Melting glaciers in Asia’s high mountains threaten to overwhelm hydropower systems
View of Broad Peak from the Godwin-Austin Glacier. The glacier in Southeast Asia’s Karakoram Mountains is near some planned hydropower projects. Credit: Maria Lee via Wikimedia Commons
Flooding in high mountain regions of Asia has been an ongoing problem for downstream communities and the growing hydropower industry.in the nearest Natural Geoscience Paperscientists have highlighted the threat of melting and harming mountain glaciers in Asia, not only to the regional hydropower system but to the food system on which billions of people depend.
From 2000 to 2019, glaciers in high mountain regions of Asia lost about 21 billion tons of mass per year, and even the most liberal estimates of glacier mass loss predict that glaciers will be about 40% smaller by 2100 than their 2019 volumes. For context, if the annual ice loss from glaciers in the region covered all of Paris, only the spire of the Eiffel Tower would be visible. The large volumes of ice released each year impact local and downstream populations. Although the region has the potential to provide hydropower to more than 350 million households, these projects could be affected by melting glaciers.
Most of the hydropower projects planned in the region—including about 240 GW, or nearly half of the potential energy production—are either near or located in previously owned glacier outburst flood. These events are extremely dangerous and have the potential to disrupt hydropower projects and cause reservoirs to overflow or fail, releasing flood waters downstream. In 2013, the Kednarth disaster, which included the bursting of Chorabari Lake, damaged at least 10 hydropower projects and killed more than 6,000 people people. Despite the region’s enormous potential for hydroelectric energy production, threats to these projects are both serious and imminent.
this Natural Geoscience The paper, led by Dongfeng Li of the National University of Singapore, provides an overview of different types of mountain landscape instabilities and their impacts. These threats include melting and melting ice, slope instability, glacial lake outburst floods, landslides that cause lakes to overflow, and erosion. Each of these hazards can disrupt hydropower projects through rapid movement of debris or water, or destabilize land through permafrost melting or erosion.
Map of planned hydropower projects and cryosphere elements in the Tibetan Plateau, Himalayas, and adjacent regions. Yellow dots represent the locations of some cryospheric hazards. Credit: Nature Geoscience
Each type of hazard poses specific risks to hydropower projects and downstream systems. Melting ice can cause slope instability because the once solid frozen ground is now more fluid and therefore more susceptible to erosion and collapse, which can lead to a number of hazards such as landslides and rock avalanches. When mudslides or melting ice or water enter glacial lakes, they can cause breach floods. Likewise, erosion or destabilization of permafrost can lead to landslides, triggering flooding. Finally, erosion itself poses a risk of mudslides or instability that can trigger landslides.
These hazards will only increase as climate change worsens and causes melting glaciers and permafrost. Still, precise, accurate predictions remain difficult to make due to the challenges of conducting research in remote high mountain regions of Asia. Predicting the future response of individual water systems to climate change is difficult due to the region’s rugged topography and variable distribution of snow-covered areas.
different Paper in the magazine water front Detailing the work of NASA’s High Mountain Asia Team (HiMAT), tasked with studying the region’s changing hydrology; the authors assert, “We lack a fundamental understanding of the key physical drivers [High Mountain Asia] river flow. This lack of understanding led their team to study the more specific effects of precipitation, runoff and snowmelt.
Models used to predict these factors are subject to large uncertainties. This uncertainty makes it difficult to plan to prevent major damage to infrastructure, including hydropower projects. While scientists understand the larger trends caused by climate change, such as increased precipitation and warmer temperatures, it remains difficult to predict local patterns and create accurate models. For example, when modeling snowmelt, snow albedo (reflectivity) can be severely skewed because it is often assumed that there are no impurities or particles on the snow. According to HiMAT article, which can lead to an overestimation of snow albedo by up to 50%. This error is important because snow melts five times faster at 50% albedo and 90% albedo.
Additionally, precipitation patterns in the region are difficult to predict because weather stations are few and far between. The variable terrain leads to sparse station coverage, which reduces the robustness of long-term precipitation data. The records of many of these stations are too short to be useful for assessing long-term trends. Therefore, further research is needed to accurately predict when disasters are likely to occur in order to protect hydropower projects and downstream communities.
View of the Baltoro glacier facing Concordia. Credit: Jihen Virut via Flickr CC
Melting glaciers and landscape damage are not only concerns for hydropower projects and downstream communities, but also have major impacts on crops and the food system as a whole. Christina Bischer, a geographer at the University of Friborg in Switzerland, said there were some agricultural problems in the region due to the uncertain flow of the glaciers. The main problem, she said, is irrigation and water supply.
Warmer temperatures are causing spring to arrive earlier, creating worse or better weather for certain crops. The amount and timing of water availability is critical to crops, so seasonal changes can also alter irrigation patterns. Bischel further explained that predicting how much glaciers will melt each year is challenging, creating problems for downstream farming communities. Farmers must be able to adapt to the release of glacier water, and if the change is too great, they may have to change the crops they grow. It was “not an option for them,” Bischel told GlacierHub. Sometimes people may even migrate north to Russia in search of better places to grow their crops, she added. She said the “big question” is that the glaciers “will eventually disappear”, which could force more farmers to relocate in the future.
Water demand for energy and food is expected to increase as temperatures rise, dams evaporate, and crop irrigation increases. Higher demand for water coupled with greater variability in precipitation will create challenges for future water allocation. One aspect of this challenge is that we currently have neither reliable systems for predicting future crop yields nor hydropower productivity based on changing water availability and precipitation.
Further research is needed to help protect agriculture and emerging hydropower infrastructure from increased risks of disasters such as melting glaciers and flooding from glacial lake bursts. The biggest obstacle to monitoring these hazards and preparing for climate risks is the lack of available data due to sparse station coverage, making it difficult to create good models for future impacts. Covering more terrain for more accurate measurements and creating long-term data and modeling for these areas is challenging, but necessary to ensure farmers and area residents are protected from hazards that could destroy infrastructure and livelihoods.
