Modeling for Complex Coastal Morphological Changes Considering Geomorphic Characteristics

Abstract

Various structures and coastal developments have been installed to mitigate the increases in coastal erosion caused by climate change, but numerical modeling studies to predict the changes in coastal morphology induced by these structures have been insufficient. This study analyzed the morphological changes in the complex coastal environment of Wonpyeong Beach, Gangwon-do, where coastal maintenance projects are underway, using XBeach simulations based on observational data. For accurate modeling, the geomorphic characteristics, such as the subsidence of submerged structures, sediment layer thickness, and spatial varying bed friction coefficients, were incorporated using satellite imagery and field survey data. The results showed that accounting for the subsidence of submerged structures represented the formation of coastal sandbars while adjusting the sediment layer thickness reduced excessive erosion around the structures. In addition, incorporating spatial variations in the bed friction coefficients improved the representation of localized erosion and deposition, even though the overall impact was limited. This study emphasizes the importance of incorporating geomorphic features for accurate predictions of morphological changes and shows the value of using satellite imagery as a supplementary tool in data-limited environments. Nevertheless, additional observational data are necessary to validate and refine the proposed approach.