Third Pole's expanding glacial lakes pose greater flood risks, research reveals

Third Pole's expanding glacial lakes pose greater flood risks, research reveals
by Simon Mansfield
Sydney, Australia (SPX) Dec 18, 2023
In a compelling illustration of the escalating impacts of climate change, a recent study has brought into sharp focus the growing threat posed by Glacial Lake Outburst Floods (GLOFs) in the Third Pole region. The Third Pole, an area covering the Tibetan Plateau and adjacent mountain ranges, including the Himalayas, Hindu Kush, and Tianshan Mountains, has become a critical zone for climate research due to its susceptibility to climate-induced changes.

Over the past thirty years, the Third Pole has witnessed a significant retreat of more than 10,000 glaciers, a phenomenon largely attributed to rising temperatures and shifting rainfall patterns. This glacial retreat has led to the formation of thousands of glacial lakes, initially seen as benign but now recognized for their destructive potential. The study, led by Associate Professor Weicai Wang from the Institute of Tibetan Plateau Research, Chinese Academy of Sciences, China, and published in the Nature Communications journal on December 12, 2023, sheds light on the increasing frequency and potential impact of GLOFs.

Glacial lakes, while often picturesque, harbor a latent destructive power. They can unleash vast volumes of water rapidly, caused by triggers like glacier collapse, snow avalanches, landslides, or natural dam failures. These events can result in GLOFs, posing substantial risks to nearby communities and infrastructure. The study highlights this threat, noting the inconsistency in risk assessment methods used in previous studies. For instance, the number of glacial lakes reported in the 2015-2020 period varied significantly, ranging from 10,000 to 30,000, based on different definitions and methodologies.

The research team undertook a detailed analysis of GLOF risks in the Third Pole, utilizing satellite images from the Sentinel-2A and Sentinel-2B missions, covering 2018 to 2022. By classifying glacial lakes based on their position and topological characteristics in relation to their source glacier, the researchers compiled an updated inventory. This inventory, combined with historical data, revealed a concerning trend of continuous expansion of glacial lakes in the region.

In analyzing GLOF activity, the researchers consolidated data on GLOF events dating back to 1900. Their findings indicate a worrying increase in GLOF occurrences, from an average of 1.5 events annually during 1981-1990 to 2.7 events in 2011-2020. This trend suggests that the frequency of GLOFs is likely to rise further, necessitating improved analytical methods and datasets for effective risk management.

A key aspect of the study was the analysis of 5,535 glacial lakes for their susceptibility to GLOFs. The team identified 1,499 lakes with high outburst flood potential. Using GLOF simulations, they investigated the 'potential disaster volume' of these high-risk lakes. The findings were alarming: approximately 55,808 buildings, 105 hydropower projects, 194 km of farmland, 5,005 km of roads, and 4,038 bridges are under threat from potential GLOFs. Dr. Wang highlighted the direct exposure of about 190,000 lives within the GLOF paths.

The implications of these findings extend beyond environmental concerns, touching on socio-economic and regional cooperation aspects. Countries like China, Kazakhstan, Nepal, India, and Pakistan, which are exposed to GLOFs in the Third Pole, face significant challenges. "Our findings underscore the significant challenges posed by the substantial potential disaster volumes in these economically disadvantaged and highly vulnerable regions," Dr. Wang emphasized. He further stressed the urgency for the relevant nations to recognize the looming GLOF threats and promote regional cooperation to mitigate these risks.

Research Report:Enhanced glacial lake activity threatens numerous communities and infrastructure in the Third Pole