Abstract
This dataset presents high-resolution (25 m) gridded maps of the annual water balance, precipitation, and evapotranspiration for the Autonomous Province of Bolzano – South Tyrol, a mountainous region in the European Alps, over the 30-year period from 1993 to 2022. The water balance is calculated as the difference between precipitation and evapotranspiration, with evapotranspiration derived using the Thornthwaite method and adjusted based on detailed land use and topographic data. Precipitation inputs were corrected using observed runoff data from nine watersheds to ensure alignment with local hydrological conditions.
The dataset is particularly valuable for its ability to represent spatial variability in water availability across the region, driven by factors such as elevation, temperature, and land use. Validation against observed streamflow data demonstrated a strong correlation (r > 0.9) and an overall underestimation of runoff by 10–13%, attributed to assumptions in the evapotranspiration calculations. These results confirm the dataset's reliability for hydrological and ecological applications.
Potential uses include modeling annual discharge at specific locations using flow accumulation and catchment delineation tools, as well as supporting ecological studies such as species distribution modeling and the delineation of dry or humid areas. Users should note that the dataset is based on potential evapotranspiration, which may slightly overestimate water demand in regions with limited soil moisture. Additionally, the static land use map may not capture temporal changes in land management.
This dataset offers a robust resource for researchers and practitioners in hydrology, ecology, and environmental management, providing critical insights into water availability in complex alpine terrains.