ICCE 2022

How to Cite

NATURE-BASED FLOOD RISK REDUCTION VIA MULTIPLE LINES OF DEFENSE. (2023). Coastal Engineering Proceedings, 37, management.189.


Sea level rise, land subsidence and population growth lead to steadily increasing flood risks in low-lying coastal areas. Hard flood defense structures such as dikes and dams should be regularly heightened and strengthened to sustain their protective function. Further, such hard structures can induce negative effects on the surrounding ecosystem. Therefore, nature-based approaches to flood risk reduction are increasingly promoted. Vegetated foreshores (such as salt marshes and mangrove forests) reduce wave loads on coastal dikes (Vuik et al., 2016). Furthermore, they are able to keep pace with sea level rise due to natural sediment accretion. However, foreshores cannot always exist in front of flood defenses, for example because of shipping lanes, protected habitats or harsh waves and currents. Even in such situations, coastal safety can be enhanced by creating salt marshes in between multiple lines of defense (double dikes). In this study, we investigate the effectiveness, costs and coastal protection benefits of nature-based flood risk reduction via multiple lines of defense.


Jonkman (2007). Loss of Life Estimation in Flood Risk Assessment: Theory and Applications. PhD thesis, Delft University of Technology.

Vuik, Jonkman, Borsje, & Suzuki (2016). Nature-based flood protection: The efficiency of vegetated foreshores for reducing wave loads on coastal dikes. Coastal engineering, 116, 42-56.

Vuik, Van Vuren, Borsje, Van Wesenbeeck & Jonkman (2018). Assessing safety of nature-based flood defenses: dealing with extremes and uncertainties. Coastal Engineering 139, 47–64 (2018).

Zhu, Vuik, …, & Bouma (2020): Historic storms and the hidden value of coastal wetlands for nature-based flood defence, Nature Sustainability, 3(10), 853-862.

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Copyright (c) 2023 Vincent Vuik, Martijn Jansen