The impact of interregional trade on both quantity- and quality-related water scarcity of Beijing-Tianjin-Hebei urban agglomeration in China

Exploring the impact of interregional trade on water resources from both quantity and quality perspectives is essential for sustainable water use in water-scarce metropolitan areas in emerging economies. This study used a multi-regional input-output model to uncover the trade-driven quantity and quality water stress through blue and grey water footprint of the Beijing-Tianjin-Hebei (BTH) region, one of the most water-scarce metropolitan in China. The results indicate that 35% of the blue water footprint and 54% of the grey water footprint in the BTH region can be attributed to local consumption. Moreover, interregional trade mitigates quantity water stress but intensifies quality water stress in the BTH region. The core cities, Beijing and Tianjin, shifted their quantity and quality of water stresses virtually to peripheral cities that located in Hebei province. We suggest that cities the water scare cities benefiting from inter-regional trade should gradually reduce their dependence on scarce water resources of other regions. Meanwhile, the cities whose water scarcity was intensified by interregional trade should improve water use efficiency to achieve sustainable water use. Our findings in China could provide references for other metropolitan areas facing similar quantity and quality water scarcity issues.