Spatially and temporally explicit water footprint accounting

The earth’s freshwater resources are subject to increasing pressure in the form of consumptive water use and pollution (Postel, 2000; WWAP, 2003, 2006, 2009). Quantitative assessment of the green, blue and grey water footprint of global production and consumption can be regarded as a key in understanding the pressure put on the global freshwater resources. The overall objective of this thesis is, therefore, to analyse the spatial and temporal pattern of the water footprint of humans from both a production perspective and a consumption perspective. The study quantifies in a spatially explicit way and with a worldwide coverage the green, blue and grey water footprint of agricultural and industrial production, and domestic water supply. The green, blue and grey water footprint of national consumption is quantified and mapped for each country of the world. The study further estimates virtual water flows and national and global water savings related to international trade in agricultural and industrial goods. Next, the study assesses the blue water scarcity for the major river basins of the world for the first time on a month-by-month basis, thus providing more useful guidance on water scarcity than the usual annual estimates of water scarcity. The study also contains five case studies: two specific product water footprint studies, two specific country water footprint studies and one water footprint study on a specific product from a specific region.