| Fluorescent tracers, often used to study longshore transports induced in the breaking zone, are here adapted to the multidirectional movements observed on macrotidal beaches, where sediment transports are dominated by wave or tide action or by the simultaneous action of both. The relative influences of these agents vary in space and time. Different techniques of quantifying fluorescent grain concentrations, by surficial or volumetric counting of samples are tested and compared. The automatic counting of fluorescent grains present in the mobile layer is also tested and validated. Comparisons, made during a preliminary experiment, between concentrations evaluated in this manner and values inferred from visual inventories are satisfactory. The different... |
