Researchers: A. Y. Hoekstra, A. K. Chapagain,P.Q. Hung

Organisations involved: University of Twente, UNESCO-IHE and RIVM

Background

The virtual water content of a commodity is the volume of water used to produce this commodity. International trade in food and other products implies international flows of virtual water. For water-scarce countries it can be attractive to import virtual water (through import of water-intensive products), thus relieving the pressure on the domestic water resources.

Objectives

The main objectives of this study are to develop a methodology to assess the virtual water content of various agricultural and industrial products, to quantify the volumes of virtual water water flows between nations and to put the virtual water balances of nations within the context of national water needs and water availability.

Results

The global volume of international virtual water flows during the period 1997-2001 in relation to the international trade in agricultural and industrial products was 1625 Gm3/yr in average. The major gross virtual water exporters were USA, Canada, France, Australia, China, Germany and Brazil and the major gross virtual water importers were USA, Germany, Japan, Italy, France and the Netherlands.

National virtual water balances related to the international trade of products. Period 1997-2001. Net exporters are shown in green and net importers in red.

Regional virtual water balances and net interregional virtual water flows related to the trade in agricultural products.Period: 1997-2001. Only the biggest net flows (>10 Gm3/yr) are shown.

Publications

2008	Hoekstra, A.Y. and Chapagain, A.K. (2008) Globalization of water: Sharing the planet's freshwater resources, Blackwell Publishing, Oxford, UK.
2008	Chapagain, A.K. and Hoekstra, A.Y. (2008) The global component of freshwater demand and supply: An assessment of virtual water flows between nations as a result of trade in agricultural and industrial products, Water International 33(1): 19-32.		2.0 MB
2004	Chapagain, A.K. and Hoekstra, A.Y. (2004) ‘Water footprints of nations’, Value of Water Research Report Series No. 16, UNESCO-IHE, Delft, the Netherlands.	Main Report Volume 1	2.50 MB
		Appendices Volume 2	1.40 MB
2005	Hoekstra, A.Y. and Hung, P.Q. (2005) Globalisation of water resources: international virtual water flows in relation to crop trade, Global Environmental Change, (15): 45-56.		0.56 MB
2003	Chapagain, A.K. and Hoekstra, A.Y. (2003) ‘Virtual water flows between nations in relation to trade in livestock and livestock products’, Value of Water Research Report Series No. 13, UNESCO-IHE, Delft, the Netherlands.		3.10 MB
2003	Hoekstra, A.Y. (2003) (ed) ‘Virtual water trade: Proceedings of the International Expert Meeting on Virtual Water Trade’, Value of Water Research Report Series No. 12, UNESCO-IHE, Delft, the Netherlands.		3.80 MB
2002	Hoekstra, A.Y. and Hung, P.Q. (2002) ‘Virtual water trade: A quantification of virtual water flows between nations in relation to international crop trade’, Value of Water Research Report Series No. 11, UNESCO-IHE, Delft, the Netherlands		0.57 MB