Study Links Climate Warming to Rising Flood Risks from Rain-on-Snow in High Mountain Asia
A study by the Chinese Academy of Sciences highlights the increasing flood risks from rain-on-snow events in High Mountain Asia due to climate warming, emphasizing the need for enhanced disaster management strategies.
A recent study published in npj Climate and Atmospheric Science reveals that climate warming is intensifying flood risks from rain-on-snow (ROS) events in High Mountain Asia. Researchers from the Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, analyzed the distribution, causes, and flood risks associated with ROS events across the region.
ROS events occur when rainfall interacts with existing snowpacks, leading to rapid snowmelt and potential flooding. The study found that High Mountain Asia experiences an average of 22.4 ROS days annually, with the Ganges Basin recording the highest frequency at 45.8 days. Most ROS events transpire during winter, especially along major rivers like the Yangtze and Amu Darya. Spring accounts for approximately 25% of these events, predominantly near Lake Balkhash, while summer events (13.5%) are mainly in high-altitude areas.
The average daily ROS intensity stands at 5.29 mm, primarily driven by rainfall (65.9%) and snowmelt (34.1%). Although the number of ROS days is decreasing by 0.031 days annually, the timing of these events is shifting earlier, and their intensity is diminishing. At lower altitudes, reduced snow days contribute to the decline in ROS events, whereas at higher elevations, increased rainfall days lead to more frequent ROS occurrences.
The study highlights the threat of ROS-induced floods, which can cause rapid snowmelt. Areas with substantial snowpack experience snowmelt rates 2.83 times higher than those with minimal snowpack. The Ganges and Irrawaddy Basins are identified as high-risk zones for ROS floods, with daily intensities reaching up to 24.87 mm. High-risk areas are typically situated at elevations between 3,000 and 4,500 meters.
Understanding the patterns and impacts of ROS events is crucial for enhancing flood prevention and disaster management strategies in mountainous regions. The findings underscore the need for improved monitoring and adaptive measures to mitigate the risks associated with climate-induced hydrological changes in High Mountain Asia.
Source: Phys.org
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