Analysis Of Hybrid Solutions For Coastal Protection Combining Physical And Numerical Cfd Modeling

Abstract

Historically, flooding and erosion challenges in coastal areas have been addressed through conventional gray/rigid structures such as breakwaters, dikes, and walls (Morris et al., 2017). As a consequence of the context of climate change, which is accompanied by a global biodiversity crisis and an increasing risk to coastal systems and communities, Nature-based Solutions (NbS) have emerged in recent years as an alternative to conventional engineering options. NbS can completely or partially mitigate coastal flooding and erosion problems while offering several additional co-benefits, such as carbon sequestration, improved water quality, habitat creation, and more (Sutton-Grier et al., 2015). Nevertheless, NbS may not be effective on their own in areas where there is insufficient available space for their development or in high-risk areas. In such cases, combining conventional engineering with nature-based solutions to obtain a so-called hybrid solution can represent an optimal approach, capable of providing the necessary risk reduction and realizing the benefits associated with natural solutions (Vuik et al., 2016). This makes hybrid solutions a highly attractive option that is currently gaining increasing interest. However, due to the limited number of real cases implemented, their relatively novel nature, and existing gaps in our knowledge about their hydrodynamic behavior, there is a pressing need to study hybrid solutions in greater detail. To this end, an experimental campaign is being conducted and is complemented by numerical CFD modeling, coupling IH2VOF and OpenFOAM models, to better understand the coastal protection services provided by the combined solution and to assess the suitability of the method of process superposition, commonly used to analyze the interaction between the flow and the hybrid solution. The main variables analyzed for this purpose are the evolution of wave height and wave run-up.