Multi-pollutant based grey water footprint of Chinese regions

Grey water footprint (GWF) is an essential indicator describing the effects of aquatic pollutants on water quantity, which is significantly influenced by interregional trade. Existing studies on the impacts of interregional trade on GWF in China have deviations. That is, traditional GWF is determined by the pollutant with the highest pollutant-specific GWF, but overlooks the influences of coexisting compounds. Coexisting compounds have large influences on GWF quantification. However, the impacts of interregional trade on the improved GWF in China have not been well characterized. This study integrates the multi-regional input-output analysis and an improved GWF quantification method considering multiple pollutants, to investigate the impacts of interregional trade on the GWF in China. Compared with traditional GWF, the improved GWF of Chinese regions decreases by 19-35%. Up to 35% of China's improved GWF is related to commodities that are produced outside of regions where they are finally consumed. Beijing-Tianjin and coastal regions outsource GWF to the central and northern regions. Sectors contributing the most to GWF outsourcing include corn, cattle, swine, poultry, and other animal husbandry. This study provides more accurate region-specific and sector-specific results for policy decisions on water resource conservation in China.

Automated summary

The grey water footprint (GWF) in China is significantly influenced by interregional trade, with traditional GWF quantification methods often overlooking the impacts of coexisting compounds. An improved GWF quantification method reveals that GWF in Chinese regions decreases by 19-35%, with up to 35% of the improved GWF related to commodities produced outside of the regions they are consumed. Sectors such as corn, cattle, swine, poultry, and other animal husbandry contribute the most to GWF outsourcing. This study provides region-specific and sector-specific results for more accurate policy decisions on water resource conservation in China.