Virtual Water Flows Related to Grain Crop Trade and Their Influencing Factors in Hetao Irrigation District, C hina

Abstract

Virtual water adds a new dimension to crop trades a nd provides a new way of thinking about water scarcity. A systematic analysis of virt ual water flows requires integration of all critical drivers of virtual water flows under a single consistent framework. The aim of this study was to assess virtual water flows relate d to trades of grain crops (wheat, corn, rice, and coarse cereals) and their influencing fac tors in Hetao irrigation district, China during 1981-2010. Results indicated that: (1) volum e of virtual water export decreased from 2.08×10 9 m 3 in 1981 to 1.27×10 9 m 3 in 2010. Volume of virtual water import fluctuated around 621.48×10 6 m 3 during study period; (2) Cultivated area per capit a and total population were the major influencing factors for virtual water export in Hetao irrigation district. Volume of virtual water import was mainly influenced by consumption and retail price index of grain crops. Combination of large volume of virtual water export and severely constrained water resources confronted Hetao irrigation district with great challenges in its sustainable development. Decreasi ng virtual water export is a mean to alleviate regional water shortage pressure, and may be achieved by measures that constrain continued population expansion. Keywords: Cereal crop, Embedded water, Irrigated area.