Title: Spatio-temporal Distribution of Glacial Lakes in Indus-Ganga-Brahmaputra River Basin: First results
Atul KUMAR, University of Hamburg, Germany
Suraj MAL, University of Delhi, India
Udo SCHICKHOFF, University of Hamburg, Germany
Glacial Lakes (GLs) in the Himalayas are increasing in numbers, area and volume as a result of climate change. Some of the glacial lakes in the Himalayas have increased to the extent that they pose severe potential threats to the downstream communities and infrastructure, in case of their failure, known as glacial lake outburst floods (. It is therefore essential to regularly monitor changes in the glacial lake and their hazard potentials. Hence,the present study presents the first results of glacial lake inventories in the three Himalayan river basins, viz., Indus, Ganges and Brahmaputra using Landsat satellite images for four time periods (1990, 2000, 2010 and 2020). A semi-automated method of glacial lake mapping developed, considering the lake area threshold (e than 0.036 km2, slope, elevation (more than 3000 m).
The study suggests that the number of glacial lakes in the three Himalayan basis has risen from 15,492 in the 1990s, to 16,192 in the 2000s, 16,853 in the 2010s and 17,629 in the 2020s. The Brahmaputra river basin has the largest number of GLs 9,704 (1990s), which increased to 9,934 in 2000s, 10,029 in 2010s, and 10,171 in 2020s. While, Indus river basin had 3,508 lakes in 1990s, which increased to 3930 in 2000s, 4369 in 2010s and 4821 in 2020s. The Ganga river basin has the least number of glacial lakes, i.e., 2282 in 1990s, 2307 in 2000s, 2431 in 2010s and 2629 in 2020s. Overall, the growth of the GLs in all the three basins is observed to be 12.07% between 1990 to 2020, whereas the highest of GLs is found to be in the Indus river basin (37.42%), followed by Ganga river basin (15.2%), and the Brahmaputra river basin (3.78%) between the same time period. These results are of practical use for disaster management authorities.
Mots clés : Glacial Lakes|Himalaya|Monitoring|Remote Sensing
A104703AK