Comparison between different infiltration models to describe the infiltration of permeable brick pavement system via a laboratory-scale experiment

Abstract

The permeable brick pavement system (PBPs) is one of a widely used low impact development (LID) measures to alleviate runoff volume and pollution caused by urbanization. The performance of PBPs on decreasing runoff volume is decided by its permeability, and it was general described by hydraulic conductivity based on Darcy's law. But there is large error when using hydraulic conductivity to describe the infiltration of PBPs, and which infiltration process is not following Darcy's law, so it is important to find more accurate infiltration models to describe the infiltration of PBPs. The Horton, Philip, Green-Ampt, and Kostiakov infiltration models were selected to find an optimal model to investigate infiltration performance of PBPs via a laboratory-scale experiment, and the maximum absolute error (MAE), Bias, and coefficient of determination (R2) were selected to evaluate the models' errors via fitting with experiment data. The results showed that the fitting accuracy of Kostiakov, Philip, and Green-Ampt models was significantly affected by the monitoring area and hydraulic gradients. Meanwhile, Horton model fitted well (MAE = 0.25–0.32 cm/h, Bias = 0.07–0.11 cm/h, and R2 = 0.98–0.99) with the experiment data, and the parameters of the Horton model often can be achieved by monitoring, such as the maximum infiltration rate and the stable infiltration rate. Therefore, the Horton model is an optimal model to describe the infiltration performance of PBPs, which can also be adopted to evaluate hydrological characterization of PBPs. HIGHLIGHTS The constant and falling head monitoring methods based on Darcy's law have large error to describe the infiltration process of PBPs.; Horton model is an optimal model used to describe the infiltration process of PBPs, and fits well with experiment data.; Horton model is flexible under different compositions of PBPs, and the parameters of the Horton model are determined based on experiment data which can use for mointoring.;

Keywords

• darcy's law
• green-ampt model
• horton model
• kostiakov model
• permeable brick pavement system
• philip model