Nature-Based Solutions (NBS) are crucial for coastal protection because they provide sustainable and adaptive measures to mitigate the effects of climate change, such as rising sea levels, coastal erosion, and extreme weather events. Unlike traditional hard-engineering solutions, NBS—including mangroves, salt marshes, coral reefs, and dunes—enhance natural coastal resilience while also supporting biodiversity, improving water quality, and offering socio-economic benefits to local communities. These solutions work by dissipating wave energy, stabilizing shorelines, and promoting sediment accretion, thereby reducing the impact of storms and flooding.

Several UNESCO meetings and reports have emphasized the importance of ecohydraulics and NBS in coastal protection, including, such as UNESCO International Hydrological Programme (IHP) Meetings – The IHP has promoted research on ecohydraulics and sustainable water management, highlighting the role of NBS in protecting coastal and freshwater ecosystems.

The research paper by Mossa, M., De Padova, D. titled Interaction between waves and vegetation is part of this contest. It was published in Sci Rep 15, 6157 (2025). DOI link. See also the paper Mossa M, De Padova D, Onorato M. Damping of solitons by coastal vegetation, Journal of Fluid Mechanics, 2025;1002:A45. https://doi.org/10.1017/jfm.2024.1185

This paper explores the interaction between wave hydrodynamics and aquatic vegetation, highlighting its significance in coastal protection. Riparian vegetation plays a crucial role in mitigating wave energy, stabilizing sediments, and enhancing ecosystem resilience. Among the most effective nature-based solutions, vegetation such as mangroves and marshes serves as a natural barrier against tsunamis and storm surges, reducing coastal erosion and providing carbon storage benefits.

The study presents a theoretical and numerical investigation into wave attenuation mechanisms involving cylindrical stem arrays, which simulate rigid vegetation structures commonly found in coastal and estuarine environments. Using both analytical models and Smoothed Particle Hydrodynamics (SPH) simulations, the research evaluates the impact of emergent and submerged rigid stems on the transmission of regular (Airy) and solitary waves over horizontal and sloping seabeds. The findings contribute to a deeper understanding of bulk drag coefficients, which are essential in predicting wave damping efficiency based on parameters such as stem density, diameter, and submersion ratio.

Mangroves and other coastal vegetation not only protect shorelines from extreme hydrodynamic forces but also help mitigate climate change by sequestering carbon. Case studies following major tsunami events, such as the 2004 Indian Ocean tsunami, underscore the critical role of mangrove forests in reducing human casualties and infrastructure damage. These findings advocate for maintaining at least a 1 km buffer zone between human settlements and the shore, reinforced by dense coastal vegetation.

The study also draws parallels between natural and artificial structures, noting similarities in wave-structure interactions involving mussel farms, offshore wind farms, and navigational poles. By modeling vegetation as rigid cylindrical obstacles, the research provides valuable insights into how engineered solutions can mimic natural wave attenuation processes.

Despite the recognized benefits of wetland and riparian vegetation in wave damping, there remains a gap in engineering methodologies for accurately quantifying these effects. This study contributes to bridging that gap by refining theoretical models and validating them against numerical simulations. The results not only confirm existing theoretical laws on wave damping but also extend their applicability to previously unexamined coastal environments.

Ultimately, this research underscores the need for integrating vegetation-based solutions into coastal management strategies. By improving our understanding of wave-vegetation interactions, policymakers and engineers can better design resilient coastal defense systems that leverage natural processes for sustainable shoreline protection.