Probabilistic assessment of debris flow peak discharge by Monte Carlo simulation

The topographic and hydrologic parameters involved in the estimation of the debris flow peak discharge in a classical approach are usually assumed to be deterministic. As a result, in such approaches, the only uncertainty in the evaluation of peak discharge is the evaluation of rainfall intensity and frequency. The present study aims to provide a probabilistic approach for estimating the debris flow peak discharge through the use of a Monte Carlo simulation method. Studies on such landslides in pyroclastic deposits have been performed in order to identify potential source areas and the main depositional mechanisms. The standard Monte Carlo simulation is used in order to propagate the uncertainties in different paramaters, related to hydrographic basin modeling, and to obtain a probability distribution for the peak discharge, related to a given return period. As a numerical example, the peak discharge of debris flow in the basin of the Corbara Stream, located in the municipality of Salerno in southern Italy, is evaluated.