“The Himalayas are highly prone to landslides.” Discuss the causes and suggest suitable measures of mitigation.
Approach · directive: “discuss / suggest”
What it asks · Explain the natural and human causes of frequent Himalayan landslides, then propose practical measures to reduce the risk.
The question has 2 parts — answer each
- Discuss the causes of Himalayan landslides: natural (geology, seismicity, slope, climate) and human
- Suggest suitable measures of mitigation: zonation and regulation, engineering, preparedness
Open with · The Himalayas are young, steep and seismically active, so heavy rain and human interference readily turn unstable slopes into landslides.
Cover
- Geology: young fold mountains with fractured, weak rock and thrust zones, and frequent earthquakes (Seismic Zones IV and V) loosen slopes.
- Slope and climate: steep gradients, intense monsoon rain, cloudbursts and glacial-lake outbursts saturate loose debris and trigger slides.
- Human causes: unplanned road cutting and blasting, hydropower tunnels, deforestation, slope construction and poor drainage; the 2013 Uttarakhand disaster showed this compounding of damage.
- Assessment and regulation: landslide hazard zonation and susceptibility maps, land-use rules that bar construction on unstable slopes, and impact assessment for roads and dams.
- Engineering and biological measures: retaining walls, slope stabilisation, surface and subsurface drainage, and vegetation cover with native species.
- Preparedness: rainfall-threshold early warning, monitoring of vulnerable slopes, disaster management plans and trained local communities.
Close with · Zoning, careful engineering and community preparedness, backed by carrying-capacity limits for fragile towns, can cut Himalayan landslide losses.
Question: UPSC's CS (Main) 2016, GS Paper I — paper ↗. Approach: Minimalist IAS, checked 30 Sept 2026 (how we verify) — UPSC publishes no model answers. ·
Model answer · 289 words (UPSC limit 200) · Minimalist IAS
The Himalayas are young, steep and seismically active, and heavy monsoon rain on slopes cut by roads and settlements makes them one of the most landslide-prone regions in the world.
Natural causes
- Geology: young fold mountains still rising, with fractured, weathered and weak rock along thrust zones such as the Main Boundary Thrust.
- Seismicity: the range lies in Seismic Zones IV and V, and earthquakes shake loose slopes and debris.
- Slope and drainage: steep gradients, rivers undercutting the toe of slopes, and glacial and moraine deposits that fail when saturated.
- Climate: intense monsoon rain, cloudbursts and glacial-lake outburst floods soak loose material and trigger slides, as in the Kedarnath disaster of June 2013.
Human causes
- Road cutting and blasting on unstable slopes, hydropower tunnelling, quarrying and the dumping of muck on hillsides.
- Deforestation and overgrazing that strip root binding; construction on steep slopes, river terraces and old landslide debris; poor drainage from fast-growing towns and pilgrim traffic beyond their carrying capacity.
Mitigation measures
- Hazard zonation: landslide susceptibility maps by the Geological Survey of India, the nodal agency, built into master plans, with no-construction zones on unstable slopes.
- Regulation: geotechnical and environmental appraisal of roads, dams and buildings, cut-slope standards for highways, and action against encroachment on natural drainage lines.
- Engineering: retaining walls, rock bolting, gabions, surface and subsurface drainage, and bio-engineering with deep-rooted native grasses and trees.
- Preparedness: rainfall-threshold early warning, monitoring of known slides, district plans under the NDMA guidelines on landslides (2009), and trained village volunteers.
- Ecological limits: catchment afforestation, eco-sensitive zone rules such as the Bhagirathi zone, and carrying-capacity studies before hill towns expand.
Landslides cannot be prevented in a rising mountain range, but zoning, careful engineering and community preparedness can keep them from becoming disasters.
Written by Minimalist IAS from facts checked at source (how we verify) — a little fuller than exam length, so every part of the question is covered; in the hall, keep the structure and trim the detail. UPSC publishes no model answers: compare your structure and coverage with this, then write your own.