关键词: 超额洪量, 洪量的空间分布, 蓄滞洪区, 水库群联合调度, 长江上中游

Abstract: According to the survey hydrology data, we built a one-dimensional hydrodynamic model from Yichang to Datong Station to research the excess flood volume in the middle and lower reaches of the Yangtze River at different frequencies in different typical years under joint operation of reservoir groups in the upper reaches. The research includes the following three aspects:① The proposed model was verified and checked well according to flood data of the Yangtze River in 1956 and 1998.② Based on the above mathematical model, the spatial distribution of excess flood volume in the middle and lower reaches of the Yangtze River at different frequencies in different typical years were analyzed according to the joint operation of 21 reservoirs in the upper reaches and the Three Gorges Reservoir.③ According to the excess flood volume in the 4 sections of the middle and lower reaches of the Yangtze River and the distribution of flood storage volume in the flood retention area near the corresponding four sections under different typical years and different frequencies, the flood safety situations of the middle and lower reaches of the Yangtze River under the above flood conditions were studied and analyzed. The results showed that:① The excess flood calculated in Jingjiang River and other three river sections were smaller than that in the nearby flood retention areas. Therefore, the joint dispatching of the flood retention areas could reduce the excess flood volume in three river sections, such as Chenglingji, ensuring the flood safety of the middle and lower reaches of the Yangtze River.② Under the joint dispatching of 21 reservoirs, when encountering designed flood with the frequency of 0.5%, there was still a large amount of excess flood in the middle and lower reaches of the Yangtze River, such as at Chenglingji. However, at present, some flood retention areas were still under planning and not fully utilized. Therefore, further planning and construction are needed.

Key words: excess flood, spatial distribution of excess flood, flood retention area, joint operation of reservoir groups, upper and middle reaches of the Yangtze River;