Coupling urbanization and landscape ecological risk in the agricultural-dominant Liaohe River Basin

As the main distribution area of cities, the rapid expansion of urbanization has profoundly altered landscape patterns in large and medium-sized river basins, triggering potential ecological risks. However, the dynamic relationship between urbanization and landscape ecological risks (LER) in agricultural-dominated river basins remains poorly understood, limiting effective environmental management. Focusing on the Mainstream of the Liaohe River Basin in northern China-a region characterized by intensive cropland and accelerating urbanization. Based on the landscape pattern indices and urbanization progress, this study employed a coupling coordination degree model to evaluate the spatiotemporal patterns and coupling relationship between urbanization and LER from 1990 to 2019. The results indicate that urbanization increased notably by 86.36%, primarily driven by infrastructure expansion. Meanwhile, the overall LER persisted at a moderate level, yet with substantial spatial heterogeneity. The dynamic coupling coordination degree (CCD) between urbanization and LER transitioned through three distinct phases: strengthening, weakening, and then strengthening again, yet it generally remained at a low level. Due to the wide distribution of cropland, the CCD is shown as urbanization lagging. These results not only revealed the spatiotemporal heterogeneity of LER under rapid urbanization but also underscored the implementing gradient management policies based on basin-specific urbanization-LER synchronization types. This study provides actionable insights for balancing socioeconomic growth and ecological security in agricultural basins undergoing rapid urbanization.