Urban energy-water nexus: Spatial and inter-sectoral analysis in a multi-scale economy

Large scale urbanization and industrial development has resulted in serious environmental challenges for China. Both energy and water are considered key to urban sustainability and for that matter resource accounting and tracing are drawing growing attention in the economy. This paper focuses on energy-water nexus of urban sectors in Shanghai (referred to year 2010) using multi-regional input-output (MRIO) analysis. This study outcome revealed that overall Shanghai is a net consumer city mainly imports embodied energy and water from domestic and developing regions of the world and exports little to developed regions. In depth analysis indicated that, except S17, S7, S10, S15 and S8 all other industrial sectors were net inflows of energy in Shanghai. Similarly, except S15, all other industrial sectors were net water consumers in Shanghai. The S16 (18.96 Mtce), S20 (11.06 Mtce) and S12 (7.71 Mtce) were ranked highest as net importer making up about 60.48% of total net inflows of embodied energy, whereas S1 (18053.48 Mt), S3 (6865.16 Mt) and S19 (2320.62 Mt) were ranked highest as net importer making up about 74.99% of total net inflows of embodied water. The developed nexus strength indicator uncovered the sectoral energy-water linkages. From a production perspective, the S15 exhibited high nexus strength level up to 1 with 50% contribution by each resource to the nexus. While from a consumption perspective, the S1 revealed high nexus strength level and water was the most frequent resource node contributing about 84% to the energy-water nexus. The energy-water nexus characteristics of industrial sectors can offer different ways to tackle environmental challenges. This study can provide a reference to policy makers in identifying key sectors that requires more focus in terms of easing environmental stress to achieve sustainability in urban development. In addition, called for coordination and regulating urban industrial trade structure in the future.