Resumen
If products were traded from regions with relatively high water productivity to regions with relatively low water productivity, water saving could be achieved. In this study, two indices—physical water-saving efficiency (volume of water savings per cubic meter of virtual water flows) and economic water-saving efficiency (value of water savings per cubic meter of virtual water flows considering water right trading)—were proposed to analyze the efficiency of inter-regional virtual water flows related to crop trade in China. Results indicated that the volume of inter-regional virtual water flows was 1.61 × 109 m3, more than 90% of which was occupied by oil-bearing crops, cereals, and beans. In terms of physical efficiency, only cereals and vegetables presented negative values. All kinds of crop trades were economically efficient, while most crops’ economic water-saving efficiency was less than 10 × 103 Yuan/m3. The application of advanced water-saving technologies, the cultivation of new crop varieties, the adjustment of regional cropping patterns, or consumption and trade patterns, could contribute to more water savings and higher physical water-saving efficiency, while the possible social, economic, and environmental tradeoffs should be considered simultaneously. Water right trading and virtual water compensation could contribute to sustainable water consumption, and full-cost pricing should be adapted in the future.