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07 May

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Glacial Lake Area In India Increased By Over 27% Since 2011: CWC Report

Introduction

A recent report released by the Central Water Commission (CWC) has revealed that the water spread area of glacial lakes within India increased by more than 27% between 2011 and July 2025. The findings underline the growing impact of climate change, accelerated glacier melt, and increasing risks of Glacial Lake Outburst Floods (GLOFs) in the Indian Himalayan Region (IHR).The report analysed glacial lakes across:

  • Ladakh
  • Jammu & Kashmir
  • Himachal Pradesh
  • Uttarakhand
  • Sikkim
  • Arunachal Pradesh

The study is significant because rapidly expanding glacial lakes increase the probability of sudden lake breaches, threatening downstream populations, infrastructure, biodiversity, and hydropower projects.


Key Findings of the CWC Report

ParameterFindings
Increase in glacial lake area27.87%
Inventory area in 20111,952 hectares
Inventory area in July 20252,496 hectares
Total lakes analysed100 glacial lakes
Lakes showing growth58 glacial lakes
Total monitored glacial lakes/water bodies2,843
Increase in Himalayan region lake area6.03%

State-Wise Lakes Under Vigorous Monitoring

State/UTNumber of Lakes
Sikkim28
Ladakh8
Jammu & Kashmir7
Uttarakhand6
Himachal Pradesh5
Arunachal Pradesh4

Sikkim recorded the highest number of vulnerable lakes under active monitoring.


Why are Glacial Lakes Expanding?

Climate Change and Glacier Retreat

The primary reason behind the expansion is:

  • Rising global temperatures
  • Accelerated glacier melting
  • Increased meltwater accumulation

As glaciers retreat, depressions created by melting ice get filled with water, forming glacial lakes.

Extreme Weather Events

Additional contributing factors include:

  • Heatwaves
  • Intense rainfall
  • Reduced snowfall
  • Changing monsoon patterns

These factors accelerate ice melt and increase lake volume.


Understanding Glacial Lakes

Types of Glacial Lakes in Himalayas

TypeCharacteristics
Supraglacial LakesFormed on glacier surfaces due to meltwater accumulation
Moraine-Dammed LakesLocated near glacier snouts and blocked by loose moraine debris

The report mentions several Supraglacial Debris Cover (SDC) lakes which remain difficult to assess fully.


What is GLOF?

Glacial Lake Outburst Flood

A GLOF occurs when the natural dam holding a glacial lake suddenly collapses, releasing massive quantities of water downstream.

Causes of GLOFs

  • Moraine dam failure
  • Ice avalanches
  • Landslides
  • Earthquakes
  • Excessive water pressure
  • Sudden glacier collapse

Risks Associated With Expanding Glacial Lakes

6

Threat to Human Settlements

Rapidly growing lakes can flood:

  • Villages
  • Roads
  • Bridges
  • Agricultural land

Hydropower Vulnerability

Hydropower projects located along Himalayan rivers are increasingly exposed to:

  • Flash floods
  • Heavy sedimentation
  • Dam damage

Ecological Damage

Potential impacts include:

  • River ecosystem disruption
  • Biodiversity loss
  • Silt deposition
  • Wetland degradation

Important Recent GLOF Events

South Lhonak GLOF (Sikkim, 2023)

  • Massive flash flood in Teesta basin
  • Chungthang hydropower project damaged
  • Large-scale downstream destruction

Kedarnath Disaster (2013)

  • Combination of cloudbursts, landslides and glacial flooding
  • One of India’s worst Himalayan disasters

Nepal GLOF Events

Recent GLOF events in Nepal have highlighted the need for:

  • Transboundary early warning systems
  • Himalayan cooperation mechanisms

Monitoring Mechanism Used By CWC

The monitoring was carried out using:

  • Sentinel-1 satellite imagery
  • Sentinel-2 satellite imagery
  • Google Earth Engine platform

Monitoring Parameters

The lakes were classified based on:

  • Increase in water spread area
  • Decrease in area
  • Stable conditions
  • Frozen conditions
  • Cloud cover limitations

Importance of Remote Sensing

Remote sensing helps in:

  • Monitoring inaccessible high-altitude lakes
  • Detecting changes in lake area
  • Assessing slope instability
  • Predicting potential hazard zones

However, it still has limitations because:

  • Data is often post-facto
  • Continuous field monitoring remains difficult

Need for Early Warning Systems

The report reinforces the importance of:

  • Automated Weather Stations (AWS)
  • Water-level monitoring systems
  • Real-time satellite surveillance
  • Community-based warning mechanisms

These systems are essential for reducing disaster risk in Himalayan states.


India’s Glacial Lake Monitoring Efforts

India has expanded glacial monitoring under multiple agencies:

  • Central Water Commission (CWC)
  • National Disaster Management Authority (NDMA)
  • National Remote Sensing Centre (NRSC)

The focus is shifting from:

  • Disaster response
    to
  • Disaster risk reduction and preparedness

Broader Climate Implications

The expansion of glacial lakes is an indicator of:

  • Rapid Himalayan warming
  • Shrinking cryosphere
  • Changing hydrological systems

The Himalayas are often called the “Third Pole” because they contain one of the largest reserves of freshwater outside the polar regions.Changes in Himalayan glaciers directly affect:

  • River flows
  • Agriculture
  • Water security
  • Energy production
  • Livelihoods in South Asia

STATIC PART

Central Water Commission (CWC)

FeatureDetails
MinistryMinistry of Jal Shakti
FunctionWater resource management and hydrological monitoring
Directorate MentionedMorphology and Climate Change Directorate

Indian Himalayan Region (IHR)

FeatureDetails
CoverageHimalayan states and UTs of India
ImportanceSource region for major rivers like Indus, Ganga and Brahmaputra

Sentinel Satellites

FeatureDetails
Operated ByEuropean Space Agency (ESA)
UseEarth observation and environmental monitoring

Google Earth Engine

FeatureDetails
TypeCloud-based geospatial analysis platform
FunctionSatellite data processing and environmental analysis

Updated – 17 October 2025 ; 06:19 PM | The Hindu BusinessLineNews Source: The Hindu BusinessLine

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