Mains Marathon 2024

Approach Provide a brief Introduction to Landslides as a Hazard in India. Examine India’s vulnerability to landslide hazards. Explain Hazard Zonation Mapping and Its Role in Disaster Mitigation. Recommend Measures for Enhancing Landslide Risk Management. Conclude Suitably.

Introduction

A landslide is a geological phenomenon involving the downward movement of a mass of rock, soil, and debris on a slope.Landslides and avalanches are among the major hydro-geological hazards that affect large parts of India besides the Himalayas, the Northeastern hill ranges, the Western Ghats, the Nilgiris, the Eastern Ghats and the Vindhyans, in that order, covering about 15 % of the landmass.

India’s Vulnerability to Landslide Hazards:

• Fragile Ecosystem:
  • Tectonic or neo-tectonic activities, associated with numerous subsurface processes like rock deformation, exhumation and reworking of rocks and surface processes such as erosion, weathering and rain/snow precipitation make the ecosystem inherently fragile.
  • The convergence of the Indian plate with the Eurasian plate in the Himalayan region has created subterranean stresses that get released in the form of earthquakes which, in turn, cause fractures and loosen the litho-structures near the mountain surface. This increases the possibilities of rock movement along the slope.
• Climate Induced Excessive Events:
  • Climate-induced excessive events like freezing/thawing and heavy rain/snow precipitation lead to avalanches, landslides, debris flow, glacial lakes outburst floods, landslide lakes outburst floods and flash floods. They add to the precariousness of the mountain system.
  • Climate change has adverse impacts on glaciers, riverine systems, geomorphology and biodiversity, which, in turn, have increased the vulnerability of people in the mountainous states.
• Anthropogenic Factors:
  • Human activities such as road construction, tunneling, mining, quarrying, deforestation, urbanization, agriculture, excessive tourism and hydroelectric projects can also cause or worsen landslides in the mountains.
  • These activities can disturb the natural balance of the slopes by removing vegetation cover, altering drainage patterns, increasing soil erosion, creating artificial cuts and fills, blasting rocks, and generating vibrations.
    • The 2013 Kedarnath Tragedy was also influenced by the unplanned development and construction activities in the area, such as hotels, roads, bridges, and dams, that had altered the natural drainage system and increased the soil erosion.
• Geological Composition:
  • Some of the mountainous rocks are made of limestone, which is more prone to water and landslides than other types of rocks because it can dissolve in weakly acidic rainwater or groundwater. This process creates caves, sinkholes, and other karst features that weaken the stability of the slopes.
• Westerly Disturbance & Monsoon:
  • Confluence of Westerly Disturbance — a low-pressure system, originating from the Mediterranean Sea, moving eastward across central Asia and northern India — and the South West Indian Summer Monsoon cause excessive and concentrated rainfall in parts of J&K, Himachal Pradesh and Uttarakhand leading to landslides and flash floods.

Hazard Zonation Mapping and Its Role in Disaster Mitigation

• Identifying and Categorizing Susceptible Areas: Hazard zonation mapping involves identifying and categorizing areas based on their susceptibility to landslides. These maps include data on slope stability, soil type, and historical landslide occurrences, helping to assess the risk levels in different areas.
• Evaluating Landslide Risks : Risk Assessment and Planning Hazard zonation maps help in evaluating landslide risks and guiding land-use planning. By identifying high-risk zones, authorities can implement regulations to avoid construction in vulnerable areas.
• Early Warning Systems These maps are instrumental in developing early warning systems by pinpointing areas that require close monitoring.
  • Such systems can issue alerts to communities at risk, allowing them to prepare or evacuate in advance.
• Resource Allocation Hazard zonation maps assist in prioritizing resources for disaster response and recovery efforts. By focusing resources on high-risk areas, authorities can better manage and mitigate the impact of landslides.
• Community Awareness and Preparedness Hazard maps enhance public awareness by providing information on landslide risks and safety practices.
  • Outreach programs using hazard maps can inform residents about safe practices and evacuation procedures.

Recommendations for Enhancing Landslide Risk Management

• Environmentally Conscious Development :
  • Proper town planning that accounts for the unique characteristics of mountainous terrain is vital.
  • Restricting heavy construction, implementing effective drainage systems, scientifically managing slope cutting, and using retaining walls are important aspects of environmentally conscious development.
    • Landslide Risk Mitigation Scheme (LRMS) envisages financial support for site specific landslide mitigation projects recommended by landslide prone states.
• Integrating Hazard Zonation into Policy:
  • Incorporate hazard zonation mapping into national and regional land-use policies to ensure that planning and development consider landslide risks.
  • Regularly update hazard zonation maps to reflect new data and changing risk patterns. Expanding the coverage of these maps can improve their effectiveness in disaster management.
    • The Landslide Atlas of India is a document that provides the details of landslides present in landslide provinces of India, including damage assessment of specific landslide locations.
• Early Warning System (EWS) :
  • The development of an integrated Early Warning System (EWS) using AI and Machine Learning (ML) algorithms is crucial. Such a system could help predict and alert communities about impending hazards, giving them valuable time to take preventive measures.
• Formation of Himalayan States Council:
  • Establishing a collaborative platform that brings together the disaster management authorities from different states in the Himalayan region is a strategic move.
  • This centralized council would enable the sharing of knowledge, experiences, and resources to effectively assess and manage the impacts of various stressors on the region.
• Sustainable Tourism:
  • Sustainable tourism can reduce landslides by promoting environmental awareness, conservation and protection of natural resources, and respect for biodiversity and ecosystems.
  • It can also provide economic incentives and social benefits for local communities, which can enhance their resilience and adaptive capacity to cope with natural hazards.
• Community Awareness and Training :
  • Conduct regular awareness campaigns and training programs for communities in landslide-prone areas. Education on recognizing early signs of landslides and evacuation procedures can save lives.

Conclusion

The National Guidelines on Landslides and Snow Avalanches, prepared by the NDMA, offer a robust framework to mitigate landslide risks across India. With the country's vulnerability shaped by geographical, climatic, and human factors, the integration of hazard zonation mapping into policy and planning is not just essential but imperative. By advancing public education, strengthening early warning systems, and fostering community participation, India can not only reduce the devastating impacts of landslides but also build a future where communities are empowered and resilient.