Qi Hang, Zeng Siyu, Shi Lei, Dong Xin
School of Environment, Tsinghua University, Beijing, 100084, China.
School of Environment, Tsinghua University, Beijing, 100084, China; Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing, 100084, China.
J Environ Manage. 2021 Jun 1;287:112350. doi: 10.1016/j.jenvman.2021.112350. Epub 2021 Mar 16.
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.
再生水已被用作各种经济活动的替代水资源，这不可避免地涉及到虚拟水贸易。然而，以往的研究尚未评估再生水对虚拟水贸易的影响。为了实现可持续的水资源管理，本研究探讨了使用再生水在省际层面平衡水资源分配的益处。采用多区域投入产出分析和生态网络分析方法，研究了中国31个省份之间虚拟再生水网络（VRWN）的空间和结构特征以及再生水利用的潜在影响。结果表明，虚拟再生水的净出口流量与淡水的净出口流量具有不同的空间格局，一些进口虚拟淡水的省份是虚拟再生水的出口省份。虽然剥削关系是VRWN中的主导生态关系（72%），但研究证实，与虚拟淡水网络（4%）相比，使用再生水以更具竞争力的关系（21%）有助于平衡中国的虚拟水贸易。发达省份通过使用再生水，虚拟淡水消费变化率下降超过10%。由于欠发达省份粮食出口量大且废水回收利用率低，这些省份使用再生水的效果不如发达省份明显。本文为理解当前的VRWN提供了新的视角，并为优化虚拟水贸易结构提供了指导。
