Context

According to the India Meteorological Department’s Statement of Climate of India 2022, heavy rain, floods and landslides claimed 835 lives in the country in the year 2022. 

About Landslides:

• Landslides are natural disasters occurring mainly in mountainous terrains where there are conducive conditions of soil, rock, geology and slope. 
• A sudden movement of rock, boulders, earth or debris down a slope is termed as a landslide. 
• Classification: Landslides are broadly classified based on the;
• type of materials involved (rock, debris, soil, loose mud)
• type of movement of the material (fall, topple, slide, rotational slide or translational slide)
• type of flow of the material
• Another category is of landslides that spread laterally. Landslides mapped in the ISRO atlas are mainly event-based and season-based.

What causes landslides?

• Natural factors: heavy rainfall, earthquakes, snow melting and undercutting of slopes due to flooding. 
• Anthropogenic factors: excavation, cutting of hills and trees, excessive infrastructure development, and overgrazing by cattle.
• Other influential factors: Some of the main factors that influence landslides are lithology, geological structures like faults, hill slopes, drainage, geomorphology, land use and land cover, soil texture and depth, and weathering of rocks.
  
  

Proneness of India to landslides:

• India is considered among the top five landslide-prone countries globally. In India, at least one death per 100 sq. km is reported in a year due to a landslide event. 
• Himalayas and the Western Ghats remaining highly vulnerable because rainfall variability pattern is the single biggest cause for landslides.
• North-Eastern states: Nearly half of the country’s landslide-prone area (0.18 sq.km) is located in the states of Assam, Arunachal Pradesh, Sikkim, Meghalaya, Mizoram, Manipur, Tripura and Nagaland.