Intensity-duration-frequency curves from rainfall stochastic models with beta shaped pulses

Many researchers have emphasized that the solution of various hydrological problems are intimately related to a better knowledge of rainfall process. In this view several rainfall stochastic models were developed during the last decade. The attention of the researchers was mainly focused on the modelling of rainfall arrival process. Less attention was addressed to the representation of the rain pulses associated to arrivals. In the present paper an attempt is made to give a better description of the pulse shape. More precisely, the shape of a single burst is depicted by a beta function whose parameters are considered as exponentially distributed random variables. Such pulse representation has been applied to the usual rainfall occurrence models. Due to the lack of theoretical knowledge on extremal properties of clustered models of point process, simulation runs (by Monte Carlo technique) have been carried out in order to test the ability of the suggested models to reproduce the characteristic behaviour of the intensity-duration-frequency curves.