基于SWMM的校园海绵城市布局优化研究:以深圳市某中学校园为例

Optimization of LID facilities planning strategy based on PSO algorithm and SWMM model:A case study of middle school campus in Shenzhen

【目的】聚焦校园海绵城市建设中低影响开发设施布局策略问题,旨在提升项目海绵城市建设的综合效益,认识校园类公共建筑项目低影响开发设施布局特点与作用机制。【方法】选取深圳市坪山区一中学校园为例,采用SWMM模拟降雨过程中的水文、水力学特性,综合考虑径流控制、污染物去除、洪涝控制三方面指标构建基于建设成本的综合效益目标,通过粒子群优化算法对校园低影响开发设施布局进行优化。【结果】优化后的低影响开发设施组合在设计排水重现期之内的模拟降雨以及日降雨和年降雨条件下可控制项目区域中75%以上径流和污染物、削减60%以上洪峰流量,减少90%以上节点积水。相关分析验证低影响开发设施位置与控制效能存在相关性,而相关程度随暴雨强度降低。在深圳降雨特征下,校园采用上游布置屋顶绿化、下凹绿地结合中下游布置雨水花园、雨水池的策略组合可实现最优综合效能。【结论】基于SWMM模拟与粒子群算法为校园类公共建筑项目提供了一种直观便捷的海绵城市低影响开发方案布局策略优化方法,可为项目海绵城市低影响开发系统建设方案设计与决策提供科学依据与指导。

[Object]Focusing on the layout strategy of LID facilities in the sponge city scheme of campus program,the character-istics and mechanism of the layout of LID system in public building construction such as school campus need to be clearly under-stood to improve the comprehensive benefits of sponge city construction and to understand.[Methods]The campus of a middle school in Pingshan District of Shenzhen was selected as the research case,whose hydrology and hydraulics characteristics in the rainfall process were simulated by SWMM model.A comprehensive benefit objective was constructed by considering the target costs of runoff control,pollutant removal and flood control via considering the construction cost.[Results]The result show that the optimized combination of low-impact development facilities can control more than 75%of runoff and pollutants,reduce more than 70%of peak flood discharge,and reduce more than 50%of node water in the project area under the conditions of simulated rainfall,measured daily rainfall and annual rainfall within the design drainage return period.Moderate correlation is verified between the location of LID facilities and the control efficiency while the relevance decrease when the raininess increase.Base on the rainfall characteristics of Shenzhen,the campus achieve the optimal efficiency by adopting the strategy of the green roof and concave-down greenbelt lied upstream combined with rain garden and rainwater tanks lied middle and downstream.[Conclusion]SWMM model simulation combined with particle swarm optimization algorithm provide an intuitive and convenient sponge city low-impact development scheme layout method for public building projects,which can provide scientific basis and guidance for the design and decision of LID placement strategy for sponge city construction of similar programs.