Glacial Lake Outburst Floods

Glacial Lake Outburst Floods

News: Three million Indians live in areas where a glacial lake outburst flood (GLOF) can happen at any time, the first global assessment of such areas has found. Together with two million Pakistanis, they form a third of the total number of people worldwide facing such a risk.

What is GLOF?
 ICIMOD or the International Centre for Integrated Mountain Development defines GLOF as the sudden release of water from a lake fed by glacier melt that has formed at the side, in front, within, beneath, or on the surface of a glacier. GLOF has the potential to catastrophically threaten people’s lives, livelihoods and regional infrastructure.
 The researchers found that it was not the size or number of glacial lakes that determined the risk to people. Instead, it was the number of exposed people that greatly elevated the potential impact of GLOFs globally especially across High Mountain Areas and the Andes.
 In the Hindu Kush Himalaya (HKH), GLOF events can be traced back to the failure of moraine-dammed glacial lakes
 The pressure on the dam, water seeping through the structure, fragmentation of the source glacier, landslides, etc., can trigger a GLOF.
 The frequency of GLOFs is expected to increase due to climate change.

Key Findings:
 The majority of the globally exposed population is located in the region of high mountain Asia and more than 50% in India, Pakistan, Peru and China.
 The population exposed to GLOFs increases with distance from a glacial lake.
 Rapid deglaciation over the last 20 years has led to the growth of many large glacial lakes.
 Increase in the population living in close proximity to glacial lakes between 2002 to 2022.
 According to the ICIMOD, Himalayan glacial lakes increased by about 9% in number, and 14% in the area.
 The best-studied glacier is north India’s Chhota Shigri, which has lost three times its mass.
 The rapid onset of GLOFs means there is insufficient time to effectively warn downstream populations.

Way Forward:
 Studying glaciers through satellite observations and learning from past events and their dynamics will help in disaster risk reduction and climate change adaptation in the region.