Risk transmission and driving factors of virtual water flows from the perspective of China's interregional water-energy-food trade

Changes in water, energy, and food (WEF) trade patterns may reshape water circulation patterns, leading to potential water supply and demand risks. Analysis of virtual water risk transmission characteristics and driving factors from the perspective of WEF trade is highly important for alleviating the risk of water shortages and promoting the efficient use of resources. In this paper, a set of methods for quantifying risk transmission values is constructed on the basis of China's interregional input-output model, and the key paths of interregional virtual water risk transmission caused by WEF trade are identified using innovative methods. On this basis, through the modified gravity model, the key driving factors of virtual water flow are discussed, and the differences in the driving factors between efficient and inefficient virtual water risk transmission paths are compared and analyzed. The results show that in interregional virtual water flows caused by WEF trade, provinces with lower water use coefficients are more inclined to transfer virtual water in, whereas provinces with higher water use coefficients are more inclined to transfer virtual water out, which restricts the comparative advantages in virtual water trade from being fully enjoyed. From 2002 to 2017, the water scarcity risk decreased in many provinces in China due to interregional WEF flows, and the impact of energy and food flows on reducing the risk of water shortages became more significant. Paths with higher risk transmission values easily appear between Zhejiang, Guangdong, Yunnan, Ningxia, and other provinces, whereas paths with lower risk transmission values appear between Hainan, Qinghai, Hubei, Fujian, and other provinces. In addition, the water use coefficient is the most important factor driving inefficient risk transmission. Improving the water use efficiency of WEF resource-intensive industries can effectively inhibit inefficient virtual water risk transmission.