The Indian Space Research Organization (ISRO) said on Monday that an analysis of decades of satellite imagery revealed that glaciers in India’s Himalayas – often called the third pole because of its vast glaciers and snow cover – are melting at an unprecedented rate, resulting in significant expansion. from glacial lakes.
“This retreat leads to the creation of new lakes and the expansion of existing ones in the Himalayan region. These bodies of water, created by melting glaciers, are known as glacial lakes and play a key role as freshwater sources for rivers in the Himalayan region,” ISRO said in a report.
“They also pose significant risks, such as Glacial Lake Outburst Floods (GLOFs), which can have devastating consequences for downstream communities. GLOFs occur when glacial lakes release large volumes of meltwater due to the failure of natural dams such as moraine or ice dams, resulting in sudden and severe flooding downstream,” the report added.
It is important to note that research conducted around the world consistently shows that glaciers around the world are experiencing unprecedented rates of retreat and thinning since the beginning of the industrial revolution in the eighteenth century.
Using satellite images from 1984 to 2023, ISRO noted that out of 2,431 glacial lakes in the Indian Himalayas – larger than 10 hectares identified during the 2016-2017 satellite survey, 676 glacial lakes have expanded since 1984. This includes 130 lakes in India. —65 lakes in the Indus River Basin, 7 in the Ganges River Basin and 58 in the Brahmaputra River Basin.
The Bengaluru-based Indian Space Agency further reported that 89% of lakes (601 out of 2,431 lakes) expanded more than twice, 10 lakes grew 1.5 to 2 times, and 65 lakes increased to 1.5 times their size in 1984.
The ISRO study further noted that 314 lakes are located between 4,000 and 5,000 meters and 296 lakes are at an altitude of more than 5,000 meters.
Glacial lakes are divided into four broad categories based on the process of their formation, namely Moraine-dammed (water dammed by moraine), Ice-dammed (water dammed by ice), erosion-dammed (water dammed in depressions created by erosion) and other glacial lakes. Among the 676 expanding lakes, most of them are dammed by moraine (307), followed by erosion (265), other (96) and ice (8) glacial lakes.
Long-term changes in the Ghepang Ghat (Indus River Basin) glacial lake at 4,068 meters in Himachal Pradesh show a 178% increase in size from 36.49 hectares to 101.30 hectares between 1989 and 2022. The rate of increase is approximately 1.96 hectares per year.
