L-矩在区域洪水频率分析中的应用

Application of L-moments in the regional flood frequency analysis

L-矩是在常规矩的基础上发展起来的估计洪水频率曲线参数值的一种新方法。为此,重点讨论它在区域洪水频率分析计算中的应用。选用洪水系列的L-变差系数和L-偏度系数作为水文站点分组聚类的影响因子,通过模糊聚类分析方法研究长江中游干流区的区域洪水频率关系。L-矩最大的特点是对洪水系列中的极大值和极小值远没有常规矩那么敏感,其求得的洪水频率曲线参数的估计值比常规矩所求得的要稳健得多。

The method of Lmoments is a new method based on the ordinary moments for estimating the parameters of the flood probability distributions. Application of Lmoments in the regional flood frequency analysis is discussed. With the LCv and LCs being selected as the clustering factors, the study of the regional flood～frequency relationship for the area of the Middle Yangtze River in China is carried out by using the fuzzy grouping method.