The quantification of uncertainty in integrated urban drainage water quality models is of paramountinterest. Indeed, the assessment of the reliability of the model results for complex water quality modelsis useful for understanding the significance of the results. However, the state of knowledge regardinguncertainties in urban drainage models is poor. In the case of integrated urban drainage water qualitymodels, due to the fact that integrated approaches are basically a cascade of sub-models (simulatingsewer system, wastewater treatment plant and receiving water body), the uncertainty produced in onesub-model propagates to the following ones depending on the model structure, the estimation ofparameters and the availability and uncertainty of measurements in the different parts of the system.Uncertainty basically propagates throughout a chain of models in which simulation output fromupstream models is transferred to the downstream ones as input. The overall uncertainty can differfrom the simple sum of uncertainties generated in each sub-model, depending on well-knownuncertainty accumulation problems. The paper presents the quantification of the uncertaintycontributions for an integrated urban drainage model developed in previous studies. Particularly, thedifferent parts of the quantifiable uncertainty have been assessed and compared by means of thevariance decomposition concept. The integrated model and the methodology for the uncertaintydecomposition have been applied to a complex integrated catchment: the Nocella basin (Italy). Theresults showed that the variance decomposition approach can be a powerful tool for uncertaintyanalysis but the possible correlation among uncertainty sources should be considered because it cangreatly affect the analysis.
|Numero di pagine||10|
|Stato di pubblicazione||Published - 2010|