At least seven people were killed and scores more were injured or are missing after flash floods inundated Sikkim.

The floods are believed to have been triggered after a lake, forming the gradual melting of a Himalayan glacial, suddenly overflowed and inundated the Teesta River basin.

A glacial lake outburst flood (GLOF) or glacial lake burst is a sudden release of water from a glacier-dammed lake.

This can happen when the dam (usually made of ice or moraine) that holds back the water fails, either due to rapid melting of the glacier, an avalanche, or some other mechanism.

The release of water can lead to catastrophic flooding downstream.

Glacial lakes form as glaciers advance and retreat, creating depressions that fill with meltwater.

These lakes are often dammed by ice or debris (moraine), and when the dam is breached or fails, the stored water is rapidly released, causing a flood.

The flood can have devastating effects on downstream communities, ecosystems, and infrastructure.

GLOFs are particularly common in mountainous regions where glaciers are present.

Climate change has increased the frequency and severity of GLOFs in some areas, as rising temperatures lead to accelerated glacier melting and changes in the stability of glacial dams.

Efforts are underway in many regions to monitor and manage glacial lakes to reduce the risk of GLOFs and to develop early warning systems to alert downstream communities in the event of a potential glacial lake outburst.

The Teesta River is one of the major rivers flowing through India and Bangladesh. It originates in the eastern Himalayas in the Indian state of Sikkim and flows through the Indian states of West Bengal and Assam before entering Bangladesh, where it eventually merges with the Brahmaputra River.

Key points about the Teesta River:

1. Origin and Course:
• The Teesta River originates from the Tso Lhamo Lake in North Sikkim, India.
• It flows through the mountainous terrain of Sikkim, cutting through deep gorges and valleys.
• After passing through Sikkim and the Darjeeling district of West Bengal, it enters the plains of West Bengal.
2. Teesta Treaty:
• The Teesta River has been a subject of water-sharing disputes between India and Bangladesh.
• The two countries signed a framework agreement in 1983 to share the waters of the Teesta River, but a final agreement has been elusive.
3. Hydroelectric Projects:
• The Teesta River and its tributaries have been harnessed for hydroelectric power generation.
• Numerous hydropower projects have been developed along the river, contributing to the region's electricity needs.
4. Ecological Significance:
• The Teesta River basin is ecologically rich and supports diverse flora and fauna.
• The river and its surroundings are of ecological importance, and efforts are made to conserve the biodiversity of the region.
5. Agriculture and Economy:
• The fertile plains along the Teesta River support agriculture, and the river plays a crucial role in the livelihoods of people living in the region.
• The river also has economic significance for activities such as fisheries and tourism.
6. Transboundary Issues:
• The sharing of Teesta River waters between India and Bangladesh has been a matter of contention.
• The equitable distribution of water resources is essential for both countries, and negotiations continue to find a comprehensive agreement.

The Teesta River is significant for both its ecological importance and its role in supporting the livelihoods of the people living in the regions through which it flows.

The ongoing discussions between India and Bangladesh regarding the sharing of Teesta River waters highlight the challenges and complexities associated with transboundary river management.