title: A novel modelling framework to prioritize estimation of non-point source pollution parameters for quantifying pollutant origin and discharge in urban catchments.
abstract: Stormwater runoff in urban catchments contains heavy metals (zinc, copper, lead) and suspended solids (TSS) which can substantially degrade urban waterways. To identify these pollutant sources and quantify their loads the MEDUSA (Modelled Estimates of Discharges for Urban Stormwater Assessments) modelling framework was developed. The model quantifies pollutant build-up and wash-off from individual impervious roof, road and car park surfaces for individual rain events, incorporating differences in pollutant dynamics between surface types and rainfall characteristics. This requires delineating all impervious surfaces and their material types, the drainage network, rainfall characteristics and coefficients for the pollutant dynamics equations. An example application of the model to a small urban catchment demonstrates how the model can be used to identify the magnitude of pollutant loads, their spatial origin and the response of the catchment to changes in specific rainfall characteristics. A sensitivity analysis then identifies the key parameters influencing each pollutant load within the stormwater given the catchment characteristics, which allows development of a targeted calibration process that will enhance the certainty of the model outputs, while minimizing the data collection required for effective calibration. A detailed explanation of the modelling framework and pre-calibration sensitivity analysis is presented.
authors.affiliation: GEAMA (Environmental and Water Engineering Group), E.T.S Caminos, Universidade de A Coruña, Campus Elviña s/n, 15071 A Coruña, Spain. Electronic address: ignacio.fraga@udc.es.
authors.forename: I
authors.initials: I
authors.lastname: Fraga
authors.affiliation: Department of Civil and Natural Resources Engineering, University of Canterbury, Private Bag, 4800, Christchurch, New Zealand.
authors.forename: F J
authors.initials: FJ
authors.lastname: Charters
authors.affiliation: Department of Civil and Natural Resources Engineering, University of Canterbury, Private Bag, 4800, Christchurch, New Zealand.
authors.forename: A D
authors.initials: AD
authors.lastname: O'Sullivan
authors.affiliation: Department of Civil and Natural Resources Engineering, University of Canterbury, Private Bag, 4800, Christchurch, New Zealand. Electronic address: tom.cochrane@canterbury.ac.nz.
authors.forename: T A
authors.initials: TA
authors.lastname: Cochrane
mesh_terms: D002947:Cities; D004784:Environmental Monitoring / Q000379:methods; D004787:Environmental Pollution; D019216:Metals, Heavy / Q000032:analysis*; D008962:Models, Theoretical; D011891:Rain; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical
keywords: Non-point-source pollution; Rainfall runoff; Sensitivity analysis; Stormwater modelling; Urban drainage