Risk of Glacial Lake Outburst Floods Being Increasing in Central Asian Tienshan Mountains

Glacial lake outburst floods (GLOFs) are sudden and rapid events caused by the sudden and rapid drainage of large amounts of water from glacially formed lakes. Since 1990, the number and area of glacial lakes worldwide have shown a significant upward trend, and the risk of GLOFs is continuously increasing.

A recent study, published in npj Climate and Atmospheric Science, conducted by a research team led by Prof. CHEN Yaning from the Xinjiang Institute of Ecology and Geography (XIEG) of the Chinese Academy of Sciences, analyzed the spatiotemporal characteristics of the glacial lakes and assessed the risk of GLOFs.

The researchers used multi-temporal Landsat series and Sentinel-2A/2B remote sensing images to extract a dataset of glacial lakes in the Central Asian Tienshan Mountains over the past 30 years. They used semi-automatic algorithm and a thresholding algorithm to extract accurate boundaries of glacial lakes. The extracted glacial lakes were carefully verified and compared with other data sources.

The results showed that the number of glacial lakes in the Central Asian Tienshan region increased from 1,837 in 1990 to 4,557 in 2023, and 75% of the glacial lakes are mainly distributed in the Central and Western Tienshan. 

In addition, the researchers used an improved GLOF model to evaluate the risk values of glacial lakes in the Central Asian Tienshan region in 2023. The final risk values of all glacial lakes were divided into five classes using the natural partitioning method. The model was then verified by the results of glacial lakes that experienced outburst floods in the past.

The results indicated that the Western Tienshan has the highest GLOF risk, with high or very high-risk values for GLOFs being 3-4 times those of other areas.

"By the mid-21st century, as the climate continues to warm, the risk and potential threat of GLOFs in the Central Asian Tienshan region will further increase, particularly in the western part of the Tienshan Mountains," said CHEN Man, first author of this study.

This study can provide a scientific basis for decision making in disaster prevention and mitigation in the downstream areas of the Central Asian Tienshan Mountains.

Article link: https://www.nature.com/articles/s41612-024-00755-6

Distribution of glacial lakes and history GLOFs in the Central Asian Tienshan Mountains (Image by XIEG)

Contact

LONG Huaping

Xinjiang Institute of Ecology and Geography

E-mail: longhp@ms.xjb.ac.cn

Web: http://english.egi.cas.cn