04-May-2024-Special-Article

HUNDREDS OF GLACIAL LAKES EXPANDING IN HIMALAYAN REGION, FLAGS ISRO 

The Indian Space Research Organisation (ISRO) has observed a concerning trend of large-scale expansion in glacial lakes in the Himalayan region between 1984 and 2023.  

This expansion, documented through satellite monitoring, poses significant risks to downstream areas and highlights the urgent need for comprehensive measures to address the underlying causes and mitigate potential hazards. 

ISRO’s Observation on Expansion of Himalayan Glaciers: 

Key Findings: 

• Of the 2,431 lakes larger than 10 hectares identified during the 2016-17 period, 676 glacial lakes have shown considerable expansion since 1984.  
• Among this group, 130 are found within India, with a notable concentration situated within the Indus, Ganga, and Brahmaputra River basins.  
• Approximately 89% of the expanded lakes have increased more than twice in size, indicating a substantial growth trend. 
• An elevation-based analysis reveals that a considerable number of these lakes are located in the 4,000 to 5,000 m range and above 5,000 m elevation. 
• Long-term changes in specific lakes, such as the Ghepang Ghat glacial lake in Himachal Pradesh, demonstrate significant expansions over time. 

Types and Number of Glacial Lakes in Himalayas: 

• Moraine-dammed (307) 
• Ice-dammed (8) 
• Erosion (265) 
• Other Glacial lakes (96) 

Causes of Expanding Glacial Lakes in Himalayas: 

Global Warming: 

• Rising temperatures accelerate glacier melting, leading to increased water input into glacial lakes. 

Retreating Glaciers: 

• Melting glaciers expose new land surfaces, facilitating the formation of new glacial lakes. 

Weakening Moraines: 

• Glacier retreat weakens natural dam walls made of rock and debris, increasing the risk of sudden collapse and Glacial Lake Outburst Floods (GLOFs). 

Increased Precipitation: 

• Changes in precipitation patterns contribute to the expansion of glacial lakes by providing additional water to fill them. 

Permafrost Thaw: 

• Thawing permafrost creates depressions that collect water, further expanding glacial lakes. 

Human Activities: 

• Infrastructure development, mining, and deforestation alter natural drainage patterns, indirectly contributing to glacial lake expansion and exacerbating climate change. 

Recent Cases of GLOF in India: 

• 2013 Uttarakhand Floods: Melting of Chorabari glacier resulted in the eruption of the Mandakini River, causing devastating floods. 
• 2014 Ladakh GLOF: Glacial Lake outburst flood hit the village of Gya in Ladakh, causing significant damage. 
• 2021 Chamoli Flash Floods: Flash floods suspected to be caused by GLOFs occurred in Chamoli district, Uttarakhand. 
• 2023 South Lhonak Lake Rupture: Continuous rainfall led to the rupture of South Lhonak Lake in northwest India, highlighting the ongoing risks associated with glacial lakes. 

Way Forward: 

Climate Change Mitigation: 

• Implement measures to reduce greenhouse gas emissions globally, such as transitioning to renewable energy and increasing energy efficiency. 

Early Warning Systems: 

• Develop and implement early warning systems for monitoring glacial lakes and disseminating timely alerts to at-risk communities. 

Engineering Measures: 

• Implement infrastructure projects to stabilize and manage glacial lakes, including spillways, drainage channels, and dams. 

Natural Infrastructure: 

• Restore and conserve natural ecosystems like wetlands and forests to regulate water flow and provide additional benefits. 

Community Engagement and Capacity Building: 

• Involve local communities in risk assessment and disaster preparedness efforts, including training in emergency response and evacuation procedures. 

International Cooperation: 

• Foster collaboration among countries sharing glacier-fed river basins to facilitate joint monitoring and coordinated action. 

Mains Question: 

1. “In the context of climate change impacts, discuss the challenges posed by the expansion of glacial lakes in the Himalayan region and suggest measures for mitigating associated risks.” (150 WORDS)