FAST READ
- — read only this box if short on time
- Sikkim has identified 40 high-hazard glacial lakes.
- Of these, 16 are Category A, the highest-risk group.
- The State is developing a dedicated Glacial Lake Outburst Flood (GLOF) risk-mitigation protocol for downstream settlements.
- GLOFs are sudden releases of water from glacier-fed lakes after failure of natural dams.
- The eastern Himalaya is highly vulnerable because of rapid warming, steep terrain and expanding glacial lakes.
WHY IN NEWS
- Sikkim's latest hazard assessment has identified 40 glacial lakes requiring high-priority monitoring.
- The exercise follows heightened concern over Himalayan GLOFs and aims to move from post-disaster relief to anticipatory risk reduction.
- The State is working on a dedicated protocol covering monitoring, warning, evacuation and downstream preparedness.
TOP DATA & FACTS
- High-hazard lakes identified: 40.
- Highest-risk Category A lakes: 16.
- Category B lakes: 2.
- Category C lakes: 9.
- A further 13 lakes were reported as unclassified within the high-hazard set.
- A GLOF occurs when water stored in a glacial lake is released suddenly.
- Natural dams may consist of moraine, ice or unstable debris.
- Triggers include ice/rock avalanches, intense rainfall, earthquakes and progressive dam weakening.
- Early-warning systems combine remote sensing, lake-level/weather instruments and downstream communication.
- Risk depends not only on lake size but also on dam stability, slope, downstream exposure and cascade effects.
HISTORICAL PERSPECTIVE
- The Himalaya contains thousands of glaciers and glacier-fed lakes.
- Warming has caused retreat and expansion of many moraine-dammed lakes.
- The 2023 South Lhonak GLOF in Sikkim demonstrated the destructive potential of cascading mountain hazards.
- Himalayan disaster policy increasingly emphasises lake inventories, field expeditions and early warning.
- GLOF management now combines cryosphere science with community-based disaster preparedness.