Probabilistic analysis of runoff simulations in a small urban catchment

• Published in: Water science and technology 1997-01, Vol.36 (8-9), p.51-56
• Main Authors: Calomino, F, Veltri, P, Piro, P, Niemczynowicz, J
• Format: Article
• Language: English
• ISSN: 0273-1223
• DOI: 10.1016/S0273-1223(97)00619-7

A principal concern affecting the outcome of hydrological design projects was the question of whether results based on the use of design storms were truly representative of actual storm events. This question was examined with the aid of a series of 51 rainfall-runoff records for storm events in the experimental Luzzi catchment (Cosenza, Italy). Initially the frequency distribution for the observed peak discharge values was analysed, after which the runoff events were simulated using the Wallrus model, with the observed rainfall data as input. The frequency distribution of peak discharges for the simulation runs was then compared with that for the measured values. Finally the rainfall events were analysed to obtain frequency distributions for several values of duration, to develop IDF curves for given frequencies and also the Chicago design storms. There was good agreement between the observed and peak discharge values even when the latter were derived from synthetic storm events; the nature of the catchment however was unusual, being small and steeply sloping and having almost 100 per cent of the impermeable surface area.