汕头市新旧暴雨强度公式对比分析

Comparison and Analysis of New and Previous Equations for Hard Rain Intensity in the City of Shantou

采用汕头国家气象站1980—2014年的年最大雨量资料对汕头市暴雨强度公式进行了修编,并与旧公式对比,结果表明:(1)新公式计算的暴雨强度值总体上大于旧公式,降雨历时越长,重现期越大,则偏大越明显,2~20年重现期平均增大了5.0%。(2)在年平均降雨量变化较平稳的气候背景下,新公式采用的资料年限的最大降水平均值大于旧公式对应资料年限的最大降水平均值,且资料中出现了强降雨样本,导致新公式比旧公式总体上偏大是合理的。(3)汕头市新暴雨强度公式可作为汕头市区室外排水设计的依据。

Using the data of annual maximum rain amount from 1980 to 2014 at a national meteorological station in Shantou,this paper formulates a new mathematical equation for the intensity of hard rain in this city and compares it with the previous one.The result is shown as follows.(1)The intensity of hard rain as determined with the new equation is generally larger than that by the previous one,and the longer the rain lasts and the larger the recurrence interval is,the more significant the increase.On average,the recurrence interval from 2 to 20 years increases by 5.0%.(2)Against the climatic background of relatively stable variation of annual mean rain amount,the maximum average rain determined with the new equation is larger than that of the previous equation for their respective years of data.As the data includes samples of intense rain,the generally larger rain amount by the new equation is reasonable.(3)The new equation for determining hard rain intensity can be used as one of the bases in outdoor drainage design in the urban districts of Shantou.