梯级水库下游设计洪水地区组成法比较研究  

Comparative Study on Design Flood Regional Composition Methods for Downstream Cascade Reservoirs

作　　者：谢雨祚 郭生练[1] 王俊[1] 钟斯睿 汪芸[1] 李帅 胡挺 XIE Yuzuo;GUO Shenglian;WANG Jun;ZHONG Sirui;WANG Yun;LI Shuai;HU Ting(State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China;Operation and Administration Center for River Basin Hydro Complex,China Three Gorges Corporation,Yichang 443133,China)

机构地区：[1]武汉大学水资源与调度全国重点实验室,湖北武汉430072 [2]中国长江三峡集团有限公司流域枢纽运行管理中心,湖北宜昌443133

出　　处：《水文》2023年第5期18-26,共9页Journal of China Hydrology

基　　金：国家重点研发计划项目(2021YFC3200305);中国长江三峡集团有限公司(0799254);国家自然科学基金(51879192)资助项目。

摘　　要：水利水电工程兴建运行改变了下游河流的水文情势和来水来沙条件,推求梯级水库下游控制断面设计洪水成了亟需解决的难题。本文综述设计洪水地区组成法的研究进展及问题,推导概率组合离散求和法和改进离散求和法,对比分析两者的离散估计误差;结合清江水布垭~隔河岩~高坝洲梯级水库应用实例,比较讨论各种设计洪水地区组成法的优缺点和实用性。结果表明:(1)基于Copula函数的改进离散求和法可直接推导公式,且无需作独立化处理;离散求和法的总误差随着相关系数ρ的增大而显著增加;当ρ>0.2时不宜使用。(2)经水布垭~隔河岩水库调蓄后,高坝洲坝址1000年一遇设计洪峰流量削减了50%左右。(3)对于单座或2座水库,离散求和法和同频率地区组成法的适用条件分别为0<ρ≤0.2和ρ>0.7,改进离散求和法和最可能地区组成法没有限制条件;对于3座及以上的梯级水库群,最可能地区组成法可得到唯一最佳方案解。研究成果可为我国《水利水电工程设计洪水计算规范》的修订提供参考。The construction and operation of water conservancy and hydropower projects have changed the hydrological situation of the downstream rivers and the conditions of streamflow and sediment transport.Calculate the design flood of the downstream con‐trol section of the cascade reservoirs has become an urgent problem.In this study,we reviewed the current design flood regional composition methods and problems,deduced the probabilistic-combined discrete summation(DS)method and the improved discrete summation(IDS)method based on copula function,and compared the sum of absolute error of DS and IDS methods.The Qingji‐ang cascade reservoirs were selected as case study,the variant design flood regional composition methods and the pros and cons were practically discussed.The results show that:(1)The derivation of the IDS method is more advanced than that of the DS method without independence transformation.The sum of absolute error of the DS method increases significantly with the increase of the correlation coefficientρ;when theρ>0.2,it is recommended to use the IDS method.(2)After the regulation of the Shuibuya-Geheyan reservoirs,the design flood peaks with 1000-year return periods are reduced by about 50%.(3)For single or two reservoirs,the application conditions for the DS and the equivalent frequency regional composition(EFRC)methods are 0<ρ≤0.2 andρ>0.7,respectively,while the IDS and the most likely regional composition(MLRC)methods have not limitations.And for three and more cascade reservoirs,the MLRC method can obtain only and optimal scheme solution.The research results could provide a reference for modifying the design flood calculation regulations in China.

关 键 词：梯级水库 洪水地区组成 COPULA函数 离散求和法 统计试验 清江流域 

分 类 号：TV122.3[水利工程—水文学及水资源]