Multiregional input-output and ecological network analyses for regional energy-water nexus within China

Water use and energy consumption are strongly interwoven in networks of economic activity. Tracking energy and water flows among regions and quantifying their interdependencies are fundamental for synergetic management of these two essential resources. In this work, we built an accounting framework to assess the performance of energy-water nexus networks within China. Water consumption for various energy types and energy consumption in all stages of water use were inventoried for different regions. Then, direct and indirect energy and water embodied in monetary flows among regions were calculated via multiregional input-output analysis to build an embodied energy network, embodied water-related energy network, embodied water network, and embodied energy-related water network. Finally, a set of ecological network analysis indices were used to analyze the properties and connection of these four networks. The results show disparities of water-related energy/total energy ratios among regions and the nexus impact on regional energy and water systems. Beijing and Shanghai have large ratios of final demand consumption because of their large population and rapid economic development. Embodied water and energy consumption in capital stock in Hainan, Ningxia represented 15% of total consumption by booming investments. We found that embodied water was transferred from western to eastern regions and northern to southern regions. Major energy export-import pairs were Xinjiang-Shanghai, Hebei-Beijing, Xinjiang-Zhejiang, and Jiangsu-Shanghai. Regions with controller/relier roles in the network were identified in the context of nexus impact, for which Beijing and Shanghai have a strong control and dependence relationship with other regions. The proposed nexus network approach may help bridge the gap between nexus modeling and regional resource management.