Landslide
Kartavya Desk Staff
Syllabus: Disaster Management
Source: TOI
Context: A tragic landslide on the Kedarnath National Highway in Rudraprayag, Uttarakhand killed one and injured five pilgrims from Chhattisgarh. Authorities have warned against travel due to ongoing extreme weather.
About Landslides:
• What is a Landslide? A landslide is the sudden downward movement of rock, earth, or debris due to gravity, often triggered by heavy rainfall, seismic activity, or human interference.
• A landslide is the sudden downward movement of rock, earth, or debris due to gravity, often triggered by heavy rainfall, seismic activity, or human interference.
• India’s Vulnerability: Around 15% of India’s landmass is landslide-prone (NDMA), especially the Himalayas, North-East, Western Ghats, and Nilgiris.
• Types of Landslides in India: Debris Flow: Common during monsoon in Western Ghats and Himalayas. Rockfalls: Observed in steep Himalayan terrains. Creeping Landslides: Slow and progressive, seen in Sikkim and Darjeeling.
• Debris Flow: Common during monsoon in Western Ghats and Himalayas.
• Rockfalls: Observed in steep Himalayan terrains.
• Creeping Landslides: Slow and progressive, seen in Sikkim and Darjeeling.
Causes of Landslides in India:
• Geological Factors: Fragile rock structures due to tectonic movement of the Indian plate at ~5 cm/year (Geological Survey of India).
• Heavy Rainfall: Intense and prolonged rainfall triggers slope failures, e.g., Malpha (Pithoragarh) and Okhimath (Chamoli).
• Seismic Activity: Earthquakes in Himalayan zones weaken slopes and trigger landslides.
• Deforestation & Urbanisation: Removal of vegetation and unregulated construction destabilizes soil layers.
• Road Construction & Mining: Blasting and excavation alter natural slopes, making them prone to collapse.
Impacts of Landslides:
• Short-term Impacts: Loss of life and injuries, e.g., Kedarnath NH landslide (May 2025). Damage to infrastructure and crops causing economic loss. Obstruction to transport, especially in remote and hilly terrain.
• Loss of life and injuries, e.g., Kedarnath NH landslide (May 2025).
• Damage to infrastructure and crops causing economic loss.
• Obstruction to transport, especially in remote and hilly terrain.
• Long-term Impacts: River sedimentation, leading to downstream flooding. Reduced reservoir life due to siltation in hydropower projects. Displacement of population and loss of arable land. Geographic isolation leading to underdevelopment.
• River sedimentation, leading to downstream flooding.
• Reduced reservoir life due to siltation in hydropower projects.
• Displacement of population and loss of arable land.
• Geographic isolation leading to underdevelopment.
NDMA Guidelines for Landslide Management:
• Hazard Zonation Maps: LHZ maps at 1:50,000 scale being prepared by NRSC, IITs, DST.
E.g., NRSC Atlas for Uttarakhand corridors.
• Early Warning Systems (EWS): Use of real-time monitoring, stress sensors, remote sensing, and GIS for timely alerts.
• Land Use Regulation: No construction in vulnerable zones, excavation norms, and slope stability measures like rock bolting and retaining walls.
• Preparedness & Capacity Building: Disaster training in schools, simulation drills, and awareness campaigns in hilly districts.
• Infrastructure Measures: Drainage improvement, vegetation cover restoration, and slope reengineering.
• Insurance & Compensation: Encouraging landslide insurance and quick relief disbursals to affected families.
• Research & Development: DST supports over 30 research projects to improve landslide prediction and mitigation technologies.
Conclusion:
Landslides are a persistent threat in India’s geologically fragile zones. With changing climate and unplanned development, their frequency is rising. Strengthening early warning systems, enforcing regulations, and raising public awareness are key to reducing future risk and impact.
• Describe the various causes and the effects of landslides. Mention the important components of the National Landslip Risk Management Strategy. (2021)