Nature-based solutions for flood mitigation in urban environments: a systematic review of methodologies for spatial suitability assessment

ABSTRACT Climate change intensifies socio-environmental impacts, prompting many countries to adopt unconventional mitigation strategies. Among these, nature-based solutions (NBS) stand out as interventions inspired by natural processes, providing multiple co-benefits. Their effectiveness, however, depends on careful planning and implementation, as inadequate design or placement can reduce performance. Despite numerous studies on NBS benefits, a systematic approach for identifying optimal urban implementation sites remains lacking. This research reviews methodologies for mapping suitable locations, aiming to support future studies in identifying the best sites for NBS. The study has two stages: (1) a systematic literature review to assess scientific progress; and (2) an analysis of selected studies focusing on input data and variables and the methodologies used for mapping potential locations. Results indicate that over 80% of input data and evaluation variables relate to physical aspects. The limited consideration of socioeconomic data in some studies may reflect their unavailability or a lack of recognition of their relevance, emphasizing the need for approaches that integrate both physical and socioeconomic factors to enable more comprehensive and practical NBS planning.