基于精细化排水数值模型的流域海绵规划研究——以清河流域为例

Study on Sponge city planning on basin scale based on the refined drainage numerical model——A case study of Qinghe river basin in Beijing

海绵城市建设规划中径流控制指标受城市功能区、下垫面类型及排水条件的综合影响,在排水区尺度科学分解该指标具有较大的挑战性。针对该问题,本研究选择典型城市流域——清河流域,基于高分辨率的管网、河网、地形和下垫面等资料,构建精细化流域综合洪涝模型,涵盖降雨产流、管网汇流、河道汇流和地表漫流等过程。以该模型为基础,开展现状年径流总量控制率分析,结合不同海绵措施实施方案,模拟不同暴雨重现期下降雨径流削减率,提出流域尺度的海绵城市建设径流控制目标,为海绵城市规划和建设效果评估提供技术支撑。

In the Sponge city construction planning, the runoff control index which is a key indicator isaffected by various factors such as the urban functional area, the type of underlying surface, and thedrainage conditions. It is challenging to scientifically decompose this index on the scale of the drainageunit for a huge basin with heterogeneous conditions. To fill this gap, a typical urban river basin, Qingheriver basin, was selected in this study and a refined comprehensive flood model was developed, based onhigh-resolution materials such as pipe network, river network, terrain and underlying surface. It coversthe processes of rainfall runoff, pipe network confluence, river confluence and surface flooding, etc. Based on the refined flood model, the current annual total runoff control rate was analyzed. Further the reductionrate of rainfall runoff under different rainstorm scenarios was simulated combined with different spongemeasures and implementation plan. Based on these results, the runoff control target of the Sponge cityconstruction was proposed on the river basin scale, which could provide technical support for Sponge cityconstruction planning and benefits evaluating.