淮安市暴雨强度公式的推导与对比

随着城市化进程加快和极端气候频率增加,传统的暴雨强度公式已无法满足淮安市现有雨情和降雨特性。为此,以传统法和直接拟合法推求1980～2016、1990～2016年的暴雨强度公式,并基于设计雨强对其加以对比,分析直接拟合法应用于淮安市的适用性和城市化进程对暴雨强度公式的影响。结果表明,直接拟合法和传统法得出的暴雨强度公式的设计雨强相差不大,但前者拟合实测雨强的绝对和相对均方差比后者分别降低了11.9%～18.2%、9.7%～12.4%,故直接拟合法可作为推求暴雨强度公式更有效的方法;较1980～2016年约增加了0.05～0.40mm/min,验证了城市化进程使暴雨强度公式结果偏大,能保证排水系统设计更安全。

Derivation and Comparison of Rainstorm Intensity Formula in Huai'an City

With the accelerating urbanization and the increasing frequency of extreme weather,the traditional rainstorm intensity formula cannot meet the Huaian’s existing rainfall regime and rainfall characteristics.The traditional method and direct fitting method have been used to derive the rainstorm intensity formula based on rainfall intensity data from 1980 to 2016 and 1990 to 2016,and comparison between these two methods have been conducted.Then the applicability of direct fitting method and the influence of urbanization process on the rainfall intensity formula have been analyzed.The results show that the designed rainfall intensity from the direct fitting method and the traditional method are similar.However,the absolute and relative mean square errors of the direct fitting method are about 11.9%-18.2%and 9.7%-12.4%lower than that of the traditional method.Therefore,the direct fitting method can be used as a new effective method to determine the rainstorm intensity formula.During the period of 1990-2016,the rainfall intensity are about 0.05-0.40 mm/min higher than that of 1980-2016,which demonstrates that the urbanization process exaggerates the result of rainstorm intensity formula and can ensure the safer design of the drainage system.