Spatiotemporal Differentiation and Driving Factors of Urban–Rural Integration in Counties of Yangtze River Economic Belt

Assessing URI and its driving mechanisms can promote urban–rural integration (URI). However, existing research has often underexplored county-scale analyses within national strategic zones in China and has given limited attention to the spatiotemporal impacts of drivers. Focusing on the Yangtze River Economic Belt (YREB) of China, this study examined the spatiotemporal dynamics of county-level URI from 2000 to 2020 and analyzed the spatiotemporal heterogeneity effects of drivers using a geo-detector and the geographically and temporally weighted regression (GTWR) model. The findings reveal the following: (1) The level of URI in the counties of the YREB generally increased over the study period, though social and spatial integration lagged behind economic and environmental integration. (2) URI decreased spatially from east to west, forming high and low levels of spatial agglomeration in the YREB’s urban agglomerations and the provincial fringes in the west, respectively. (3) Economic development, social fixed asset investment, transportation accessibility, and geographical conditions drove the spatiotemporal differentiation of URI in YREB counties. The elevation significantly hindered URI in the eastern region, while URI in the central region was significantly promoted by social fixed asset investment and transportation accessibility, despite the inhibitory effect of the slope. In the western region, economic development played a critical facilitating role, but the slope remained a limiting factor. Tailored strategies are needed for different regions to promote URI.