Sikkim embarks on critical expedition to address glacial flood risks

Gangtok: To mitigate risks of glacial lake outburst floods and enhance climate resilience, the Sikkim government is launching its fourth and final expedition for 2024 from November 27 to December 5.

The mission responds to the alarming increase in glacial lake hazards due to climate-induced glacier retreat, with 40 high-risk glacial lakes identified in Sikkim alone, according to an official release.

In the earlier expeditions, a comprehensive assessment of several high-risk lakes was completed. Additionally, Automatic Weather and Water Level Monitoring stations have been installed at Shako Chho and South Lhonak Lake, with support from the Swiss Development Corporation.

These monitoring stations have started providing daily weather data, water level data, and photographs. They also have a built-in alert system in case of sudden water level changes, the release said.

Building on the earlier studies, the focus is now on designing robust glacial flood mitigation strategies. The expedition team is exploring two mitigation proposals -- lowering the lake water level at Shako Chho and a retention structure at Dolma Sampa.

Accordingly, a lake discharge study and subsurface geophysical analysis of the southern lateral moraine are planned at Shako Chho Lake.

At Dolma Sampa in Lhonak Valley, comprehensive studies will be undertaken, including subsurface geophysical investigations, discharge assessment of Goma Chu, topographical mapping, debris deposition analysis, and flood-level measurements.

The studies will help refine glacial flood modelling, provide insights into subsurface geology, and inform the design of retention structures to mitigate potential glacial lake outburst floods (GLOFs).

The participants include scientists and engineers from the Science and Technology Department and the Mines and Geology Department, supported by the Indian Army's 27 Mountain Division and the Indo-Tibetan Border Police.

The expedition team's main challenges will be the high altitude of 17,000 feet and sub-zero temperatures. This expedition underscores Sikkim's commitment to proactive disaster risk reduction, addressing cascading natural hazards amplified by climate change and protecting its communities and ecosystems, the release said.