Morphodynamics of embayed beaches: The effect of wave conditions

Abstract

Embayed beaches are abundant along many coastlines of the world, yet our understanding of the role of wave conditions on their morphodynamics still needs to be furthered in order to better predict their dynamics. In this paper, a numerical modeling approach was used to determine the response of embayed beaches to varied wave forcing. The process-based numerical model, Delft3D, was used to simulate 16 wave conditions. Results indicate that complex flow patterns develop within the bay which drive long-shore and cross-shore currents. These currents actively interact to promote the formation of a stable bay shape. The resulting bathymetry in the bay is highly dependent on the incident wave conditions. It is also shown that beach rotation can occur for the same mean wave direction due to changes in the directional spreading. The numerical modeling approach has given agreeable results, and can be further used to explore the importance of other factors affecting embayed beach morphology, such as nearshore processes and bay geometry.