Abstract
In river-sea confluence zones, where land-sea interactions are highly concentrated, achieving synergy between ecological conservation and high-quality development is essential for regional sustainability. As the only river-sea transition zone in the Yellow River Basin, Shandong Province serves as a critical ecological security barrier while facing increasing pressure from intensive development and resource-environment constraints. Against this backdrop, this study takes Shandong Province as the research area and constructs a multi-level analytical framework integrating ecological conservation and high-quality development. From the dual perspectives of intra-system coordination and inter-system coupling, it evaluates coordination levels and identifies spatial differentiation patterns under land-sea integration. The results show that ecological conservation in Shandong is generally coordinated, forming “acore-periphery” spatial pattern, although uncoordinated areas remain concentrated along major rivers and lake regions. High-quality development remains at a relatively low level overall, with pronounced imbalance among the five development concept subsystems; in particular, innovation exhibits weak coordination with other subsystems and constitutes a key constraint. Moreover, the relationship between ecological conservation and high-quality development is dominated by incoordination, with more than 70% of the area classified as uncoordinated, while coordinated regions are mainly distributed in southern Shandong and parts of the Jiaodong Peninsula, showing a fragmented pattern. These findings indicate that the coordination relationship is jointly shaped by resource-environment constraints and land-sea coupling processes. By incorporating a land-sea integrated perspective, this study refines the analytical framework for understanding the interaction between ecological conservation and development, and provides empirical support for differentiated governance and sustainable development in river-sea transitional zones.