不同拟合方法推求暴雨强度公式研究

Study on the formula of deducing heavy rain intensity by different fitting methods

人口大县沭阳县一直借用临近城市的暴雨公式,急需编制能反映本地降雨规律的暴雨强度公式,为其城市排水防涝系统规划和设计提供科学依据。基于沭阳县气象站1981-2015年共计35a的自记暴雨雨量资料,选取11个降雨历时的年最大值作为实测样本,分别基于P-Ⅲ型分布、指数分布和耿贝尔分布进行理论频率曲线分析,确定重现期-降雨强度-历时关系推求暴雨强度公式,绘制新公式和现行采用公式的暴雨强度-历时-重现期关系曲线进行对比分析。结果表明:新公式与现行采用公式的计算结果相差较大,因此有必要对沭阳县进行暴雨强度公式重新编制。

The populous County Shuyang County has been borrowing nearby city＇s rainstorm formula. It is necessary to compose its own formula of rainstorm intensity to provide scientific basis for the planning and design of urban drainage and waterlogging system. In this paper,based on the precipitation data of Shuyang county collected for 35 years from 1981 to 2015,11 annual rainfall maximum were selected as the measured samples. Based on the P-Ⅲ distribution,exponential distribution and Gumbel distribution,the theoretical frequency curve analysis is carried out to determine the recurrence period-rainfall intensity to the time（ P-i-t） relationship table,and to calculate the storm intensity formula. By drawing the new formula and the old formula of rainstorm intensity ~ period curve the comparative analysis was made The results show that the difference between the two models is large,so it is necessary to compose the formula of rainstorm intensity in Shuyang county.