Prediction of Reservoir Sedimentation in the Long Term Period Due to the Impact of Climate Change: A Case Study of Pleikrong Reservoir

Abstract

Reservoirs are essential structures to provide reliable water supply, hydropower, and flood control. Climate change could be a significant factor that increases the sediment yield leading to rapid reduction of the reservoir’s storage capacity and design life. Previous studies of reservoir sedimentation-related impact of climate change often coupled a hydrological model with the raw outputs of general circulation model (GCM)/regional circulation model (RCM), which shows bias when comparing with observations data. This study aims to integrate the soil and water assessment tool (SWAT) model with 14 bias-corrected GCM/RCM models under two emissions scenarios, representative concentration pathway (RCP) 4.5 and 8.5, applied to Pleikrong reservoir to estimate its sedimentation in the long term period. The results show the reduction in reservoir storage capacity due to sedimentation ranges from 25% to 62% by 2050, depending on the defferent climate change models. The reservoir reduced storage volume’s rate in considering the impact of climate change is much faster than in the case of no climate change. The outcomes of this study will be helpful for a sustainable and climate-resilient plan of sediment management for the Pleikrong reservoir.