High-resolution climate datasets in hydrological impact studies: Assessing their value in alpine and pre-alpine catchments in southeastern Austria

Abstract Study region Catchments: Wolzerbach, Raab; Styria; Austria. Study focus The study was carried out to investigate the fitness for purpose of the high-resolution Austrian National Climate datasets (OKS15) in hydrological applications. Provided as a standard for climate impact studies in Austria in 2016, the potential of the OKS15 data for hydrological impact studies has not previously been assessed. To fill this research gap, we evaluated the OKS15 datasets for the recent climate period (1961–2005) to determine their suitability for hydrological analyses. Hydro-meteorological indicators of the OKS15 datasets, as well as of the data used to obtain them by bias correcting and downscaling the EURO-CORDEX models, were assessed at different spatio-temporal scales and compared to the raw EURO-CORDEX data. The hydrological model WaSiM was driven with the different datasets to generate the hydrological simulations used for validation against long-term observations. New hydrological insights for the region Hydro-meteorological indicators obtained from OKS15 models are comparable to observations and associated with less uncertainty than the raw EURO-CORDEX data. We thus consider the OKS15 dataset basically appropriate for hydrological impact studies. However, despite bias correction, some biases in the OKS15 data remain and differences in timing, magnitude and spatial characteristics lead to deviations in hydrological indicators at different scales.