"Atlas of glacial lake which is formed due to the Climate Change in Ganga basin released"

30th June,2021

"Atlas of glacial lake which is formed due to the Climate Change in Ganga basin released"

With major concerns mounting over the impact of climate change on Himalayan ice belts, the Ministry of Jal Shakti has released an updated atlas of glacial lakes that are part of the Ganga river basin. About 4,707 glacial lakes have been mapped till now, in the Ganga basin. Last year in December, a similar inventory of glacial lakes was prepared for the Indus river basin.

For the present day study, glacial lakes with water spread area more than 0.25 ha were mapped using Resourcesat-2 (RS-2) Linear Imaging Self Scanning Sensor-IV (LISS-IV) satellite data. Based on its process of lake formation, location, and type of damming material, glacial lakes are identified in nine different types, majorly grouped into four different categories.

The area mapped spans from the origin of the river to foothills of Himalayas covering a 2,47,109 sq. km of catchment area. The study portion of Ganga River basin covers major part of India and trans-boundary region. The Atlas is available on Bhuvan portal of NRSC and ISRO.

The expected “use” of the atlas, according to a statement from the Ministry was to create a “comprehensive and systematic” glacial lake database for Ganga River basin. The atlas could be used as reference for carrying out changes in the lakes as time passes, the spatial extent (expansion/shrinkage), and formation of new lakes.

The information on glacial lakes melting including their type, hydrological, topographical, and associated glaciers are useful in identifyng the potential critical glacial lakes and consequent Glacial Lake Outburst Flood (GLOF) events. These refer to disasters whereby a deluge of water from such a lake can trigger a big disaster in the country. The Chamoli disaster of February this year was first thought to be a GLOF event but later, scientists have concluded that it was caused due to the breaking off of a mass of rock and ice.