Evaluation of Permeable Brick Pavement System Infiltration Performance via Experiment and SWMM

The effect of permeable pavement in reducing stormwater runoff is dependent on its infiltration performance. The monitoring and modeling methods were adopted to analyze infiltration performance of permeable pavement and was primarily based on Darcy’s law in previous studies. But Darcy’s law disregards the changing infiltration rate with the change of water content in permeable pavement medias. Neglecting the infiltration rate change frequently resulted in significant deviation between the monitoring and modeling results. To address these issues, the accuracy of two modeling methods for the infiltration performance of permeable brick pavement system ($PBPs$) was evaluated. The first is the low impact development ($LID$) module of the stormwater management model ($SWMM$), and the second is a new equivalent modeling approach based on the Horton model for $PBPs$. According to the results, the Horton model accurately described the infiltration performance of $PBPs$ in $SWMM$. Under high return periods situation, the coefficients of determination ($R^2$) and Nash-Sutcliffe efficiency coefficients ($E_{ns}$) reach 0.82 and 0.88, respectively, and the simulation error ranges from 6.57% to 8.75%. The experimental and simulation results of the $LID$ module in $SWMM$ were compared in greater detail. The result demonstrated that the $LID$ module of $SWMM$ underestimated the infiltration capacity of $PBPs$ because it ignored the fluctuating infiltration rate throughout the whole $PBPs$ infiltration process. Therefore, the proposed equivalent modeling method is superior to simulating the infiltration performance of $PBPs$ in $SWMM$, and the Horton model improved the simulation accuracy of $PBPs$ infiltration.