Global modeling of water resources and water use

The integrated global water resources and use model WaterGAP (Water - Global Analysis and Prognosis) serves for assessing the global freshwater system, with a specific focus on the interactions between humans and and the terrestrial part of the global water cycle. Since 1996, it has been developed at the University of Kassel (Center for Enviromental Systems Research), while from 2003 onward, further model development is being done both in Kassel and at the University of Frankfurt.

For the whole land area of the Earth (except Antarctica), WaterGAP computes both water resources (surface runoff, groundwater recharge, river discharge, water storage in soil, groundwater and surface water bodies) and water use (surface water and groundwater abstractions as well as return flows in the water use sectors irrigation, livestock, households, thermal power plant and manufacturing) at a spatial resolution of 0.5 degree (55 x 55 km at the equator). With a temporal resolution of 1 day or 1 month, WaterGAP is applied for assessing the dynamic development of the human-water system between 1900 and 2100. To this end, the model estimates the impact of demographic, socioeconomic and technological change on water use as well as the impact of climate change and variability on irrigation water use. In the WaterGAP Global Hydrology Model WGHM, the impact of climate (change), water use and dams on water flows and storages, e.g. renewable water resources, river flow regimes and groundwater storage, is computed.

In the course of developing WaterGAP, a number of global data sets were developed. A short introduction to WaterGAP can be found in Wikipedia, while a list of publications on WaterGAP can be found at Please check also some examples of WaterGAP output.