WARiBaS, Water Assessment on a River Basin Scale. A computer program for calculating water demand and water satisfaction on a catchment basin level; to be used for global scale water stress analysis

Based on spatially interpolated climate data (monthly precipitation and potential evapotranspiration and temperature) and physiography (watershed boundaries, soil properties, surface slope and aquifer permeability), monthly crop water requirements and river runoff are calculated on a 0.5 degree world grid. This allows the calculation of demand (industrial water use, drinking water, irrigation water) and resources (groundwater and surface water), differentiated in space (e.g. upstream/downstream) and time (seasonality). The method was used in Africa as a first case study. Results of a second application, this time on global scale, are reported in the RIVM main background document to UNEP's first Global Environment Outlook.