Virtual Water is the water embodied in a product not in real sense but in virtual sense.
The water required to produce a product is known as virtual water.
It is also known as embedded water or exogenous water. Exogenous water is the water that the countries import in virtual sense and it is exogenous to the importing countries.
In quantitative term one approach defined the virtual water content as volume of water that is used in actual to produce the product. It depends on production conditions such as time and place of production and water use efficiency. e.g. for producing 1 kg of grain in arid environment requires two to three times more water than growing the same grain in humid country.
In second approach virtual water is defined with the perspective of user. It is defined as amount of water that would have been required to produce a product at the location where it is produced.
VALUE OF VIRTUAL WATER
- In water scarce conditions import of virtual water in water deficient country reduce the pressure on water resources.
- Virtual water can be seen as alternative source of water.
- Virtual water can be used as an instrument to solve the geopolitical problems and water wars.
- By exporting virtual water products the nations get economic benefits
- Virtual water trade from high water productive nations to low water productive nations implies real water savings
- Water Footprint is making a connection between consumption pattern and impacts on water.
FACTORS TO QUANTIFY THE VIRTUAL WATER CONTENT OF PRODUCTS
- Virtual water content determination is not an easy task. It depends on many factors such as:
- The place and period
- The point of measurement (e.g. either water use is measured at water withdrawal point or at field level).
- The production method and efficiency of water use.
- The method of attributing water inputs to intermediate products to virtual water content of final products.