International trade in agricultural commodities and water use in agriculture: The case of Tunisia
Résumé
The article investigates the link between agricultural trade and the use of irrigation water in Tunisia. We build a database that matches region-level information on country’s agricultural production, water footprint, and trade. We highlight the heterogeneity of Tunisian governorates in terms of crop specialization, and of irrigation water footprint of their agricultural production and exports. Our results reveal that most governorates export a larger fraction of their irrigation water than of their agricultural production. Olives and dates, flagship products of Tunisia’s agriculture, account for the vast majority of the virtual water "hidden" in the exports of primary or processed agricultural products. In contrast, the irrigation water productivity of these products is not very high. We estimate this productivity at USD 1/m³ for the exports of dates and at USD 2-3/m³ for the exports of olives and olive oil. Citrus fruits, tomatoes, and cereals, which are cultivated with a major input in rainfall, feature a productivity of irrigation water up to ten times higher. However, most of them are consumed domestically because Tunisia is less competitive in these products on international markets.