Quantification of virtual water balance of Tunisia: flows embedded in the main produced, consumed and exchanged agricultural commodities

This paper estimates the virtual water content and flows of Tunisia embedded in its main exchanged strategic agricultural commodities, with clear quantification of both green and blue water. Comprehensive surveys of inputs and outputs of the main agricultural commodities consumed and exported in Tunisia were conducted and validated in all bioclimatic regions of the country. Virtual water content was also estimated for the same crops in different bioclimatic areas. Our calculations show that Tunisia is a net virtual water "importer". We also surprisingly show that, even though olive production is mostly rain fed, olive oil production is still identified as the most water-demanding commodity (7 [m.sup.3]/kg) in Tunisia due to the need of blue water for its processing. By exporting 145.9 thousand tons of olive oil and 97.8 thousand tons of date in 2013, Tunisia has respectively lost 1079.6 and 283.6 Million [m.sup.3] of virtual water. On the other hand, by importing 2146.6 thousand tons of cereals and 15.7 thousand tons of potato in the same year, Tunisia has respectively saved 2901.7 and 3.14 Million [m.sup.3] of water resources. Key word: Trade, Agriculture, Virtual Water, Tunisia Jel classification: Q25, Q27, Q17 Ce travail evalue la teneur en eau virtuelle et les flux de la Tunisie incorpores dans ses principaux produits agricoles strategiques echanges, avec une quantification precise de l'eau verte et bleue. Une enquete approfondie des principaux produits agricoles consommes et exportes en Tunisie a ete realisee et validee dans toutes les regions bioclimatiques du pays. La teneur en eau virtuelle a egalement ete estimee pour les memes cultures dans differentes regions bioclimatiques. Nos calculs montrent que la Tunisie est un pays "importateur net " d'eau virtuelle. Nos resultats montrent aussi que, meme si la production d'olives est principalement non-irriguee, la production d'huile d'olive est toujours identifiee comme le produit le plus exigeant en eau (7 [m.sup.3] / kg) en Tunisie en raison de la necessite de l'eau bleue pour. sa transformation. Des lors, en exportant 145.9 mille tonnes d'huile d'olive et 97.8 mille tonnes de dattes en 2013, la Tunisie a perdu respectivement 1079.6 et 283.6 M[m.sup.3] d'eau. D'autre part, en important 2146.6 mille tonnes de cereales et 15.7 mille tonnes de pommes de terre dans la meme annee, la Tunisie a economise respectivement 2901,7 et 3.14 6 M[m.sup.3] de ressources en eau. Mot cle: Commerce, Agriculture, Eau Vir