2 lakh lives, infrastructure threatened due to glacial lake outburst floods in Third Pole, reveals study

New Delhi, December 16

Roughly two lakhs lives are endangered by potential glacial lake outburst floods (GLOFs) in the Third Pole, spanning the Tibetan Plateau, the surrounding Himalayas, Hindu Kush, and Tianshan Mountain ranges, a new research has found.

Triggered by climate change, these potential GLOFs also threaten the infrastructure in the region, including buildings, hydropower projects, roads and bridges, researchers at the Chinese Academy of Sciences, China, said in their study.

Of the 5,535 glacial lakes in the region, they have identified almost 1,500 that have a “high potential” for outburst floods.

After analysing data since 1900, they also found that yearly GLOF occurrences heightened in frequency, from an average of 1.5 events during 1981-1990 to 2.7 during 2011–2020.

Overall, these findings are concerning for countries like India, China, Kazakhstan, Nepal, and Pakistan which are exposed to GLOFs in the Third Pole, the researchers said in their study published in the journal Nature Communications.

“Approximately 55,808 buildings, 105 existing or planned hydropower projects, 194 (square kilometres) of farmland, 5,005 kilometres of roads, and 4,038 bridges are threatened by the potential GLOFs,” said the study’s corresponding author Weicai Wang, associate professor, Chinese Academy of Sciences.

“Our findings underscore the significant challenges posed by the substantial potential disaster volumes in these economically disadvantaged and highly vulnerable regions,” said Wang.

Warming temperatures and altered rainfall patterns stemming from climate change are considered to have caused over 10,000 Third Pole glaciers to retreat over the past three decades, facilitating the formation of thousands of glacial lakes.

When triggered by events like glacier collapse, snow avalanches, landslides, or the collapse of natural dams, glacial lakes can release vast volumes of water swiftly, leading to destructive outbursts, or GLOFs.

Given the enormous threat these GLOFs pose to the exposed communities and industries, previous research have made efforts to understand their triggers and assess their risks to enable preventive decision-making.

However, the researchers said, these studies contain several inconsistencies, such as the number of glacial lakes reported, arising out of the differences in the inquiry methods employed. They said that depending on the definition used, the number varied from 10,000 to 30,000 in the 2015-2020 period.

In this study, the researchers identified and classified all glacial lakes in the Third Pole region based on their position and characteristics in relation to their source glacier, using satellite images taken between 2018 and 2022. They then analysed the changes in GLOF activity over the past decades, using data from as far back as 1900.

The researchers predicted the observed “worrisome” trend of yearly increase in GLOF instances to continue, which they said underscored the need for developing better analytical methods and datasets to stay ahead of potential disasters.

“Considering the projected extension of GLOF threats under future climate change scenarios, it is crucial for the relevant nations surrounding the Third Pole to recognize the urgency of addressing GLOF threats and to promote regional cooperation,” said Wang.