The Spatiotemporal Variation Characteristics of Urban Sustainability Based on the SDGs in Yangtze River Delta, China

At present, most developing countries need to improve the quality of the built environment by means of large-scale infrastructure construction, thereby promoting rapid urbanization. The quality of the built environment (Q(U)) and its environmental pressure (P-U) have become our primary focus to achieve a globally acknowledged vision of the Sustainable Development Goals (SDGs). In this study, we proposed an overall workflow by combining the proven urban sustainability (S-U) assessment tool with the evaluation process and the analysis of the spatiotemporal dimension to investigate the urban characteristics of the 41 cities in the Yangtze River Delta. Our results showed an upward trend of urban sustainability from 2010 to 2018, but there are still 19 cities with unsustainable urbanization processes. The megalopolis is rapidly progressing toward an imbalanced state. Specifically, the urban sustainability of the southern region performs better than the northern region, coastal cities perform better than the inland cities, and the regional peripheral cities perform better than the inner cities. Across the 41 cities in the delta, five different relational trends between Q(U) and P-U have been found to predict their future development. The results of this research will help decision-makers to coordinate the future development of regional integration between cities and to target the alleviation of the adverse chain reaction brought about by the situation of imbalance or further improving urban sustainability.