M. Ghafouri1 and C.E. Swain Abstract Urban stormwater non-point source pollutants are recognized as a major cause of receiving waters quality deterioration. To date most research has focused on specifying temporal variations of stormwater quality parameters which includes high uncertainties and also increases the risk of pollution control structures failure. Traditionally, the temporal variations of quality parameters in forms of either pollutograph or Event Mean Concentration (EMC) is obtained by sampling stormwater at the outlet of urban catchments for quality analysis in addition to measurement of flow rate over years. Spatial variations of the runoff quality are the key factor in non-point source pollution studies. This research investigates spatial variability of urban runoff quality parameters such as Total Phosphorous (TP), Total Nitrogen (TN), Suspended Solids (SS) and Biochemical Oxygen Demands (BOD) in relation to land use of urban catchments. In spatial analysis, stormwater will be sampled over the whole catchment area for a number of rainfall events during a year without any requirement to measure flow rate. This research showed comparable results for average pollutant concentrations with those of other urban catchments in Australia where traditional sampling method was used. The research outcomes will reliably estimate pollutants concentration for improved and efficient design of pollution control structures for each land use. KEY WORDS: Spatial analysis, temporal analysis, stormwater, Event Mean Concentration, geostatistics, pollutants Introduction 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 recognized as a major source of pollutants, is now considered as a
References: Allison R.A., Walker T.A., Chiew F.H.S., O’Neill I.C., McMahon T.A. (1998): From roads to rivers – Gross pollutant removal from urban waterways. Report No 98/6, CRC for Catchment Hydrology. AQUALM-XP,(1996): User’s Manual, Version 2.2, XP-SOFTWARE, Canberra. Argue J., (1999): Aspects of Stormwater Quality. Source Control-Stormwater Management Design Procedures, Urban Water Resources Centre, University of South Australia, Feb. 1999. Chiew F., (1995): An Overview of Urban Water Research Studies in Australia, In Background Papers – Urban Water Lifecycles Partnership, ACSTEC Future Needs, 2010, AGPS, Canberra. Chiew F.H.S., McMahon T.A. (1999): Modelling runoff and diffuse pollution loads in urban areas. Water Science & Technology, Vol. 39, No. 12, pp. 241-248. Chiles J.P. and Delfiner P. (1999): Geostatistics, Modelling spatial uncertainty. John Wiley & Sons, Inc. Huber W.C. and Dickinson R.E. (1988): Stormwater Management Model, Version 4 User’s Manual SWMM-4. Dept. Of Environmental Engineering Sciences, University of Florida. Mason C.F. (1996): Biology of Freshwater Pollution, Harlow, Longman. Novotny V., Olem H. (1994): Water quality, prevention, identification and management of diffuse pollution. Van Nostrand Reinhold Publishers, New York. Poon K.F., Wong RWH, Lam MHW, Yeung HY, Chiu TKT. (2000): Geostatistical modelling of the spatial distribution of sewage pollution in coastal sediments. Water Research, 34(1):99-108,2000 Jan. Robertson G.P. (2000): Geostatistics for the Environmental Sciences. Gamma Design Software, GS+TM for Windows, Version 5. Plainwell, Michigan 49080 . Swain C.E. (2003):. Urban stormwater quality modelling of Rippleside catchment. BEng project, School of Engineering and Technology, Deakin University, Australia. Thomas N.D., Reese A.J. (1995): Municipal stormwater management. Lewis Publishers. Victorian Stormwater Committee (1999): Urban stormwater: Best-practice environmental management guidelines, CSIRO Publishing. Journal of Spatial Hydrology 45 Wanielista M. P., Kersten R. And Eaglin R. (1997): Hydrology: Water quantity and quality control, 2nd Edition, John Wiley &b Sons, New York. (SMADA model, Developed by Eaglin R. as an attachment to the book). Yuan Y., Hall K and Oldham C. (2001): A preliminary model for predicting heavy metal contaminant loading from an urban catchment. Science of the Total Environment. 266(1-3): 299307. Zug M., Phan L., Bellefeur D .and Scrivener O. (1999): Pollution wash-off modelling on impervious surfaces: Calibration, validation, transportation. Water and Science Technology. 39(2):17-24, 1999. Journal of Spatial Hydrology 46