Glacial Lake Outburst Floods (GLOF)

Context: A new study published in Nature Communications observed that three million Indians live in areas where a glacial lake outburst flood (GLOF) can happen at any time.

Important Highlights of the Study

• Global distribution of glacial basins: The study grouped the global glacial basins into the following:
  • High Mountain Asia (HMA): This region encompasses the Himalayas, Karakoram, Hindu Kush, and Pamir Mountain ranges and is home to the largest concentration of glaciers outside of the Polar Regions.
  • Andes: The Andes Mountain range in South America is home to numerous glacial basins, including those in the Chilean and Peruvian Andes.
  • European Alps: The European Alps, which span across several countries including France, Switzerland, Italy, and Austria, are home to a large number of glacial basins.
  • The Pacific Northwest (PNW): This glacial basin is located in the north-western region of North America and encompasses parts of the United States and Canada.
  • High Arctic and Outlying Countries: The remaining basins outside of the above ranges were referred to as ‘High Arctic and Outlying Countries’.
• Exposure to GLOFs: Globally, 90 million people across 30 countries live in basins containing glacial lakes. Of these, 15 million (16.6 per cent) live within 50 kilometers of a glacial lake.
  • Most vulnerable region: The majority of the globally exposed population amounting to 9.3 million (62 per cent) are located in the region of high mountain Asia (HMA).
  • Most vulnerable countries: Just four highly populous countries accounted for more than 50 per cent of the globally exposed population: India, Pakistan, Peru and China.
  • India: Three million Indians live in areas where a glacial lake outburst flood (GLOF) can happen at any time, as per the study.
• Climate change and GLOFs: The study also noted that glaciers across the world have undergone rapid deglaciation over the last 20 years in response to climate changes.
  • This has led to the growth of many large glacial lakes and consequently a growth in overall GLOF lake conditions.
  • For example, in the past two decades, glacial lakes have increased by 93% in the Andes region and 37% in the HMA.

About Glacial Lake Outburst Floods (GLOFs)

• ICIMOD or the International Centre for Integrated Mountain Development defines a GLOF as ‘the sudden release of water from a lake fed by glacier melt that has formed at the side, in front, within, beneath, or on the surface of a glacier’.
• Causes: There are several causes of GLOFs, including:
  • Structural failure: When glaciers start to melt, they can create glacial lakes. The water in these lakes can put pressure on the natural dam that holds the water in, causing it to fail.
  • Earthquakes: Earthquakes can cause sudden changes in the shape and stability of a glacial lake and its dam, leading to a GLOF.
  • Climate change: Rising temperatures and increased rainfall can lead to more meltwater and therefore more glacial lakes, as well as increase the risk of GLOFs.
  • Human activities: Human activities, such as construction or mining, can cause changes in the area around a glacial lake that can lead to a GLOF.
• Impact: GLOF has the potential to catastrophically threaten people’s lives, livelihoods and regional infrastructure.
• The National Disaster Management Authority (NDMA) to tackle Glacial Bursts: Some of the key measures recommended by the NDMA include:
  • Risk assessment: Conducting regular assessments of the risk posed by GLOFs in order to identify vulnerable areas and communities, and to prioritize areas for intervention.
  • Early warning systems: Establishing early warning systems that can detect potential GLOFs and provide timely alerts to communities and authorities.
  • Disaster management plans: Developing and implementing disaster management plans that outline the measures to be taken in the event of a GLOF, including evacuation plans, rescue and relief operations, and post-disaster rehabilitation.
  • Capacity building: Building the capacity of local communities, authorities, and emergency responders to respond to GLOFs and other natural disasters, through training and awareness programs.
  • Risk reduction measures: Implementing risk reduction measures, such as glacial lake stabilization to mitigate the risk posed by GLOFs.

Sharing is caring!