Sand transport under the combined influence of waves and tidal currents: an assessment of available formulae

Various formulae are used to predict the transport of sand under the combined influence of waves and currents. These approaches include the use of the unidirectional formulae of Einstein (1950), Frijlink (1952), Yalin (1963), Engelund and Hansen (1967), Sternberg (1972), Ackers and White (1973) and Gadd et al. (1978) modified, for the presence of waves, in accordance with the techniques described by Bijker (1967) and Swart (1976) and those of Bagnold (1963), Madsen and Grant (1976) and Vincent et al. (1981).

Predicted rates are compared with measurements, based upon fluorescent sand tracer studies, in an area of high tidal current and wave energy (northern Bristol Channel, U.K.). In general, predicted rates are lower than those measured and only the formulae of Madsen and Grant (1976) and the modified formula of Sternberg (1972) appear to provide realistic estimates of transport under wave- and tidally induced currents, in comparison with the field measurements.