Quantifying and assessing the infiltration potential of green infrastructure in urban areas using a layered hydrological model

Abstract

Spatial heterogeneity in hydrological responses is an important element in urbanized watersheds. One of the main challenges in simulating urban hydrology is the lack of layered information and knowledge of the true infiltration potential of stormwater infrastructure systems. In this study, changes in the infiltration characteristics of three green infrastructures (GIs), with and without underground barriers, were simulated during a designed rain event in Xiamen, China, using a layered, one-dimensional infiltration model. The variations in the maximum infiltration rate (MIR) and cumulative infiltration (CI) for permeable pavements, vegetative swales, and rain gardens were found to differ in response to 204 scenarios of pervious material thickness, even though they were linearly correlated. Comparisons between the GIs, with and without barriers, revealed that the MIR was almost unchanged, while CI varied considerably with the depth to the impervious layer. To explore the impacts of barriers on infiltration potential, simulations with depths to the impervious layer from 700 to 1000 mm were compared. We statistically evaluated the infiltration potential with all possible scenarios for the GIs. Identifying the potential impacts of infiltration processes beneath GI can be beneficial in urban stormwater management.