Introduction:
- A landslide is a natural event where rock, debris, or soil moves down a slope under the influence of gravity.
- It is triggered by a combination of geo-specific factors like slope, lithology, rock structure, land use/cover, and geomorphology.
- Approximately 12.6% of India’s land area, excluding snow-covered regions, is prone to landslides.
Regions in India most susceptible to landslides include:
- North East Himalaya, including Darjeeling and Sikkim Himalaya
- North West Himalaya (Uttarakhand, Himachal Pradesh, Jammu & Kashmir)
- Western Ghats and Konkan hills (Tamil Nadu, Kerala, Karnataka, Goa, Maharashtra)
- Eastern Ghats of Araku area in Andhra Pradesh
- The landslide-prone Himalayan regions also fall within earthquake-prone zones (IV and V), making them vulnerable to earthquake-induced landslides.
Body:
Factors Contributing to Landslides:
- Landslides involve the downward movement of rock, boulders, loose mud, soil, and debris, often causing destruction to vegetation and infrastructure.
The factors contributing to landslides can be classified into two categories:
Conditioning Factors:
- Include soil composition, topography, rock type, geomorphology, and slope angles.
- These factors make specific regions more susceptible to landslides.
Triggering Factors:
- Include heavy rainfall, seismic activity, and human-induced activities such as unplanned construction, deforestation, and changes in land use.
- Anthropogenic activities like road and bridge construction, along with large-scale forest degradation, exacerbate landslide risk.
Example:
- In Kerala, according to S Abhilash, Director of the Advanced Centre for Atmospheric Radar Research (ACARR) at Cochin University of
- Science and Technology, many landslides occur in plantation areas. The replacement of native trees with shallow-rooted crops like tea and coffee is a major triggering factor, as these crops fail to hold the topsoil effectively.
Conclusion:
- India accounts for approximately 8% of global landslide-related fatalities, with 847 deaths and thousands displaced between 2001 and 2021, as per studies by IIT-Madras.
- Sikkim has the highest percentage of landslide-prone land area (57.6%), while Kerala is the most vulnerable state outside the Himalayas, with over 14% of its land classified as having “very high susceptibility” to landslides.
Legacy Editor Changed status to publish August 28, 2024