India and Pakistan at Risk of Flooding from Glacial Lakes: New Study

Subject: Geography

Section: Physical Geography

Concept:

According to a new study, Glacial lake outburst floods threaten millions globally’ published in the journal Nature, around 15 million people across the world face the risk of sudden and deadly flooding from glacial lakes, which are expanding and rising in numbers due to global warming.
More than half of those who could be impacted live in four countries: India, Pakistan, Peru, and China.
Glacial lake outburst floods (GLOFs) are a type of flood that occurs when a glacial lake or a dam containing the lake fails.

Important Findings of the study

This study estimates that 15 million people live within the 50 km danger zone of glacial lakes.
It adds that populations in High Mountains Asia (HMA) — a region stretching from the Hindu Kush all the way to the eastern Himalayas — are the most exposed and on average live closest to glacial lakes with around one million people living within 10 km of a glacial lake.
Another interesting finding of the study is that the glacial flood risks don’t only depend on the size and number of glacial lakes in an area.What also matters is the number of people living in the area, their proximity to the danger zone as well as the levels of social vulnerability.

Glacial lake outburst floods (GLOFs)

A glacial lake outburst flood is a type of catastrophic flood that occurs when the dam containing a glacial lake fails, releasing a large volume of water.
This type of flood is typically caused by rapid melting of glaciers or the buildup of water in the lake due to heavy precipitation or the inflow of meltwater.
In February 2021, Chamoli district in Uttarakhand witnessed flash floods which are suspected to have been caused by GLOFs.

Causes:

These floods can be triggered by a number of factors, including changes in the volume of the glacier, changes in the water level of the lake, and earthquakes.
According to NDMA (National Disaster Management Authority), glacial retreat due to climate change occurring in most parts of the Hindu Kush Himalayas has given rise to the formation of numerous new glacial lakes, which are the major cause of GLOFs.