Variabilità pluviometrica nel bacino del Fiume Coghinas in funzione del suo potenziale erosivo

The analysis carried out on the pluviometric variability in the Coghinas river (Northen Sardinia), during the period 1921-90, had the double purpose of following the rain fluctuations in the basin and also putting in evidence the relations linked to the variations of the erosive potential of rain itself. Such analysis was helpful in order to classify the ten years single periods on the basis of humidity degree: in most of the stations the ten years period 1931-40 resulted prevailingly humid due to high contributions of autumn and spring precipitations. The last decade (1981-90) resulted definitely dry because of strong reduction of winter rainfall and to a lower extent of autumnal rainfall. Besides, the sensible reduction of winter rainfall in this last decade in respect of the normal previous periods has led to a change in the pluviometric regime from type IAPE (mediterranean) to type AIPE (submediterranean). At last, the degree of rain erosivity produced by Fournier’s Index in accordance with the CORINE program, has revealed as a general rule a direct relation with both station’s altitudes and yearly rainfall, however in internal stations whereas altitudes exceed 400 meters the erosive potential is related with the pluviometric regime of the single years.