Experiment and simulation of the vegetative swale to control road stormwater

In order to quantitatively analyze the hydrological performance of vegetative swale facilities and optimize the value of their design parameters, the feasibility of SWMM model to simulate the effects of vegetative swale facilities on rainwater storage in urban roads was verified through simulated runoff experiments conducted by the experimental vegetative swale. The optimized design parameters of facilities were put forward through model scenario analysis, and the influence of facilities on improving road drainage standards and long-term runoff reduction was evaluated. The research results show that SWMM model has good accuracy in simulating the hydrological performance of vegetative swale facilities. For smaller rainfall return period and slope ratio, larger storage depth, vegetation coverage rate and area load ratio, vegetative swale facilities have stronger storage capacity. It is suggested that the design rainfall return period should not exceed 10 a, storage depth should be above 10 cm, slope ratio should be at least 3, vegetation coverage rate should be above 0.5, and area load ratio should be above 5%. The drainage standards of 3 a, 5 a, and 10 a can be raised to 15 a, 20 a, and 30 a respectively after simulating the use of the vegetative swale in an urban road in Beijing, and in 64 years of operation, the vegetative swale can remove almost all runoff in itself and catchment area, which can provide reference for the design and application of vegetative swale facilities on roads.