Source: Risk from glacial lake floods (The Indian Express, April 4, 2024)
Alarmed by the rising threat of glacial lake outburst floods (GLOFs), Uttarakhand has constituted expert teams. These teams will assess the risk posed by five particularly hazardous glacial lakes in the region. These lakes, vulnerable to breaches due to climate change, could unleash devastating floods if they burst.
- Uttarakhand government has formed two teams of experts.
- Purpose: To evaluate the risk posed by five potentially hazardous glacial lakes.
Goal of Risk Assessment:
- Minimize the possibility of Glacial Lake Outburst Floods (GLOFs).
- Aim: Provide more time for relief and evacuation in case of a breach.
Identified Glacial Lakes:
- National Disaster Management Authority (NDMA) identified 188 glacial lakes in Himalayan states.
- Thirteen of these lakes are in Uttarakhand.
- Risk: Potential breach due to heavy rainfall.
Global Warming Impact:
Rising surface temperatures globally, including India.
- Result: Increased risk of GLOFs.
- Studies indicate approximately 15 million people at risk from sudden flooding.
- Cause: Glacial lakes expanding and increasing due to global warming.
Understanding GLOFs:
- GLOFs: Abrupt discharge of water from glacial lakes.
- Glacial Lakes: Large bodies of water in front of, on top of, or beneath a melting glacier.
- Glacier withdrawal leaves depressions filled with meltwater.
- Result: Formation of glacial lakes.
Read | Everything You Wanted To Know About Glacial Lake Outburst Flood (GLOF)
Spotlight on GLOFs: Causes and Impact
Rise in GLOF Events:
- Global temperature rise leads to increased glacier melting.
- Rapid infrastructure development in vulnerable areas contributes to spike in incidents.
Research Findings:
- Study published in Nature (2023) by Taigang Zhang, Weicai Wang, Baosheng An, and Lele Wei.
- Increased frequency of GLOFs since 1980 in Himalayan region.
- Analysis focused on southeastern Tibet and China-Nepal border area.
Findings:
- Approximately 6,353 sq km of land at risk from potential GLOFs.
- Threats to 55,808 buildings, 105 hydropower projects, 194 sq km of farmland, 5,005 km of roads, and 4,038 bridges.
Another analysis published in Nature (February 2023) by Caroline Taylor, Rachel Carr, Stuart Dunning, Tom Robinson, and Matthew Westoby.
- Focus: India and Pakistan.
- Co-author Tom Robinson emphasizes vulnerability despite smaller lake size.
Findings:
- 3 million people in India and 2 million in Pakistan face GLOF risk.
- India and Pakistan among highest GLOF danger globally due to large vulnerable populations.
Situation in Uttarakhand: GLOF Events and Risk Assessment
GLOF Incidents:
- Two major GLOF events in Uttarakhand in recent years.
- June 2013: Devastating impact on Kedarnath valley, resulting in numerous casualties.
- February 2021: Flash floods in Chamoli district due to glacier lake burst.
Glacial Lake Risk Assessment:
- Uttarakhand has 13 glacial lakes prone to GLOF.
- Categorized into three risk levels: ‘A’, ‘B’, and ‘C’.
‘A’ Category Lakes:
- Five highly sensitive glacial lakes.
- Vasudhara Tal in Dhauliganga basin, Chamoli district.
- Four lakes in Pithoragarh district:
- Maban Lake in Lassar Yangti Valley,
- Pyungru Lake in Darma basin,
- Unclassified lake in Darma basin,
- Another unclassified lake in Kuthi Yangti Valley.
- Lakes’ areas: 0.02 to 0.50 sq km.
- Elevations: 4,351 to 4,868 metres.
Impact of Rising Temperatures:
- Study by Potsdam Institute for Climate Research (PIK) and The Energy and Resources Institute (TERI).
- Prediction: Hill annual average maximum temperature may increase by 1.6-1.9 degree Celsius (2021-2050).
- Result: Exacerbation of GLOF risk in Uttarakhand.