The Impact of Focused Recharge with LID Devices on Groundwater Dynamics and Water Quality under Natural Rainfall Conditions

摘要

Various low impact development (LID) measures have been proposed to mitigate the negative impact of urbanization. The infiltration-type LID devices, such as rain gardens, have been found effective in restoring some predevelopment hydrology through focused recharge to groundwater with enhanced infiltration. However, the focused recharge from LID devices may bring pollutants down to the groundwater and poses potential threat to water quality. The magnitude of such negative impact is subject to several environmental factors, including rainfall pattern, water table depth, and the soil properties. This research presents a field monitoring study on the effect of rain garden infiltration on local groundwater dynamics and water quality in Xi'an, China. The preliminary results showed that even sparsely distributed rain gardens had certain effect on groundwater dynamics, forming a groundwater mound underneath the recharge point; the effect of focused recharge on groundwater quality was even more significant. Further investigation is needed to determine the regional effect of more densely constructed LID measures on groundwater dynamics.