which constitute about 29.64% are predominantly with < 5 ha in water spread.


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-Type-wise Distribution
Type: table
Table: Table 26: Area range-wise vs. Type-wise distribution of GL in Indus River basin

| S. No. | Lake Area Range (ha) | Types of Glacial Lake: M(e) | Types of Glacial Lake: M(l) | Types of Glacial Lake: M(lg) | Types of Glacial Lake: M(o) | Types of Glacial Lake: I(s) | Types of Glacial Lake: I(d) | Types of Glacial Lake: E(c) | Types of Glacial Lake: E(v) | Types of Glacial Lake: E(o) | Types of Glacial Lake: O | Total |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 0.25 - 0.5 | 49 | 74 | 13 | 333 | 432 | 0 | 7 | 0 | 431 | 39 | 1,378 |
| 2 | 0.5 - 1 | 44 | 69 | 5 | 261 | 263 | 0 | 14 | 0 | 528 | 55 | 1,239 |
| 3 | 1 - 5 | 200 | 71 | 22 | 276 | 102 | 1 | 103 | 1 | 1,177 | 63 | 2,016 |
| 4 | 5 - 10 | 60 | 6 | 3 | 27 | 10 | 0 | 47 | 0 | 215 | 13 | 381 |
| 5 | 10 - 50 | 49 | 5 | 2 | 7 | 2 | 0 | 44 | 1 | 156 | 21 | 287 |
| 6 | > 50 | 5 | 0 | 0 | 1 | 0 | 1 | 5 | 0 | 9 | 13 | 34 |
| | **Total** | **407** | **225** | **45** | **905** | **809** | **2** | **220** | **2** | **2,516** | **204** | **5,335** |

S. No.
Lake Area Range (ha)
Types of Glacial Lake: M(e)
Types of Glacial Lake: M(l)
Types of Glacial Lake: M(lg)
Types of Glacial Lake: M(o)
Types of Glacial Lake: I(s)
Types of Glacial Lake: I(d)
Types of Glacial Lake: E(c)
Types of Glacial Lake: E(v)
Types of Glacial Lake: E(o)
Types of Glacial Lake: O
Total


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area range-Type-wise Distribution
Type: text

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Elevation range-wise Distribution
Type: text

Elevation ranges over the entire study area has been classified into four different categories viz., low altitude (up to 3,000 m), medium altitude (3,001 - 4,000 m), high altitude (4,001 - 5,000 m), and very high altitude (> 5,000 m). Table 27 and Figure 34 shows the distribution of the glacial lakes in the Indus basin as per elevation range-wise. Majority of glacial lakes are situated above 4,000 m elevation i.e. 4,657 (87.29% of the total lake count) with total lake area of 14,007.46 ha (80.53%) and remaining 12.71% glacial lakes are below 4,000 m elevation


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Elevation range-wise Distribution
Type: table
Table: Table 27: Elevation range-wise distribution of GL in Indus River basin

| S. No. | Elevation Range (m) | No. of Lakes | Total Lake Area (ha) | Total Lake Area (%) |
|---|---|---|---|---|
| 1 | up to 3,000 | 21 | 47.70 | 0.27 |
| 2 | 3,001 - 4,000 | 657 | 3,339.87 | 19.20 |
| 3 | 4,001 - 5,000 | 2,797 | 8,301.35 | 47.73 |
| 4 | > 5,000 | 1,860 | 5,706.11 | 32.80 |
| | **Total** | **5,335** | **17,395.03** | **100.00** |


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Elevation range-wise Distribution
Type: text

***

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area-Elevation range-wise Distribution
Type: text

Glacial lake distribution has been analyzed as per area range vs. elevation range-wise, given in Table 28 and Figure 35. It is noted that, more than 50% of glacial lakes (2,797) are situated in high altitude range i.e. 4,001 - 5,000 m amsl, which also constitutes maximum total lake area within that range i.e. 47.73%. However, very few glacial lakes (only 21) lies up to 3,000 m amsl, has maximum of its lakes with 0.25 - 0.5 ha lake area range. Figure 35 shows that maximum of lakes lying-in high-altitude range is of size ranging 1 - 5 ha (i.e. 1,156), followed by lakes in very high altitude range within in 1 - 5 ha (i.e. 677).


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area-Elevation range-wise Distribution
Type: table
Table: Table 28: Area range-wise vs. Elevation range-wise distribution of GL in Indus River basin

| S. No. | Lake Area Range (ha) | Elevation Range (m): up to 3,000 (No. of lakes) | Elevation Range (m): up to 3,000 (Total Lake Area ha) | Elevation Range (m): 3,001 - 4,000 (No. of lakes) | Elevation Range (m): 3,001 - 4,000 (Total Lake Area ha) | Elevation Range (m): 4,001 - 5,000 (No. of lakes) | Elevation Range (m): 4,001 - 5,000 (Total Lake Area ha) | Elevation Range (m): > 5,000 (No. of lakes) | Elevation Range (m): > 5,000 (Total Lake Area ha) | Total (No. of lakes) | Total (Lake Area ha) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 0.25 - 0.5 | 10 | 3.48 | 219 | 78.99 | 648 | 232.79 | 501 | 181.68 | 1,378 | 496.93 |
| 2 | 0.5 - 1 | 4 | 2.62 | 141 | 97.19 | 640 | 456.15 | 454 | 321.46 | 1,239 | 877.42 |
| 3 | 1 - 5 | 5 | 12.18 | 178 | 396.19 | 1,156 | 2,656.42 | 677 | 1,481.49 | 2,016 | 4,546.28 |
| 4 | 5 - 10 | 0 | 0.00 | 39 | 275.31 | 206 | 1,439.59 | 136 | 932.39 | 381 | 2,647.29 |
| 5 | 10 - 50 | 2 | 29.42 | 70 | 1,449.25 | 135 | 2,393.35 | 80 | 1,430.82 | 287 | 5,302.84 |
| 6 | > 50 | 0 | 0.00 | 10 | 1,042.95 | 12 | 1,123.06 | 12 | 1,358.27 | 34 | 3,524.27 |
| | **Total** | **21** | **47.70** | **657** | **3,339.87** | **2,797** | **8,301.35** | **1,860** | **5,706.11** | **5,335** | **17,395.03** |


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Area-Elevation range-wise Distribution
Type: text

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Type-Elevation range-wise Distribution
Type: text

Glacial lake distribution has been analyzed as per type-wise vs. elevation range-wise, given in Table 29 and Figure 36. The dominant lake type in the basin i.e., Other Glacial Erosion lakes (i.e. 47.16% in number and 47.41% in extent) are predominantly located in the elevation range of 4,001 - 5,000 m (64.67%). The two other dominant lake types, namely, Other Moraine Dammed and Supra-glacial lake are distributed in both 4,001 - 5,000 m and > 5,000 m elevation ranges. 56.26% of Moraine-dammed glacial lakes, which constitute 29.65% of the total lakes, lies in the very high-altitude range of > 5,000 m amsl. Elevation range-type-wise distribution of glacial lakes has been represented in Figure 37.


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Type-Elevation range-wise Distribution
Type: table
Table: Table 29: Type-wise vs. Elevation range-wise distribution of GL in Indus River basin

| S. No. | Elevation Range (m) | Types of Glacial Lake M(e) | Types of Glacial Lake M(l) | Types of Glacial Lake M(lg) | Types of Glacial Lake M(o) | Types of Glacial Lake I(s) | Types of Glacial Lake I(d) | Types of Glacial Lake E(c) | Types of Glacial Lake E(v) | Types of Glacial Lake E(o) | Types of Glacial Lake O | Total |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | up to 3,000 | 2 | 1 | 0 | 6 | 11 | 0 | 0 | 0 | 0 | 1 | 21 |
| 2 | 3,001 - 4,000 | 20 | 34 | 0 | 41 | 240 | 0 | 48 | 1 | 246 | 27 | 657 |
| 3 | 4,001 - 5,000 | 102 | 128 | 13 | 345 | 396 | 0 | 125 | 1 | 1,627 | 60 | 2,797 |
| 4 | > 5,000 | 283 | 62 | 32 | 513 | 162 | 2 | 47 | 0 | 643 | 116 | 1,860 |
| **Total** | | **407** | **225** | **45** | **905** | **809** | **2** | **220** | **2** | **2,516** | **204** | **5,335** |

S. No.
Elevation Range (m)
Types of Glacial Lake M(e)
Types of Glacial Lake M(l)
Types of Glacial Lake M(lg)
Types of Glacial Lake M(o)
Types of Glacial Lake I(s)
Types of Glacial Lake I(d)
Types of Glacial Lake E(c)
Types of Glacial Lake E(v)
Types of Glacial Lake E(o)
Types of Glacial Lake O
Total


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.2 Basin-Wise Statistics > Type-Elevation range-wise Distribution
Type: text

***

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS

GLACIAL LAKE ATLAS OF INDIAN HIMALAYAN RIVER BASINS


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.3 Inter Comparison of Basins
Type: text

Glacial lakes in all the three basins namely Brahmaputra, Ganga, and Indus River basin are compared for number of glacial lakes, total lake area, lake types and their elevation ranges in the following sections.

5. RESULTS
5.3 Inter Comparison of Basins


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.3 Inter Comparison of Basins > Basin-wise Distribution
Type: text

Table 30 shows the basin-wise distribution of number of glacial lakes and their water spread area for the Indian Himalayan River Basins. Figure 38 shows the basin-wise distribution of number of glacial lakes for the Indian Himalayan River Basins. Lakes are predominantly distributed in Brahmaputra basin (64.19%) followed by Indus basin (19.02%), occupying a total lake extent of 92,990.74 ha and 17,395.03 ha respectively.

5. RESULTS
5.3 Inter Comparison of Basins
Basin-wise Distribution


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.3 Inter Comparison of Basins > Basin-wise Distribution
Type: table
Table: Table 30: Basin-wise distribution of GL in Indian Himlayan River Basins

| S. No. | Basin | No. of Lakes | Total Lake Area (ha) | Total Lake Area (%) |
|---|---|---|---|---|
| 1 | Brahmaputra | 18,001 | 92,990.74 | 70.95 |
| 2 | Ganga | 4,707 | 20,685.12 | 15.78 |
| 3 | Indus | 5,335 | 17,395.03 | 13.27 |
| | **Total** | **28,043** | **1,31,070.90** | **100.00** |

S. No.
Basin
No. of Lakes
Total Lake Area (ha)
Total Lake Area (%)


Document: IHR GlacialLake Atlas (1)
Section: 5. RESULTS > 5.3 Inter Comparison of Basins > Basin-wise Distribution
Type: figure
Figure: Figure 38: Basin-wise distribution of GL in Indian Himlayan River Basins

**Figure 38: Basin-wise distribution of GL in Indian Himlayan River Basins**