基于多目标优化的服务区低影响开发设施设计及效果评价

Design and Effect Evaluation of Low-impact Development Facility in Service Area Based on Multi-objective Optimization

为了解决低影响开发(LID)设施的最优成本效益问题,构建了以年径流控制总量、污染物综合削减率、总建设养护费用为目标函数和以各项LID设施的调蓄容积和可建设面积为约束条件的LID设施多目标优化模型,采用第二代非支配排序遗传算法(NSGA-Ⅱ)求解,并结合层次分析法对优化解集进行综合评价,为LID设施组合优化提供了更加科学有效的方法。进而利用该模型对合浦服务区LID设施建设进行了组合优化,形成一套最具经济与效益的LID设施建设方案,并通过构建SWMM模型对其降雨径流与污染物控制效果进行了评估。结果表明:LID设施的布设能够有效削减服务区降雨径流与污染物负荷,径流峰值削减率超过25%,各类污染物削减率均超过25%,SS污染物削减率超过30%。

In order to solve the problem of optimal cost-effectiveness of low-impact development(LID)facilities,a multi-objective optimization model for LID facilities that takes the total amount of annual runoff control,comprehensive pollutant reduction rate and total construction and maintenance cost as the objective functions,and the storage capacity and buildable area of various LID facilities as the constraints is constructed.The model is solved by using the second generation non-dominated sorting genetic algorithm(NSGA-Ⅱ),and the optimal solution set is evaluated comprehensively combining with the analytic hierarchy process to provide a more scientific and effective method for LID facility combination optimization.Then,the combination of LID facilities construction in Hepu service area is optimized by using the model,and a set of LID facilities construction scheme with the most economic and benefit is obtained,and the control effect of rainfall runoff and pollutant is evaluated by establishing a SWMM model.The result shows that the layout of LID facilities can reduce the load of rainfall runoff and pollutant effectively in the service area with the reduction rate of peak runoff exceeding 25%,the reduction rate of various pollutants exceeding 25%,and the reduction rate of SS pollutants exceeding 30%.