Spatio-temporal evolution of coupling coordination between new infrastructure and regional sustainability in China

To achieve high-quality development, it is crucial to encourage the coordinated development of new infrastructure (NI) and regional sustainability (RS). Based on the coupling mechanism of NI and RS, this study develops a comprehensive evaluation index system, coupling coordination degree model (CCDM), spatial autocorrelation model, and standard deviation ellipse model used to estimate the coupling coordination degree (CCD) of NI-RS in China mainland between 2013 and 2020 and analyze the temporal and spatial evolution characteristic. The results showed the following: (1) The NI index fluctuated and increased, while the RS index increased year by year, showing a gradient-decreasing distribution pattern from east to west; (2) CCD increases year by year, but the spatial distribution is unbalanced, and CCD in eastern coastal areas is significantly higher than that in western areas. (3) The CCD of NI and RS showed a significant spatial positive correlation, showing that the high-value cluster in the east and the low-value cluster in the west. (4) The standard deviation ellipse of the national CCD showed a northeast-southwest distribution, the center of gravity migrated to the southwest, and the spatial clustering characteristics were significant. (5) Finally, the GM (1,1) model indicates a steady increase in CCD from 2021 to 2025. Based on the location distribution and evolution of the CCD between NI and RS in China, corresponding policy suggestions are put forward.