长江流域月季降水量的概率分布特征分析

Comparison and Analysis of Probability Distribution Characteristics of Monthly and Seasonal Precipitation in the Yangtze River Basin

利用长江流域712站1951—2015年的月、季降水资料,分析了站点降水在正态分布和Γ分布的空间服从情况。结果表明:对于月降水,大部分站点能服从Γ分布,通过Γ检验的站点表现出时空差异,两湖流域表现尤为突出,两湖流域在1和7—12月Γ特性表现较好,但在2—6月通过Γ检验的站点较少。季降水量服从正态分布的比例要高于Γ分布,春、冬季降水的正态分布服从性要好于夏、秋季;而对于Γ分布,春、夏季的服从性要好于秋、冬季。月、季降水中都存在一定比例的站点同时服从两种分布或都不服从这两种分布。

The normal distribution and Gamma distribution of precipitation in Yangtze River Basin were analyzed by using monthly and seasonal precipitation data at 712 stations from 1951 to 2015.The results show:most stations passed Gamma distribution test for monthly precipitation,and small part of stations for normal distribution test.The stations that passed the Gamma test showed spatio-temporal differences,such as those in Poyang Lake and Dongting Lake are good on Gamma distribution for January,July-December,and few sites that passed the Gamma test from February to June.For seasonal precipitation,the normal distribution is more popular than those in the Gamma distribution.The normality for spring and winter was better than that for summer and autumn.The Gamma distribution,in spring and summer are better than that in autumn and winter.a nother part of stations obeyed both distributions or disobeyed each of.