Linkage analysis for the water-energy nexus of city

Rapid urbanization and the expansion of metropolitan areas have resulted in severe demands on water and energy resources, which threaten the sustainability of the urban economy and environment. In this paper, an input-output model and linkage analysis are used to detect the synergetic effects of water and energy consumption and interactions among economic sectors. Beijing is chosen as a case study to investigate the water-energy nexus and the water and energy importing and exporting functions of major economic sectors. The results reveal that the agriculture and food processing sectors are major virtual water suppliers, while petroleum and natural gas processing, and electricity production sectors are major embodied energy suppliers. These energy suppliers mainly import intermediate products to satisfy the final demand of Beijing, thus transferring resources pressure to other regions. With rapid urbanization, the real estate industry sector chain has become an important water-energy nexus node and resources transfer node. The real estate sector needs large amounts of virtual water and embodied energy resource inputs to continue its production and thereby promote the growth of logistical industries. The transportation sector was also found to be important energy consumer and energy transfer node. In addition, the services sector, contributing one fourth of Beijing's total GDP, is a key water-energy nexus node because it consumes considerable amounts of both virtual water and embodied energy resources to support its production pattern.