Variations of infiltration capacity with flow hydraulic parameters in permeable stormwater channels

Abstract

ABSTRACT Permeable channels are commonly adopted for urban stormwater management as an infiltration device. However, in the design of such channels, the effects of flow hydraulic parameters (i.e. water level, channel cross section and flow velocity) on the infiltration capacity of a permeable channel have usually been neglected. In this study, the variations of infiltration capacity with flow hydraulic parameters in permeable channels were investigated in various cases of static and dynamic flows. For the static phase, physical channels models were fabricated in the laboratory and the investigations were performed under ponding condition, while a grassed channel model was constructed for the dynamic phase. The results show that the water level and channel side slope affected the infiltration capacity more than the base width. The results also show that increasing the hydraulic residence time significantly affected the infiltration rate. Observed infiltration rates were used to develop a predictive infiltration model that considers the flow hydraulic parameters by adding them to the Kostiakov model. The use of this infiltration model promises better prediction accuracy of the infiltration rate in permeable channels.