Integrating technical and societal strategies in Nature-based Solutions for urban flood mitigation in Guangzhou, a heritage city

Abstract

This study presents a comprehensive methodology for the implementation of Nature-based Solutions (NbS) in the context of urban flood mitigation, specifically within the heritage city of Guangzhou, China. The investigation delves into the roles of urban morphology and impermeability in exacerbating flood risk through enhanced runoff accumulation and reduced infiltration. A key focus is the spatial heterogeneity of flood susceptibility, influenced by the disparate distribution of various building types and demographic segments. This research integrates susceptibility and vulnerability assessments with spatial analysis of NbS and multi-criteria decision-making, facilitating the identification of pivotal zones for NbS application. Findings underscore the critical role of urban design in flood risk management and reveal the efficacy of vegetation-based strategies, namely vegetated swales and bioretention cells, which account for 8.41% and 7.08% of the total area, respectively, in curbing urban flood impacts. Recommendations for heritage city innovation include the prioritization of vegetation-integrated road layouts coupled with a gradual enhancement of grey infrastructure in historical areas. The study culminates in providing strategic insights for policymakers and urban planners in heritage cities, underscoring the necessity of a balanced approach to technical feasibility and conservation imperatives in NbS deployment.

Keywords

• Nature-based solutions
• Urban flood mitigation
• Technical and societal integration
• Heritage city resilience
• Flood risk management