珠海市年雨量和年最大日雨量多年一遇的极值计算

用皮尔逊-III型分布分别对珠海市年雨量和年最大日雨量两种变量进行拟合,进而计算了它们在不同重现期下的极值。结果表明:珠海市50年一遇的估算年雨量和年最大日雨量分别是2 908 mm和565 mm,100年一遇的分别是3 042 mm和648 mm。用澳门和珠海的雨量历史资料验证发现:澳门在104年间出现的最大年雨量是3 041.4 mm,与珠海百年一遇估算雨量吻合;珠海平均7.2年出现一次2 500 mm以上年雨量,而该雨量的估算重现期是7.5年,亦十分接近;年最大日雨量的估算重现期则比实际重现期小些。可见拟合良好,对其不同重现期下的极值估计结果可信。

Computation of Extreme Values of Yearly Rainfall and Annual Maximum Daily Rainfall for Return Periods of Multiple Years in Zhuhai City

The yearly rainfall and annual maximum daily rainfall of Zhuhai city are fit by Pearson-III distribution,and the corresponding extreme values for different return periods were computed.The results show that: in Zhuhai,for the 50-year return period,the estimated extreme yearly rainfall and the maximum daily rainfall are 2 908mm and 565mm respectively,while they are 3 042mm and 648mm for 100-year return period respectively.The maximum yearly rainfall during 104 years in Macao is 3 041.4mm,which is close to the estimated yearly rainfall of Zhuhai in 100-year return period;In Zhuhai,on the average,every 7.5 years,the yearly rainfall will exceed 2 500mm,and the estimated return period for 2 500mm rainfall is 7.2 years.Similar results were also retrieved for the annual maximum daily rainfall.So the conclusion can be drawn that Pearson-III distribution fit quite well for the two variables in Zhuhai,and the estimation of extreme values were reasonable and reliable.