"Glacial Lake Atlas of Ganga River Basin "

• Ministry of Jal Shakti has released atlas of glacial lakes that are part of the Ganga river basin.
• The glacial lake atlas has covered glacial lakes partially of Ganga basin from its origin to foothills of Himalayas covering a catchment basin of 2,47,109 sq. km which is in part of India and transboundary region.

Key points:

• A total of 4,707 glacial lakes are mapped within the Ganga basin with a complete lake water spread area of 20,685 ha.
• In December 2020, a similar exercise had been carried out for the Indus River basin.
• For the present study, glacial lakes with water spread area greater than 0.25 ha were mapped using Resourcesat-2 (RS-2) Linear Imaging Self Scanning Sensor-IV (LISS-IV) satellite data.
• Glacial lakes are identified in nine different types, majorly grouped into four categories based on its process of lake formation, location, and type of damming material.
• It is completing hydrological studies using satellite data and geospatial techniques.

Benefits of Atlas: :

• It provides a comprehensive and systematic glacial lake database for Ganga River basin with size > 0.25 ha
• It can be used as reference data for carrying out change analysis, both with respect to historical and future time periods
• The atlas also provides authentic database for regular or periodic monitoring changes in spatial extent (expansion/shrinkage), and 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 outburst floods.
• Central and State Disaster Management Authorities can make use of the atlas for disaster mitigation planning and related program.

Glacial lake:

• A glacial lake is a body of water with origins from glacier activity.
• They are formed when a glacier erodes the land, and then melts, filling the depression created by the glacier.