Description: Assessing global freshwater resources and human water demand is of value for a number of needs but challenging. The global water use and water availability model WaterGAP is in development since 1996 and serves a range of applications and topics as such as Life Cycle Assessments, a better understanding of terrestrial water storage variations (e.g., jointly with satellite observations), water (over)use and consequently depletion of water resources, as well as model evaluation and model development. In the paper connected to this dataset, the newest model version, WaterGAP 2.2d is described by providing the water balance equations, insights to input data used and typical model applications. The most important and requested model outputs (total water storage variations, streamflow and water use) are evaluated against observation data. Standard model output is described and the reader is guided to the location where those data can be downloaded. Caveats of specific output data and an overview of model applications as well as an outlook of future model development lines are presented as well.

Description: Assessing global freshwater resources and human water demand is of value for a number of needs but challenging. The global water use and water availability model WaterGAP is in development since 1996 and serves a range of applications and topics as such as Life Cycle Assessments, a better understanding of terrestrial water storage variations (e.g., jointly with satellite observations), water (over)use and consequently depletion of water resources, as well as model evaluation and model development. In the paper connected to this dataset (doi:10.5194/gmd-14-1037-2021), the newest model version, WaterGAP 2.2d is described by providing the water balance equations, insights to input data used and typical model applications. The most important and requested model outputs (total water storage variations, streamflow and water use) are evaluated against observation data. Standard model output, driven by the climate input WFD-WFDEI (for the years 1901-2016) is described. Caveats of specific output data and an overview of model applications as well as an outlook of future model development lines are presented as well. Here, the reader can download model output driven by an alternative climate forcing, the so called GSWP3-W5E5 forcing (available for the years 1901-2019). This climate forcing was created in the ISIMIP context (https://www.isimip.org) and is described in https://www.isimip.org/gettingstarted/input-data-bias-adjustment/details/80/ as Combination of W5E5 v2.0 (Cucchi et al., 2020, doi:10.5194/essd-2020-28 and Lange et al., 2021, doi:10.48364/ISIMIP.342217) for 1979-2019 with GSWP3 v1.09 (Kim, 2017, doi:10.20783/DIAS.501) homogenized to W5E5 for 1901-1978. The homogenization reduces discontinuities at the 1978/1979 transition and was done using the ISIMIP3BASD v2.5.0 bias adjustment method (Lange, 2019, doi:10.5194/gmd-12-3055-2019 and Lange, 2021, doi:10.5281/zenodo.4686991).