A New Approach to Evaluate the Sustainability of Ecological and Economic Systems in Megacity Clusters: A Case Study of the Guangdong–Hong Kong–Macau Bay Area

An emergy analysis is used to assess the sustainability of urban agglomerations’ eco-economic systems, which are generally measured by emergy–value indicators using a combination several system indicators. However, this assessment approach not applicable economically developed high-density agglomerations. The application traditional entropy value evaluation method needs be expanded further strengthen complex eco-economic–social relationships in megacity cluster regions. In study, taking Guangdong–Hong Kong–Macau Greater Bay Area (GBA) as case we study new for evaluating sustainable development capacity cities. This based on power and construct all social–economic–natural subsystems system, it couples degree with coordination degree. (1) shows that clusters more accurate comprehensive. rankings provided Zhaoqing, Jiangmen, Huizhou, Guangzhou, Macau, Foshan, Zhongshan, Dongguan, Zhuhai, Shenzhen. Hong Kong most representative, high index, but has lowest level clear incoherence within system. (2) current structure GBA city extremely unreasonable. resource-consuming common characteristic low coordinated development. Although have some potential terms renewable resources, recycling rate waste low, consumption nonrenewable resources high. effective use land become an important factor bottlenecking development, other cities face such problems, except Huizhou. (3) can divided into three categories according method. Category 1 mainly includes Kong, Shenzhen, degrees ranging between 0.0 0.135 highest density (ED) values dependent external emergy. They levels per capita (EUC), living standards, quality life. severely restricts economic resulting extreme ecological environmental carrying pressure. 2 whose range from 0.143 0.179. these at middle amongst whole GBA. Their main characteristics flow subsystem indices category 3, each its own characteristics. 3 include 0.192 0.369. These characterized relatively ED EUC values, quality, their certain potential. self-sufficiency (ESR) natural support capacity, loading ratio (ELR) still much higher than national average. innovation levels, ranked > 3. conditions blue–green space protection, < results provide scientific consistent directions ecological–economic–social systems decision-making services systems.