Inter-regional agricultural virtualwater flow in China based on volumetric and impact-oriented multi-regional input-output (MRIO) approach

Virtual water trading is an effective strategy to alleviate water shortage. Several different methods have been developed to achieve quantitative description and evaluation of virtual water, which can be broadly divided into volumetric and impact-oriented water footprint approaches. The former focuses on the consumption of water resources, while the latter puts greater emphasis on assessing the water use impacts. Based on the volumetric and impact-oriented water footprint, this paper conducted a comprehensive study on the virtual water flow of agricultural products among regions in China. The results show that different water footprint evaluation methods have different tendencies in evaluating virtual water flow. Volumetric virtual water mainly flows from northwest and northeast China to north and east China, while impact-oriented virtual water mainly flows from northwest and central south China to east and north China. Northwest China is the largest net export region of agricultural virtual water, and it is dominated by direct water consumption. In addition, we compared the net export volume of virtual water and the water shortage situation among regions in China. North China, where the water shortage is very serious, mainly relies on external water sources, while northwest China, which also faces a water shortage problem, exports a large amount of virtual water to external sources. The findings of this study highlight the importance of taking full account of the response measures in both cases when formulating policies. In other words, the virtual water strategy should consider water quantity and water quality simultaneously.