Abstract:There are mainly two difficulties in the process of solving the optimal flood control operation for the cascade reservoirs,which are the uncertainty of reservoir inflow forecasts and the complexity of solution for the optimization model.In order to solve these problems,a joint distribution function of upper and interval basin floods was established by using copula function,and inflow hydrographs of cascade reservoirs were obtained by stochastic simulation method.Furthermore,a flood control optimization model for cascade reservoirs and a new algorithm,named Paralleled DE and PSO (PDP), were proposed.The Qingjiang cascade reservoirs were selected as the case study.The results showed that the stochastic simulation method based on the copula function, by which the variety and randomness of regional flood composition are considered, can simulate the worst situation for flood control operation.The proposed PDP algorithm is much easier to gain the optimum global solution than the other algorithms presented in this paper.The flood control risk at the downstream can be further reduced by this optimal flood control operation model for the cascade reservoirs.