Phenomenological validation of a regional rainfall frequency analysis

The interpretation of the experimental evidence of the presence of a double component in the distribution of rainfall annual maxima (RAM) observed alo ng he Tyrrhenian coast of Italy is discussed here. Using a simple model for rainfall storm generation the effect of the presence or absence of the Eur opean blocking condition on the generation of the double component in the R AM is investigated. The model is calibrated on the essential meteorological characteristics of the Mediterranean storms provided both by remote sensin g and high resolution raingauge data. It allows to give a physical explanat ion for the variability of the parameters distribution with time observatio n interval. The maxima extracted from the model generated rainfall time ser ies show statistical properties very similar to those obtained by sample da ta. In particular the model derived rainfall frequency curves and intensity duration frequency curves show a good agreement with the observed ones. (C ) 2001 Elsevier Science Ltd. All rights reserved.