BIANCOTTI A., DESTEFANIS E., FRATIANNI S. & MASCIOCCO L.
Osservazioni su pluviometria e idrologia della valle di Susa (Alpi occidentali) – On precipitation and hydrology of Susa Valley (Western Alps)
Pages 51-58
Abstract
The Susa Valle y is a transvers e glacial valley belonging to the Cot – tian and Graian Alps. For thi s stu dy, climatological and hydrological data from different sour ces have been collected and analysed. Monthly cumulated values of precipitations, discharge and hydrometric height have been calculated from daily data. Annual pr ecipitation value s result quite constant along th e year within a range from 700 to 900 mm, with exception of Ga d , a dr y site (aro und 600 mm/ y). The annual distribution of precipi tatio n shows a b imoda l trend, with a winte r main mini – mum and an autumn maximum with secondary maximum in spring or summer according to the pl ace considered. Th e plu viornetric rate is thu s suba lpine or sub cont inental. Peak discharge and hydrometric hei – ght maximum generally occu r in March and in June, togeth er with secondary maximum of precipitat ions and the melting of snow cover. Water reso urces in Susa Valley have b een assessed on annual bas is. By taking ann ual values for rainfall (isohye tal method) and run off comparison, a water balan ce has been calculated at St. Antonino gauging station . Also on th e basis of th e lith ologies outcropping on the area, it emerges that mean avera ge precipitation (886 mm) are balanc ed by an evap otranspira tion of 318 mm, a water run off of 350 mm and a gro un dwa ter flow of 218 mm.