Why in the News?

Many people have died, and hundreds are feared trapped after three landslides hit Kerala’s Wayanad district.

About Wayanad

Wayanad is the only plateau in Kerala, forming a continuation of the Mysore Plateau, part of the Deccan Plateau.
The Kabini River, a tributary of the Kaveri River, originates in Wayanad.
The Chaliyar River, the fourth longest river in Kerala, also originates on the Wayanad plateau.
Wayanad is home to the Wayanad Wildlife Sanctuary.

Susceptibility to Landslides:

The region predominantly has laterite soil, which is highly prone to erosion.
The steep and undulating terrain of Wayanad makes it naturally susceptible to landslides.
Wayanad receives intense and prolonged monsoon rains that cause water infiltration, leading to soil saturation and increased pore water pressure, which destabilizes slopes.
Large-scale deforestation for agriculture and settlement reduces the binding capacity of the soil and its ability to absorb water, exacerbating the risk of landslides.

What are Landslides?

A landslide is the downward and outward movement of materials including rock, earth, or debris down a slope due to gravitational force. Landslides are disasters of hydrogeological origin, resulting from the failure of materials falling down a slope due to gravity.
India is among the top five landslide-prone countries globally, with at least one death per 100 sq km reported annually due to landslides.

Regional Distribution

North-western Himalayas: 66.5% of landslides.
North-eastern Himalayas: 18.8% of landslides.
Western Ghats: 14.7% of landslides.

Key Policy Initiative: National Landslide Susceptibility Map

The National Remote Sensing Centre (NRSC) under ISRO released the Landslide Atlas of India in 2023.
This detailed guide identifies landslide hotspots across the country with a 100 sq. m resolution overview of landslide susceptibility.
The map highlights traditional high-risk areas and uncovers new regions of concern, broadening the scope of landslide monitoring.
Scientists conducted a risk assessment based on 80,000 landslides recorded between 1998 and 2022 across 147 districts in 17 states and two Union Territories, creating a “Landslide Atlas” of the country.

Key Highlights of the Landslide Atlas:

Top States by Landslide Events:

Mizoram: 12,385 events in the past 25 years.
Uttarakhand: 11,219 events.
Other states: Kerala, Jammu and Kashmir, Nagaland, Arunachal Pradesh, and Tripura.

Districts with Maximum Landslide Exposure:

Arunachal Pradesh: 16 districts.
Kerala: 14 districts.
Uttarakhand and Jammu and Kashmir: 13 districts each.
Himachal Pradesh, Assam, and Maharashtra: 11 districts each.
Mizoram: 8 districts.
Nagaland: 7 districts.

Highest Landslide Density and Risk Exposure:

Rudraprayag and Tehri Garhwal districts in Uttarakhand.

PYQ:

[2021] Describe the various causes and the effects of landslides. Mention the important components of the National Landslide Risk Management Strategy.

Landslides in Wayanad