银川市降水量正态分布特征

分析降水量正态分布特征,可以为降水量分析与预测中选用合适的统计方法和统计模型提供依据,提高降水量分析与预测能力。利用银川市4个气象站(银川站、永宁站、贺兰站、灵武站)1960～2008年的降水量实测资料,运用2χ拟合优度检验和柯尔莫哥洛夫——斯米诺夫检验(K-S检验)对各站月、季和年降水量进行了正态分布检验。检验结果表明:银川市各气象站年降水量和季降水量均服从正态分布,夏季降水量正态性最好,冬季降水量正态性最差。6～9月份银川市各气象站月降水量均服从正态分布;11月至次年2月份月降水量均不服从正态性分布。各气象站中,通过正态性检验月份最多的是灵武站,通过正态性检验月份最少的是银川站,这与银川站多出现极端降水有一定关系。

Normal Distribution Characteristics of Precipitation in Yinchuan City

Analyzing the normal distribution of precipitation can provide a basis for the appropriate choice of statistical methods and statistical models in the process of analysis and forecasts for precipitation and for the enhance of the capabilities of precipitation analysis and forecasting.According to the observational rainfall data collected from weather station including Yinchuan Station,Yongning Station,Helan Station and Lingwu Station in Yinchuan area,the normal distribution characteristics of monthly,quarterly and annual rainfall was inspected with Chi-square test and Kolmogorov-Smirnov test（K-S test） for each station.Test results showed that the annual precipitation and seasonal precipitation are subjected to normal distribution in every station in Yinchuan city,and the normality of precipitation in summer is the best whereas the normality of precipitation in winter is the worst.Monthly precipitations from June to September in Yinchuan city are subjected to normal distribution and monthly precipitation distributions from November to February in the following year are not subjected to normality.Monthly precipitation in Lingwu station passed most normality test whereas monthly precipitation of Yinchuan station passed the least test of normality,which should be attributed in a certain extent to more extreme precipitation happened in Yinchuan station.