春季降水量概率分布函数对比分析——以宜宾市为例

Comparative analysis on probability distribution function of spring precipitation: Taking Yibin city as an example

利用四川省宜宾市的1953—2010年的春季降水量数据资料,分别应用正态分布、Gamma分布、对数正态分布和P-Ⅲ型分布对该地区的降水分布特征进行研究。在此基础上,利用离差平方和最小准则进行4种分布函数的拟合优度检验。结果表明,4种分布函数均能拟合宜宾市春季降水分布;通过拟合优度检验表明,对数正态分布对宜宾市春季降水量的拟合效果最好,Gamma分布次之,P-Ⅲ型分布和正态分布的拟合效果相对较差。

By utilizing spring precipitation data of Yibin city in Sichuan province from 1953 to 2010, normal distribution,Gamma distribution, logarithmic normal distribution, P-Ⅲ distribution were applied to study the region’s precipitation distribution characteristics. Based on this, the minimum of sum square variation method was used for goodness of fit test of the four distribution functions. The result shows that the four distribution functions can all fit with precipitation distribution of spring in Yibin city. The goodness of fit tests show that logarithmic normal distribution is best fit with the precipitation distribution of spring in Yibin city, Gamma distribution is the second best. The fitting effect of P-Ⅲ distribution and normal distribution is relatively poor.