TEESTA VALLEY : ENVIRONMENT

TEESTA  VALLEY : ENVIRONMENT

NEWS: Act fast to mitigate a disaster in Teesta Valley, groups urge PM, CMs 

WHAT’S IN THE NEWS?

The October 2023 GLOF in Teesta Valley caused over 100 deaths, infrastructure destruction, and ecological damage, leaving areas like NH10 vulnerable before the 2025 monsoon. Mitigation measures include monitoring glacial lakes, afforestation, disaster-resilient infrastructure, and early warning systems.

Teesta Valley GLOF and Related Issues

Key Issues and Damage from the 2023 GLOF:

Human Casualties:

  • Over 100 lives were lost due to the sudden flood.
  • Families in West Bengal's Kalimpong district remain displaced, with 65 families still in relief camps.

Infrastructure and Livelihood Impact:

  • Destruction of critical infrastructure, including military installations, roads, and bridges.
  • Disruption of livelihoods in agriculture, tourism, and local businesses.

Ecological Damage:

  • Severe environmental damage across Sikkim and West Bengal.
  • Soil erosion, disruption of biodiversity, and alterations to river ecosystems.

Ongoing Threats:

  • Areas like Teesta Bazaar remain unstable and continue to sink.
  • NH10, vital for connecting Kalimpong and Sikkim, remains highly vulnerable during monsoons, affecting the region's economy.

Glacial Lake Outburst Flood (GLOF):

Definition:

  • A sudden release of water from a glacial lake caused by the failure of natural dams formed by moraines, ice, or debris.

Key Features:

  • Suddenness: Rapid occurrence with minimal warning.
  • High Energy: Floodwaters carry debris, enhancing their destructive force.
  • Impact Range: Can travel hundreds of kilometers, causing widespread destruction.

Causes of GLOFs:

Triggering Events:

  • Rapid Glacier Melting: Accelerated by global warming.
  • Avalanches or Landslides: Increased pressure on natural dams.
  • Ice Calving: Sudden collapse of glacier parts into the lake.
  • Seismic Activity: Earthquakes destabilize the lake structure.

Dam Weakness:

  • Moraine dams are naturally unstable.
  • Heavy rainfall saturates and weakens the dam, leading to failure.

Impacts of GLOFs:

Human and Social: Significant loss of life and displacement of communities.

Infrastructure Damage: Destruction of roads, bridges, and hydropower facilities.

Environmental Consequences: Soil erosion, landscape alteration, and biodiversity loss.

Economic Losses:

  • Loss of livelihoods in agriculture and tourism.
  • High costs of reconstruction and rehabilitation.

Prevention and Mitigation Strategies:

Monitoring and Early Warning Systems:

  • Use satellites and remote sensing to monitor glacial lakes.
  • Install real-time warning systems downstream of vulnerable lakes.

Structural Measures:

  • River Management: Deepen and redirect the Teesta River using NHPC expertise to control overflow risks.
  • Infrastructure Strengthening: Rebuild roads, bridges, and critical installations with disaster-resilient designs.
  • Evacuation Centers: Equip centers with solar power and robust facilities.

Non-Structural Measures:

  • Install automated flood alert systems using sirens and mobile notifications.
  • Provide backup communication tools like ham radios and walkie-talkies.
  • Conduct public awareness campaigns for disaster preparedness.

Land-Use Planning and Zoning:

  • Identify high-risk zones for evacuation and resettlement.
  • Avoid building infrastructure in vulnerable areas and provide fair compensation for relocation.

Afforestation and Ecosystem Restoration:

  • Large-scale afforestation programs to prevent soil erosion and regulate river flow.
  • Initiatives to restore the valley’s ecological balance.

Teesta River Overview:

Source and Origin:

  • Originates from Tso Lhamo Lake, North Sikkim, at an altitude of 5,330 meters.

Course:

  • Flows southward through Sikkim, creating deep gorges and valleys.
  • Enters West Bengal before merging with the Brahmaputra River in Bangladesh.

Length and Tributaries:

  • Total length: Approximately 309 km.
  • Largest tributary: Rangit River.

Drainage Basin and Discharge:

  • Covers parts of Sikkim, West Bengal, and Bangladesh.
  • High seasonal discharge during the monsoon (June–September).