Virtual Water Trade (VWT) - Virtual water represents the amount of water that has been used at the producer scale to produce the exported goods. The bilateral trade matrices of VWT are obtained by multiplying bilateral trade data, expressed in metric tons, by the unit water footprint of supply. Unit Water Footprint of production (uWFp) and supply (uWFs) - uWF measures the amount of water required to produce a unit amount of product and it can be expressed as m3/ton or, equivalently, as l/kg. The production-side uWF refers to the producer scale (e.g., farms). It depends on the local actual evapotranspiration and yield of any crops. It is available for primary crops (e.g., wheat, soybean) over 1961-2016 and for animal products in year 2000. The supply-side uWF refers to the consumer scale (e.g., a person, a community, a company, a country). It is available for primary (e.g., wheat, soybean) and processed crops (e.g., flour, soybean oil) over 1986-2016. Water Footprint of production (WF) - WF of production quantifies the total amount of water used at the producer scale to produce any primary crops and animal products in year 2000. It is expressed in cubic meter (m3).

Exporting Country

    Importing Country


        Item Category

        We provide annual data for the crop category and an average value centered on year 2000 for the animal category.





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                In the present database we propose a differentiation between the uWF of production (uWFp) and the uWF of supply (uWFs) of primary and processed crops. The uWFp refers to locally-produced crops whose water footprint depends on the crop actual evapotranspiration and crop yield, with values which are here estimated annually starting from 1961. The uWFs refers to the domestic supply of primary crops, which relies both on local production and on international trade. Domestic supply is used as human consumption, food manufacturing, feed for livestock and as export towards other countries. The impossibility to track local production and imports into consumption and exports, within each country, makes the uWFs the best indicator to be used in conjunction with consumption and export data. The uWFs of primary crops is computed averaging local production and imports, after identifying the countries of origin of the goods thanks to an appropriate procedure applicable from 1986.

                Processed crops are produced from a root product which may or may not originate from local production. The absence of systematic FAO data about the production of processed crops prevents the differentiation between the unit water footprint of production and of supply. Therefore, processed crops considered in this study will have a single unit water footprint, depending on country and year, computed applying some conversion factors to the uWFs of the root product. Finally, animal-based products are here considered only with the WaterStat values, without temporal variability.

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