'Size doubled in four decades': ISRO expresses concern over Himalayan glacial lakes expansion
Produced by: Tarun Mishra
ISRO's Findings on Himalayan Glacial Lakes
The Indian Space Research Organisation (ISRO) has reported a significant increase in the size of glacial lakes across the Himalayas, particularly in India, based on recent satellite imagery analysis.
Decades of Satellite Data
Satellite data spanning the last three to four decades has revealed notable changes in glaciated regions, indicating substantial alterations in glacial lakes within the Indian Himalayan river basins.
Credit: ESA
Expansion of Glacial Lakes
Among the lakes identified in 2016-17, larger than 10 hectares, 89 percent have visibly expanded since 1984. Specifically, 130 of these lakes are situated in India, with varying numbers in the Indus, Ganga, and Brahmaputra River basins.
Sensitivity to Climate Change
The Himalayan Mountains, often called the Third Pole, are highly sensitive to global climate changes, with glaciers worldwide retreating at unprecedented rates since the Industrial Revolution. This retreat leads to the formation and enlargement of glacial lakes.
Risks Associated with Expansion
The expansion of glacial lakes poses significant risks, including Glacial Lake Outburst Floods (GLOFs), which can have devastating consequences for downstream communities.
Challenges in Monitoring
Monitoring and studying these lakes are challenging due to the rugged terrain, but satellite remote sensing technology offers a valuable tool for inventory and monitoring.
Elevation-Based Analysis
A significant number of expanding lakes are located in the 4,000 to 5,000 metres range and above 5,000 metres elevation, categorized into four broad categories based on their formation process.
Example of Expansion
For instance, the Ghepang Ghat glacial lake in the Indus River Basin, located in Himachal Pradesh, India, has shown a 178 percent increase in size between 1989 and 2022.
Importance of Satellite Analysis
Satellite-derived analyses provide crucial insights into glacial lake dynamics, essential for assessing environmental impacts and developing strategies for GLOF risk management and climate change adaptation in glacial environments, as highlighted by ISRO.