GS3 PYQ 2021 (Mains Answer Writing): Landslides | UPSC Mains: Internal Security & Disaster Management PDF Download

Describe the various causes and the effects of landslides. Mention the important components of the National Landslide Risk Management Strategy. (UPSC GS3 2021)

A landslip/landslide is defined as the rapid movement of a mass of rock, debris, or earth, down a slope under the influence of gravity. They are a natural phenomenon whose frequency has significantly increased due to anthropogenic causes.

Causes of Landslides

• Climate change: Rising global temperature has led to extreme rainfall events, increased melting of glaciers; as a result, more water flows over the steep slope. This increased water presence saturates the soil which results in solifluction (soil/mud flow) increasing landslide risk. E.g. Increased flooding and landslip incidents in Kerala. 
• Tectonically active Himalaya: Himalayas being a young fold mountain range, lies above an active convergent zone which is prone to earthquakes. Seismic activity induced vibration can overcome frictional force responsible for holding the sediments together. Also, it makes easier for water to seep into the soil. 
• Population pressure: Rising population over a fixed land availability increases pressure on land. Deforestation and dam construction for developmental activities, slope modification significantly reduces soil binding capacity, making them prone to erosion and landslides. E.g. Char Dham project in Uttarakhand. 
• Nature of rivers: Rivers in Himalayas are in their youthful stage. Swift flow of river over a steep slope result in vertical corrosion and down-cutting. This enhances the occurrence of landslides.

Effects of Landslides

• The impact of a landslide can be extensive, including loss of life, destruction of infrastructure, damage to land and loss of natural resources.  
• Landslide material can also block rivers and increase the risk of floods.  
• Deep landslides, triggered by major earthquakes or volcanic activity can destroy thousands of square kilometres of land and kill thousands of people.  
• Landslides have a devastating effect on farmers’ livelihoods as they can prevent access to land for years, destroy seed and food stocks and will commonly result in the loss of livestock and standing crops.

Important components of the National Landslide Risk Management strategy

• Generation of User-Friendly Landslide Hazard Maps 
• Development of Landslide Monitoring and Early Warning System 
• Awareness Programmes 
• Capacity Building and Training of Stakeholders 
• Preparation of Mountain Zone Regulations & Policies 
• Stabilization and Mitigation of Landslides and Creation of Special Purpose Vehicle (SPV) for Landslide Management.