菏泽市气候极值的统计分布和再现期研究

Statistical Distributions and Return Periods of Climate Extremes in Heze

科学合理地估算某地区的气候极值再现期是气象科技服务的重要内容,对当地经济建设具有重要意义。对菏泽市35种气候极值,分别都用皮尔逊Ⅲ型(PearsonⅢ)、对数正态(log-normal)、耿贝尔(Gumbel)、韦伯(Weibull)分布函数进行拟合,用χ2检验选出最优者。使用选出的最优分布函数,用多个再现期算出再现期极值,列成表格以备气象服务中使用。通过最优分布函数的选取,对哪个类型的气候要素较多服从于哪个分布函数问题进行了研究。研究结果发现极端气温类型的极值和日数类型的极值较多服从于皮尔逊Ⅲ型分布,降水和其他类型的极值较多服从于耿贝尔分布。简要介绍了计算中使用Excel的技巧。

It is important content of meteorological science and technology service to evaluate the return periods of climate extremes scientifically and reasonably, and it is of great significance to local economic development. For 35 kinds of climate extremes in Heze, by means of the Pearson Ⅲ, log normal, Gumbel, and Weibull distributions, the fittings of the climate extremes are conducted respectively. The optimal distribution functions are selected through χ2 test, and the climatic extremes of return periods are calculated through several return periods. Through the selection of the optimal distribution functions, the certain types of climate element subordinates to certain distribution function are studied. The results show that the extremes of the number of days and extreme temperatures are more likely obedient to the Pearson Ⅲ distribution, while precipitation and other extremes are more likely obedient to the Gumbel distribution. Some tips for using Excel calculation are introduced briefly.