Swash zone dynamics of a sandy beach with low tide terrace during variable wave and tide conditions

Abstract

A field experiment was conducted on a sandy beach with a low tide terrace (Nha Trang, Vietnam) to investigate the swash zone hydro- and morphodynamics throughout different tide and wave conditions. A 2D Lidar was used to measure runup properties and bed level changes on the swash zone. An energetic monsoon wave event provided energetic conditions during the initial stage of this experiment while mild wave conditions were observed during the remaining days. Swash dynamics were clearly modulated by wave and tide conditions. Preliminary results indicate that wave climate is linked with extreme runup and beach erosion and recovery processes while tide level seems to affect swash spectral signature (dominated by infragravity band during low tide and incident band during high tide) and linked with asymmetrical morphological response of the swash.