Area of ​​Himalayan glacial lakes increased by 10.81% from 2011 to 2024: report

A man tries to lift a car submerged in mud in a flood-hit area along the Teesta River in Rongpo, east Sikkim, India, Sunday, Oct. 8, 2023. Rescuers continued to dig through slushy debris and icy water in the hunt for survivors after a glacial lake burst a dam in India’s northeastern Himalayas shortly after midnight on Wednesday, washing away homes and bridges and forcing thousands to flee. | Photo: AP

Glacial lakes and other bodies of water throughout the territory The area of ​​the Himalayan region increased by 10.81%. from 2011 to 2024 due to climate change, indicating an increased risk of Glacial Lake Outflows (GLOFs), according to a government report.

Central Water Commission (CWC) report accessed PTIstates that with a 33.7% increase in surface area, lakes in India have experienced even greater growth.

Read also | Glacial lakes rise as glaciers retreat

“The total inventory area of ​​glacial lakes in India was 1,962 hectares during 2011, which increased to 2,623 hectares during 2024 (September). The area increased by 33.7%,” the report says.

It also identified 67 lakes in India that have increased in surface area by more than 40%, placing them in the high-risk category for potential GLOFs.

Ladakh, Himachal Pradesh, Uttarakhand, Sikkim and Arunachal Pradesh showed the most marked expansion, signaling an increased risk of GLOF and the need for enhanced monitoring and disaster preparedness.

The total area of ​​glacial lakes and other bodies of water in the Himalayan region has increased by 10.81% from 533,401 hectares in 2011 to 591,108 hectares in 2024 due to climate change, the report said.

Read also | The flood in Sikkim became one of the worst climate disasters in Asia in 2023

The rapid expansion of these lakes is attributed to accelerated melting of glaciers due to rising temperatures in the region, which can have serious consequences for downstream communities, infrastructure and biodiversity.

From a physical point of view, shrinking mountain glaciers and expanding glacial lakes are among the most recognizable and dynamic effects of climate warming in this environment, the report says.

“Therefore, under such changing environmental conditions, careful monitoring of the relative change in water distribution area in even smaller lakes has become very important in this region,” the report said.

Flash and often catastrophic floods occur when glacial lakes breach their natural moraine dams, releasing large volumes of water downstream.

The CWC emphasized that increasing water spread in these lakes requires strict monitoring and urgent risk management strategies.

A senior official said that to overcome the difficulty in tracking these remote lakes, the CWC has used advanced satellite technology, including the Sentinel-1 Synthetic Aperture Radar (SAR) and Sentinel-2 multispectral imagery, which provide accurate and all-weather monitoring.

“The high-resolution capabilities of these satellites allow the CWC to detect changes in lake size with an accuracy of up to 10 meters, even under challenging conditions such as cloud cover. This monitoring technology is critical to providing timely information on the status of these high-risk lakes. , thereby allowing early intervention when necessary,” the official said.

Read also | Government to review dams vulnerable to floods from glacial lakes

The CWC report also highlighted transboundary risks from expanding glacial lakes in neighboring countries, including Bhutan, Nepal and China.

Given the interconnected nature of river basins across the Himalayan watershed, cooperation with these countries is critical to managing the potential impacts of GLOF, it stressed.

The report called for collaborative efforts to monitor and share data to create a more comprehensive risk assessment and mitigation strategy.

He stressed the urgent need for international and regional cooperation in developing early warning systems, improving disaster response plans and promoting community awareness initiatives to protect vulnerable populations.

Read also | Satellite images covering Indian Himalayan river catchments show dramatic changes in glacial lakes

The consequences of the expansion of the glacial lake area go beyond flood risks and could affect the availability of water in the region’s major river systems, including the Ganges, Brahmaputra and Indus.

Using data from 2011 and comparing five- and 10-year averages, the CWC report found patterns in glacial lake expansion that allow authorities to pinpoint high-risk areas.

The official quoted above said that in an effort to shorten monitoring intervals and improve data accuracy, the CWC aims to establish a robust system for early detection and response to the challenges developing through the Himalayan glacial lakes.