"Nepal Glacier Collapse Exposes Himalayan Dam Risks and Transboundary Data Gaps"
GLOF (Glacial Lake Outburst Flood)
sudden release of water from a glacial lake when its moraine or ice dam fails.
High Mountain Asia (HMA)
the Tibetan Plateau and surrounding ranges, Earth's most important freshwater tower.
The Himalayas are among the world's youngest and most tectonically active mountain systems. They formed from the ongoing collision of the Indian and Eurasian plates and continue to rise, making the region inherently prone to earthquakes, landslides, and avalanches. Glaciers across the range feed major river systems, the Indus, Ganga, and Brahmaputra, that sustain hundreds of millions of people downstream. The broader zone known as High Mountain Asia (HMA), which includes the Tibetan Plateau and surrounding ranges, functions as the planet's most critical freshwater reservoir.
Climate change has accelerated glacial retreat across the HMA at a rate roughly double the global average. As glaciers melt, meltwater collects behind natural dams of rock debris called moraines, forming Glacial Lakes. These lakes are inherently unstable. When a moraine wall fails, triggered by an earthquake, an ice avalanche, or heavy rainfall, the stored water releases suddenly, producing a Glacial Lake Outburst Flood (GLOF). In steep Himalayan valleys, a GLOF can travel at devastating speed, carrying ice, rock, and debris far downstream within minutes. The 2013 Kedarnath disaster and multiple events in the Bhotekoshi valley are well-documented examples of this hazard class.
Against this backdrop, all Himalayan nations, India, Nepal, Bhutan, and China, have pursued large-scale hydropower development. Dams offer electricity and water regulation for remote populations, but they also introduce new risks into an already fragile geological setting. The NCERT Class X geography curriculum explicitly notes that large dams can induce earthquakes, cause poor sediment flow, and ironically trigger the very floods they are meant to control.
A GLOF begins when a glacial lake's natural dam, usually a moraine, fails suddenly. The failure can be triggered by an earthquake, a large ice or rock avalanche falling into the lake, rapid snowmelt, or prolonged heavy rainfall. Once the dam breaches, water rushes down the valley at high velocity, picking up sediment, boulders, and debris. The resulting flow is far more destructive than a normal flood of equivalent volume because of its density and speed. Downstream infrastructure, bridges, roads, hydropower intakes, and settlements, is typically destroyed within minutes of the wave's arrival.
The Yarlung Tsangpo river, which becomes the Brahmaputra after entering India through Arunachal Pradesh, originates on the Tibetan Plateau and drains one of the most seismically active corridors in Asia. A massive hydropower project is under construction on this river near the Arunachal Pradesh border. Chinese researchers have identified an active fault line directly beneath this project, with the surrounding terrain described as having a loose structure and weak cohesion. …
Differentiate the causes of landslides in the Himalayan region and Western Ghats.
Consider the following statements:
1.In India, the Himalayas are spread over five States only.
2.Western Ghats are spread over five States only.
3.Pulicat Lake is spread over two States only.
Which of the statements given above is/are correct?
With reference to the Himalayan rivers joining the Ganga downstream of Prayagraj from West to East, which one of the following sequences is correct?
Consider the following statements regarding glacial hazards in the Himalayan region:
1.High Mountain Asia (HMA) is warming at approximately double the global average rate.
2.A Glacial Lake Outburst Flood (GLOF) occurs when a glacial lake's moraine or ice dam fails suddenly.
3.Reservoir-Induced Seismicity refers to earthquakes caused exclusively by the weight of water in a reservoir.
How many of the above statements are correct?
Consider the following pairs regarding Himalayan hydropower development:
Claim — Figure
1.Dams built or planned in the Tibetan region since 2000 — At least 193
2.Hydropower projects listed in Nepal's database — More than 570
3.India-China expert-level mechanism on transboundary rivers established — 2002
How many of the above pairs are correctly matched?
With reference to the Yarlung Tsangpo river, consider the following statements:
1.It is the upper course of the Brahmaputra river, originating on the Tibetan Plateau.
2.A large hydropower project under construction on this river has been found to sit above an active fault line.
3.After entering India, it flows through the state of Sikkim before reaching Assam.
Which of the statements given above is/are correct?
Which of the following best describes the primary reason why large dam construction in the Himalayas increases earthquake risk in the surrounding area?
Consider the following statements about transboundary river governance in the Himalayan region:
1.India and China signed a Memorandum of Understanding on transboundary rivers in 2002.
2.The existing India-China expert-level mechanism covers real-time glacial-lake monitoring and GLOF early warning.
3.Nepal officially publishes detailed hydropower project and licensing information, unlike China which lacks any consolidated public database.
Which of the statements given above is/are correct?
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