| Flood management
since revealed that it did survey two at-risk lakes back in September in preparation for installing early warning systems in the event of glacial lake outbursts, and now plans to install them at most of the 56 glacial lakes in India that are considered to be at risk. Although other specialists in Himalayan hazards suggest that there could be about 200 glacial lakes across the region that are in a dangerous state and could burst at any time, especially as global warming induced changes are happening at speed in the Himalayas, and require constant monitoring and mitigation.
Millions at risk A team of academics, including Northumbria
University’s Dr Matt Westoby and colleagues from Newcastle University and the University of Canterbury in New Zealand, recently warned that millions of people are at risk of GLOF on a global scale. In their study published in Nature Communications,
the team discovered that since 1990, the number, area, and volume of glacial lakes globally has grown rapidly, increasing by 53%, 51%, and 48% respectively. Concurrent with the rapid growth of glacial lakes, many catchments downstream have experienced rapid and large increases in population, infrastructure and hydroelectric power schemes, while agriculture has intensified. Areas most at risk from GLOFs were also identified and it has been estimated that around 15 million people globally could be under threat, with populations living in High Mountains Asia (India, Pakistan, China) and the Andes (Peru and Bolivia) the most exposed to this danger.
Along with her colleagues, the paper’s lead author,
Caroline Taylor, presents a global compilation of glacial lake conditions, exposure, and vulnerability mapping, to quantify and rank the damage potential from GLOFs in 2020, and discovered that more than half of the globally exposed population are found in just four countries: India, Pakistan, Peru, and China. “Whilst much excellent research to date has focused
on GLOF hazard and exposure at the regional scale, or for individual flood events, this research is the first of its kind to explore the danger posed by GLOFs at a truly global scale,” Westoby said. “This is significant from a disaster risk reduction perspective because it allows us to identify those regions of the world that should be a focus for targeted GLOF risk management. It also allows us to identify regions where further work is needed to better understand the complex societal factors which we show to be a key driver of GLOF danger.” The authors explain that due to increased interest
surrounding GLOFs over the last few decades, “a clear geographical disparity has emerged between where GLOFs are occurring and the hotspots of research”. Between 1990 and 2015, Iceland, the North American Cordillera and Hindu-Kush-Karakoram were the most prominent GLOF research hotspots with 180, 144, and 142 published research items, respectively. And then since 2015, the Himalayas have emerged as the primary research focus, accounting for 36% of the studies undertaken between 2017 and 2021. “As such,” the authors say, “these ‘hotspot’ regions
are often cited as having the highest GLOF danger. While true in part, our results also indicate that as of 2020, the potential for large GLOF impacts is also high across the Andes, and as a nation, danger in Peru is third highest globally.”
www.waterpowermagazine.com | December 2023 | 23 This is because over the last two decades, glaciers
across the Andes have undergone rapid deglaciation in response to climate changes leading to the growth of many large glacial lakes and consequently a growth in overall GLOF lake conditions. Taylor et al state that the number of glacial lakes across the region increased by 93% compared to just 37% in High Mountain Asia across the same period. Concurrent with this increase, populations living in close proximity to glacial lakes have grown, increasing overall exposure to GLOF while, according to the authors, regional vulnerability remains high as a result of deep-rooted corruption and poor standards of living. In comparison to other regions, the number of GLOF
research items across the Andes stands at less than 8% of the research conducted between 1979 and 2021 (<100 items). “We suggest this data sparsity across the Andes is perhaps preventing meaningful assessments of actual GLOF risk in the region and urgently requires attention, particularly given the second- and third-most dangerous basins are found in this region, and the region as a whole is ranked second for GLOF danger globally,” the authors say, suggesting that this region should be targeted for more detailed study.
Globally important There is much debate about how glacial lake outburst
floods might change in the future. According to Taylor et al, existing glacial lakes will expand and many new lakes will form as glaciers continue to recede due to climate change, altering the spatial pattern of GLOF danger. As the authors conclude: “GLOFs can be highly destructive and can arrive with little prior warning, causing significant damage to property, infrastructure, and agricultural land, and resulting in extensive loss of life. However, the impact varies significantly across the globe; in the last 70 years, several thousand people have been killed by GLOFs in the Cordillera Blanca alone, most from a small number of events, while only 393 deaths in the European Alps can be directly linked to GLOF activity over the last 1000 years. The continued ice loss and expansion of glacial lakes due to climate change therefore represents a globally important natural hazard that requires urgent attention if future loss of life from GLOF is to be minimised and the UN’s Sustainable Development Goals (particularly Goal 11—Disaster Risk Reduction) are to be met.”
Above: Glacial lake in Nepal
References
https://www.bbc.co.uk/news/ world-asia-india-67050830
https://www.reuters.com/ world/india/india-lake-that- flooded-was-poised-get-early- warning-system-2023-10-05/
Taylor, C., Robinson, T.R., Dunning, S. et al. Glacial lake outburst floods threaten millions globally. Nat Commun 14, 487 (2023). https://
doi.org/10.1038/s41467-023- 36033-x
Below: Laguna Humantay glacial lake is set against the backdrop of the Andes in Peru. There is concern that data sparsity across the Andes is perhaps preventing meaningful assessments of actual glacial lake outburst flood risk in the region
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