The CWC report states that of the 100 glacial lakes over 10 hectares in size, there was an increasing trend in water spread area in 34, a decreasing trend in 20, a “no change trend” in 44.

• CWC monitors 902 glacial lakes and water bodies across states and transboundary areas using remote sensing.
  • 90 GLOF (Glacial Lake Outburst Flood) project-based studies are approved under the National GLOF Risk Mitigation Program (2021-2026).
• National GLOF Risk Mitigation Program is being implemented in four states-Arunachal Pradesh, Himachal Pradesh, Sikkim and Uttarakhand.

About Glacial Lake and Glacial Lake outburst flood (GLOFs)

• Glacial lakes: It is water formed by melting glaciers, usually at or near the glacier's base.
• GLOFs: A GLOF is a flood resulting from the sudden and rapid release of water from a glacial lake, often caused by the failure of a moraine dam or ice dam.
  • E.g., the 2023 South Lhonak GLOF that damaged Teesta III Dam in Sikkim.
• Geographical Distribution: Commonly associated with glacial regions, especially in mountainous areas with significant glacial activity. E.g., the Himalayas, Andes, and Alps.
• Impacts: GLOFs can result in devastating downstream flooding, destruction of infrastructure, and loss of life.
• Triggering Mechanism: The primary trigger for a GLOF is the collapse or breach of a moraine dam or ice dam holding back water in a glacial lake.