Rehabilitation of concrete canals in urban catchments using low impact development techniques

摘要: Summary Urbanization generally increases surface runoff and pollutant loading decreases infiltration dry weather flow in canals. Efforts to handle the increased runoff, such as widening deepening canals, further degrade landscape riverine habitats. To avert negative effects of changes, low-impact development (LID) has been adopted restore natural processes enhance nutrient removal from urban recent years. However, installation LID techniques often requires space, which can be very limited intensely developing catchments. This study proposes install a structure, referred Green Channel Cover (GCC), space available on top an open concrete canal retain stormwater at receiving end water body. The bioretention module Environmental Protection Agency’s Storm Water Management Model 5 was used simulate through proposed GCC. peak depth heavily urbanized, tropical catchment reduced by up 14% presence GCC, occupied only 0.07% area. GCC also retained 36 mm storm during flows, resulted reduction, especially high intensity rainfall events with precipitation rates greater than 25 mm h −1 . A sensitivity analysis showed that hydraulic conductivity depths soil storage layers did not influence reduction much percent impervious area catchment. partial opening allows direct sunlight into canal, successfully tested for efficiency reducing flows. Overall, found good augmentation existing rehabilitation measures