The Driving Mechanism of Urban-Rural Integration from the Perspective of Flow Space in the Pearl River Delta of China

The free flow of urban and rural elements, particularly population mobility, serves as a critical prerequisite for achieving urban-rural integrated development. However, existing studies inadequately address the bidirectional human mobility and its multidimensional driving mechanisms. To bridge this gap, this study apply flow-based geographically weighted regression (FGWR), integrating mobile phone signaling data and multisource geospatial datasets to quantify the spatial heterogeneity of daily population mobility patterns and their determinants. Key findings reveal spatial polarization: population flows exhibit a strong core-periphery structure centered on Guangzhou-Foshan, with long-distance rural-to-urban mobility dominated by regional cores, whereas urban-to-rural flows are constrained to shorter distances. Dualistic drivers are identified: structural factors such as industrial upgrading suppress bidirectional mobility, while administrative boundaries and high-speed rail (HSR) networks act as accelerators; asymmetric public service effects show that public service provision attracts rural-to-urban influx but inhibits reverse flows. Spatially varying mechanisms further demonstrate that public services exert stronger impacts on urban-to-rural mobility in the Foshan-Dongguan corridor, administrative boundaries most significantly shape bidirectional flows in Foshan, and Shenzhen-Dongguan interactions dominate suburbanization processes. These findings advance theoretical frameworks on urban-rural mobility by decoupling bidirectional mechanisms and empirically validating the non-stationarity of spatial effects through FGWR. Practically, they inform targeted policies for reducing mobility frictions and fostering equitable integration.