Urban resilience assessment based on contradiction between supply and demand of the daily activity-environment system: A case study on Nanjing, China.

In addition to safety and risk issues, urban resilience research should focus more comprehensive and universal contradictions. Considering the main contradictions of Chinese urban development, and the connotation of urban resilience, a theoretical framework is constructed based on the contradiction between supply and demand of the daily activity-environment system. Furthermore, an assessment index system of urban resilience is also developed that considers both volume and quality of demand and supply and has a grade standard. Finally, utilizing multi-source geographic big data, Nanjing is taken as a case study, the spatial characteristics and optimization path of urban resilience are identified. The main conclusions are as follows: (1) The activity-environment system resilience presents a "center-periphery" sprawling spatial structure, and it is mainly at the level of "reluctant resilience" and "almost lack of resilience". (2) The evolution of the activity-environment system resilience is still absolutely volume driven, and the positive drive of relative quality is limited or even reversed. In addition, all the bilateral local spatial autocorrelations are generally represented as "center-periphery" separated spatial structures, but it is not always consistent with the overall trend. (3) For the governance of urban resilience, it is necessary to focus on common improvement and matching of absolute volume and relative quality in contents, orderly flow, accumulation and dispersion of supply and demand in ideas, and the strong support of new ideas and technologies in methods.