Virtual water

As a virtual water or water that water is called latent, being spent to produce a product. Considering the balance of the virtual water consumed per day any German about 4000 - 5000 liters of water. The term was coined by the English geographer John Anthony Allan to 1995. For his performance, he received the 2008 " Stockholm Water Prize " of the Stockholm International Water Institute.

With virtual water the amount of water indicated that accrues after an extensive record as actually used quantity for each product. In the manufacture of microchips 32 liters of water are consumed in the production of 1 kilogram of beef 15,000 liters. In the balance sheet is also at first glance, a hidden water consumption. For example, falls in the production of beef not only the consumption of drinking water for the animals, but also the natural rainfall and irrigation of the fields and meadows, which provide the feed. A distinction is made ( rainfall and natural soil moisture ) and " blue virtual water " ( irrigation ) between " green virtual water ".

Accounting of virtual water

The investigations aim at a future economic water consumption in regions with water shortages. In particular, should be made transparent, that water-intensive and export-oriented agricultural use is environmentally and economically absurd comparatively unprofitable in dry regions of the world. Water poor countries can deliberate import of goods whose production requires a lot of water, their own water conserving resources.

The calculation of the virtual water also makes it possible to investigate the international transfer of products in bound water. Germany exported virtual water that is consumed in industrial production and imports of virtual water, particularly in agricultural products ( which include the most water consuming cotton heard ). In Germany belongs to the ten largest importers of virtual water.

With the accounting virtual water especially the UNESCO -IHE Institute for Water Education UNESCO busy. The Institute publications include this consumption amounts of virtual water:

Water Footprint

The English term 'water footprint', translatable with footprint of water use, including the total amount of water needed for the production of goods and services, which takes the population of a country to complete. Thus, this definition also includes quantities of water were consumed outside the country for goods that are produced for this country. Here, the water consumption for " blue ", " green " and " gray " water distinguished: the " blue footprint" refers to the groundwater and surface water that is evaporated directly in production. The "green footprint" describes the amount of water that evaporates through the vegetation itself and is thus especially in the agricultural economy. The "gray footprint" includes the amounts of water that are contaminated by production processes.

The Water Footprint Network is a network of scientists who work at these issues with the UN. Examples of water footprints of different countries:

• The water consumption index in China is about 700 cubic meters per capita per year; about 7 % of which are imported via freight.
• In Germany, this index is 1.545 m³. The causes lie in the high consumption of industrial products and meat: Their Hidden water import exceeds the export of virtual water clear 106 parts of water introduced are 70 parts of executed quantity of water over.
• The water footprint of Japan is 1,150 cubic meters per capita per year; about 65 % of them are already being used outside the country.
• The water consumption index of the United States, whose trail of water, is 2,483 cubic meters per capita per year.