南京主城区设计暴雨计算研究

Study on design rainstorm in Nanjing main urban area

科学合理地推求城市设计暴雨过程直接关系到城市防洪安全。论文以南京市为研究对象,基于由年最大值法选取得到的1982-2015年1h南京市面平均雨量样本,从P-Ⅲ型分布函数、耿贝尔分布函数、指数分布函数中优选拟合最佳的分布函数,并结合南京站1h雨量样本计算主城区设计面雨量;在对比分析同倍比法与同频率法推求不同历时典型暴雨时程分配的优缺点的基础上,选择同频率法由设计面雨量推求得到南京市主城区历时12h的不同重现期设计暴雨过程。结果表明:P-Ⅲ型曲线拟合最优,同频率法求得的暴雨时程分配更符合防洪排涝工程的要求。研究成果可为确定城镇防洪排涝工程的设计标准提供科学依据。

Calculating the urban design rainstorm process scientifically and rationally is directly related to urban flood control safety. The paper took Nanjing as the research object,and the 1 h average rainfall samples of Nanjing from 1982 to 2015 were obtained based on annual maximum method. The paper selected the optimal function from the P-Ⅲ distribution function,the Gumbel distribution function and the exponential distribution function,and the distribution of surface rainfall in the main urban area was calculated based on the 1 h rainfall sample of Nanjing Station. Based on the comparative analysis of the advantages and disadvantages of typical rainstorm schedule of different duration by the same ratio method and frequency method,the same frequency method was chosen to estimate the design process of rainstorm in the main urban area of Nanjing after 12 h＇s different return period. The results show that the P-Ⅲ curve is the best,and the rainstorm time distribution obtained by the same frequency method is more in line with the requirements of flood control and drainage engineering. The research results can provide scientific basis for the design standard of urban flood prevention