This map of the average annual amount of surface water used in each ecoregion gives an indication both of water resources development and of the potential impact of water consumption on freshwater ecosystems. The data used to calculate water use are from WaterGAP, a global hydrologic model developed by the University of Kassel in Germany. The model only considers water that is withdrawn from surface water systems, and considers four water use sectors: industrial, domestic, livestock, and irrigation. For this analysis, all sectors have been combined. Water use analysis shows where human development has concentrated its water use, or where surface water resources are most exploited.  Due to limited data availability, groundwater use and non-consumptive water use (like storage in reservoirs, hydropower, or pollution) are not considered, even though these put additional stress on water resources. The results form an essential input to the ‘surface water abstraction stress to rivers’ map, also found on this website.