Impact of landslide on the water supply capacity of the Shihmen Reservoir in Taiwan under climate change

Climate change has altered precipitation patterns, significantly affecting water resources management and supply systems. Reservoirs, including Shihmen Reservoir in Taiwan, are particularly vulnerable due to changes in rainfall distribution and topographic factors, leading to sedimentation from events such as landslides and debris flows. These events pose direct and indirect threats to the water quality and supply capacity of reservoirs.

The frequency of heavy rainfall events has increased, resulting in heightened soil and rock erosion. Consequently, a larger amount of sediment is entering the reservoir, degrading its water quality. Currently, Shimen Reservoir is operating at only 2/3 of its storage capacity, with 1/3 of the reservoir now filled with deposited silt. This situation poses a significant risk to future water supply.

To assess future rainfall trends at Shihmen Reservoir, we compared TCCIP statistical downscaling data for Taiwan with weather generation data. Our analysis focused on understanding the impact of landslide sediments on the storage capacity of Shihmen Reservoir and identifying potential risk indicators, including resilience, reliability, and vulnerability.

This study underscores the profound impact of climate change on Shihmen Reservoir, specifically highlighting the repercussions of rainfall failure on water quality and supply capacity.