Abstract: Jinan, a central city in the Yellow River Basin and a renowned “City of Springs,” is characterized by a distinctive spring-centered water ecosystem. A comprehensive assessment of the spatiotemporal changes in its surface water connectivity, identification of the key influencing factors, and development of scientifically sound and feasible optimization pathways are of considerable significance for enhancing water circulation, improving water quality, and promoting the restoration of spring-centered ecosystems. Based on the geomorphological pattern characterized by mountains in the south and water systems in the north, this study established a three-dimensional evaluation framework integrating structural, process, and functional connectivity. Multi-source data, including remote sensing interpretation and geospatial analysis, were used to systematically reveal the spatiotemporal evolution and driving mechanisms of surface water connectivity in Jinan from 1985 to 2022, and multi-scale optimization strategies were subsequently proposed. In practical terms, the concept of sponge city development was incorporated into the design of restoration pathways, and a coordinated optimization strategy for spring conservation and water supply in northern karst cities was proposed, providing a technical framework for addressing the imbalance between water supply and demand. The results showed that surface water connectivity in Jinan exhibited a fluctuating upward trend over the past four decades. Spatially, connectivity was generally higher in the southern mountainous areas than in the northern urban areas. Influenced by agricultural water conservancy projects, the transitional zone generally developed a positive cycle of structural optimization and functional improvement. Ecological restoration projects alleviated the degradation of urban water connectivity, although the fragmentation of the water network caused by urban expansion remained evident. Quantitative attribution analysis using geodetector indicated that GDP and annual precipitation were the dominant factors explaining the spatial differentiation of connectivity, and that human activities had become the principal driver of connectivity evolution. Based on these findings, differentiated restoration strategies were proposed, including mountain closure for afforestation and the construction of stepped infiltration basins to restore groundwater in the southern karst region; river dredging and ecological-weir construction to reconstruct water corridors in the northern plain; and the promotion of sponge-city projects and smart management in built-up areas to enhance blue-green coordination.

Key words: Jinan City, surface water connectivity, landscape pattern indices, ecological restoration strategies, Yellow River Basin