暴雨和降水偏态系数分析

采用统一的统计参数计算方法分析计算了全国0.51万~1.36万个雨量站历时为10 min~3 d的暴雨资料、210个站历时为1 d~90 d和1 a的降水资料的偏态系数和变差系数比值R_sv。探讨了皮尔逊Ⅲ型频率分布曲线的R_sv特性;分析了R_sv的地域分布、R_sv与雨量历时的关系,并研究了对R_sv有影响的多个因子。研究表明,在目前资料条件下,不宜对各个地区各种历时的暴雨频率分析均采用单一的R_sv值(3.5)。

Analysis of skewness coefficient of rainstorm and precipitation

The ratio of the skewness coefficient to the variation coefficient is computed with uniform method for the rainfall data from 5 100-13 600 stations with durations of 10-min-3-day and 210 stations with durations of 1-day-90-day and 1-year.The ratio of skewness to variation (R_sv) characteristics of the Pearson type Ⅲ frequency distribution are approached; the regional distribution of R_sv and the R_sv-duration relation are analyzed,and the same affected factors on R_sv are studied.On the condition of the data at present,the single R_sv value of 3.5 is not suitable for each region and each duration in rainstorm frequency analyses.