This study quantifies the green, blue and grey water footprint of global crop production in a spatially-explicit way for the period 1996-2005. The assessment is global and improves upon earlier research by taking a high resolution approach, estimating the water footprint of 126 crops at a 5 by 5 arc minute grid. We have used a grid based dynamic water balance model to calculate crop water use over time, with a time step of one day. The model takes into account the daily soil water balance and climatic conditions for each grid cell. In addition, the water pollution associated with the use of nitrogen fertilizer in crop production is estimated for each grid cell. The crop evapotranspiration of additional 20 minor crops is calculated with the CROPWAT model. In addition, we have calculated the water footprint of more than two hundred derived crop products, including various flours, beverages, fibers and biofuels. We have used the water footprint assessment framework as in the guideline of the Water Footprint Network (Hoekstra et al., 2009).
|Value of Water Research Report
|UNESCO-IHE Institute for Water Education