Describe the various causes and the effects of landslides. Mention the important components of the National Landslide Risk Management Strategy. UPSC 2021, 15 Marks

Q18. भूस्खलन के विभिन्न कारणों और प्रभावों का वर्णन कीजिए  राष्ट्रीय भूस्खलन जोखिम प्रबंधन रणनीति के महत्त्वपूर्ण घटकों का उल्लेख कीजिए  ( 250 शब्दों में उत्तर दीजिए)
Q18. Describe the various causes and the effects of landslides. Mention the important components of the National Landslide Risk Management Strategy. (Answer in 250 words) 15

Answer:

  • Landslides refer to the rapid movement of rock, soil, and vegetation down the slope under the influence of gravity. Earth flow, mass movement, mudflow, rotational slip, and avalanches are different types of landslides.
  •  The intensity and magnitude of the landslide depends on the geological structure, angle of dip of the slope, nature of sedimentary rocks, and the human interaction with the slope.Causes of Landslides

     

    1. Rainfall and Snowfall-
    • Heavy and continuous rainfall lead to heavy landslides in the areas of steep slopes where National Highways and roads have been constructed. For example; The Nashri area between BatoteRamban- Ramsu, and Banihal (Jammu and Kashmir) is frequently subjected to landslides. 
    1. Earthquakes and Volcanic Eruptions-
    • Earthquakes are the most important cause of landslides in the folded mountainous areas like Himalayas in India. In the Kashmir valley, the earthquake of 1905 resulted into landslides in the lesser and the Greater Himalayas in which several thousand people lost their lives.
    • Volcanic eruptions also trigger landslides in the mountainous regions.
    1. Mining, Quarrying and Road cutting-
    • The continuous extraction and quarrying of coal, minerals, and stones from the mines and quarries and the development of roads by cutting the steep slopes in the folded mountains causes landslides.
    • Examples: Frequent landslides in Himalayas and the Eastern and Western Ghats.
    1. Loading by construction of houses-
    • The unplanned growth of towns and cities in the hilly areas without following the geology of that region causes landslides. 
    • For example: The eastern slope of Nanital (Uttarakhand) is sinking because of the heavy load of hotels and residential structures.
    1. Deforestation-
    • Deforestation and other human activities also induce landslides.

    Effects of landslides

    Short Term Effects 

    • Loss of Lives and Properties.
    • Roadblocks, destruction of railway lines. 
    • Channel blocking due to rock – falls
    • Diversion of river courses due to landslides causing floods
    • Loss of natural Beauty.

    Long term impacts:

    • Permanent landscapes can be changed.
    • Cultivable land can be loss.
    • Soil erosion and permanent loss of fertile soil.
    • Population shift and relocation of populations and establishments.
    • Drying up natural water resources.

    National Landslide Risk Management Strategy 

    National Landslide Risk Management Strategy was made by NDMA. It clearly brings out the message for the need to strengthen and mainstream landslide disaster preparedness, mitigation, response and relief mechanism through mapping, early warning system (EWS), awareness generation, capacity building, formulation of mountain zone regulations / policies and mitigation of problematic landslides. 

    Important components:

    • Landslide Hazard Zonation – It covers aspects of reliability and validation of landslide zoning maps in Indian scenario and proposes future plan of activities for landslide zoning. 
    • Landslide Monitoring and Early Warning System 
    • Awareness Programmes – It aims towards a culture of awareness generation and preparedness; so that people in the society become alert and aware in case of an emergency or take some preventive measures before the disaster strikes. 
    • Capacity Building and Training of Stakeholders –The key recommendations include a Nationwide Training Need Assessment (TNA) in Landslide Risk Management and Inclusion of new technology inputs for capacity building and training programs on landslide DRR. 
    • Preparation of Mountain Zone Regulations and Policies 
    • Stabilization and Mitigation of Landslide and Creation of Special Purpose Vehicle (SPV) for Landslide Management.

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