Table 4 Nature-based adaptation measures and their advantages, disadvantages, co-benefits, and tradeoffs
Measure | Advantages | Disadvantages | Co-benefits | Tradeoffs |
|---|---|---|---|---|
Set-Back | - Alleviates stress on levees by providing extra space for floodwaters (Chambers et al., 2023). - Enhances the capacity to manage large volumes of water. - Facilitates improved filtration and water quality (Singh et al., 2018). | - High initial costs for planning, land acquisition, and construction. - Can change sediment dynamics, requiring careful management (Lammers et al., 2024). High costs to obtain real estate landward of levee | - Can aid in floodplain restoration (Singh et al., 2018). - Improves groundwater recharge and floodplain functionality. - Enhances recreational opportunities and aesthetic value of landscapes. | - Requires land acquisition and potential relocation of infrastructure (Chambers et al., 2023). - May impact existing land use and property values. |
Permeable Pavements | - Reduces stormwater volume and rate, alleviating pressure on drainage systems (Lee et al., 2023). - Lowers the carbon footprint associated with drainage construction (Iqbal et al., 2022). | - Prone to clogging, which diminishes performance and requires costly maintenance (Kia et al., 2021). - Conventional designs may not be suitable for heavily trafficked roads due to durability concerns. | - Facilitates natural hydrological processes like infiltration, storage, evaporation, and detainment of runoff (Zhu et al., 2021). - Reduces the need for extensive and expensive traditional drainage systems. | - Requires new design guidance and standards. - Initial installation costs may be higher compared to traditional pavements. - Ongoing maintenance is crucial to ensure performance, particularly in areas with high sediment loads. |
Green Roofs and Walls | - Reduces surface runoff and enhances infiltration (Liu et al., 2020). - Stores rainfall in a soil substrate and delays runoff peak generation. | - Structural limitations in older buildings may impede installation (Cristiano et al., 2020). - The scope of implementation is limited by the available roof and wall space. | - Enhances biodiversity by providing habitats for various species (Basu et al., 2021). - Reduces energy consumption by insulating buildings (Teotónio et al., 2021). - Improves urban aesthetics and contributes to ecosystem restoration. | - The need for regular maintenance and irrigation may increase operational costs. - Higher initial costs compared to traditional roofing and wall systems. |
Wetland Restoration and Creation | - Provides carbon storage, sediment trapping, and nutrient retention. - Reduces flood risks by controlling water flow rates (Kumar et al., 2021). | - Potential for exacerbating flooding under certain geographical conditions (Wu et al., 2020). - May face challenges due to urban expansion and land use changes (Rojas et al., 2022). | - Supports biodiversity and habitat restoration (Tomscha et al., 2021). - Provides additional ecosystem services such as water purification. - Contributes to carbon sequestration. | - Integration with existing urban infrastructure can be complex and costly. - Long-term maintenance and monitoring are required to ensure sustained benefits (Spieles, 2022). |
Riparian Buffers | - Supports watershed function, enhances baseflow, reduces peak flows (Gay et al., 2022). - Facilitate energy and matter exchange (Kuriqi et al., 2021). | - Varying effectiveness across different subbasins. - Requires proactive management strategies and policy reforms (Graziano et al., 2022). | - Enhances aquatic habitat suitability and improves river dynamics and bank stability. - Provides social and cultural benefits through the creation of green spaces (Riis et al., 2020). | - Challenges of proactive management and policy implementation to protect and restore riparian zones. - Balancing urban development and conservation efforts (Olokeogun et al., 2020). |
Beach and Shoreface Nourishment | - Protects people and property from coastal flooding (Sancho, 2023). - Facilitates rapid post-flood recovery. - Counteracts coastal erosion. | - Requires effective monitoring of coastal erosion and deposition (Tiede et al., 2023) - Necessitates comprehensive environmental impact evaluations to ensure sustainable development (de Schipper, 2021; Mendes et al., 2021). | - Enhances the aesthetic and recreational value of coastal zones, benefiting local communities and economies (Saengsupavanich et al.,2023). - Supports marine resource utilization and infrastructure protection. | - Maintenance costs can be higher than hard structures due to shorter maintenance intervals (Staudt et al., 2021). |
Living Shorelines | - Mitigates erosion, wave damage, and flood risks (Meguro & Kim, 2021). - Stabilizes sand dunes and dissipates wave energy (Jones & Pippin, 2022). | - Depends on factors such as wave energy, land use, sediment volumes, and community willingness. - Regulatory challenges and jurisdictional complexities (Manuel et al., 2021). | - Habitat creation and improved ecosystem services. - Recreation opportunities. - Increased economic value (U.S. DOT, 2019). | - May face resistance compared to traditional hard armoring methods. - Municipalities need to play an active role in facilitation and planning. |
Vegetation on Levee Slopes | - Stabilizes levee slopes (van Zelst, 2021). - Reduces erosion (Boechat Albernaz et al., 2020). | - Effectiveness can be influenced by the width of the levee and vegetation type (Rosenberger & Marsooli, 2022). - May increase the risk of vegetation fires. | - Can provide a habitat for wildlife. - Sequesters carbon and mitigates climate change. | - Effectiveness depends on local climate and soil conditions. - Requires ongoing maintenance and monitoring (Boechat Albernaz et al., 2020). |
Forest Fire Prevention | - Reduces the risk of wildfires, which can exacerbate flooding by increasing erosion and runoff (Ebel, 2020; Carabella et al., 2019). | - Requires ongoing efforts and investment in fire prevention measures (Xu et al., 2023). | - Enhances overall ecosystem health and resilience. - Supports biodiversity by maintaining natural habitats. | - It may be challenging to implement in remote or inaccessible areas (Yilmaz et al., 2023). |
Bio-Inspired Improvements of Soils in Flood Protection Infrastructure | - Increases shear strength, stiffness, and erosion resistance of levee and embankment soils, improving slope stability during high water levels (Liu et al., 2024) | - Urea-based MICP generates ammonium; compliance with water-quality limits requires post-treatment or alternative pathways (Su et al., 2022) | - Can immobilize dissolved heavy metals and other contaminants, offering ancillary soil- and water-quality benefits (Rajasekar et al., 2025) | - Continuous monitoring (pH, Ca²⁺, NH₄⁺, microbial viability) and increase operation-and-maintenance costs |
