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: This dataset provides decadal changes in total terrestrial water storage (TWS) across global endorheic basins, as observed by the Gravity Recovery and Climate Experiment (GRACE) satellites from April 2002 to March 2016. GRACE observations applied here are monthly equivalent water thickness (EWT) anomalies in the JPL 3-degree equal-area mason solution (JPL-RL05M version 2). Endorheic basin extents are acquired from the 15-second HydroSHEDS drainage basin dataset, with regional supplement of the Global Drainage Basin Database (GDBD). The global endorheic basins cover a total area of 33.7 million square kilometers, ranging from 52.8º S to 62.0º N and from 122.8º W to 157.6º E. TWS changes are calculated at two enumeration scales: 173 endorheic units and 10 endorheic zones (including Western North America, Dry Andes and Patagonia, Sahara and Arabia, Great Rift Valley and Southern Africa, Australia, Central Eurasia, and four secondary zones in Central Eurasia: the Caspian Sea Basin, the Aral Sea Basin, the Inner Tibetan Plateau, and Other Central Eurasia). At the unit scale, we provide 1) the trend of deseasonalized TWS anomalies from April 2002 to March 2016 and, 2) the trend uncertain (one standard deviation) propagated from the inherent errors in the original mascon data and the residuals of the best-fit linear trend fitting. At the zonal scale, we provide detailed monthly time series of 1) TWS anomalies (both original values and deseasonalized values) and 2) TWS uncertainties propagated from the inherent mason errors and rescaling uncertainties due to signal leakage in fringe mascons. Please see the source paper (Wang et al. 2018) for detailed data references, collections and processing.

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).