Effect of tidal range on longshore current variation with respect to cross-shore location of a barred beach

Abstract

ABSTRACT Longshore and cross-shore currents in the surf zone were observed on a dissipative barred beach for 20 days using a horizontally mounted acoustic-Doppler current profiler (H-ADCP). This novel deployment strategy allowed for the synoptic measurement of the longshore current at approximately mid-depth at several cross-shore locations. The longshore current data were analyzed with wave and tide level data to show the effect of tidal range on the variation of the longshore current with respect to cross-shore location. The longshore current was higher near the outer bar area than that observed near the inner bar. Moreover, the current became higher during the low tide and lower during the high tide. A longshore current model was proposed using the spring and neap tide data sets and then applied to the remaining observation period during large events of incident wave energy flux. The model with the relative water level luded provided sufficient accuracy to account for the tide effects.