Landslides are the downhill movement of rock, debris or earth due to slope failure, triggered by natural or anthropogenic factors.
Causes of Landslides
Natural Causes
Intense or Prolonged Rainfall leads to liquefaction – Eg- 2018 Kerala floods triggered major landslides in Idukki and Wayanad.
Hydrological Factors: Water seepage through porous materials raises pore pressure and weakens the slope.
Earthquakes – Seismic shaking destabilises slopes.
Weathering & Erosion
Physical and chemical weathering reduce slope strength
River undercutting erodes base material.
Snowmelt – Eg- Landslides linked to glacial retreat in Chamoli (Uttarakhand).
Volcanic Activity – Though rare in India, globally volcanic regions face debris flows and lahars.
Anthropogenic Causes
Unregulated Construction– Eg- Frequent landslides along Char Dham highway in Uttarakhand.
Deforestation – Reduces root binding capacity and slope cohesion. Eg- Western Ghats tea and cardamom plantations.
Mining & Quarrying Activities– Eg- Quarry-linked landslides in Kerala’s Idukki district.
Poor Drainage –Blocked drains, leaking pipelines, and slope saturation trigger failures.
Unplanned Urbanisation – Unscientific hill-cutting and unsustainable tourist influx. Eg- Joshimath Crisis in Uttarakhand
Effects of Landslides
Loss of Life and Injury – Eg- 2024 Wayanad landslide killed 250+ people and injured 400
Damage to critical Infrastructure– Eg- Frequent closure of NH-44 in J&K and HP.
Economic Losses – 1% to 2% of the Gross National Product (GSI)
River Blockage due to debris creates temporary dams and flash floods. Eg- 2021 Rishiganga disaster.
Environmental Degradation – Loss of forests, soil fertility, biodiversity, and increased erosion.
Disaster induced displacement – as per Internal Displacement Monitoring Centre (IDMC), India recorded 5.4 million displacements in 2024 due to disasters Eg- Joshimath crisis (2023).
Components of the National Landslide Risk Management Strategy (NLRMS)
Landslide Hazard Zonation Mapping using GIS, remote sensing, LiDAR.
At macro scale (1:50,000 / 25,000)
At meso level (1:10,000)
Developing landslide monitoring & early warning systems – Eg- use of Rainfall thresholds, automated sensors, Doppler radar support etc
Awareness generation and capacity building of local communities in landslide safety and mitigation.
Land use regulation – Eg- Restricting construction in high-risk slopes.
Creation of Special Purpose Vehicle (SPV) for Landslide Management
Mitigation Measures –
Engineering solutions – Retaining walls, slope drainage, rock bolting, geo-textiles,
Nature based solutions – Afforestation in himalaya
Establishment of a National Landslide Inventory for modelling and planning.
Response & Relief – SOPs for search and rescue, emergency shelters.
Institutional Mechanism & Coordination – Defining roles of NDMA, GSI, MoRTH, state DMAs and local bodies.
Research & Development – Geotechnical studies, rainfall-landslide correlations.
To prevent a catastrophe like the Wayanad Landslide of 2024, engineering as well as nature-based solutions along with early warning systems, and effective land use practices are essential.
