Rainfall Runoff Response Characteristics of Typical Urban Roads Based on Laboratory Tests

Aiming to address the lack of available and accurate runoff coefficients of various roads in urban flooding simulations and effectiveness assessments of permeable pavement on runoff reduction, the rainfall-runoff response characteristics of typical urban road pavements were investigated by laboratory-scaled tests. The results showed that average runoff coefficients and initial runoff times of pervious road pavements were almost 0.1 ∼ 0.2 and 7 ∼ 20 times those of impervious pavements, respectively. Moreover, permeable brick (PB) pavement presented better capacity for runoff mitigation than permeable asphalt concrete (PAC) pavement when the average rainfall intensity was 1.11 or 1.80 mm/min. The average runoff coefficient of cement concrete (CC) pavement ranged from 0.939 to 0.985 under all rainfall intensity and longitudinal slope combinations, while that of asphalt concrete (AC) was between 0.907 and 0.961. These results may be beneficial to improving the precision of runoff computation generated from roads or other site areas in urban flooding simulations.