Himalayan Glacial Lakes Expand by More than Double in 38 Years: ISRO

The results of the ISRO analysis have raised concerns about the expansion of glacial lakes in the Indian Himalayas due to warming, and the potential cascading consequences in the lower regions, according to experts. ISRO’s report, ‘Satellite Insights: Expanding Glacial Lakes in the Indian Himalayas,’ revealed that 89 percent of the 601 glacial lakes studied have expanded more than twice, with some growing between 1.5 and 2 times. Elevation-based analysis indicates that a significant number of these lakes are located in the 4,000 to 5,000 meters range and above 5,000 meters.

Notably, the long-term changes in the Ghepang Ghat glacial lake in Himachal Pradesh demonstrate a 178 percent increase in size between 1989 and 2022. This growth equates to approximately 1.96 hectares per year, highlighting the substantial changes occurring in the region. ISRO emphasizes the significance of satellite-derived long-term change analyses in understanding glacial lake dynamics, particularly in assessing environmental impacts and developing strategies for glacial lake outburst flood (GLOF) risk management and climate change adaptation.

However, the study faced challenges due to the difficult terrain, but satellite remote sensing technology proved to be an effective tool for inventory and monitoring due to its wide coverage and revisit capability. The Himalayan mountains, known as the “Third Pole,” are highly sensitive to climate change, with glaciers experiencing unprecedented rates of retreat and thinning since the 18th century. The retreat of glaciers leads to the formation of new lakes and the enlargement of existing ones in the Himalayan region, which play a crucial role as freshwater sources for rivers.

The potential risks associated with glacial lakes, including dam failures triggered by various factors such as avalanches, extreme weather events, and environmental changes, underscore the importance of monitoring and understanding the dynamics of these lakes for long-term risk management.