Context:
The waters from South Lhonak Lake in the Sikkim Himalayan region breached. Thus causing a rise in the downstream level of the Teesta river. The flash floods inflicted damage on the Chungthang dam, a component of the state’s largest hydropower project, releasing over 5 million cubic meters of water from the reservoir. Consequently, this led to disruptions in electricity, communication, and transportation systems.
| Must Read Blogs | |
| Carbon Trade and COP 28 | The Green Climate Fund |
| Types of Plains | Tackling Himalayan Flood Vulnerability |
| Glacial Erosional Landforms | Sikkim: The India State of Khanchendzonga |
Key Details:
Cause of Vulnerability:
The South Lhonak Lake, situated in the Sikkim Himalayas, led to the flooding after its waters breached, impacting downstream areas, particularly the Teesta river.
Increasing global temperatures have accelerated glacier melt in the region, contributing to the formation and expansion of glacial lakes, making them prone to such outburst events.
Sikkim’s Glacial Lake Situation:
Sikkim’s Disaster Management Authority identifies over 300 glacial lakes, with around 10 marked as vulnerable to potential outburst floods.
A report by the Sikkim Forest and Environment Department highlighted a significant increase in the area of South Lhonak Lake. Glacier melt attributed to this expansion, which took place over the past five decades.
Understanding GLOF:
Glacial Lake Characteristics: These water bodies develop due to melting glaciers and are often held back by unstable ice or debris.
Risks Associated: As these lakes grow in size, they pose dangers because of their precarious dams. If the barriers break, it can result in the sudden release of immense water volumes. This phenomenon is termed as glacial lake outburst floods (GLOF), which can cause downstream flooding.
Trigger Factors: GLOFs can be initiated by various events such as earthquakes, heavy rainfall, or avalanches of ice or debris falling directly into these lakes.
Impact and Risks:
Immediate Effects: Flash floods from the South Lhonak Lake disrupted vital infrastructure, including the Chungthang dam, leading to power, communication, and transportation disruptions.
Long-term Concerns: The escalating frequency of such incidents due to glacier melt poses continuous threats to downstream regions and infrastructure.
Understanding glacial lake outburst floods is crucial due to their unpredictable nature and potential to cause widespread devastation downstream. Monitoring and managing these vulnerable lakes in high-altitude regions are essential steps in mitigating the risks associated with GLOFs.
Read Also: Khangchendzonga National Park, Sikkim
