Abstract:

On the basis of optimal operation and experimental water impoundment scheme for the Three Gorges Reservoir, 6 different schemes of impounding water in advance were proposed. The flood control risk and comprehensive utilization benefits were calculated to determine the optimal impoundment schemes for the Three Gorges Reservoir. Two typical years of 1952 and 1964 were selected to obtain the seasonal design flood hydrographs. Results show that the best scheme is to impound water from 145m on September 1 to 160.0m on September 30 with a continuous and uniform process. The flood control risk ratio and risk loss ratio of seasonal design flood once in 1 000 years are 0.39% and 1.47% respectively, which are within controllable range; compared with the original scheme, the optimal schemes can generate 2.465 billion kWh extra hydropower and save 2.532 billion m³    flood water resource. The full storage ratio and average storage level at the end of impounding period increase to 95.35% and 174.8m, respectively.  

Key words: water resources, impounding water in advance, flood control risk, benefit analysis