Virtual water

The virtual water trade (also known as trade in embedded or embodied water), a concept introduced by Tony Allan, is the hidden flow of water if food or other commodities are traded from one place to another. For instance, it takes 1,340 cubic meters of water (based on the world average) to produce one metric tonne of wheat. The precise volume can be more or less depending on climatic conditions and agricultural practice. Hoekstra have defined the virtual-water content of a product (a commodity, good or service) as "the volume of freshwater used to produce the product, measured at the place where the product was actually produced".[1] It refers to the sum of the water use in the various steps of the production chain.

History

The virtual water concept, also known as embodied water, was coined by John Anthony Allan (Tony Allan) in 1993. He received the Stockholm Water Prize for this innovative concept late in 2009.

Water footprint

The concept of virtual water trade was introduced to refer to the idea that countries can save domestic water by importing food. Imported food, however, comes from somewhere. In 2002, Arjen Y. Hoekstra, while working for UNESCO-IHE, introduced the concept of water footprint[8] The water footprint shows the link between consumer goods or a consumption pattern and water use and pollution. Virtual water trade and water footprint can be seen as part of a bigger story: the globalization of water.

Embodied energy

Some researchers have attempted to use the methods of energy analysis, which aim to produce embodied energy estimates, to derive virtual, or embodied water estimates.[9]

Criticism

Australia's National Water Commission considers that the measurement of virtual water has little practical value in decision making regarding the best allocation of scarce water resources.[10]

Limitations of the virtual water measure

Key shortcomings of virtual water measures are that the concept:

  1. It relies on an assumption that all sources of water, whether in the form of rainfall or provided through an irrigation system, are of equal value.[11]
  2. It implicitly assumes that water that would be released by reducing a high water use activity would necessarily be available for use in a less water-intensive activity. For example, the implicit assumption is that water used in rangeland beef production would be available to be used to produce an alternative, less water-intensive activity. As a practical matter this may not be the case, nor might the alternatives be economic.[11]
  3. It fails as an indicator of environmental harm nor does it provide any indication of whether water resources are being used within sustainable extraction limits. The use of virtual water estimates, therefore, offers no guidance for policymakers seeking to ensure that environmental objectives are being met.[11]

The deficiencies with the concept of virtual water mean that there is a significant risk in relying on these measures to guide policy conclusions. Accordingly, Australia's National Water Commission considers that the measurement of virtual water has little practical value in decision making regarding the best allocation of scarce water resources.[12]

Other limitations more specific to the MENA (the Middle East & North Africa) region include:

  1. In MENA rural societies, farmers are by tradition politically influential and would prohibit new policies for water allocation. Reallocating the water resources adds a huge burden on the farmers especially when a large portion of those farmers use their land for their own food consumption which happens to be their only source of food supply.[13]
  2. Importing food could pose the risk of further political dependence. The notion of "self-sufficiency" has always been the pride of the MENA region.[14]
  3. The use of virtual water lies in the religious regulations for charging for water. According to Al-Bukhari, Prophet Mohammad's teachings, the Prophet said: "People are partners in three: Water, Herbs and Fire" (referring to basic energy resources). Therefore, and because farmers are generally poor and rainwater, rivers, and lakes are like a gift from God, the MENA countries might find it difficult to charge the farmers the full cost for water.[14]

Virtual water content of selected products

The following table shows the average virtual water content of some selected products for a number of selected countries (m3/ton):[15]

ProductUSAChinaIndiaRussiaIndonesiaAustraliaBrazilJapanMexicoItalyNetherlandsWorld average
Rice (paddy)1,2751,3212,8502,4012,1501,0223,0821,2212,1821,6792,291
Rice (husked)1,6561,7163,7023,1182,7931,3274,0031,5862,8342,1802,975
Rice (broken)1,9031,9724,2543,5843,2091,5254,6001,8223,2572,5063,419
Wheat8496901,6542,3751,5881,6167341,0662,4216191,334
Maize4898011,9371,3971,2857441,1801,4931,744530408909
Soybeans1,8692,6174,1243,9332,0302,1061,0762,3263,1771,5061,789
Sugar cane103117159164141155120171175
Cotton seed2,5351,4198,2644,4531,8872,7772,1273,644
Cotton lint5,7333,21018,69410,0724,2686,2814,8128,242
Barley7028481,9662,3591,4251,3736972,1201,8227181,388
Sorghum7828634,0531,2125822,853
Coconuts7492,2551,9542,545
Millet2,1431,8633,2694,5344,596
Coffee (green)4,8646,29012,18028,11917,373
Coffee (roasted)5,7907,48814,50033,47520,682
Tea (made)11,1107,0029,205
Beef13,19312,56016,48237,76221,16711,68115,497
Pork3,9462,2114,3976,5596,3773,7904,856
Goat meat3,0823,9945,18710,2524,1802,7914,043
Sheep meat5,9775,2026,69216,8787,5725,2986,143
Chicken meat2,3893,6527,7365,0132,1982,2223,918
Eggs1,5103,5507,5314,2771,3891,4043,340
Milk6951,0001,3691,3451,1439151,0018122,382861641990
Milk powder3,2344,6486,3686,2535,3174,2554,6543,77411,0774,0052,9824,602
Cheese3,4574,9636,7936,6715,6754,5444,9694,03211,8054,2783,1904,914
Leather (bovine)14,19013,51317,71022,57515,92918,38418,22211,86440,48222,72412,57216,656

See also

References
  1. Hoekstra AY, Chapagain AK (2007). "Water footprints of nations: water use by people as a function of their consumption pattern". Water Resources Management. 21 (1): 35–48. doi:10.1007/s11269-006-9039-x.
  2. , Turton, A.R. 1998. The Hydropolitics of Southern Africa: The Case of the Zambezi River Basin as an Area of Potential Co-operation Based on Allan's Concept of ‘Virtual Water’. Unpublished M.A. Dissertation, Department of International Politics, University of South Africa, Pretoria, South Africa.
  3. Turton, A.R., Moodley, S., Goldblatt, M. & Meissner, R. 2000. An Analysis of the Role of Virtual Water in Southern Africa in Meeting Water Scarcity: An Applied Research and Capacity Building Project. Johannesburg: Group for Environmental Monitoring (GEM).
  4. Earle, A. & Turton, A.R. 2003. The Virtual Water Trade amongst Countries of the SADC. In Hoekstra, A. (Ed.) Virtual Water Trade: Proceedings of the International Experts Meeting on Virtual Water Trade. Delft, the Netherlands, 12–13 December 2002. Research Report Series No. 12. Delft: IHE. Pp. 183-200.
  5. Berrittella M, Hoekstra AY, Rehdanz K, Roson R, Tol RS (2007). "The Economic Impact of Restricted Water Supply: A Computable General Equilibrium Analysis". Water Research. 41 (8): 1799–813. doi:10.1016/j.watres.2007.01.010. PMID 17343892.
  6. Allan T (1998). "Watersheds and problem sheds: Explaining the absence of Armed Conflict over water in the Middle East". Middle East Review of International Affairs. 2 (1). Archived from the original on November 27, 2006.
  7. Earle, A. 2003. Watersheds and Problemsheds: A Strategic Perspective on the Water/Food/Trade Nexus in Southern Africa. In Turton, A.R., Ashton, P.J. & Cloete, T.E. (Eds.) Transboundary Rivers, Sovereignty, and Development: Hydropolitical Drivers in the Okavango River Basin. Pretoria & Geneva: AWIRU & Green Cross International. Pp. 229-249.
  8. . Water Footprint Network https://waterfootprint.org/en/about-us/aims-history/. Retrieved 10 June 2020. In 2002, Arjen Hoekstra, whilst working at the UNESCO-IHE Institute for Water Education, created the water footprint as a metric to measure the amount of water consumed and polluted to produce goods and services along their full supply chain. Missing or empty |title= (help)
  9. Lenzen M, Foran B (2001). "An Input-Output analysis of Australian water usage". Water Policy. 3 (4): 321–40. doi:10.1016/S1366-7017(01)00072-1.
  10. http://content.webarchive.nla.gov.au/gov/wayback/20160615091008/http://archive.nwc.gov.au/__data/assets/pdf_file/0005/11885/DistilledJuly2008.pdf ISSN 1833-1491
  11. Virtual Water - The concept of Virtual Water
  12. Distilled: eNewsletter of Australia's National Water Commission, Edition 30 — July 2008
  13. Slide 1 Archived July 18, 2011, at the Wayback Machine
  14. Expert Statement on Virtual Water Archived July 22, 2011, at the Wayback Machine by Dr. Hazim El-Naser and Mohammad Abbadi (2005).
  15. Craswell, E.; Bonnell, M.; Bossio, D.; Demuth, S.; van de Giesen, N. (2007). Integrated Assessment of Water Resources and Global Change: A North-South Analysis. Springer Netherlands. p. 40. ISBN 978-1-4020-5591-1. Retrieved August 8, 2015.

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