Darjeeling Landslides and India’s Landslide Risk Framework
Why in the news
Intense rain in the Darjeeling and Kalimpong districts of West Bengal set off several landslides. At least 14 people died and important structures were damaged, underlining growing climate-linked disasters in the fragile Eastern Himalaya.
Key facts
- Damaged infrastructure included the Dudhia Bridge and the Teesta Bazaar link road.
- A landslide is the downslope movement of rock, soil or debris under gravity; it occurs when shear stress beats shear strength.
- Causes: heavy rain, earthquakes, deforestation, unplanned construction and road cutting.
- As per the Geological Survey of India (GSI), about 13% of land (0.42 million sq. km) is landslide-prone.
- High-risk regions: Himalayas, Northeastern Hills, Western Ghats, Nilgiris, Eastern Ghats.
- The Northeast holds 42% of the hazard zone because of steep slopes, fragile geology, strong monsoon, loose construction and tree loss.
Why Darjeeling is vulnerable
- Sits in the Eastern Himalaya on young, unconsolidated rocks that erode easily.
- Monsoon downpours cause waterlogging and loosen the soil.
- Road cutting and hydropower tunnelling disturb natural drainage.
- The region is seismically active.
NDMA approach
| Component | Main points |
|---|---|
| National Landslide Risk Management Strategy (2019) | Vulnerability mapping, hazard zonation, early warning; uses IMD rainfall data and ISRO terrain imagery |
| Landslide Hazard Zonation maps | 1:50,000 scale, prepared by GSI; being digitised for state GIS portals |
| Mitigation | Vegetation and bio-engineering, better drainage, retaining walls, gabions, shifting homes from chronic slide zones |
| Institutional work | NDMA works with GSI, NRSC (ISRO), DST, CSIR; real-time GIS monitoring and data sharing |
Way forward
- A pan-Himalayan sustainable development policy covering land-use planning, ecological zoning and climate adaptation.
- Geo-hazard mapping, early warning systems and green infrastructure.
Exam angle
- Share of landslide-prone area: 13% (GSI).
- Scale of LHZ maps: 1:50,000.
- Strategy year: 2019; coordinating body: NDMA.