Glacial lakes and water bodies across the Himalayan region experienced a 10.81% increase in area from 2011 to 2024 due to climate change, raising the risk of Glacial Lake Outburst Floods (GLOFs), as per a government report.
The Central Water Commission (CWC) report, accessed by PTI, highlights:
- A 7% increase in area across various lakes.
- 67 lakes in India showed over a 40% increase in surface area, placing them in the high-risk category for potential GLOFs.
- Regions with notable expansions include Ladakh, Himachal Pradesh, Uttarakhand, Sikkim, and Arunachal Pradesh.
Glacial Lakes
- Glacial lakes, like the South Lhonak Lake, are large bodies of water that sit in front or on top or beneath a melting glacier. These glacial lakes are mostly dammed by unstable ice or sediment composed of loose rock and debris.
Glacial Lake Outburst Flood (GLOF):
- As the glacial lakes grow larger, they become more dangerous because they are dammed by unstable ice or sediments composed of loose rock and debris.
- When the boundary around these glacial lakes breaks, huge amounts of water rush down the side of the mountains, which causes flooding in the downstream areas. This is called glacial lake outburst floods or GLOF.
Examples of Glacial Lake Outburst Floods (GLOF) in India
- Uttarakhand Kedarnath Flash Flood (2013): Triggered by a GLOF in the Chorabari Tal glacial lake.
- Chamoli District, Uttarakhand: GLOF event in the Nanda Devi Glacier
Reasons for Glacial Lake Outburst Floods (GLOF)
- Melting of Glaciers: Rising temperatures increase glacier melt, raising water levels and pressure on unstable lake boundaries, leading to outbursts.
- Avalanches and Earthquakes: Landslides or avalanches displace large water volumes, breaching natural dams.
- Extreme Weather: Heavy rainfall, storms, and sudden temperature shifts destabilize lakes, triggering GLOF.
- Climate Change: Accelerated glacier melting and more frequent cloudbursts in hotspot regions increase GLOF risk.
- Volcanic Activities: Volcanic heat near glaciers accelerates melting, heightening GLOF chances.
- Weak Moraine Embankments: Moraines, acting as natural dams, are prone to breaching.
- Human Activities: Infrastructure like dams and roads increase geological stresses, contributing to GLOF risks, as seen in Chamoli (2021).
Impacts of Glacial Lake Outburst Floods (GLOF)
- Loss of Life: Sudden floods catch residents off guard, leading to fatalities.
- Infrastructural Damage: Floodwaters destroy roads, bridges, buildings, and power plants, causing economic loss and service disruptions.
- Agricultural Damage: Crops, land, and livestock suffer, leading to food shortages and economic hardship for farmers.
- Environmental Harm: GLOFs devastate local biodiversity, harming flora and fauna.
Way Forward
- Identify Dangerous Lakes: Locate high-risk lakes to plan safe development nearby.
- Enhanced Technology: Use Synthetic-Aperture Radar for real-time monitoring.
- Controlled Flood Channels: Reduce lake water volume with controlled breaching or siphoning.
- Early Warning Systems: Expand EWS in the Himalayas for timely alerts.
- Comprehensive Alarm Systems: Use smartphones with traditional alarms for quick evacuation.
- Construction Codes: Develop guidelines for safe infrastructure in vulnerable zones.
- Local Training: Train locals in disaster response, as they are often first responders.
A proactive, technology-driven, and community-centric approach is critical to mitigating GLOF risks and protecting lives, infrastructure, and ecosystems.
