不同资料年限下城市暴雨公式型式研究

Study on Influence of Different Data Years on Urban Storm Intensity Formula

考虑到近20年城市化进程的快速推进,较久远的降雨数据无法反映现有城市化水平下的降雨特性。以淮安市为例,选取1980~2016、1990~2016年两种不同年限资料作为基础数据,基于城市暴雨分公式与总公式的精度和设计雨强对比,进行暴雨公式研究。结果表明,1990~2016年暴雨强度分公式和总公式的设计雨强均高于1980~2016年的设计雨强,表明城市化进程使暴雨公式结果偏大,更贴近目前城市雨情现状;暴雨强度分公式重现期越小精度越高,整体精度高于总公式约30%~40%,结合设计雨强因素分析可知,当重现期偏小时选取分公式,当重现期不低于50年时选取总公式。研究成果可为城市防洪排涝、海绵城市建设的工程规划与设计提供参考。

Considering the rapid advancement of urbanization in the past two decades,the long-term rainfall data cannot capture the rainfall characteristics under the existing urbanization level.Based on the data sets from 1980-2016 and from 1990-2016,Taking Huaian City for an example,this study conducted the storm formula analysis,which compared the accuracy and the design rain intensity between the urban storm total formula and the sub-formula.The results show that the design rain intensity of the sub-formula and the total formula from 1990 to 2016 are higher than those of 1980-2016,indicating that the urbanization process makes the rainstorm formula result larger,which is closer to the current urban rain situation.When the return period of the sub-formula is higher,the accuracy is higher.The overall accuracy of the sub-formula is higher than the total formula by about 30%-40%.Combined with the analysis of the design of rain intensity factors,we can know that when the return period is small,the sub-formula is selected;When the return period is not less than 50 a,the total formula is selected.The results can provide references for construction planning for urban flood control and the design of the sponge city.