Assessment of data availability influence on integrated urban drainage modelling uncertainty

In urban water quality management, several models are connected and integrated for analysing the fate of pollutants from the sources on the urban catchment to the final recipient; classical problems connected with the selection and calibration of parameters are amplified by the complexity of the modelling approach increasing their uncertainty. The present paper aims to study the influence of dataset extension on the modelling response uncertainty with respect to the different integrated modelling outputs (both considering quantity and quality variables). At this scope, a parsimonious home-made integrated modelling approach has been used allowing for analysing the combinative effect between sewer system, treatment plant and receiving water body; the uncertainty analysis approach has been applied to an experimental catchment in Bologna (Italy). The number of available data points has been fictitiously reduced obtaining datasets with extension ranging between 25% and 100% of the measured data. For each of the datasets, uncertainty analysis has been performed and its propagation from upstream submodel to the downstream ones has been assessed. The results are interesting and show a strong influence of dataset extension on model uncertainty.