Assessment of the water-energy-food nexus under spatial and social complexities: A case study of Guangdong-Hong Kong-Macao.

Water, energy, and food resources are indispensable and irreplaceable resources for the survival and development of human society. This study systematically assessed the three resources system in Guangdong, Hong Kong, and Macao based on constructed direct and nexus-oriented, multi-regional input-output, and ecological network analysis models. Various network analysis (e.g., control, utility, hierarchy, and robustness) was adopted to identify the critical factors of inter-regional resources trade from a perspective of supply-demand. The results indicated that Guangdong, Hong Kong, and Macao have complex control linkages in the three resources trade network, and Guangdong is the key to improving the three resources network structure. The three resources network existed highly competition and exploitation in the three regions. Industrial development is unbalanced and competitive for the three resources. The wholeness water-energy-food trade network of the three regions stayed in a positive environment, but the positive effect level was relatively weak. The three resources network robustness in the three regions is at a medium level. Hong Kong and Macao's water-energy-food network systems have a high vulnerability, and the lowest system robustness was food-related energy in Hong Kong. Finally, we provide some measures to help the sustainable development of the water-energy-food resource system in the three regions, such as cross-regional coordinated management, integration industries development, seawater toilets-flushing, sea rice, and renewable energy.