.. _introduction: Introduction ############ WaterGAP is a state-of-the-art global-scale water resource and water-use simulation model. WaterGAP was used to support the sustainable development of the Earth system by assessing water scarcity for humans, drought hazards, ecologically-relevant streamflow characteristics, the impacts of human water use and dam construction as well as freshwater-related scenarios of the future [1]_. Recent focus has been on quantifying the impact of climate change on the global freshwater system, including the streamflow regime, groundwater recharge, floods, and droughts. WaterGAP is an open-source software with the aim of increasing reproducibility among researchers. Acknowledgement of funding ########################## ReWaterGap receives funding from the German Research Foundation (DFG). For further information, see the official project description `here `__. References ########## .. [1] Müller Schmied, H., Cáceres, D., Eisner, S., Flörke, M., Herbert, C., Niemann, C., Peiris, T. A., Popat, E., Portmann, F. T., Reinecke, R., Schumacher, M., Shadkam, S., Telteu, C.E., Trautmann, T., & Döll, P. (2021). The global water resources and use model WaterGAP v2.2d: model description and evaluation. Geoscientific Model Development, 14(2), 1037–1079. https://doi.org/10.5194/gmd-14-1037-2021