앙상블 하천유량 예측 기법과 용수 감량공급 기법을 이용한 합천댐의 가뭄 시 운영 방안

Abstract

Practical reservoir operation preparing for droughts needs an appropriate reservoir operating rule and a prediction of future inflow. A reservoir operation method studied in this research includes a derivation of discrete hedging rule applying a linear programming, an ensemble stremflow prediction, and reservoir simulations observing the derived heding rule. The hedging phases consist of concern, caution, alert, and severe. Dam operators supply water based on the available water and the phase in which the available water is. Available water of a reservoir is defined by the current storage plus the inflow volume of the future time period. The future inflow volume was computed by ensemble streamflow prediction using historical weather condition scenarios and precipitation forecast. The tank model with soil moisture structure was used to simulate ensemble streamflow. Reservoir operations of Hapcheon Dam, Korea were simulated applying the derived hedging rule curves and ensemble streamflow predictions. The results showed the reduction of maximum and overall water supply deficit. The derived hedging rule curves are certainly worth practical reservoir operation for water supply, because they can be easily understood by dam operators under the proper future inflow forecasting such as the ensemble streamflow prediction.