Strategic Deployment of Nature-Based Solutions for Urban Flood Management in High-Density Urban Landscapes

Urban flooding poses a significant challenge in high-density urban landscapes (HDULs), exacerbated by rapid urbanization, limited permeable surfaces, and climate change. Nature-based solutions (NBS) have emerged as a promising alternative to conventional grey infrastructure, offering multifunctional benefits for flood risk reduction, ecosystem restoration, and urban resilience. This study proposes a comprehensive framework integrating spatial multi-criteria evaluation (SMCE) with analytical hierarchy process (AHP) and entropy weighting (EW) methods to assess exposure, vulnerability, and adaptability factors influencing flood risks in Shenzhen, China. The study identifies key priority areas for NBS implementation and evaluates four NBS schemes based on their technical feasibility and spatial suitability. Results reveal that indices such as river network density (26.6%) and impervious surface percentage (26.5%) significantly influence exposure, while cultural heritage (31.2%) and emergency shelters (58.0%) dominate vulnerability and adaptability assessments, respectively. The prioritization map highlights critical zones requiring immediate intervention, emphasizing the need for integrated strategies addressing urban planning and socio-cultural dimensions. This research provides actionable insights for urban policymakers and planners, underscoring the transformative potential of NBS in mitigating urban flood risks and advancing sustainable urban development.