随着城市雨水管理信息化的快速发展，数学模型逐渐在城市雨水系统规划设计中得到广泛应用，但模型的模拟精度已成为制约其广泛应用的瓶颈问题之一。以某低影响开发（low impact development，LID）雨水系统为例，基于SWMM模型，系统分析了不同重现期条件下，低影响开发设施占比和汇流路径的差异对雨水径流水量控制效果的影响。模拟结果表明：与不考虑汇流路径相比，考虑汇流路径时雨水径流外排总量削减率为4.32%~26.53%，峰值削减率为38.46%~61.40%。因此，汇流路径对雨水径流外排总量和峰值流量影响均较大，且随着LID设施占比升高而增大，随着降雨重现期的增加而降低。在场地开发过程中，可以通过合理的汇流路径设计，提高场地中LID设施对雨水径流的控制效果。同时，在利用模型对场地雨水控制利用效果评估时，也应充分考虑汇流路径对模拟结果的影响。
With the rapid development of urban stormwater management informationization, stormwater management models have been widely used in its planning and design. However, the model accuracy has become the bottleneck of the popularization of the modes. In this paper, taking a LID rain water system as the example, the influence of different proportion of the LID system, and different flow paths in low impact development stormwater system on runoff with differerent represent periods, was systematically analyzed using stormwater management model (SWMM). The simulation results showed that the reduction rate of the total amount of rainwater runoff discharge was 4.32%~26.53%, and the peak reduction rate was 38.46%~61.40%, when the confluence path was considered in the simulation. Therefore, the confluence path was proved to be with great influence on the total discharge and peak discharge of rainwater runoff, and it increased with the increase of LID facilities and decreased with the rise of rainfall return period. In the process of site development, we could improve the control effect of LID facilities on stormwater runoff through reasonable confluence path design. And when using the model to evaluate the effect of rainwater control and utilization, the influence of confluence path on the simulation results should also be fully considered.