Optimal flood control operation for the Three Gorges and Qingjiang cascade reservoirs

Both separate and joint flood control operation models or the Three Gorges and Qingjiang cascade reservoirs are proposed. The models were solved by the modified progressive optimality algorithm according to the procedure of optimization-veritication-adjustment and its constraint conditions were treated by dynamic penalty function. Four typical years of 1954, 1981, 1982 and 1998 were selected to derive the design flood hydrographs for the corresponding return periods by the peak and volume amplitude method. The conventional, separate and joint cascade operation Hood control models were performed for these reservoirs. The results show that the separate cascade operation gives full play to the role of flood control storage compensation between cascade reservoirs, while joint cascades operation can also perform storage compensation between two cascades. The Jingjiang River flood control standards can be raised to 118-year and 136-year design floods based on 1982 typical year, and 150-year and 168-year design floods based on the average of four typical years, respectively.