Modeling of Turbidity Current and Evaluation of Diversion Plans at Shihmen Reservoir in Taiwan

Turbidity currents occur often at Shihmen reservoir in Taiwan, which has experienced increased sediment delivery over the last two decades. Due to limited sluicing capability, a major portion of the fine sediments have deposited in the reservoir causing a significant loss of the storage capacity. Further, extreme events have produced such high sediment concentrations that water supply has been interrupted causing unexpected economic and political turmoil. Various projects have been proposed and/or started to extend the reservoir life and maintain water supply. In this study, a two-dimensional (2D) layer-averaged turbidity current model is developed; the calibration and application of the numerical model to Shihmen reservoir is reported. The study finds that the developed turbidity current model, with appropriate calibration, predicts well the turbidity current movement and the sediment deposition pattern.