No abstract

Abstract:In urban drainage modelling, rainfall temporal variability can be considered as one of the most critical knowledge elements when dealing with rainfall-runoff models input data. The rainfall data temporal resolution usually available for practical applications is often lower than that requested for the rainfall-runoff simulation in urban areas, greatly compromising model accuracy. The present paper evaluates the influence of rainfall temporal resolution on the uncertainty of the response of rainfall-runoff modelling in urban environments.Analyses have been carried out using historical rainfall-discharge data collected for about 10 years in Parco d'Orleans experimental catchment (Palermo, Italy). The historical rainfall data have been taken as a reference rainfall, and resampled data have been obtained through a rescaling procedure with variable temporal windows. The shape comparison between 'true' and rescaled rainfall data has been carried out using a non-dimensional performance index. Monte Carlo simulations have been carried out, applying two different rainfall-runoff models, using the recorded data and the resampled events. The results of the simulations were used to derive, for both models, the cumulative probabilities of peak discharges conditioned on the observation according to the GLUE (Generalized Likelihood Uncertainty Estimation) methodology.

No abstract

The assessment of flood risk is a difficult task and usually requires solution of a flood routing problem as a part of the assessment. Due to the large number of scenarios that have to be developed and analyzed, simplified numerical models are used for the computation of flooded areas in each scenario. More sophisticated models are often too complex to manage or, due to their design generality, not well suited to deal with the specific needs of flood routing problems. A comparison among three different models, with varying degrees of simplification and abstraction, is presented and discussed. Some considerations on the effectiveness of simpler models are drawn, focusing on the prediction of flooded areas.

No abstract