淮河流域极值降水的统计参数特征及在水文频率分析中的意义

以淮河流域为研究区域，利用线性矩精确求解极值降水统计特征值，为极值降水频率估计值的计算提供理论基础和依据.主要结果表明：淮河流域各站点的年最大日降雨量（Annual Maximum Precipitation，AMP）的均值和离差范围分别为92.79~130.28 mm和0.193~0.266；各站点的AMP分布都为右偏分布，即至少有一半以上的AMP值是小于平均值的，有少数的AMP值远大于平均值，且对平均值的影响较大；各站点的分布相对于正态分布而言，都属于尖峰厚尾.极值降水统计特征值的空间分布表明：大值主要分布在流域的西南山区和东部丘陵地带，即这些地方具有更多更强的AMP极值.极值降水统计参数不仅能够反映AMP的一般平均水平和年际AMP的波动情况，还能更好地掌握AMP的两端分布情况，特别是尾端的暴雨极值.因此分析极值降水统计参数可以给洪涝灾害提供很好的指导.

Statistics parameters characteristics of precipitation extreme and its significance for hydrologic frequency analysis in Huaihe River basin

Statistical characteristics of precipitation extreme are computed and analyzed by using L-moment method in Huaihe river basin in this paper,which can provide theoretical basis for frequency estimates.The results indicate that the mean and deviation of annual maximum precipitation(AMP) range from 92.79 mm to 130.28 mm,and 0.193 to 0.266,respectively.The AMP distribution of each site is right skewness,that is to say,more than half of the AMP values are less than the average,with only a few greater than the average value which have bigger influence on the average.Compared with normal distribution,the distribution of AMP from each site are rush peak and thick tail.The spatial distribution of statistical parameters show that the high values mainly distributed in the southwest mountain areas and eastern hills,which means AMP in these regions are more and stronger than that in other regions.Statistical parameters of precipitation extreme can not only reflect the general average and annual fluctuations of annual AMP,also grasp the ends of the AMP distribution,especially tail end of precipitation extreme.So,analysis of precipitation extreme parameters can provide good guidance for flood control.