title: Worse than imagined: Unidentified virtual water flows in China.
abstract: The impact of virtual water flows on regional water scarcity in China had been deeply discussed in previous research. However, these studies only focused on water quantity, the impact of virtual water flows on water quality has been largely neglected. In this study, we incorporate the blue water footprint related with water quantity and grey water footprint related with water quality into virtual water flow analysis based on the multiregional input-output model of 2007. The results find that the interprovincial virtual flows accounts for 23.4% of China's water footprint. The virtual grey water flows are 8.65 times greater than the virtual blue water flows; the virtual blue water and grey water flows are 91.8 and 794.6 Gm3/y, respectively. The use of the indicators related with water quantity to represent virtual water flows in previous studies will underestimate their impact on water resources. In addition, the virtual water flows are mainly derived from agriculture, chemical industry and petroleum processing and the coking industry, which account for 66.8%, 7.1% and 6.2% of the total virtual water flows, respectively. Virtual water flows have intensified both quantity- and quality-induced water scarcity of export regions, where low-value-added but water-intensive and high-pollution goods are produced. Our study on virtual water flows can inform effective water use policy for both water resources and water pollution in China. Our methodology about virtual water flows also can be used in global scale or other countries if data available.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China. Electronic address: caibeiming@gmail.com.
authors.forename: Beiming
authors.initials: B
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China. Electronic address: wangchencheng@nju.edu.cn.
authors.forename: Chencheng
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China; Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), Nanjing University of Information Science & Technology, Jiangsu 210044, China. Electronic address: zhangb@nju.edu.cn.
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
mesh_terms: D000383:Agriculture; D002681:China; D014867:Water; D062066:Water Resources; D014881:Water Supply
chemical_list: D014867:Water
keywords: Multiregional input-output analysis; Virtual water flows; Water footprint; Water scarcity