重庆主城区暴雨强度公式推算和应用探讨

Calculation of Rainstorm Intensity Formula for the Main Urban Areas of Chongqing and Its Application

根据重庆市主城区沙坪坝、北碚、巴南、渝北站1981-2013年逐分钟降水资料,基于年最大值和年多个样法两种数据采样方式,采用皮尔逊Ⅲ型分布、耿贝尔分布和指数分布曲线拟合,分别编制了暴雨强度公式。结果表明:年最大值法取样推求的暴雨强度值在10 a以下重现期部分小于年多个样法,在11-30 a重现期部分两者差别小,在31-100 a重现期部分年最大值法大于年多个样法。4站均以年多个样法取样推求的暴雨强度公式误差最小。巴南和北碚选用1981-2013年、渝北与沙坪坝选用1991-2013年降水数据根据年多个样法取样采用指数分布曲线拟合推算的暴雨强度公式。通过分析各历时降水量空间分布特征,划定了新编暴雨强度公式在重庆主城区的适用范围。

Using the minutely precipitation data during 1981 — 2013,which is from the stations of Shapingba,Beibei,Banan and Yubei in the main urban areas of Chongqing,the rainstorm intensity formula fitted by the Pearson Ⅲ distribution,Gumbell distribution and exponential distribution was made respectively by using the annual multisampling method and annual maximum value method.The results show that rainstorm intensity calculated by the formula using annual maximum value method is less than that calculated by the formula by annual multisampling method for the reappearing period less than 10 years.In the 10 —30 years reappearing period,the difference of the two is slight,and the rainstorm intensity calculated by the formula according to annual maximum value method is more than that calculated by the formula according to annual multisampling method.The error of rainstorm intensity formula according to annual multisampling method is the least for the four stations.The rainstorm intensity formula of Beibei and Banan is made fitted by exponential distribution according to annual multisampling method based on the precipitation data from 1981 to 2013.The rainstorm intensity formula of Yubei and Shapingba is made fitted by exponential distribution according to annual multisampling method based on the precipitation data from 1991 to 2013.The applicability of new formula to calculate the rainstorm intensity in the main urban area of Chongqing is determined by analyzing the spatial distribution features of precipitation in different times.