This thesis investigates long-term changes in river discharge across 22 Piedmont catchments in northwestern Italy and tests their consistency with trends in precipitation, temperature, and potential evapotranspiration (PET). Daily flows were aggregated to annual, seasonal, and monthly scales. Trends were assessed with the Mann–Kendall test and Sen’s slope. Summer low flows decline in a coherent and spatially robust way, most clearly in July and August minima. This marks stronger drought stress. High-flow indicators do not rise uni- formly; annual and seasonal maxima are mixed or not significant, so flood change appears less systematic in Piedmont than in nearby Mediterranean basins. Temperature and PET increase strongly at all time scales, with the steepest slopes in summer.