GLACIAL LAKE OUTBURST FLOOD (GLOF)

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Picture Courtesy: https://www.icimod.org/mountain/glacial-lake-outburst-flood/

Context: Uttarakhand government is evaluating the Glacial Lake Outburst Flood (GLOF) risk due to climate change-induced glacial melt, leading to the formation and expansion of unstable permanent lakes.

Details

• Uttarakhand has experienced significant GLOF events in recent years, notably in 2013 in the Kedarnath Valley and in 2021 in parts of the Chamoli district. These events resulted in loss of lives and widespread destruction, highlighting the urgent need for proactive measures to mitigate the risk.
• Rising surface temperatures globally, including in India, have accelerated glacier melting, leading to the formation and expansion of glacial lakes.
• As glaciers sink, they leave behind depressions that fill with meltwater, forming potentially hazardous lakes. With continued global warming, the risk of GLOFs is expected to increase, necessitating comprehensive risk assessments to identify vulnerable areas.

Glacial Lake Outburst Floods (GLOFs)

• Glacial Lake Outburst Floods (GLOFs) are sudden and often devastating events triggered by the breach or collapse of natural barriers, such as moraines or ice dams, which contain water from glacial melt. These floods occur when large volumes of water are released rapidly downstream, posing significant risks to communities, infrastructure, and ecosystems located in the path of the floodwaters.

What is meant?

• GLOFs occur when water stored in glacial lakes is released suddenly due to the failure of natural dams holding back the water. Glacial lakes form as glaciers retreat and leave behind depressions that fill with meltwater. The increased volume of water in these lakes can overwhelm the natural barriers, leading to a catastrophic release of water downstream.

What are the Impacts

• Human Impact: GLOFs can result in loss of life, injuries, and displacement of populations. Communities located downstream of glacial lakes are particularly vulnerable to these sudden floods.
• Infrastructure Damage: Floodwaters carrying debris, rocks, and ice can cause extensive damage to roads, bridges, hydropower facilities, and other infrastructure along river valleys.
• Economic Losses: The destruction of infrastructure and disruption of economic activities can result in significant economic losses for affected regions.
• Environmental Consequences: GLOFs can alter river courses, deposit sediments, and impact habitats and biodiversity downstream. They can also contribute to water quality degradation.

What are the Challenges?

• Remote Locations: Glacial lakes are often located in remote and rugged mountainous areas, making access and monitoring difficult.
• Limited Data and Monitoring: Gathering accurate data on glacial lakes and their behaviour requires specialized equipment and expertise, which may be lacking in remote regions.
• Climate Change: Accelerated glacier retreat due to climate change is leading to the formation of new glacial lakes and increasing the frequency of GLOF events.
• Complex Terrain: The steep and unstable terrain of mountainous regions complicates the implementation of mitigation measures and emergency response efforts.

Steps Taken to address the risks associated with GLOFs

• Monitoring and Research: India has invested in monitoring technologies, including satellite imagery and remote sensing, to track changes in glacial lakes and assess potential GLOF hazards.
• Early Warning Systems: The installation of early warning systems in vulnerable areas to provide timely alerts to downstream communities in the event of a GLOF.
• Infrastructure Development: Constructing protective measures such as debris dams, reservoirs, and embankments to mitigate the impact of GLOFs on downstream areas.
• Capacity Building: Conducting training programs, workshops, and awareness campaigns to enhance the preparedness and response capabilities of local communities and authorities.

Way Forward

• Enhanced Monitoring and Research: Continued investment in monitoring technologies and research to better understand glacial dynamics, lake formation, and GLOF triggers.
• Improved Early Warning Systems: Strengthening and expanding early warning systems to ensure timely alerts and evacuation of at-risk populations.
• Infrastructure Investment: Prioritising investments in infrastructure projects that mitigate GLOF impacts, such as flood protection structures and hazard mapping.
• Community Engagement: Engaging local communities in risk reduction efforts, including land-use planning, evacuation drills, and awareness campaigns.

Conclusion

• Glacial Lake Outburst Floods (GLOFs) are complex natural hazards exacerbated by climate change and glacier retreat. Addressing the risks associated with GLOFs requires a comprehensive and multi-faceted approach involving scientific research, monitoring, early warning systems, infrastructure development, and community engagement. By adopting proactive measures and building resilience, India and other vulnerable regions can reduce the impacts of GLOFs and safeguard human lives and livelihoods in mountainous areas prone to glacial lake formation.

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GLACIAL LAKE OUTBURST FLOOD

SOURCE:

INDIAN EXPRESS

WIKIPEDIA

PRACTICE QUESTION Q. Consider the following statements: Statement 1: Glacial Lake Outburst Floods (GLOFs) are sudden and rapid releases of water from glacial lakes, often triggered by a glacier or moraine failure. Statement 2: GLOFs occur due to the damming of meltwater behind glaciers, leading to a buildup of water pressure that eventually breaches natural or man-made barriers. Which one of the following is correct in respect of the above statements? A) Both Statement-1 and Statement-2 are correct and Statement-2 is the correct explanation for Statement-1 B) Both Statement-1 and Statement-2 are correct and Statement-2 is not the correct explanation for Statement-1 C) Statement-1 is correct but Statement-2 is incorrect D) Statement-1 is incorrect but Statement-2 is correct Answer: A