Researchers study the risk of glacial lake explosions at the Third Pole

The Third Pole, spanning the Tibetan Plateau and surrounding Himalayan, Hindu Kush and Tianshan mountain ranges, is extremely vulnerable to the effects of climate change. Warming temperatures and changing precipitation patterns have caused the retreat of more than 10,000 glaciers from the region over the past three decades, facilitating the formation of thousands of glacial lakes.

Although seemingly harmless, these bodies of water have enormous destructive potential, particularly due to their ability to cause glacial lake floods (GLOF). When triggered by events such as glacier collapse, snow avalanches, landslides, or the collapse of natural dams, glacial lakes can rapidly release large quantities of water, leading to GLOFs. destructive.

Since GLOFs pose an immense threat to communities and industries located near the Third Pole’s glacial lakes, efforts have been made to understand their triggers and assess their risks with the aim of facilitating preventive decision-making.

Unfortunately, the methods used to assess these risks vary considerably between studies. For example, the number of reported glacial lakes varied between 10,000 and 30,000 during the period 2015-2020, depending on the definition used. These inconsistencies make it difficult to create a reliable dataset for further data analysis and GLOF risk assessment.

In this context, a research team led by Associate Professor Weicai Wang from the Tibetan Plateau Research Institute of the Chinese Academy of Sciences, China, decided to conduct a more detailed analysis of GLOF risks in the Third Pole . The study, published in Natural communications on December 12, 2023, highlights the need for urgent action and regional cooperation for the economically disadvantaged and highly vulnerable regions of the Third Pole.

To do this, the researchers first obtained satellite images from the Sentinel-2A and Sentinel-2B missions between 2018 and 2022. Then, they identified and classified all the glacial lakes based on their position and topological characteristics in relation to to their source glacier. This updated inventory of glacial lakes, coupled with previous datasets, allowed them to analyze changes in this region over the past decades, revealing a continued and worrying expansion of glacial lakes.

Additionally, they analyzed changes in GLOF activity by consolidating datasets of GLOF events in the Third Pole, dating back as far as 1900. Their results, unlike previous studies, revealed a worrying trend, indicating a increase in GLOF occurrences from an average of 1.5 events per year between 1981 and 1990 to 2.7 events between 2011 and 2020.

The researchers noted that the expansion of glacial lakes and the appearance of new ones will likely lead to an increase in the number of GLOFs per year in the future, highlighting the need to develop better analysis methods and datasets to stay one step ahead of potential disasters. .

Finally, the team analyzed the sensitivity to GLOFs in 5,535 glacial lakes and identified 1,499 of them with high potential for flash flooding. The researchers also studied the “potential disaster volume” based on GLOF simulations of these high-risk lakes. The results were worrying to say the least.

“Approximately 55,808 buildings, 105 existing or planned hydroelectric projects, 194 km² “Agricultural land, 5,005 km of roads and 4,038 bridges are threatened by potential GLOFs,” says Dr Wang. “Additionally, using regional population distribution data, we estimated that approximately 190,000 lives are directly exposed in GLOF paths,” he said. explain.

Overall, these results are concerning, especially for countries exposed to GLOFs at the third pole, including China, Kazakhstan, Nepal, India, and Pakistan. “Our results highlight the significant challenges posed by the large volumes of potential disasters in these economically disadvantaged and highly vulnerable regions,” said Dr. Wang.

“Given the projected expansion of GLOF threats in future climate change scenarios, it is crucial that relevant nations surrounding the Third Pole recognize the urgency of responding to GLOF threats and promoting regional cooperation.”

In the future, we hope that this work will lead to better risk management strategies for GLOFs and promote cooperation between Third Pole countries. Additionally, and perhaps most importantly, these findings should also raise awareness of the many ways in which climate change threatens our lives.