Measuring the spatial sharing of open green space in metropolitan areas through a multi-scale collaborative governance framework

Globally, cities encounter challenges in improving public access to open green spaces (OGS). In China, the development of shared OGS aligns with its eco-urbanization strategy, but practical implementation has revealed structural contradictions from multi-scale governance disconnections. This study employs Jinan as a case to develop a district-unit-site (DUS) multi-scale framework, incorporating the Dagum Gini coefficient and coupling coordination degree model to assess OGS spatial sharing. Findings underscore disparities in current OGS sharing, as indicated by the Dagum Gini coefficient, primarily due to imbalanced patterns with the most pronounced differences at the district level. OGS sharing is categorized into high coupling-low coordination, low coupling-high coordination, and low coupling-low coordination types. The model reveals a 'dumbbell-shaped' distribution: the city core has higher sufficiency but collaborative imbalance, while eastern/western wings are balanced yet insufficient. Corresponding gradient governance solutions are proposed for different areas, offering replicable approaches for enhancing OGS spatial sharing in metropolitan areas.