title: Analysis of parameter uncertainty of a flow and quality stormwater model.
abstract: Uncertainty is intrinsic to all monitoring programs and all models. It cannot realistically be eliminated, but it is necessary to understand the sources of uncertainty, and their consequences on models and decisions. The aim of this paper is to evaluate uncertainty in a flow and water quality stormwater model, due to the model parameters and the availability of data for calibration and validation of the flow model. The MUSIC model, widely used in Australian stormwater practice, has been investigated. Frequentist and Bayesian methods were used for calibration and sensitivity analysis, respectively. It was found that out of 13 calibration parameters of the rainfall/runoff model, only two matter (the model results were not sensitive to the other 11). This suggests that the model can be simplified without losing its accuracy. The evaluation of the water quality models proved to be much more difficult. For the specific catchment and model tested, we argue that for rainfall/runoff, 6 months of data for calibration and 6 months of data for validation are required to produce reliable predictions. Further work is needed to make similar recommendations for modelling water quality.
authors: Department of Civil Engineering and eWater CRC, Institute for Sustainable Water Resources, Monash University, Victoria 3800, Australia. cintia.dotto@eng.monash.edu.au
authors: C B S
authors: CB
authors: Dotto
authors: A
authors: A
authors: Deletic
authors: T D
authors: TD
authors: Fletcher
mesh_terms: D001315:Australia; D002138:Calibration; D008962:Models, Theoretical; D011891:Rain; D015203:Reproducibility of Results; D035501:Uncertainty; D014867:Water / Q000592:standards*; D014872:Water Movements
chemical_list: D014867:Water