From Risk Maps to Nature-Based Solutions Hotspots: Evidence-Based Upscaling for Climate Adaptation in West-Flanders (BE)

Nature-based solutions (NbS) are key to climate adaptation policy, yet upscaling across diverse landscapes remains challenging. Within the HEU-NBRACER project, we developed a process framework to up- and outscale NbS. This framework is applied to the Province of West-Flanders, Belgium, where climate adaptation strategies have been co-designed by integrating evidence-based science with participatory governance.

First, we assessed risk at detailed spatial scales by combining available current and future spatial multi-hazard mapping with local vulnerability and exposure indicators. These risk maps informed stakeholder dialogues to prioritize risks and co-define a shared vision for climate resilience.

At the same time, concrete NbS-actions were co-designed and demonstrated with municipal actors and stakeholders. This process captured perceived co-benefits, barriers, and enablers, ensuring context-specific feasibility and alignment with policy and planning.

Next, solutions were identified and organized into a portfolio of process-based strategies (e.g., sponge landscape for water storage and retention; evapotranspiration-driven cooling for urban heat mitigation). Using a hotspot mapping approach, we identify where specific NbS are most effective by jointly considering biophysical effectivity (e.g., infiltration potential, connectivity) and risk reduction needs (e.g., locations with high flood or drought risk and vulnerable population):

NbS hotspot score=hazard score ×vulnerability score ×effectivity score

The hotspot approach applied in this framework aligns with the methodology used by the Flemish climate portal (Klimaatportaal), ensuring consistency with governmental tools and facilitating integration into policy processes.

For each strategy, we provide an overall score for climate benefits (drought and flood mitigation, soil erosion control, water quality improvements) and ecosystem services (food production, carbon sequestration and biodiversity enhancement) using multi-criteria scoring informed by expert interviews and literature study. During a co-design process informed by the NbS hotspot scores, local stakeholders finally identified actionable pathways to also implement those NbS. This is done for a specific subregion in West-Flanders, as part of the Landscape Park Zwinstreek.

Results deliver a portfolios of strategies, NbS hotspot maps, and actionable pathways to support decision-making and implementation. The framework bridges science, practice, and policy, enabling transparent prioritization, stakeholder ownership, and scalable NbS deployment for climate adaptation.