Medium-Term Variation of Bar Movement and Its Linkage to Wave Climate

Abstract

Longshore bars are a common site in sandy beaches which is influential on currents, morphology variation and the marine eco system. Longshore bar reacts to the variation of environmental factors and wave properties like wave height, water depth, wave period, wave skewness and it tends to move seaward or shoreward while changing its amplitude. According to Lippmann and Holman, (1990) short term bar migration has been triggered when the wave height or the wave height to water depth ratio are large. Elgar et al. (2001) has shown that short term seaward bar migration was caused by velocity skewness, undertow velocity and acceleration skewness. Influence of the wave breaking on the seaward bar migration has been identified as minimum according to Sallenger and Howd (1989).