南京市鼓楼区LID空间配置与雨洪调控效益研究

Research on spatial distribution and stormwater regulation benefits of low impact development in Gulou District,Nanjing,China

低影响开发(LID)能够实现源头径流控制,已成为缓解城市内涝的重要策略。以南京市鼓楼区为例,运用GIS和SWMM模型构建LID的空间配置方案,并在城市尺度上模拟分析5个降雨事件下LID组合方案的雨洪调控效应,最后基于费效比方法定量评价成本效益。结果表明:研究区LID的适建面积占总面积的16.33%,其结果可为LID规划建设所参考;LID建设后地表径流系数平均可减少0.26,但随降雨重现期的增加径流削减率总体呈递减趋势;LID的雨洪调控效应受诸多降雨特征及LID自身属性特性的多重交互影响;屋顶绿化+透水铺装组合的成本效益最好,包含生物滞留池的方案成本效益相对偏低,综合来看屋顶绿化+透水铺装+生物滞留池+植草沟方案建设潜力最大。研究结果可为城市尺度上LID的空间规划、海绵城市建设和城市雨洪管理提供决策参考和案例借鉴。

Low impact development (LID) can control the source flow and has been one of the most important strategy to release urban flood disasters. This study used the Stormwater Management Model (SWMM) as a modelling tool to assess the spatial distribution of LID for stormwater runoff control in Gulou District, Nanjing City. The simulation results indicated that: the suitable area of LID accounted for 16.33% of the total area, which have a significant impact on runoff;The net flow coefficient can be reduced by an average of 0.26. With the increase of rainfall period, the efficiency of runoff reduction was decreasing. The flood peak increases with the increase of rainfall intensity and the scale of LID in general. With the increase of rainfall period, the efficiency of flood peak reduction was decreasing slowly. The combination of green roof and permeable pavement has the best cost-effectiveness, while the scheme including bio-detention pool has relatively low cost-benefit. In general, the scheme of green roof + permeable pavement + bio-detention pool + grass ditch has the greatest potential This study can provide decision-making references and case references for LID's spatial planning, sponge city construction and urban storm water management on an urban scale.