Why in the news?

  • Land Subsidence in Uttarakhand’s Chamoli district triggers panic among the local residents.

Land Subsidence in India

  • What is it?:
    • The gradual or sudden sinking of the Earth’s surface due to natural or anthropogenic causes.
    • It results in tilting, cracking of structures, flooding, and long-term land degradation.
  • Causes of Land Subsidence in India:
    • Natural Factors:
      • Tectonic Movements: Himalayan orogenic activity, fault lines.
      • Karst Topography: Dissolution of limestone rocks in Meghalaya, Manipur.
      • Glacial Retreat: Melting of glaciers leading to voids and sinking ground.
    • Anthropogenic Factors:
      • Over-extraction of Groundwater (most dominant): Delhi, Punjab, Haryana, Uttar Pradesh, Gujarat.
      • Unregulated Mining: Coal (Jharkhand, West Bengal), limestone (Rajasthan, Meghalaya).
      • Urbanisation & Infrastructure Load: Rapid construction on unstable soil.
      • Riverbank Erosion & Sand Mining: Ganga basin states.
  • Major Affected Regions:
    • Delhi–NCR: Land subsidence in Gurugram, Faridabad due to groundwater over-extraction.
    • Himalayan Towns: Joshimath (Uttarakhand, 2023 crisis), Rudraprayag, Kinnaur.
    • Coalfields: Jharia (Jharkhand), Raniganj (West Bengal) due to abandoned mine collapses.
    • Indo-Gangetic Plains: Punjab, Haryana, Western UP due to agricultural groundwater stress.
    • North-East India: Limestone mining in Meghalaya, Manipur due to karst subsidence.
  • Impacts:
    • Human Settlements: Cracking of houses, displacement (Joshimath).
    • Infrastructure Damage: Roads, railways, dams, and tunnels destabilised.
    • Agriculture: Reduced groundwater table, soil compaction, and reduced productivity.
    • Flood Risk: Lowered land levels in Bihar and UP increase flood vulnerability.
    • Economic Losses: Rehabilitation costs, mining accidents, urban damages.
  • Government Response:
    • Groundwater Regulation: CGWA notification, Jal Shakti Abhiyan, Atal Bhujal Yojana.
    • Joshimath Rehabilitation Plan (2023): ₹165 crore sanctioned for relief.
    • Mine Closure Plans: Guidelines for scientific mine closure (MoC).
    • Urban Planning: NITI Aayog advisory on Himalayan sustainable development.
  • Way Forward:
    • Scientific Urban Planning: Restrict construction in fragile zones.
    • Water Management: Aquifer recharge, rainwater harvesting.
    • Remote Sensing Monitoring: ISRO’s InSAR, GIS-based risk mapping.
    • Community Awareness: Early warning systems, disaster preparedness.
    • Policy Integration: Link climate change adaptation with land use planning.