the difference between virtual water and virtual water footprint
Answers
water footprint is quite simply the volume of water used. At the individual level, this is expressed in litres. But at the national level, this becomes complex - The water footprint of a nation is equal to the use of domestic water resources, minus the virtual water export flows, plus the virtual water import flows.
The total ‘water footprint’ of a nation is a useful indicator of a nation’s call on the global water resources. The water footprint of a nation is related to dietary habits of people. High consumption of meat brings along a large water footprint. Also the more food originates from irrigated land, the larger is the water footprint. Finally, nations in warm climate zones have relatively high water consumption for their domestic food production resulting in a larger water footprint. At an individual level, it is useful to show the footprint as a function of food diet and consumption patterns.
Virtual water is the amount of water that is embedded in food or other products needed for its production. Trade in virtual water allows water scarce countries to import high water consuming products while exporting low water consuming products and in this way making water available for other purposes [World Water Council].
For example, the virtual water content (in m3/ton) for potatoes is 160. Others examples - maize=900; milk=900; wheat=1350; soybean=2300; rice=3000; poultry=2800; eggs=4700; cheese=5300; pork=5900; and beef=16000.
Showing people the 'virtual water' content of various consumption goods will increase the water awareness of people.