基于SWMM模型的西北坡地校园海绵化改造方案研究

Research on the Sponge Renovation Scheme of Sloping Campus by SWMMModel in Northwest China

受全球气候变暖的影响,我国西北干旱半干旱地区夏季暴雨发生的频率和强度逐年提高。选取该地区排水系统完善但具有洪涝风险的坡地校园,应用暴雨洪水管理模型(Storm Water Management Model,SWMM)分析暴雨情景下校园淹没情况,并据此制定海绵化改造方案。研究发现,暴雨情景下学校地表径流主要分布在3条南北干道上。根据模型分析结果可知,设计长历时降雨情景下,超载管段数量为52个;设计短历时降雨情景下,超载管段数量最多为194个,潜在洪涝风险很大。秉持“源头控制、客水引流、中途滞蓄、末端排放”的基本思路制定海绵化改造方案,包括设计屋顶花园21处、雨水花园19处、植草沟14处、透水铺装34处和下沉式绿地38处。海绵化改造方案在长历时降雨情景下能够达到83.02%的年径流总量控制率,预期降低洪涝危害显著。研究结果可为西北坡地校园海绵化改造实践与雨水生态景观构建提供参考。

Due to global warming,the frequency and intensity of summer rainstorms are increasing in arid and semiarid regions of Northwest China.A sloping university campus with complete drainage systems but with flood risks was taken as an example.The storm water management model(SWMM)was applied to analyze flooding under storm conditions and develop a sponge renovation plan.The study finds that there were surface runoff mainly on three north-south roads of the campus.According to the model analysis results,the overloaded pipelines reached 52 under long duration rainfall;Under the design of short-duration rainfall,there were great potential flood risks caused by 194 overloaded pipelines.Following the principles of"source control,water diversion,midstream storage,and end discharge",the renovation plan includes 21 roof gardens,19 rain gardens,14 grass swale,34 porous pavement,and 38 sunken green belt.This plan achieved a total annual control rate of 83.02%under long-duration rainfall setting,significantly reduced flood hazards.The results can provide a reference for the practice of sponge transformation and the ecological landscape in sloping campuses in Northwest China.