CWatM RCP4.5 Hydrological Data – Daily and Monthly Outputs

Dataset Description This dataset provides daily and monthly hydrological simulation outputs from the Community Water Model (CWatM), generated specifically for the ACCREU (Assessing Climate Change Risk in Europe) project. The simulations follow the ISIMIP3b protocol and use bias-adjusted climate forcing data from five global climate models (GCMs): GFDL-ESM4, IPSL-CM6A-LR, MPI-ESM1-2-HR, MRI-ESM2-0, and UKESM1-0-LL. The simulations include historical climate conditions and the SSP2-4.5 future climate scenario. The dataset provides total runoff (qtot) at daily and monthly temporal resolutions and river discharge (dis) at monthly resolution, on a regular 0.5° × 0.5° spatial grid. Future simulation outputs cover the period 2015–2100. These simulations were conducted to support climate change impact assessments within ACCREU, providing hydrological inputs to other participating impact models and enabling analyses of future water availability and climate-related risks across sectors. Simulation Configuration Parameter Description Impact model Community Water Model (CWatM) Model version 1.06 (27 April 2021) Experiments historical_histsoc_default, ssp245_2015soc-from-histsoc_default Climate scenario SSP2-4.5 Climate drivers GFDL-ESM4, IPSL-CM6A-LR, MPI-ESM1-2-HR, MRI-ESM2-0, UKESM1-0-LL Spatial aggregation Regular grid Horizontal resolution 0.5° × 0.5° Vertical resolution Not applicable Future simulation period 2015–2100 Output Variables Variable Description Temporal Resolution qtot Total runoff Daily and monthly dis River discharge Monthly Input Data and Model Configuration Climate forcing The simulations use bias-adjusted atmospheric climate data from five global climate models participating in ISIMIP3b: GFDL-ESM4 IPSL-CM6A-LR MPI-ESM1-2-HR MRI-ESM2-0 UKESM1-0-LL Climate variables: hurs, huss, sfcWind, tasmax, tas, tasmin, rlds, psl, rsds, ps, pr Temporal resolution of input data: Input Temporal Resolution Climate variables Daily Atmospheric CO₂ Annual Land use / land cover Annual Soil characteristics Constant Soil data: GSWP3-HWSD Land cover representation and Vegetation Dynamics Each 0.5° grid cell is partitioned into fractions representing water, sealed surfaces, forest, and other land cover. Land cover is updated annually using the HYDE 3.2 database. Data Access and Availability Due to the large size of the simulation outputs, the underlying data files are hosted externally on the IIASA Accelerator. This Zenodo record provides a permanent DOI, dataset documentation, and citation information. The files can be accessed through the GitHub-hosted download interface, which provides a browsable folder structure and direct download links to the individual files. Download the CWatM hydrological dataset Model Information and References Model homepage: https://cwatm.iiasa.ac.at/ ISIMIP3b model documentation: CWatM – ISIMIP3b Reference publication: Burek, P., et al. (2020). Development of the Community Water Model (CWatM v1.04) – a high-resolution hydrological model for global and regional assessment of integrated water resources management. Geoscientific Model Development, 13, 3267–3298. https://doi.org/10.5194/gmd-13-3267-2020 Licensing Model output license: Creative Commons CC0 1.0 Universal (CC0) CWatM model license: GNU General Public License v3.0 (GPL-3.0) Contact Dor FridmanInternational Institute for Applied Systems Analysis (IIASA)Email: [e-mail] This dataset is part of the ISIMIP3b ensemble. See: https://www.isimip.org/impactmodels/details/257/#tab_isimip3b