Sustainable Development of City River Network Structural Connectivity and Functions: Integrating the River Ecological Sensitivity Index

Urbanization has greatly accelerated the degradation of river systems, a trend likely to intensify in the future. While extensive research has examined the historical impacts of urbanization on river morphology, less attention has been paid to the present-day sustainability of river network structural connectivity and functions. To fill this gap, this study applies the Minimum Cumulative Resistance (MCR) model in Guangdong Province to characterize spatial competition between ecological conservation and urban expansion. A River Ecological Sensitivity Index is derived from river buffer zones and incorporated into a complex network framework to adjust edge weights, allowing simulations of potential structural and functional changes in the current river network under a coordinated land-use expansion scenario. In addition, a conservation-priority scenario is simulated to evaluate its capacity to sustain and optimize network functionality. The results show that: (1) highly sensitive segments are concentrated in the Pearl River Delta but remain scattered in other regions; (2) high-sensitivity river segments are concentrated in urban agglomerations, while low-sensitivity segments are mainly distributed in suburban areas; (3) the current river network is dominated by nodes of degree 1 and 3, while coordinated expansion reduces level-4 closeness centrality nodes by 9.74% and increases level-1 connectivity nodes by 12.73%; (4) without proactive conservation, Guangdong’s network functionality will decline—protecting 24% of highly sensitive segments is sufficient to maintain ecological and water-supply functions, while 32% is required to secure flood control capacity. These findings provide practical insights for guiding urban river governance and advancing sustainable development. Graphic abstract