Les épisodes de précipitations abondantes (période 1951-1991) dans l'Italie du nord et la Sardaigne

The apparition of episodes of abundant precipitations is one of the aspects of the pluviometrie rhythm. The aim of this research consists of carrying out an analysis of the space temporal distribution of the number of days with abundant precipitation and also of their frequency. The research takes into consideration 13 pluviometrie stations of Northern Italy and 8 stations in Sardinia for which we have daily data relative to the period 1951-1991; we demonstrate how 40 mm of rain/day represent the threshold that best defines abundant precipitations. This criteria has allowed us to define the base matrix used for following elaborations. The principal data obtained put into evidence, in Northern Italy, the straight and direct connection between the total rain and the number of days characterised by the precipitations > 40 mm and they demonstrate, moreover, to which extent the most regionalized episodes of abundant rain appear during the autumnal months.