Cross-sectoral urban energy-water-land nexus framework within a multiscale economy: The case of Chinese megacities

Energy, water, and land (EWL) are finite, critical, and intertwined resources in urban system, and the resource management of EWL plays a key part in urban sustainable development. Previous studies lacked a general framework and a deeply cross-sectoral analysis that simultaneously considered all the sectors within the urban economic system of multiple resources. This study introduced an urban ternary multidimensional nexus (UTMDN) framework for modelling complex urban EWL nexus, connecting in-and trans-boundary interactions by the environmental extended multiscale input-output (EE-MSIO) model. We applied this approach to a comparative study of four Chinese megacities in different economic sectors. Results showed that the top -consuming sectors of EWL were heterogeneous and the impacts of urban consumption-oriented behaviour extended beyond the urban boundaries. In particular, the sectors of construction, electricity, gas & water, and others were the main consumption-based energy consumers. The agriculture and food sectors were the major consumption-based water and land consumers. These sectors mostly relied on domestic imports for the four megacities. By contrast, Chongqing's embodied water and land flows in the agriculture sector relied more on local (in-boundary) supply. The obtained results proved that this framework could constitute a solid foundation for assessing the cross-sectoral, in-and trans-boundary EWL nexus of critical sectors centred on cities. These sectoral-based analyses can support industrial restructuring and collaborative management of EWL resources for future urban development.

Automated summary

Energy, water, and land are finite and critical resources in urban systems, and their management is crucial for urban sustainable development. This study introduced a framework that integrates the interconnections between different sectors within the urban economic system to analyze the energy, water, and land nexus. The results show that urban consumption-oriented behavior has impacts beyond city boundaries and different sectors play different roles in resource consumption.