南通市短历时暴雨强度变化趋势探析

Analysis on variation trend of short duration rainstorm intensity in Nantong City

利用南通市代表雨量站营船港闸站1990—2020年的数据资料,采用年最大值法和P-Ⅲ型分布曲线拟合得到最新的暴雨强度公式,精度满足《城市暴雨强度公式编制和设计暴雨雨型确定技术导则》要求。将计算的历时5、10、15、20、30、45、60、90、120、180 min,重现期2、3、5、10、20 a的设计暴雨强度与2011年编制的暴雨强度公式的相应成果进行比较,结果表明,新公式总体上比2011年公式计算雨强偏大,在此基础上对近年来气候变化条件下南通市短历时降雨特征进行了分析。

Based on the data of Yingchuangang sluice station of Nantong Representative rainfall station from 1990 to 2020, the annual maximum method and P-Ⅲ distribution curve fitting are used to obtain the latest rainstorm intensity formula, and the accuracy meets the requirements of the technical guidelines for the preparation of urban rainstorm intensity formula and the determination of rainstorm type in design. The calculated design rainstorm intensity lasting for 5, 10, 15, 20, 30, 45, 60, 90, 120 and 180 min with return periods of 2, 3, 5, 10 and 20 years is compared with the corresponding results of the rainstorm intensity formula compiled in 2011. The results show that the rainfall intensity calculated by the new formula is higher than that calculated by the formula in 2011. On this basis, the characteristics of short duration rainfall in Nantong under the condition of climate change in recent years are analyzed.