Abstract ID: 3.8706 | Reviewing | Poster | TBA | TBA

Glaciers are shrinking driven by climate change, endangering their function in regulating water supply in alpine regions, particularly in a time where snow droughts are becoming increasingly important. To assess the significance of glaciers in mitigating snow-drought effects, we centered on the severe 2022-2023 snow drought in the Italian Alps. We analyzed glacier-melt contribution to streamflow during these years against the 2011-2023 historical timeframe in two catchments: Dora Baltea (Aosta Valley) and Adda (Lombardy). Glacier contribution to streamflow increased two to three-fold during these snow droughts across both river basins. This shift of glacier contribution to streamflow stemmed from four principal processes, evident with varying degrees of consistency and replicability over time: an earlier onset of the glacier melt season, an intensification of glacier melt contribution, an earlier seasonal peak in glacier melt contribution and an extension of the glacier melt season. Glacier melt contribution to streamflow remains very sensitive to short-term meteorological events, that is a rapid drop in temperatures alongside early or late snowfalls. These findings underscore the vital role of glacier melt in sustaining streamflow through severe droughts. They also stress the necessity of integrating glacier dynamics into water governance strategies for alpine areas confronting increasingly frequent and intense drought events.