Long Term Hydrological Effects of Bioretention on Expressway Service Area

Abstract

Taking an expressway service area as the study object, based on the SWMM and VADOSE/W models, the long-term water balance of exfiltration type bioretention (ZR) and anti-seepage type bioretention (ZF) were quantified, and the performance of bioretention on the long-term hydrological effects of the service area was studied. The results show that the ZR can significantly increase the annual underground discharge ratio compared with ZF, thereby reducing the underdrain outflow ratio, but has little effect on the overflow ratio and evapotranspiration ratio. ZR can significantly improve the hydrological balance of the service area, and increase the annual runoff control rate by 48.21%, and the utilization rate of rainwater resources in the service area can reach 73.47% by the combination of ZF and reservoir. For typical annual rainfall events, the average values of runoff reduction rate, runoff peak reduction rate and runoff delay of traditional service area were 59.45%, 57.17% and 5.19 h respectively, those of service area with ZR were 91.56%, 95.22% and 20.55 h respectively, and those of service area with ZF were 68.59%, 86.67% and 15.22 h respectively. ZR and ZF can both effectively improve the rainfall regulation ability of the service area, and the performance of ZR is relatively better. Furthermore, the correlation between runoff characteristics and rainfall characteristics for three types of service areas was analyzed, which can provide a reference for forecasting and controlling rainwater runoff in the service area.

Study on Water Diffusion Characteristics in the <i>In-situ</i> Soil of Exfiltration Type Bioretention

“…Gao [43] used the VADOSE/W model to study the ponding and outflow processes of a bioretention pond collecting runoff from roads and proved that the model can effectively simulate the hydrological effects of twodimensional bioretention. Additionally, Pan [32] studied the long-term water balance of a two-dimensional bioretention area of an expressway service area, based on the VADOSE/W model.…”

“…For example, through field experiments Guo [31] showed that the concentrated infiltration of runoff by bioretention had a significant effect on groundwater recharge. Pan [32] studied the long-more than 2 m to avoid nearby structural foundations being negatively affected by water seepage over a long period of time.…”