Variation in Discharge, Precipitation and Temperature in Po River and Tributaries Basins

This report provides a preliminary analysis of discharges, precipitation and temperature data since 1923 for 18 closure sections of Po river and its tributaries. First we have investigated the consistency of the data, evaluating the inter-basin correlations, and the relationship between precipitation and discharge timeseries. This analysis provides a coherent picture, suggesting that the data used are reliable. Then we have explored the variation in temperature, precipitation and discharge in each sub-basin. While temperatures show a clear positive trend, precipitation and, generally discharge series did not show any trend at annual scale. Greater changes have been observed at monthly scale, with discharge increasing in May and October. However, the higher values of interannual variability (estimates with the standard deviation of the series), compared to these variations, suggest care in interpreting these results