Sikkim to launch expedition to assess threatened glacial lakes from August 28

Gangtok, August 25: Sikkim is preparing for a vital expedition aimed at assessing five glacial lakes facing significant threats in the state.

The mission, estimated to cost Rs. 32 lakhs, is scheduled to run from August 28 to September 14. The lakes under scrutiny are Gurudongmar A, B, and C, Sakho Chu, and Khangchu Lake, all situated in the Mangan district, near the Tibet border.

The expedition follows a previous mission by the National Disaster Management Authority (NDMA) and Swiss experts, which was conducted before the 2023 Glacial Lake Outburst Flood (GLOF) at South Lhonak Lake, costing Rs. 48 lakhs.

Sandeep Tambe, Secretary to the Department of Science and Technology of Sikkim, will lead the expedition.

The team will comprise experts from six departments, including the State Disaster Management Authority (SDMA), Mines and Geology, Water Resources, Forest, Science and Technology, and research scholars from Sikkim University.

This expedition is critical in light of recent GLOF events. Tambe emphasised a multidisciplinary approach to mitigate glacial hazards, addressing flood threats from the lakes, avalanche-induced floods, and water discharge management. “Our mitigation strategy includes methods such as siphoning, pumping, tunneling, channeling, and deepening the lakes to manage water levels,” Tambe said.

Key objectives include testing the strength of moraine dams created by glaciers and installing pressure probes to monitor water levels. This study is particularly crucial following the recent GLOF incident on October 4, 2023.

The SDMA has formed a special task force for glacial lake mitigation and is collaborating with the United Nations Development Programme (UNDP), neighbouring countries Nepal and Bhutan, and Swiss experts.

An automatic weather station has also been set up at Sakho Chu to provide real-time data on the lake's condition.

In addition to the five targeted lakes, Sikkim has several other glacial lakes under threat, including three in Geyzing district and 13 in Mangan district.

Of particular concern is Sakho Chu, which holds 25-27 million cubic meters of water, has no outlet, and is bordered by high moraine structures. This lake is close to Thangu, the last habitable village before the cold desert regions. The Zemu Glacier, the largest in the area, also faces threats from climate change.