Describe the various causes and the effects of landslides. Mention the important components of the…

Question

Describe the various causes and the effects of landslides. Mention the important components of the National Landslide Risk Management Strategy.

Ghissu Editorial · Accepted Answer

Landslides result from fragile geology, intense rain, earthquakes and slope-disturbing construction, and they kill suddenly, cut connectivity and destroy livelihoods. The NDMA's National Landslide Risk Management Strategy (2019) rests on hazard mapping, early warning, awareness, capacity building, regulation and slope stabilisation.

**Introduction**

A landslide is the downslope movement of rock, soil or debris when gravity overcomes slope strength. The Geological Survey of India counts about 12.6% of India's land as prone to them.

**Causes of Landslides**

SKETCH: forcefield | What tips a slope
center: Slope stability
driving: Heavy rain, Earthquake, Toe cutting, Added load
restraining: Root binding, Rock strength, Good drainage, Gentle gradient

1. **Fragile terrain**: Fractured Himalayan rocks along thrusts and weathered laterite in the Western Ghats fail easily on steep slopes.
2. **Rain and quakes**: Cloudbursts raise pore-water pressure, as at Kedarnath in 2013, while the 2011 Sikkim earthquake set off numerous slides.
3. **Human disturbance**: Road cutting, quarrying, deforestation and unregulated building undercut slopes, as at Malin in Pune district in 2014.

**Effects of Landslides**

1. **Loss of life**: Malin lost about 150 people, and Kavalappara and Puthumala in Kerala were buried in 2019.
2. **Economic loss**: Highways are cut, and hydropower plants, farms and pilgrimage traffic suffer.
3. **Ecology and displacement**: Debris dams rivers, and survivors lose homes and land.

**Components of the National Landslide Risk Management Strategy**

1. **Hazard mapping**: Susceptibility and zonation maps, building on GSI's 1:50,000 work, locate risk.
2. **Early warning**: Rainfall thresholds and field instruments give timely alerts.
3. **Awareness and capacity**: Training engineers, planners and communities.
4. **Regulation and mitigation**: Mountain zone regulations, slope stabilisation and a proposed Special Purpose Vehicle.

**Way Forward**

1. **Binding maps and green engineering**: Make zones mandatory in master plans and pair drainage with vetiver on cut slopes.

**Conclusion**

Landslides are a natural process made deadly by careless construction; the strategy's mapping, warning and regulation can shift India from relief to risk reduction, as the Sendai Framework urges.

Describe the various causes and the effects of landslides. Mention the important components of the National Landslide Risk Management Strategy.

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