The "Gravity" for global virtual water flows: From quantity and quality perspectives

The virtual water trade (VWT) has been proposed as a means of balancing national water budgets while also saving water globally. Since humans require both sufficient quantity and quality of water, the drivers of VWT flows should be thoroughly examined, including its three components. Multiregional input-output (MRIO) and gravity methods are used to investigate the influence of multiple factors on the green, blue, and grey water trading flows among 177 countries in 2014. Several factors were found to be strongly correlated with the grey water trade, offering valuable insight into water resource management, especially about water pollution. The findings verify the driving effects of socio-economic status and agricultural activities on virtual water trade. The study shows that the influence of water resources endowment on the virtual water trade flow is relatively small compared to economic structure in determining virtual water trade flows. The paper contributes to the research on the interaction between virtual water trade and various factors, which can assist decision-makers in optimizing economic structure by integrating water quantity and quality factors and realize sustainable management of water resources.