生物滞留带结构层参数对道路径流滞蓄效应影响

基于非饱和土壤水分运动理论，采用数值模拟方法研究了4种降雨作用下生物滞留带结构层参数对设施积水、产流及径流调控效应的影响特性。结果表明:生物滞留带表层积水受蓄水层深度影响显著，随蓄水层深度由20 cm增加到30 cm，设施的溢流控制水量平均提高0.196 m3左右，但积水时长增加可达85 min；生物滞留带各结构层参数对穿孔管产流均有一定影响，随种植土层与砂滤层厚度比或内部储水区高度增加，穿孔管产流时刻推迟，产流峰值减小，而蓄水层深度的增加则可导致穿孔管产流时刻提前、产流峰值增大；在4种降雨作用下，5类滞留带径流量平均消减率为16.71%~37.31%，径流峰值平均消减率为41.53%~63.90%，产流平均延迟时间为97.75~166.50 min；当滞留带发生溢流时，设施的径流调控能力显著降低，且结构层参数对设施径流调控效果的影响减弱。

Effects of bioretention structural layer parameters on detention and retention for road runoff

Based on theoretical unsaturated soil water movement, the effects of different bioretention structural layer parameters on ponding, outflow, and runoff regulation were studied under four types of rainfall using a numerical simulation method. Based on the results, ponding was significantly affected by the depth of the surface aquifer. With increasing depth from 20 cm to 30 cm, the overflow control water was increased by about 0.196 m³, while the ponding duration increased by up to 85 min. Bioretention structural layer parameters all had some influence on the outflow of the perforated pipe. As the soil layer to sand layer thickness ratio or the internal water storage zone height increased, the outflow of the perforated pipe was delayed and the peak of the flow decreased, while the increase in aquifer depth led to the advancement of the outflow time and increase in the flow peak. Under the four types of rainfall studied, the average runoff reduction rate of the five types of bioretention ranged from 16.71% to 37.31%, the average reduction rate of the runoff peak ranged from 41.53% to 63.90%, and the average runoff delay time ranged from 97.75 min to 166.50 min. In the case of overflow, the performance of bioretention methods on runoff regulation was significantly reduced, and the effects of structural layer parameters on runoff regulation were weakened.