What is Virtual Water?

Figure: The backbone of the GVWTN, with the blue dots representing net exporters and red dots representing net importers (Suweis et.al 2011)

This concept of "virtual water" was defined by J.A. Allen (1998) as the water which is embedded in commodities. Since an individual is classed as short of water if they are unable to access one cubic metre of high quality drinking water each year, there are many regions in the world where water scarcity is a major issue. The movement of "virtual water" between these regions is known as the Global Virtual Water Trade Network (GVWTN).

The network shown in this figure from Suweis et.al. (2011) represents that 80% of the total water volume only moves through 4% of the total number of links, meaning that a small number of countries have a large network of connections. This creates a disparity between water-rich countries and those which are water-poor. For example, the United States, Argentina and Brazil are some of the main exporters of water shown in this figure, whereas Japan and China are some of the larger importers.