Probabilistic analysis of the variation of water resources availability due to rainfall change in the Crati basin (Italy

This work presents a probabilistic analysis of the variability of the annual areal rainfall that could occur in a large drainage basin of Southern Italy (Crati River) at verifying of hypothetical scenarios of change in rainfall pattern. The probabilistic law assumed to describe the rainfall data observed in time periods with different statistical behaviours is the trans-normal distribution. In response to the rainfall pattern change evidenced since 1981, three assumptions about the variability of the parameters of the trans-normal distribution have been taken, with estimation based on rainfall data observed in the period 1981-2008. The probabilistic models thus obtained are used for simulations of annual rainfall for a future 30-year period through Monte Carlo techniques. Finally, the maximum deficit of water potential in n consecutive years at fixed occurrence probabilities are evaluated for each hypothetical rainfall pattern change.