The modelling of sandwave evolution resulting from suspended and bed load transport of sediment

A numerical model is used to determine changes in the bed morphology resulting from the bed load and suspended transport of sand. The ability of the model to predict mean and turbulent quantities and the suspended transport of sand is assessed by appeal to laboratory flume experiments and field observations. The model is then applied to investigate changes that may be expected to occur in an initial bedform corresponding to asymmetrical sandwaves characteristic of those found in the coastal and estuarine environment. It is found that suspended transport may frequently dominate over bed load transport in producing changes in the bedform structure. The predicted evolution of the bedform is reasonably consistent with observations made of sediment fluxes and sandwave migration in the Taw Estuary, England.