Landslide Prone Regions in India

 A. Himalayan region

• The Western Himalayas (Jammu & Kashmir, Uttaranchal, Himachal Pradesh, and Uttar Pradesh)
• The Eastern & North-eastern Himalayas (Arunachal Pradesh, Sikkim, and West Bengal)
• The Naga-Arakan Mountain belt (Nagaland, Manipur, Mizoram and Tripura).

B. Peninsular India

• The Western Ghats region (Maharashtra, Goa, Karnataka, Kerala & Tamil Nadu).
• The Plateau margins of Peninsular India and Meghalaya plateau in North-East India.

Landslide refers to the sudden movement of rock mass, debris, soil, or vegetation down the slope due to the force of gravity. It is a type of mass wasting, which denotes any downward movement of soil and rock, and areas with steep slopes are more susceptible to landslides. Mass movement, Earth flow, mud flow, debris flow, rotational slides, avalanches are some of the examples of landslides. Landslide is one of the major hydro-geological hazards which affect a large portion of India. According to the Geological Survey of India (GSI), 12.6 per cent of the total country’s land area (around 0.42 million square kilometres) is prone to landslides. The Himalayas of Northwest and Northeast India and the Western Ghats of Peninsular India are the most vulnerable regions to landslides.

Landslide may be caused by natural factors such as heavy rain, snowfall, earthquake, or it may be induced by human factors like over-interference with the slope-stability by deforestation, unplanned construction, or mining. The intensity and magnitude of the landslide largely depend on the geological structure, slope angle, nature of rocks, and human interaction. It is observed that the causes of landslides in the Himalayan region and the Western Ghats are different. Landslides in the Himalayan region are usually due to natural causes such as high seismicity due to plate tectonic movement, easily erodible sedimentary rocks, young and energetic rivers with high erodible, heavy downpour, and snowfall whereas landslides in the Western Ghats are mainly due to concentrated rainfall, overburdening of hills, mining, and quarrying.