Inter-county virtual water flows of the Hetao irrigation district, China: A new perspective for water scarcity

The implementation of a virtual water trading policy at small and localized scales may potentially contribute to alleviating water scarcity and improving local water management. This study analyzed inter-county virtual water flows related to crop transfer and its relationship with water scarcity in the Hetao irrigation district during 2001-2010. The inter-county virtual water flows was 34.29 × 106 m3/y, and the largest exporter and importer were Dengkou and Qianqi counties, respectively. More than 90% of the virtual water flows originated from counties with lower water stress and was transferred to those with higher water stress. The water scarcity index (the ratio of water withdrawal to availability) was negatively correlated with virtual water balance (the difference between virtual water exports and imports). Counties with relatively high water stress benefited from the current pattern of virtual water flows, but the Hetao irrigation district lost 1.96 × 106 m3 of water annually. In the future, a more accurate evaluation of virtual water flows and a comprehensive understanding of the concept of water scarcity are needed for alleviating water scarcity and forming better production and trade strategies at the scale of irrigation districts.