建筑小区雨水花园空间布局对径流过程影响规律研究

INFLUENCE LAW OF RAINWATER GARDENS SPATIAL LAYOUT ON RUNOFF PROCESS IN BUILDING COMMUNITIES

为探究建筑小区雨水花园空间布局对径流过程的影响规律,采用耦合SWMM(暴雨洪水管理模型)管网模块和GAST模型(基于GPU加速技术的地表水动力数值模型)的一二维耦合水动力模型,并以西咸新区天福和园小区为例,模拟计算了实测降雨条件下的径流过程。以雨水花园为研究对象,分别在该小区上、中、下游布设雨水花园,模拟6种重现期,共18种典型工况下其对管网出口径流的调控效果。结果表明:该耦合模型可精确可靠地模拟城市管网排水及地表积涝过程,纳什效率系数为0.80和0.76,模拟结果较好;随着设计降雨重现期增加,径流总量控制率逐渐降低;在相同重现期下,将雨水花园布设于下游侧的径流总量控制率较布设于上游侧时提升了5.33~8.74百分点,提升效果较明显。可见,该研究结果可为优化建筑小区雨水花园空间布局提供参考。

To explore the influence of the spatial layout of rainwater garden in the building community on the runoff process, a 1D and 2D coupling hydrodynamic model with SWMM(storm flood management model) pipe network module and GAST(surface hydrodynamic numerical model based on GPU acceleration technology) was adopted in this research, and the runoff process under the measured rainfall condition was simulated and calculated by taking Tianfuheyuan community in Xixian New Area as an example. The rainwater gardens were arranged in the upper, middle and lower reaches of the Tianfuheyuan community respectively, to simulate the regulation effect on the outlet runoff of the pipe network, and more than 6 return periods and 18 typical conditions were conducted in this paper. The results showed that the coupling model could be used to accurately simulate the process of urban pipe network drainage and surface inundation;the Nash efficiency coefficients were 0.80 and 0.76 in the two measured rainfall events, representing good accordance with the measured data. With the increase in design rainfall return period, the total runoff control rate decreased gradually. Under the same return period, the total runoff control rate of the rainwater garden arranged on the downstream side was increased by 5.33% to 8.74% compared with that on the upstream side, and that’s an obvious improvement. The research results can provide a reference for optimizing the spatial layout of rainwater gardens in building communities.