Evaluation of Longshore Transport Equations with OBS Sensors, Streamer Traps, and Fluorescent Tracer

Abstract

Abstract Measurements of longshore sediment transport rate were conducted on a reflective to intermediate sandy beach during energetic sea breeze activity. The suspended load transport was obtained with optical backscatter sensors, current meters, and streamer traps, whereas the total load rate was measured with fluorescent sand tracer. The streamer trap measurements revealed an exponential vertical distribution of the suspended sediment flux, with the degree of vertical mixing decreasing in the onshore direction. A continuous time series of longshore suspended sediment flux across the surf zone was obtained by combining streamer trap measurements with data collected with surf zone instruments. Comparison of the suspended longshore flux with the total longshore flux derived from the dispersal of fluorescent tracer indicated that the relative contribution of suspended load to total load was ca. 35%. The movement of sand tracer further demonstrated that nearshore sediments were transported obliquely across ...