Flood Season Division And Reansonable-Determination Of Limited Water Level Of Cascade Resevoirs

An effective way to realize floodwater utilization is to change the conservative design limited water level, on which a research focuses redently. But now only single reservoir was studied. The Shiquan, Xihe reservoir on upstream of Hanjiang were researched in this paper. Firstly the flood law was analyzed, the flood season staging was put forward, and the corresponding food control level was computed. Then the joint operation of flood of Shiquan, Xihe reservoir were studied, and the reasonable combination of flood season staging of cascade reservoirs were given. Then main contributions were as follows:(1) The Golden-section algorithm was used to compartmentalize the peak discharge, the inflow flood data of Shiquan, Xihe reservoir were analyzed by the probability statistic theory, the corresponding probability of flood distribution law of month, ten days and the times of annual probable were computed. All the results provided certain theoretical basis for the flood seasons division and the computation of each stage limited water level.(2) The main flood season of Shiquan, Xihe reservoirs were divided and the corresponding periods were got. According to the probability distribution of the occurring time of the first flood and the ending time of the final flood from July to September, the Fuzzy Statistic Analysis was used to divide the main flood season of cascade reservoirs, and the each stage period was got.By fitting the flood season membership functions according to the each stage period and the characteristic data of cascade reservoirs, the limited water level of each stage period were computed, and the flood seasons partition scheme was used to correct the each stage period limited water level.(3) The flood control capacity of Shiquan reservoir was checked. The characteristic data of Shiquan reservoir has changed which influenced by some factors as reservoir sedimentation. Combining the design flood data and the actual operation rules, the flood control capacity and the storage-outflow capacity of Shiquan reservoir were checked by adopting the new characteristic data. The results shows that the flood control safety was not influenced by reservoir sedimentation(4) By the flood region composition theory, the reasonable combination of limited water level under cascade reservoirs was put forward. According to each stage limited water level and the two flood frequency combination of cascade reservoirs, the different combination of limited water level of cascade reservoirs were calculated. In terms of the benefit maximization and risk minimum principle, the reasonable combination of limited water level under cascade reservoirs was put forward, and the risk transfer characteristics of cascade reservoirs operation could be found.(5) The flood control capacity maximization model was established, POA and DPSA arithmetic were applied to study the flood joint optimal operation of cascade reservoirs, which would provide some theoretical basis for the joint operation of cascade reservoirs.