The concept of virtual water associates with some consumer goods or intermediaries the quantity of water necessary to their manufacture.
It also gives when they are needs for pure water, which will not be reusable then without treatment, one undervaluing for the quantity of energy necessary to produce them, since in permanent mode this pure water can come only from one process of evaporation which one knows consumption in energy.
It seems to be the analog for the water of the concept of gray energy for energy.
Use of the concept
Daniel Zimmer, director of the World council of water and intervening with the session of the forum entitled “Exchanges and geopolitics of virtual water”, to the World forum of the water of 2003 with Kyōto indicates this:
-
“To consume a Kilogram corn, it is also, in the facts, to consume the thousand of Liter S of water which it was necessary to make push this cereal. To eat one kilogram of Ox, it is also to consume them: 13000 liters of water which were necessary to produce this quantity of meat. This volume corresponds so that we call hidden water, or virtual. It is because they are not conscious of this phenomenon that so many human beings employ this resource also great quantity. (...)”
- “the differences in the use of this virtual water are striking from one continent to another. If, in Asia, one consumes some on average: 1400 liters per day and, this figure borders them: 4000 liters in Europe and North America. Approximately 70% of the water used by the human activities are devoted to its food production. (...)”
- “Among the principal importers Nets of virtual water, one can quote the Sri Lanka, the Japan, the Netherlands, the South Korea, the China, the Spain, the Egypt, the Germany and the Italy. ”
- “the differences in the use of this virtual water are striking from one continent to another. If, in Asia, one consumes some on average: 1400 liters per day and, this figure borders them: 4000 liters in Europe and North America. Approximately 70% of the water used by the human activities are devoted to its food production. (...)”
Some orders of magnitude
According to the World council of water, the quantity of water necessary to produce various types of food varies considerably according to the type of production:
An inhabitant of the the United States, with the food mode rich in meat, would consume: 5400 liters of virtual water per day, whereas a vegetarian would only use any: 2600 liters.
Virtual water in the international relations
Virtual water plays a part in the exchanges between country. Indeed, a country whose water resources are weak does not may find it beneficial to export products, for example fruits or meat, whose production requires a great quantity of water. Countries like the Jordan and Israel direct some their exports according to consumed water. The World council of water tries to evaluate world virtual water flows| Random links: | Bus with imperial | Park Ozoir-the-Tool bag | Peros Banhos | Bradić | Bélmez of Moraleda |