湖北省荆门市城区新一代暴雨强度公式的研制

The rainstorm intensity formula for the urban of Jingmen in Hubei province

利用湖北省荆门市气象站1974—2014年分钟降水数据,采用"年最大值法"进行资料选样,采用指数分布、耿贝尔分布和P-Ⅲ分布进行分布曲线拟合得到雨强一历时一重现期(i-t-T)三联表,采用最小二乘法、高斯牛顿法求解暴雨强度分公式和总公式参数,根据误差最小原则确定最优方法,并将新公式与现用公式计算所得雨强进行比较。结果指出:P-Ⅲ分布各降水历时下的相对均方根误差较小;采用P-Ⅲ分布、最小二乘法参数组合方法计算分公式和P-Ⅲ分布、高斯牛顿法参数组合方法计算总公式误差较小;新分公式和总公式较现用公式算出的对应雨强整体偏大。建议相关排水规划部门在设计地下管网时加大管径的设计。目前,该公式经荆门市政府同意已发布执行。

Using the minutely precipitation data from 1974 to 2014 of Jingmen weather station, rainstorm intensity formula are derived based on the annual maximum value method, in which exponential distribution, Gumbell distribution and P-Ⅲ distribution are chosen, respectively,to get the rainstorm intensity-listing time-return period form. The rainstorm intensity formulas are calculated by the least square and Gauss-Newton methods, and the best one is chosen. The results show that the relative root mean square error by the P-Ⅲ distribution is much smaller. The integral formula is made by the P-Ⅲ distribution and the least squares method. The total formula is made by P-Ⅲ distribution and Gauss-Newton method. The rainfall intensity calculated by the latest integral and total formulas are overall larger than the currently being used one, suggesting that it＇s necessary for the relevant departments to increase the pipe size when designing the underground pipe networks.At present, the formula have been published and executed by the government of Jingmen city.