Measuring urban environmental sustainability performance in China: A multi-scale comparison among different cities, urban clusters, and geographic regions

Assessing urban environmental sustainability is fundamentally important for guiding urban areas to achieve more sustainable urban development. We followed the theme-oriented framework to select eight indicators for measuring urban environmental sustainability performance in China using three aspects: waste emissions, resource consumption, and environmental initiatives. These eight indicators were measured per unit area, per capita, and per GDP for 286 prefecture-level cities, 22 urban clusters, and 7 geographic regions of China from 2000 to 2010. Among the 7 geographic regions, the East China region had the greatest intensity of waste emissions, resource consumption, and environmental investment per unit area. In comparison, the Central China region had greater water consumption and wastewater discharge measured per capita and per GDP. The North China region had greater waste gas emissions and energy consumption measured per capita and per GDP than the other regions. The three northern regions of China (North China, Northeast China, and Northwest China) also had the greatest solid waste emissions measured per capita and per GDP. The expansion of the built-up area per GDP was the greatest in the western regions (including Northwest China and Southwest China), indicating a very low urban land-use efficiency for these two regions. Among the 22 urban clusters, the 12 well-developed urban clusters had greater waste emissions, resource consumption, and environmental investment per unit area than the 10 less-developed urban clusters. The well-developed urban clusters also had larger environmental investment as a share of GDP than the less-developed urban clusters, but waste emissions and resource consumption per GDP were much lower for the well-developed urban clusters. Among the 286 prefecture-level cities, the cities with greater waste emissions and resource consumption per unit area also had greater environmental investment per unit area, but these cities increased their environmental investment at a relatively slower rate than the increase in their waste emissions and resource consumption. The cities that spent a larger share of GDP on pollution reduction had relatively lower waste emissions per GDP, but more investment should be targeted at improving resource efficiency, especially for those resource-intensive cities. In summary, the well-developed urban clusters and cities in the eastern region of China generally had much greater waste emissions and resource consumption per unit area (i.e., greater impacts), while they had lower waste emissions and resource consumption per capita and per GDP (i.e., higher efficiency) relative to the less-developed urban clusters and cities in central and western regions. Based on these findings, we proposed several countermeasures for improving urban environmental sustainability for different cities, urban clusters, and geographic regions of China.