Glacial Melting in High Mountain Asia Has the Potential to Overwhelm Hydropower Systems
Flooding in High Mountain Asia has been a continuous issue for downstream communities and a growing hydropower sector. In a recent Nature Geoscience paper, scientists emphasized the specter of glacial melting and hazards in High Mountain Asia, not only to regional hydropower systems but in addition to food systems that billions of individuals depend on.
Between 2000 and 2019, glaciers within the High Mountain Asia region lost roughly 21 billion tons of mass per yr, and even probably the most liberal estimates of glacier mass loss predict that the glaciers will shrink by about 40% in comparison with 2019 volume by 2100. For context, if the quantity of ice lost by the region’s glaciers annually were to cover Paris, only the spire of the Eiffel Tower could be visible. This massive volume of ice being released every yr has consequences for local and downstream residents. Though the region has the potential to offer hydropower to over 350 million homes, these projects may very well be jeopardized by the impacts of glacial melting.
A lot of the region’s planned hydropower projects — encompassing roughly 240 gigawatts or nearly half of the potential energy production — are either near or in areas which have previously had glacial lake outburst floods. These events are extremely dangerous, with the potential to wreck hydropower projects and cause reservoir overflows or dam breaks that release deluges of water downstream. In 2013, the Kednarth disaster, which included the Chorabari Lake outburst, damaged at the least 10 hydropower projects and killed over 6,000 people. Although the region holds great potential for hydropower energy production, the threat to the projects is each severe and imminent.
The Nature Geoscience paper — led by Dongfeng Li of the National University of Singapore — outlines various kinds of mountain landscape instabilities and their effects. The threats included melting and thawing of ice, slope instability, glacial lake outburst floods, landslides that cause lakes to overflow, and erosion. Each of those hazards can damage hydropower projects through rapid flows of debris or water, or by destabilizing the land through the thawing of permafrost or erosion.
Each kind of hazard comes with its own specific risks to hydropower projects and downstream systems. Thawing ice causes instability within the slopes since the once solid, frozen ground is now more fluid, and thus more vulnerable to erosion and slumping that might cause quite a few hazards, reminiscent of landslides and rock-ice avalanches. When debris flows or melting ice or water enter glacial lakes, they could cause outburst floods. Likewise, erosion or the destabilization of permafrost can even result in landslides that cause outburst floods. Lastly, erosion poses its own risk of debris flows or destabilization that might trigger landslides.
These hazards will only increase as climate change worsens and causes further glacial melt and permafrost thaw. Nonetheless, firm, precise predictions remain difficult due to challenges to research in distant High Mountain Asia. As a consequence of the rugged terrain and variable distribution of snow- and ice-covered areas within the region, predicting the long run responses of individual water systems to climate change is kind of difficult.
A special paper within the journal Frontiers in Water details the work of NASA’s High Mountain Asia Team (HiMAT) tasked with studying the changing hydrology within the region; the authors asserted that “we lack a basic understanding of the important thing physical drivers on [High Mountain Asia] river flow.” This lack of knowledge prompted their team to review the more specific impacts of precipitation, runoff, and snowmelt.
The models which can be used to predict these aspects are vulnerable to large uncertainties. This uncertainty makes it difficult to plan to stop major damage to infrastructure, including hydropower projects. While scientists understand the larger trends brought on by climate change, reminiscent of increased precipitation and better temperatures, it remains to be difficult to predict local patterns and create accurate models. For instance, snow albedo (reflectivity) will be highly misrepresented when modeling snowmelt because there is usually an assumption that there aren’t any impurities or particles on top of the snow. In accordance with the HiMAT article, this will result in as much as a 50% overestimation of the snow albedo. This error is important, because the snow melt rate is five times faster at a reflectivity of fifty% versus 90%.
Moreover, the precipitation patterns of the region are hard to predict because weather stations are few and much between. The variable terrain contributes to the sparse station coverage, which reduces the robustness of long-term precipitation data. A lot of these stations have records too short to be very useful in assessing long-term trends. Thus, further research will probably be required so as to make accurate predictions about when hazards may occur so as to protect hydropower projects and downstream communities.
Not only are glacial melt and landscape hazards a priority for hydropower projects and downstream communities, but in addition they have a big impact on crops and the general food system. Christine Bischel, a geographer on the University of Fribourg in Switzerland, stated that among the agricultural issues arise on this region attributable to uncertain glacial flows. The most important issues are irrigation and water availability, she said.
Increased temperatures cause spring to begin earlier, creating worse or improved climates for certain crops. The quantity and timing of water availability is crucial for crops, so shifting seasons will change irrigation patterns as well. Bischel further explained that predicting how much of the glacier will melt is difficult from yr to yr, which presents issues for downstream agricultural communities. Farmers must give you the option to adapt to the glacial water releases, and if the shifts develop into too great they could need to shift which crops they cultivate. That is “not their selection,” Bischel told GlacierHub. She added that sometimes people may even migrate north so far as Russia to search out higher places to grow their crops. She stated that the “biggest problem” is that the glaciers will “eventually disappear,” which can force much more farmers to migrate in the long run.
Water demand for each energy and food is predicted to extend as temperatures, evaporation from dams, and irrigation for crops increase. The upper demand for water combined with higher variability in precipitation will create challenges for water allocation in the long run. One aspect of this challenge is that we currently have neither robust systems for predicting future crop production nor hydropower productivity based on changing water availability and precipitation.
Further research is required to assist protect agricultural and emerging hydropower infrastructure from the increasing risks of glacial melting and hazards reminiscent of glacial lake outburst floods. The most important obstacle to monitoring these hazards and being prepared for climate risks is the shortage of usable data attributable to sparse station coverage, which makes it difficult to create good models for future impacts. Covering more of the terrain to take more accurate measurements and create long-term data and modeling for these areas is difficult but essential to make sure that each farmers and regional residents are protected against hazards that may destroy infrastructure and livelihoods.