江苏夏季逐日降水极值统计特征诊断研究

本文利用江苏省5个代表性测站历年逐日降水资料，借助于非正态假设下的（Gamma分布）极值统计特征诊断方法，由一般平均统计特征量（均值，方差，自相关），估计计算其极端降水统计特征（平均出现频率，间隔时间，持续时间）并分析其年代际变化规律，结果表明，江苏地区夏季降水极值特征的年际和年代际变率具有一定的规律性，降水量极值出现频数的年际变化具有准2-3年和准7-10年周期。指出降水极值出现次数不仅取决于降水量，还取决于逐日降水变率和各年内降水的持续性。

THE DIAGNOSIS RESEARCH FOR EXTREMUMSTATISTICAL CHARACTER OF SUMMER''SDAILY PRECIPITATION INJIANGSU PROVINCE

By using of daily precipitation data of five representative stations in Jiangsu province in past years,by means of the diagnosis method of extremum statistical character based on the abnormal hypothesis (Gamma distribution),according to general average statistical character (mean, variance, lag correlation) ,the statistical character of extreme precipitation is reckoned and the interannual and decennary change are also analysed. Results show that the extremum character of summer's precipitation in Jiangsu takes on some regularities, and the interannual change of precipitation extremum's frequence has quasi 2-3 and quasi 7 -10 years'periods. It is also indicated that the extremum frequence is decided not only by the precipitation but also by the daily precipitation variability and the duration of precipitation in every year.