Hur, D.-S; Shin, S.; Lee, S.-Y., and Jeong, Y.-M., 2023. Analysis of shoreline change due to the installation of hybrid coastal structure with Submerged Aquatic Vegetation (SAV). In: Lee, J.L.; Lee, H.; Min, B.I.; Chang, J.-I.; Cho, G.T.; Yoon, J.-S., and Lee, J. (eds.), Multidisciplinary Approaches to Coastal and Marine Management. Journal of Coastal Research, Special Issue No. 116, pp. 638-642. Charlotte (North Carolina), ISSN 0749-0208.

Recently, they have been designed and constructed as a complex defense method to protect the beach with nourishment. In this study, the Submerged Aquatic Vegetation (SAV) among the soft defense methods (Hybrid coastal structure), which are more flexible than the hardness method, is compared and evaluated with the conventional method. The numerical analysis method used is a 3D numerical model based on the Navier–Stokes equation and can be used to analyze the 3D hydraulic characteristics of the method to address coastal erosion. Based on the results, the N-line model, a model that depicts coastline changes, can be used for comparison. The effectiveness and validity of the numerical model were examined by comparing and analyzing its results with those of the existing hydraulic experiment. The model accurately reproduced the quantitative and qualitative changes in the shoreline behind the structure, as well as the change in wave height due to the wave control function of the Submerged Breakwater (SB). As a result, changes to the waves and stratified nearshore currents owing to 3D fluid movement in surrounding waters can be confirmed using the existing hardness method used to respond to coastal erosion, and the hydraulic characteristics are analyzed and compared with the conventional method using the wave control characteristics of the installed vegetation zone. Furthermore, the wave-breaking height and the wave-breaking direction are examined from the results based on the 3D hydraulic characteristics of the vegetation zone and the conventional hardness method to compare the shoreline changes. Compared with the existing hardness method, the change in the wave breaking direction is lower owing to the wave control capability of the SAV resulting from the drag coefficient of vegetation, leading to the advance of the shoreline being relatively small.