Modeling Alpine Droughts: Bias-Correction and Downscaling of a Climatic Single-Model Large Ensemble

The Alps serve as Europe's water tower, making perialpine regions heavily dependent on their water balance and susceptible to climate and management induced changes in water availability. In recent decades, the Alps have experienced an increasing number of droughts, leading to severe impacts on hydropower production, drinking and irrigation water allocation, ecosystem health, and tourism. These trends necessitate a comprehensive understanding of future drought patterns in the region.

To evaluate and analyze alpine droughts, regional climate model data from a single-model large ensemble comprising 50 members from 1990 to 2099 is used. The ensemble approach enables both future projections and the quantification of natural climate system variability, thereby enhancing the robustness of the results. This is particularly crucial when analyzing extreme events such as droughts, as it increases confidence in the observed signals while reducing uncertainty in the projections.

Given the heterogeneous landscape and climatic conditions of the study area, our methodology needs high-resolution spatial data specifically optimized for the considered terrain. The approach combines advanced downscaling techniques with a terrain-specific bias-correction method to generate reliable estimates of precipitation patterns and other critical climate parameters.

The resulting dataset is designed to serve diverse research needs, from hydrological studies to engineering applications and tourism geography. These high-resolution climate projections provide a broad range of hydroclimatic services and will contribute to the development of drought early warning and prediction systems, the implementation of optimized cross-sectoral drought risk management strategies and the enhancement of regional adaptation capabilities to drought conditions.

This comprehensive approach bridges the gap between climate modeling and practical applications, providing stakeholders with robust scientific foundations for decision-making in drought management and adaptation planning.

The presented study is conducted in the frame of the A-DROP project, funded through the INTERREG Alpine Space Programme.