Analysis of dam stability based on future climate change scenarios

In Korea, the frequency of extreme rainfall during summer has increased over the past 30 years. The average annual precipitation is predicted to increase by at least 4% and up to 16% in the second half of the 21st century due to climate change. When designing dam construction and flood control capacity improvement projects, the probable maximum precipitation (PMP) and probable maximum flood (PMF) are estimated through the hydrological analysis process to ensure the stability of the dam. In this study, considering recent extreme precipitation patterns, the impact of climate change on dams was analyzed and evaluated. Projected PMPs were calculated and compared for 37 dams under K-water’s management . Also, the study examined temporal and spatial changes in PMP by dividing the entire period into three periods (P1: 2021 ~ 2040, P2: 2041 ~ 2070, P3: 2071 ~ 2100) and applying the spatial interpolation method. A hydrological stability review of four dams (Soyang, Choongju, Hoengsung, Pyeonghwa) on the Han River was conducted through comparing existing PMF (based on dam construction, design, and flood control capacity improvement projects) with projected PMF from climate change scenarios for the three periods. The rate of change in PMF over time, overflow of the dam, and whether it was possible to improve the capacity of the dam were evaluated. This hydrological stability assessment of PMP and PMF is noteworthy when considering the timing of dam construction and the recent extreme rainfall pattern.