Droughts in glacierized catchments of the Italian Alps: evolution and emerging high-elevation variabilities (2000–2024)

High-elevation regions are increasingly exposed to intensifying droughts, challenging the role of mountains as reliable water towers. Glacierized catchments represent particularly complex systems, where atmospheric forcing, snow and glacier dynamics, and hydrological processes interact across multiple timescales to shape drought impacts.
Despite this complexity, drought processes in glacierized alpine basins remain only partially explored. Here we focus on glacierized catchments across the Italian Alps, including basins in north-western and north-eastern Italy (Piedmont, Aosta Valley, and Trentino), a climatic transition zone between Mediterranean and continental alpine regimes where drought responses may differ from those observed in other alpine regions, while downstream water availability supports hydropower production, irrigation, drinking water supply, and alpine ecosystems.
This study investigates how droughts have manifested and evolved in Italian glacierized catchments over the period 2000–2024, analyzing their spatial and temporal variability and their propagation across meteorological, snow, glacier, and hydrological compartments. Meteorological droughts are characterized using precipitation and temperature anomalies derived from the BigBang dataset, while snow droughts and glacier melt contributions are assessed using snow water equivalent and melt simulations from the S3M Italy model. Hydrological drought conditions are further investigated using streamflow observations provided by regional monitoring agencies. The analysis aims to examine how meteorological variability, hydrological mechanisms, and glacier melt influence drought duration and intensity, and how these relationships have evolved over the last two decades, particularly at high elevations.
By providing an integrated assessment of drought mechanisms in southern alpine glacierized basins, this work addresses a key knowledge gap in mountain hydroclimatology. The results will improve understanding of how glacierized catchments respond to drought under ongoing climate change, offering a basis for future investigations of high-elevation drought signals and their implications for alpine water resources, as well as for assessing drought impacts across different environmental compartments in mountain regions.