设计流量推求中特大值判断方法的改进  

An improvement in judging the extraordinary value of flood frequency(design flood discharge) analysis

作　　者：黄伟昊[1,2] 左利钦[1] 李寿千[1] 盖永伟[1] 

机构地区：[1]南京水利科学研究院,江苏南京210029 [2]河海大学水利水电学院,江苏南京210098

出　　处：《水利水运工程学报》2012年第5期8-12,共5页Hydro-Science and Engineering

基　　金：国家973计划资助项目(2012CB417002);"十二五"国家科技支撑计划(2012BAB04B03);国家自然科学基金资助项目(51061130546;51009096)

摘　　要：设计洪峰流量的推求过程中,特大值判断的正确与否对洪水频率分析的精度有着较大的影响.而在特大值判断的过程中,Ex+kσ常作为水文频率分析中特大值判断的准则,其中k为经验常数,其取值的不同常会给设计流量的计算带来较大的误差.采用数值模拟方法,生成符合PⅢ型曲线分布的样本,再通过适线拟合,探讨了k值与样本总量、变差系数及偏态系数之间的相互关系,并在此基础上建立了k值估计公式.最后,通过将该k值的估计公式应用于天然河道设计流量的推求过程中,取得了良好的效果.In the process of determining the design quantity of flow,the correctness of judging the extraordinary value has a significant influence on the accuracy of hydrologic frequency analysis.In the process of the hydrologic frequency analysis,the result of Ex＋kσ is often taken as a standard in judging the extraordinary value.As there is no unified rule,the value of k is usually determined as an experiential value which brings errors to the design quantity of flow.In this paper,based on the distribution of PⅢ curve,samples are created by a numerical simulation method to study the relationship between the k value and the samples′ amount,variation coefficient and skewness coefficient.A formula to calculate the value of k is also derived and performed well in the hydrologic frequency analysis of a natural river,which reveals the superiority of the improved method in this paper in judging the extraordinary value mentioned.

关 键 词：洪水频率 特大值 设计洪峰流量 重现期 频率分析 

分 类 号：TV122[水利工程—水文学及水资源]