Functional resonance analysis of ownership continuity in catchment-scale governance of nature-based solutions

Graphical abstract shows how continuity of catchment objectives across scales and governance functions supports nature-based solutions. Nature-based solutions (NBS) can support urban flood mitigation, water-quality improvement and climate adaptation, yet their effectiveness at catchment scale depends on coordination across multiple actors, governance functions and spatial scales. This study examines how ownership of catchment-scale objectives is maintained as responsibilities shift during NBS planning, construction and operation. The functional resonance analysis method was adapted for governance analysis and applied to five NBS cases in four Baltic Sea Region cities. The analysis mapped governance functions, responsible authorities, planning scales, governance mechanisms, and mission keepers – actors who preserve catchment-scale objectives across ownership transitions. The cross-case comparison identified three recurring patterns of interacting governance variability: fragmented ownership transitions, misalignment between strategic and implementation scales, and dependence on temporary pilots and individual expertise. More mature governance systems institutionalized catchment integration, reinforced continuity of mission ownership across functions and scales, and connected monitoring and learning with future planning. Based on these findings, a mission-oriented joint operational model is proposed as a transferable governance logic emphasizing institutionalized catchment integration, continuity of mission ownership, reinforcing governance mechanisms and adaptive learning.