Increasing Influence of Temperature on Recent Hydrological Extremes across European Alpine Rivers

Four of the largest river basins in Europe – Rhine, Rhône, Po, and Danube – rely heavily on Alpine headwaters. Recently, these basins have experienced intensifying hydroclimatic fluctuations, including catastrophic floods and prolonged droughts, highlighting the vulnerability of these basins to climatic variability. Understanding the potential drivers behind changes in streamflow patterns, particularly the relative contributions of precipitation and temperature, is essential for improving the attribution of extreme hydrological events and informing sustainable freshwater resource management. However, relatively short instrumental hydroclimatic records in the European Alps limit our understanding of the long-term influence of climate variability on hydrological extremes. This research integrates proxy-based reconstructions with paleo-climate reanalysis to assess streamflow variations over an extended timeframe. Through statistical regression, we quantify how changing rainfall and temperature patterns contribute to the onset of extreme events, with a specific focus on recent droughts. By comparing historical trends with future projections across different climate scenarios, we aim to identify the primary climatic drivers of hydrological extremes and their evolution over time. This work emphasizes the necessity of long-term perspectives in attributing extreme events and securing water resources in the Alps.