Integrating seasonal climate variability and spatial accessibility in ecosystem service value assessment for optimized NbS allocation

Nature-based Solutions (NbS) efficiently manage ecosystem services (ESs) to address socio-environmental challenges. Strategic NbS planning must consider ecological and social benefits, especially in urban areas with limited resources. However, systemic planning approaches remain lacking in terms of urban climate variability. This study proposes a novel method to optimize ES benefits from NbS allocation, emphasizing ES dynamics under seasonal climate change in an urbanizing Korean city. We estimate seasonal impacts on ecosystem service value (ESV) using dynamic corrections. The Gravity-based Two-Step Floating Catchment Area (G2SFCA) method identifies priority NbS allocation areas based on fine-scale distributions of ecological supply and social demand under different scenarios. Our findings show that water bodies sensitive to seasonal climate changes need strategic management. For NbS planning, prioritizing highly populated areas with low ES access, and deprioritizing sparsely populated areas with limited accessibility due to lower demand, promotes efficient and equitable ES distribution. Considering both the contribution and sensitivity of ESs in terms of supply and demand leads to optimized NbS allocations, maximizing benefits. The study emphasizes the urgent need for integrated natural and social assessments in NbS planning, proposing a framework to guide planners in enhancing NbS implementation efficiency for sustainable urban environments.