WaterGAP

It supports understanding the freshwater situation across the world's river basins during the 20th and the 21st centuries, and is applied to assess water scarcity, droughts and floods and to quantify the impact of human actions on e.g. groundwater, wetlands, streamflow and sea-level rise.

[11] Model input includes time series of climate data (e.g. precipitation, temperature and radiation) and information such as characteristics of surface water bodies (lakes, reservoirs and wetlands), land cover, soil type, topography and irrigated area.

[10] Diffuse groundwater recharge is modeled as a function of total runoff, relief, soil texture, hydrogeology and the existence of permafrost or glaciers.

To allow a plausible representation of the actual freshwater situation, version 2.2d of WGHM is tuned against observed long-term mean annual streamflow at 1319 gauging stations.

[3] In many studies, WaterGAP served to estimate the impact of climate change on the global freshwater system, e.g. on groundwater,[27][28][29] wetlands,[30] streamflow[31][32][33][34] and irrigation requirements.

[36][37] In addition, the alteration of ecologically relevant river flow characteristics and wetland dynamics due to human water use and dams was studied.

[38][39] These time series also served to estimate the contribution of water storage variations on the continents to sea level rise.