P-III型分布的适应性与水文设计值的误差分析

Adaptability of Pearson Type Ⅲ Distribution and Analysis for the Error of Hydrologic Design Value

针对P-III型对其它分布(正态分布、二参数对数正态分布、第一型极值分布、第三型有界极值分布、克-闵分布、P-I型分布、P-V型分布等)的适应性进行了研究,并对它们的结果进行了分析。研究表明,用P-III型分布估计上述总体的水文变量时,平均而言,其百年一遇设计值的相对误差一般不超过15%,千年一遇设计值的相对误差一般不超过20%,在实际工作中,可将这两个结果作为设计值安全系数的依据。

A study is performed on the adaptability of the Pearson TypeⅢDistribution to the hydrologic populations obeying other distributions,such as Normal Distribution,two-parameter Logarithm-normal Distribution,Extreme-value TypeⅠDistribution,Extreme-value TypeⅢDistribution,K-M Distribution,Pearson TypeⅠDistribution,Pearson Type V Distribution,and so on.The analysis of the results shows that if the Pearson TypeⅢDistribution was used for the estimation of the hydrologic design values of the above distributions,the average relative errors of estimated values were less than15%for100-year design flood,and less than20%for1000-year design flood,providing a basis for estimation of safety coefficients of hydrologic design values in practice.