What the reclaimed water use can change: From a perspective of inter-provincial virtual water network.

Reclaimed water has been used as an alternative water resource for various economic activities, which inevitably is involved in the virtual water trade. However, the effect of reclaimed water on the virtual water trade has not been evaluated in previous studies. For the sake of sustainable water management, this study explored the benefits of reclaimed water use for balancing the water resource allocation at the interprovincial level. Multiregional input-output analysis and ecological network analysis were used to investigate the spatial and structural characteristics of the virtual reclaimed water network (VRWN) among 31 provinces in China and the potential effect of reclaimed water use. The results show that the net export flows of virtual reclaimed water have different spatial patterns from those of freshwater, some provinces that import virtual freshwater are exporters of virtual reclaimed water. Although the exploitative relationship is the dominant ecological relationship in the VRWN (72%), it is confirmed that reclaimed water use contributes to balancing the virtual water trade of China with a more competitive relationship (21%) than in the virtual freshwater network (4%). The virtual freshwater consumption change rate in developed provinces decreases by more than 10% through reclaimed water use. Due to the high food exports and low application of wastewater reclamation in less developed provinces, the effect of reclaimed water use in those provinces is not as obvious as that in developed provinces. This paper offers a new perspective for understanding the current VRWN and guidance for the optimization of the virtual water trade structure.