Road-Ecology Coupled Networks and the Evolution of County Spatial Structure

Rural spatial restructuring in rapidly urbanizing regions is jointly shaped by road expansion and ecological constraints, yet existing studies often examine transportation and ecological systems in isolation. This study develops a coupled “road–ecology” network framework to investigate the evolution of county spatial structure in Huangchuan County, China, from 2013 to 2023. Using administrative village, transportation, and land-use data, we construct and analyze road and ecological networks with complex network metrics, multilayer network analysis, and Exponential Random Graph Models (ERGM). The results show that the road network evolved from a single-center hierarchical structure toward a balanced multi-center configuration, while the ecological network maintained structural stability through strengthened regional ecological clustering. The coupled network underwent a transition from spatial exclusion to limited integration, and its persistently negative interlayer assortativity values are consistent with ecological land configuration acting as a spatial constraint on road expansion. Multilayer network metrics further indicate a trend toward increased local coordination in the road-ecology coupled system, indicating a gradual evolution toward a more spatially coordinated configuration. This study advances the application of multilayer network approaches in rural spatial research and provides a new perspective for understanding sustainable county spatial restructuring under driving-constraint balance.