UPSC MainsGENERAL-STUDIES-PAPER-III202115 Marks250 Words
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Q18.

Describe the various causes and the effects of landslides. Mention the important components of the National Landslide Risk Management Strategy.

How to Approach

This question requires a multi-faceted answer. First, define landslides and then comprehensively discuss their causes (geological, hydrological, anthropogenic). Next, detail the effects – economic, environmental, and social. Finally, focus on the National Landslide Risk Management Strategy (NLRMS), outlining its key components. Structure the answer into introduction, causes, effects, NLRMS components, and conclusion. Use examples to illustrate points.

Model Answer

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Introduction

Landslides, also known as mass wasting, are the movement of rock, earth, or debris down a slope. They represent a significant geological hazard, particularly in mountainous regions like the Himalayas, the Western Ghats, and the North-Eastern states of India. Recent events like the Joshimath land subsidence (2023) and frequent landslides during the monsoon season highlight the increasing vulnerability and the urgent need for effective risk management strategies. Understanding the causes and effects of landslides, coupled with a robust management framework, is crucial for disaster mitigation and sustainable development.

Causes of Landslides

Landslides are rarely caused by a single factor; they are usually triggered by a combination of predisposing conditions, triggering events, and amplifying factors.

  • Geological Factors: Weak or weathered materials, fractured rocks, young sedimentary deposits, and naturally weak geological formations contribute to instability.
  • Hydrological Factors: Heavy rainfall, snowmelt, groundwater levels, and changes in stream flow patterns saturate the soil, reducing its shear strength and increasing pore water pressure.
  • Anthropogenic Factors: Deforestation, unscientific road construction, quarrying, mining, urbanization, and agricultural practices alter slope stability. For example, blasting for road construction weakens the rock structure.
  • Earthquakes: Seismic activity can trigger landslides, especially in areas with steep slopes and unstable ground.

Effects of Landslides

Landslides have far-reaching consequences, impacting various aspects of life and the environment.

  • Economic Losses: Damage to infrastructure (roads, bridges, buildings), disruption of transportation networks, loss of agricultural land, and damage to property.
  • Environmental Impacts: Alteration of river courses, sedimentation of reservoirs, loss of biodiversity, and soil erosion.
  • Social Impacts: Loss of life, displacement of communities, psychological trauma, and disruption of livelihoods.

National Landslide Risk Management Strategy (NLRMS)

Recognizing the increasing threat, the National Landslide Risk Management Strategy (NLRMS) was launched in 2019 by the National Disaster Management Authority (NDMA). It adopts a comprehensive and integrated approach to manage landslide risk.

Key Components of NLRMS:

  • Multi-Hazard Mapping & Micro-Zonation: Identifying areas prone to landslides through detailed mapping and vulnerability assessment. This involves using technologies like LiDAR and GIS.
  • Landslide Susceptibility Mapping: Creating maps showing the likelihood of landslides occurring in different areas.
  • Early Warning Systems: Establishing real-time monitoring and early warning systems to alert communities at risk. This includes installing rain gauges, inclinometers, and extensometers.
  • Capacity Building & Training: Enhancing the skills of professionals and communities in landslide risk assessment, mitigation, and response.
  • Awareness & Education: Raising public awareness about landslide hazards and promoting preparedness measures.
  • Institutional Strengthening: Strengthening the institutional framework for landslide risk management at the national, state, and local levels. This includes establishing a National Landslide Mitigation and Management Centre (NLMMC).
  • Regulation & Enforcement: Implementing and enforcing regulations related to land use planning, construction activities, and environmental protection in landslide-prone areas.

The NLRMS also emphasizes the importance of integrating landslide risk management into development planning and promoting sustainable land use practices. It advocates for a proactive and preventive approach, rather than a reactive one.

Conclusion

Landslides pose a significant threat to life, property, and the environment in India, particularly in its mountainous regions. A comprehensive understanding of their causes and effects, coupled with the effective implementation of the National Landslide Risk Management Strategy, is crucial for mitigating this hazard. Prioritizing preventive measures, strengthening early warning systems, and promoting sustainable land use practices are essential steps towards building a more resilient future. Continuous monitoring, research, and community participation are also vital for long-term success.

Answer Length

This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.

Additional Resources

Key Definitions

Shear Strength
The internal resistance of a soil or rock to deformation or failure. It is a crucial factor in slope stability, as a decrease in shear strength increases the risk of landslides.
LiDAR
Light Detection and Ranging (LiDAR) is a remote sensing technology that uses laser light to create a high-resolution 3D model of the terrain, which is crucial for landslide susceptibility mapping and hazard assessment.

Key Statistics

Approximately 15% of India’s land area is prone to landslides (Source: National Disaster Management Authority, 2019).

Source: NDMA

The Himalayas experience approximately 20% of global landslide events (as of 2020, based on various geological surveys).

Source: Geological Survey of India (GSI) reports

Examples

Malin Landslide (2014)

The Malin landslide in Maharashtra in July 2014, which claimed over 150 lives, was triggered by heavy rainfall and exacerbated by deforestation and unscientific construction practices. It highlighted the vulnerability of settlements in landslide-prone areas.

Frequently Asked Questions

What is the role of deforestation in causing landslides?

Deforestation removes the protective cover of trees and vegetation, which bind the soil together with their roots. This reduces the soil's shear strength and increases its susceptibility to erosion and landslides, especially during heavy rainfall.

Topics Covered

GeographyDisaster ManagementEnvironmentLandslidesNatural DisastersRisk Assessment