Energy–water nexus of urban agglomeration based on multiregional input–output tables and ecological network analysis: A case study of the Beijing–Tianjin–Hebei region

Abstract

The nexus between energy and water introduces cross-sectoral vulnerabilities, which provides cross-cutting opportunities to mitigate urban energy and water demand pressure. The existing nexus research has generally been limited to inventorying energy-related water and water-related energy. In this study, we propose a hybrid framework to study the interwoven connections of energy consumption and water use for urban agglomerations. The energy-related water and water-related energy are also systematically inventoried with the multi-regional input–output method. Then, a multi-regional nexus network is established, based on ecological network analysis, to explore the structural properties and sectoral interactions between sectors within urban agglomerations. A case study of the Beijing–Tianjin–Hebei region shows the differences of direct energy/water and embodied energy/water consumption between sectors and regions. There are significant changes of control/dependence relationships between sectors and regions after considering the urban agglomeration nexus. Also, the effect of the nexus on water networks is smaller than energy networks. The nexus effect on energy and water networks for Beijing is bigger than those of Tianjin and Hebei. The recycling rates in water networks are around 20–23%, which are lower than those of energy networks (28–30%). The recycling rates of Tianjin and Beijing are higher than that of Hebei. According to the results of energy and water flows between regions, Beijing and Tianjin are dependent on Hebei for water and energy resources, while Hebei is more self-sufficient. The multi-regional network approach presents great potential for bridging nexus analysis with sustainable planning for urban agglomerations by simultaneously mitigating the energy and water burden.