Glacial Lake Atlas of Ganga River Basin released

• The present glacial lake atlas is based on the inventoried glacial lakes in part of the Ganga River basin from its origin to the foothills of the Himalayas covering a catchment area of 2,47,109 sq. km.
• The study portion of the Ganga River basin covers part of India and the transboundary region.
• The Atlas is available on the Bhuvan portal of NRSC, ISRO (https://bhuvan.nrsc.gov.in/nhp/ ), India WRIS Portal (www.indiawris.gov.in ) and the NHP website of DoWR, RD & GR (www.nhp.mowr.gov.in).
• This is an initiative under NHP, a Central Sector Scheme implemented by the Department of Water Resources, River Development & Ganga Rejuvenation (DOWR, RD & GR).
• The National Hydrology Project or NHP-Bhuvan Portal is a repository of information on the initiatives undertaken by NRSC under NHP with a facility to download the reports and knowledge products being developed by NRSC. Link for the portal: https://bhuvan.nrsc.gov.in/nhp/
• National Remote Sensing Centre (NRSC), Indian Space Research Organization (ISRO), Hyderabad as one of the Implementing Agencies under the National Hydrology Project (NHP), is carrying out hydrological studies using satellite data and geospatial techniques.
• As a part of the responsibilities entrusted to NRSC under NHP, detailed glacial lake inventory, prioritization for Glacial Lake Outburst Flood (GLOF) risk, and simulation of GLOF for selected lakes have been taken up for all the catchments of Indian Himalayan Rivers.
• Under this activity, an updated inventory of glacial lakes using high-resolution satellite data was prepared for the Indus River basin and published in December 2020, and currently, an updated inventory of glacial lakes has been prepared for the Ganga River basin.
• In the present study, glacial lakes with a water spread area greater than 0.25 ha have been mapped using Resources at-2 (RS-2) Linear Imaging Self Scanning Sensor-IV (LISS-IV) satellite data using visual interpretation techniques.
• A total of 4,707 glacial lakes have been mapped in the Ganga River basin with a total lake water spread area of 20,685 ha.

Benefits of Glacial Lake Atlas

• The possible uses of the Glacial Lake Atlas for the water resources professionals, researchers, disaster management authorities and other stakeholders for managing the glacial lakes as well as to mitigate the possible adverse impacts of Glacial Lake Outburst Floods (GLOF) and climate change.
• The atlas provides a comprehensive and systematic glacial lake database for the Ganga River basin with a size > 0.25 ha
• In the context of climate change impact analysis, the atlas can be used as reference data for carrying out change analysis, both with respect to historical and future time periods
• The atlas also provides an authentic database for regular or periodic monitoring changes in spatial extent (expansion/shrinkage), and the formation of new lakes
• The atlas can also be used in conjunction with glacier information for their retreat and climate impact studies.
• The information on glacial lakes like their type, hydrological, topographical, and associated glaciers are useful in identifying the potential critical glacial lakes and consequent GLOF risk.
• Central and State Disaster Management Authorities can make use of the atlas for disaster mitigation planning and related program.