清江水布垭和隔河岩梯级水库防洪库容互补关系研究

Flood Prevention Storage Complementary Relationship of Shuibuya-Geheyan Cascade Reservoirs in Qingjiang River

采用同频率组成法和最可能组成法推求隔河岩水库的洪水地区组成,基于不降低设计防洪标准的原则推求了水布垭和隔河岩梯级水库防洪库容互补关系。结果表明,采用同频率组成和最可能组成方法,推求隔河岩水库设计洪水地区组成合理可行;当清江流域发生20~200年一遇洪水时,水布垭-隔河岩水库防洪库容具有近似线性互补关系,折算系数均值为0.63,其他重现期洪水的折算系数为1;不同典型年和设计频率对防洪库容折算系数的影响较小;在确保预留总防洪库容不少于10亿m^(3)前提下,实现隔河岩水库汛期运行水位动态控制,与原设计各预留5亿m^(3)方案相比,清江梯级电站年均汛期可增发电量9100万kW·h(+5.1%)。

The equivalent frequency regional composition method and most likely regional composition method are adopted to analyze the flood regional composition of Geheyan Reservoir,and the complementary relationship between flood prevention storage of Shuibuya and Geheyan cascade reservoirs are derived based on the principle of not lowering down the designed flood prevention standard.The results show that:(a)the two flood regional composition methods can be effectively implemented to derive flood regional composition;(b)the mean value of complementary relationship coefficient between two cascade reservoirs is 0.63 when the floods with return periods of 20 to 200-year occurred in Qingjiang River basin,and equal to 1 for other floods;(c)different typical year flood hydrographs and design flood frequencies do not significantly influence the results;and(d)under the condition of remaining not less than 1 billion m^(3) total flood prevention storage of two reservoirs,the dynamical control of the water level of Geheyan Reservoir can increase the power generation by 91 million kW·h(an increase of 5.1%)during the flood period when compared with original design scheme of remaining 0.5 billion m^(3) storage for each reservoir.