基于正交试验的SWMM模型参数全局综合敏感性分析

Global Comprehensive Sensitivity Analysis of SWMM Model Parameters Using Orthogonal Experiment

为提高SWMM模型模拟降雨径流的精度,克服传统方法未能考虑不同参数间协同作用及计算过程复杂的缺点,提出了一种基于全局综合敏感性分析法的正交试验设计方法,依托铁山服务区SWMM模型,利用正交试验方法分析了不同降雨强度条件下不透水区糙率系数、透水区糙率系数、不透水区洼地蓄水、透水区洼地蓄水、霍顿最大下渗率、最小下渗率及渗透衰减常数7个参数对径流峰值和径流系数的敏感性,利用极差和方差两种方法分析了径流峰值和径流系数的影响因素。结果表明,霍顿最大下渗率、渗透衰减系数、透水区糙率系数、透水区洼地蓄水对径流峰值影响显著,不透水区糙率系数在5年及以上重现期降雨条件下对径流峰值影响显著;下渗相关参数及透水区洼地蓄水对服务区径流系数影响显著。

In order to improve the simulation precision of rainfall runoff using SWMM model and deal with the disadvantages of traditional methods which are without consideration of synergies between different parameters and difficult to calculate,a global comprehensive sensitivity analysis method of orthogonal experiment design method was presented to quantitatively analyze the sensitivity of SWMM model parameters on rainfall runoff characteristics and identify the sensitive parameters.Then the presented method was applied in Tieshan service area SWMM model,and the sensitivity of peak runoff and runoff coefficient due to impervious area roughness,pervious area roughness,impervious area depression storage,pervious area depression storage,maximum infiltration rate,minimum infiltration rate and infiltration rate decay constant was studied.The range and variance analysis results indicate that the maximum infiltration rate,infiltration rate decay constant,pervious area roughness and pervious area depression storage have a significant effect on peak runoff,impervious area roughness has a significant effect on peak runoff under rainfall conditions of 5 years or more return period.Infiltration related parameters and pervious area depression storage have significant impact on runoff coefficient.