Hydrometeorological extremes in the Adige river basin, Italy

Sammanfattning: This study aimed at describing the characteristics of daily precipitation and discharge extremes in the Adige river basin at the city of Trento. Annual maximum series for the period 1975−2014 were analyzed in terms of trends, seasonality indices and L-moments. A Mann-Kendall trend analysis showed a weak but significant signal of decreasing ex-tremes; the percentages of sites with significant negative trends were overall larger than the significance levels. Precipitation extremes were characterized primarily by autumn storms, while floods had a stronger seasonality with peaks occurring predominantly in June and July which indicated that the timing not solely explained by rainfall maxima. The Adige basin was found to be a homogenous region with respect to precipitation, but the results did not support a corresponding assumption for discharge. A regional fre-quency analysis was performed for precipitation data and found both the Pearson type III and generalized normal distributions to be adequate regional frequency distributions. The extreme daily precipitation at Trento with a 100-year return period was estimated to be between 114 and 148 mm/d.