Spatial Analysis of Land Use Effects on Urban Stormwater Quality

Urbanisation, development and populating of an area create different pollutants, which are carried by stormwater to receiving waters such as rivers and lakes and deteriorate their quality and endanger their ecosystems. Urban stormwater once was recognised as a major source of pollutants to be disposed, is now considered as a valuable resource for non-drinking purposes in cities. Urban stormwater non-point source pollutants are recognised as a major cause of receiving waters quality deterioration. To date most efforts have focused on specifying the temporal variations of quality parameters in forms of either pollutograph or event mean concentration (EMC). EMC is usually obtained by a number of measurements of runoff quality and quantity at a single measuring station mainly at the catchment outlet. This method is a systematic approach with deterministic variations, which does not show the error associated with the estimation. However, due to the spatial variability of pollutants over the catchment, the pollutant magnitude estimated by this method is highly variable which creates significant uncertainties. The spatial variations of the runoff quality are the key factors in non-point source pollution studies. This research investigates variability of urban runoff quality parameters using spatial sampling method. The research outcomes will reliably estimate pollutants concentration for improved and efficient design of pollution control structures for each land use. The focus of this research is on spatial analysis of pollutants in urban catchments, which enable designers to target the pollutants as close as possible to their source of origination. This research investigates the distribution of urban stormwater pollutants in relation to land use by focusing on spatial variability of major pollutants such as total phosphorous (TP), total nitrogen (TN), suspended solids (SS) and biochemical oxygen demands (BOD).