长春市新一代暴雨强度公式的推求研究

Derivation of a New Generation of Stormwater Intensity Formula for Changchun

以长春国家基准气候站1983年-2012年连续30年的暴雨样本资料为基础，分别采用年多个样法和年最大值法选样，利用指数分布、皮尔逊～Ⅲ型分布和耿贝尔分布进行频率分析，采用图解法结合最小二乘法和拟牛顿法对长春市新一代暴雨强度公式进行了推导。结果表明：①增加了150min和180min两个选样降雨历时时段，不会影响公式的精度；②在参数推求过程中，重现期为O．25年、0．33年和100年的平均误差较大，建议重点推求重现期为1—20年的暴雨强度公式；③采用年多个样法选样、指数分布曲线优化、拟牛顿法参数推求的暴雨强度公式的平均误差最小，满足《室外排水设计规范（2011年版）》（GB50014--2006）的要求；（鸯当降雨历时〉10min时，选用新一代暴雨强度公式计算，安全性更高。

The rainfall data of 30 years from 1983 to 2012 were collected from Changchun National Benchmark Weather Station. To obtain a new generation of stormwater intensity formula, annual multisample method and annual maximum value method were used to select the samples. Frequency optimization was completed by exponential, Pearson-Ⅲ and Gumbel distribution, and the derivation of the formu- la parameters was performed using graphical method combined with quasi-Newton method and least square method. The results showed that： （1） the formula accuracy was not affected by rainfall durations of 150 min and 180 min; （2） the return periods of0. 25,0.33 and 100 years had large errors, return periods of 1 to 20 years were desirable for the formula during the parameters derivation; （3） the stormwater intensity formula derived by annual multi-sample method, exponential distribution and quasi-Newton method had minimal error, meeting the Code for Design of Outdoor Wastewater Engineering （GB 50014 -2006 ） ; （4） the new generation of stormwater intensity formula was safe and effective, especially when the rainfall duration was more than 10 min.