Extended exergy-based urban ecosystem network analysis: a case study of Beijing, China
Sustainable development of urban areas has been a hot topic of ecosystem management research for years. Based on the account of the extended exergy utilization in the society of Beijing, which is considered as the composition of extraction (Ex), conversion (Co), agriculture (Ag), industry (In), transportation (Tr), tertiary (Te) and households (Do) sectors, an urban metabolism network models are constructed to gain insights into the metabolic processes that orient to sustainable urban development. The results showed that a great deal of energy and resources have to be consumed to maintain the structure and function of a city. The social system in Beijing is a highly competitive network, and there are 8 competitive relations and only two mutualistic ones. The Do- and Ag-sector are the major controlling factors of the system. Do- and In-sector have the larger environmental burden. The conclusions indicate that the exergy-based network analysis can be refined to become an integrative tool for evaluation, policymaking and regulation for ecosystem management concerning structure and efficiency at urban levels.