Context

• According to the 'Satellite Insights: Expanding Glacial Lakes in the Indian Himalaya' report recently released by ISRO, at least 89 percent of the 2,431 glacial lakes in the Himalayas identified in the year 2016-17 have expanded significantly since 1984.

key points

• Experts say the results of ISRO's analysis are worrying because the expansion of glacial lakes due to global warming could have widespread consequences in downstream areas.
• Notably, satellite data collections over the past three to four decades provide valuable feed into changes in glaciated environments.
• ISRO said in the report that long-term satellite imagery covering catchments of Indian Himalayan river basins from 1984 to 2023 indicates significant changes in glacial lakes.
• A total of 601 glacial lakes, or 89 percent, have expanded more than twice.
• While 10 lakes have expanded by 1.5 times and up to double their size, sixty-five lakes have expanded by 1.5 times.
• Of the 2,431 glacial lakes larger than 10 hectares, 676 have expanded significantly, and at least 130 of these lakes are in India – 65 (Indus River Basin), 7 (Ganga River Basin), and 58 (Brahmaputra River Basin). .
• Further altitude based analysis reveals that 314 lakes are located in the range of 4,000 to 5,000 metres, and 296 lakes are above 5,000 metres.
• ISRO said long-term changes in the Ghepang Ghat glacial lake (Indus River Basin), located at an altitude of 4,068 meters in Himachal Pradesh, predict a 178 per cent increase in size between 1989 and 2022 from 36.49 to 101.30 hectares. And the rate of this increase is about 1.96 hectares per year.

Importance of these satellite based data

• Long-term change analyses conducted via satellite also provide valuable insights to understand glacial lake dynamics, which can be used to assess environmental impacts and develop strategies for glacial lake outburst flood (GLOF) risk management and climate change adaptation in glacial environments. are necessary to develop.
• Apart from this satellite remote sensing technology, however, also helps as an excellent tool for inventory and monitoring due to its wide coverage and revisitability.
• The Himalayan mountains are often called the 'Third Pole' because of their extensive glaciers and snow cover, and they are highly sensitive to changes in global climate, both in terms of their physical characteristics and their social impacts.
• In such a situation, it is very important to collect data and analyse it and take necessary measures.

Effect of melting glaciers

• If we talk about positive results, the water generated from melting glaciers has an important role as a source of freshwater for the rivers in the Himalayan region.
• However, they also pose significant risks, such as glacial lake outburst floods, which can have devastating consequences for downstream communities.

Important Facts For Exams

Glacial lake outburst flood

• GLOFs occur when glacial lakes release large amounts of meltwater due to the failure of natural dams, such as moraines or dams made of ice, resulting in sudden and severe flooding.
• These dam failures can be caused by a variety of factors, including snow or rock avalanches, extreme weather events, and other environmental factors.

ISRO

• Established: 15 August 1969
•  Headquarters: Bengaluru, Karnataka
• Chairman:Dr. S. Somnath