UPSC Prelims Practice Questions — Danger from above

Q1. Among the glacial lakes of the Indian Himalayas identified through long-term satellite imagery as having notably expanded, which one of the following dam types accounts for the largest number of such lakes?

  • A. Moraine-dammed lakes, impounded behind ridges of unconsolidated debris deposited by a formerly larger glacier
  • B. Ice-dammed lakes, the only category in the Himalaya whose barrier can fail catastrophically
  • C. Erosion-based lakes, which invariably drain gradually and never breach their confining rim
  • D. Bedrock-dammed lakes, which are permanently stable because their barrier is solid rock

Q2. South Lhonak, the Sikkim lake that burst in October 2023, is classified as a proglacial lake. Such a lake is best described as one that occupies which of the following positions?

  • A. A basin lying immediately in front of a glacier snout, commonly impounded by the moraine the glacier deposited
  • B. A shallow water body ponded on the upper ice surface of a glacier, deepened by absorbed solar radiation
  • C. A cavity of meltwater held beneath the glacier bed and sealed by the overlying weight of ice
  • D. A depression in frozen ground beyond the ice margin, kept water-filled by a seasonally thawing active layer

Q3. In reports on the 26 August 2026 Rasuwa disaster, authorities monitored a 'barrier lake' that had accumulated about 2 million cubic metres of water by the following morning. In that context, the barrier lake refers to which one of the following?

  • A. Water ponding upstream of the ice-and-rock debris that choked the river channel after the avalanche
  • B. Water held back by a ridge of debris left along the edge of a retreating high-altitude glacier
  • C. Water stored behind the diversion structure of a run-of-the-river hydropower project on the corridor
  • D. Water impounded where a thickening tributary glacier advanced across the trunk valley drainage

Q4. As reported on 27 August 2026, how many districts of Nepal were identified as affected by the Bhote Koshi-Trishuli flash flood?

  • A. Four
  • B. Five
  • C. Seven
  • D. Nine

Q5. The National Glacial Lake Outburst Flood Risk Mitigation Project, sanctioned for Arunachal Pradesh, Himachal Pradesh, Sikkim and Uttarakhand with an outlay of about Rs 150 crore, is driven by which one of the following bodies?

  • A. The Central Water Commission, functioning under the Department of Water Resources in the Ministry of Jal Shakti
  • B. The National Disaster Management Authority, functioning under the aegis of the Ministry of Home Affairs
  • C. The National Remote Sensing Centre, functioning under the Department of Space in the Prime Minister's Office
  • D. The Geological Survey of India, functioning under the Ministry of Mines as the nodal earth-science agency

Q6. The Hindu Kush Himalaya region is described as feeding how many major river basins?

  • A. Six
  • B. Eight
  • C. Ten
  • D. Fourteen

Q7. The institution whose assessments of Hindu Kush Himalayan ice loss and of the August 2026 avalanche are widely cited is ICIMOD. Which one of the following correctly describes its founding basis and character?

  • A. A regional intergovernmental knowledge centre set up in 1981 by agreement between the Government of Nepal and UNESCO, serving eight member countries
  • B. A specialised agency of the United Nations created in 1981 under a General Assembly resolution, open to all mountain states as members
  • C. A regional body constituted in 1981 under the SAARC charter framework, with membership confined to the association's South Asian states
  • D. A regional office of the United Nations Environment Programme opened in 1981, reporting to its governing body on Asian mountain ecosystems

Q8. In the damage assessment reported on 27 August 2026 for the Nepal flash flood, how many suspension bridges were recorded as destroyed?

  • A. Thirty-five
  • B. Forty
  • C. Forty-five
  • D. Fifty-five