Dynamics of Mountain Reno River Basin (Northern Italy) in the Last Century: Possible Relationship with Human Activity and Climate Change

The purpose of the Mountain Reno River Basin assessments is to analyse the trend of inflows and outflows and suspended solids from the 1920s to present. The Mountain Reno River Basin is situated in North-Central Apennines,(Emilia Romagna Region, Italy) and its area is 1061 km2. The data set consisted of the monthly and annual rainfall data (91 years), the flow data (90 years) and suspended sediment transport data (36 years) (S.I.M.I stations, ARPA-SMR). On annual basis, the rainfall showed a decreasing trend -16%. Seasonal precipitation showed a negative trend in winter and spring, and a positive one 17.1%, in summer during the period 1960-2006 compared to the 1926-1959 period. Time series for rainfall intensity indicated a significant increasing trend in the last years, where the extreme value were maximum in February (1947) and in November (2004) respectively. In terms of flow, the significative negative trend was equal to -49%, -41m3/s per 100 years of maximum discharge and -58%, -15 m3/s per 100 years of average discharges.. Total suspended solids showed an average reduction of 46% in 100 years, differently from the summer season, which an increase of 56% SSY have been observed. Moreover, were described the Reno riverbed pattern, the morphological features of the floods river flow and minimum river flow from 1863 to 2008. The decreasing trend in streamflow observation data, particularly strong since the 1960s, may be mainly due to climate variability and human factors even if difficult to separate them in different role and weight.