Analysis of Observed Streaming in Field Measurements

Abstract

Analysis of velocity and suspended sediment concentration data from field measurements at Pearl Beach in New South Wales, Australia, reveals the existence of onshore currents in the close vicinity of the rippled bed, whereas the velocity is offshore directed farther up in the water column. This might be caused by wave-induced streaming beneath irregular waves over ripples. To test this hypothesis, a simple one-dimensional vertical bottom boundary layer model capable of capturing streaming was applied, yielding a qualitatively fair agreement between the predicted and measured mean velocity and suspended sediment concentration profiles, although the predicted suspended sediment concentration was 1 order of magnitude smaller. Overall, these model results support the hypothesis of the mean near-bed onshore velocity caused by wave-induced streaming over ripples.