Inter-regional Virtual Water Flow In China Based On Resource- And Environment-oriented Multi-Regional Input-Output Approach

Clean water is the sixth indicator of the United Nations Sustainable Development Goals?SDGs?.Also,it is not only a natural resource that human beings depend on but also a strategic resource for sustainable economic and social development.Sustainable water conservation and consumption is a major challenge for China.This paper introduces the concepts of resource-and environment-oriented water footprints.The former focuses on water resource consumption,while the latter focuses on the assessment of the environmental impact of water use.The Multi-Regional Input-output Approach model evaluated inter-regional resource-and environment-oriented water footprint in China and analyzed the virtual water flow in China caused by trade.It provides a scientific reference for water resource management in different regions and industries in China.This paper first evaluates China's resource and environment-oriented water footprint and virtual water flow in 2012 and 2015 based on a multi-region input-output model.The results show that the agricultural sector is the sector with the highest water footprint,accounting for more than 70%of the total water footprint.In 2012,agricultural resource-and environment-oriented water footprints were the highest,382487×10⁶ m³ and 62464×10⁶ m³ H₂Oeq respectively.In 2015,the resource-and environment-oriented water footprint of each sector decreased to some extent compared with 2012,but the proportions of resource-and environment-oriented water footprint of the agricultural sector were increased.The agricultural sector's water consumption coefficient is much higher than in other industries,so there is very high water saving space in this sector.Due to the difference in economic development technology level,the resource-oriented unit GDP water consumption of Northwest China ranks first in the country,reaching176.29 m³/10⁴ yuan in 2012.While North China is the largest environment-oriented virtual net water export region,reaching 36.2 m³H₂Oeq/10⁴ yuan in 2012,which shows that the cost of water consumption environment in North China is too high.Much of the virtual water is moving from the poor west to the rich east.Northwest China is the largest resource-oriented virtual water net export region,while North China is the largest environment-oriented virtual water net export region,and East China is the largest resource-and environment-oriented virtual water net import area.The underdeveloped regions mainly rely on exporting water-intensive products to exchange with technology-intensive products in developed regions,resulting in western regions to achieve the same economic growth with eastern regions that need to pay more resources and environmental costs.Agriculture,as the industry with the largest water consumption,the amount of water resources consumed in the production process and the environmental impact caused by the use of pesticides and fertilizers cannot be ignored.Based on the multi-region input-output model,this study combined the water quality and quantity of the agricultural sector to account for and evaluated resource-and environment-oriented agricultural virtual water flows.The results show that different water footprint evaluation methods have different tendencies in evaluating virtual water flow.Resource-oriented virtual water mainly flows from Northwest and Northeast China to North and East China,while environment-oriented virtual water mainly flows from Northwest and Central South China to East and North China.Northwest region is the largest net export area for agricultural virtual water,with resource and environment-oriented virtual water net export values of 37736×10⁶ m³ and 362237×10⁶ m³ H₂Oeq,respectively.In addition,we compared the net export volume of virtual water and the water shortage situation in various regions of China.North China,where the water shortage is very serious,mainly relies on external water sources,while northwest China,which also faces a water shortage problem,exports a large amount of virtual water to external sources.Based on the above research results,this study proposes that to pay more attention to water resource consumption.Also,we must pay attention to the impact of water use on the environment when formulating relevant water use policies.Policy guidance that considers only water consumption is likely to have a negative impact on the water environment.Therefore,this study puts forward a series of policy recommendations such as accelerating the technology transfer of key water-saving and emission-reduction potential industries and regions,and establishing a cross-regional virtual water compensation mechanism through regional trade,to ensure the maximum sustainable use of water resources among regions in China.