Nature-based solutions for natural hazards in Costa Rica: Evidence, gaps, and challenges

Nature-based Solutions (NbS) are increasingly promoted to reduce disaster impacts while providing biodiversity, climate, and social co-benefits, yet evidence in tropical developing contexts remains fragmented. This study presents a systematic literature review of NbS for natural-hazard management in Costa Rica, combining a bibliometric mapping of peer-reviewed research with a qualitative synthesis of national experiences reported in scientific and technical sources. Searches in Scopus, Web of Science, and Google Scholar were complemented by targeted retrieval from Costa Rican university repositories and institutional platforms. Eligible documents explicitly describe NbS or ecosystem-based approaches linked to hazard mitigation, adaptation, or disaster risk reduction and provided sufficient information to classify hazard focus, ecosystem context, and intervention type. Evidence was coded using internationally recognized NbS frameworks and grouped by hazard category, ecosystem/landscape setting, NbS type, reported indicators, benefits, and implementation barriers. Results indicate a marked increase in NbS-related publications and project reporting since 2007. Documented interventions are concentrated in watershed and forested landscapes and mainly target flood regulation, erosion control, and slope stabilization through restoration, riparian buffers, reforestation, and agroecological or green infrastructure measures. Outcomes are commonly reported using hydrological and ecological indicators, while standardized evaluation of effectiveness, equity, and long-term maintenance is less consistent. Key constraints include fragmented governance, limited financing for monitoring and upkeep, and uneven integration of NbS into territorial planning. The review identifies priorities to strengthen NbS mainstreaming in Costa Rica, including improved evaluation protocols, cross-sector coordination, and clearer incorporation of co-benefits into planning and investment decisions.