Interaction of Shallow-Water Waves and Bottom Topography

Modification of a linear bar-trough system by a standing edge wave

“…Davidson-Arnott and McDonald (1989) present field evidence which suggests that the presence of an undertow very close to the bed is an important control in maintaining the equilibrium of nearshore bars. Boczar-Karakiewicz et al (1986) showed theoretically that longperiod, incident surface gravity waves in shallow water will be subject to reflective trapping by bottom undulations and a nonlinear resonance will yield positive feedback between the wave form and the growing bar forms. There are limitations to all bar genesis models, and the controversy concerning bar origin remains unresolved because the manner in which nearshore forms evolve in the field has not yet been fully documented, and since scaling problems preclude their complete examination in the laboratory.…”

Model for the Formation and Evolution of Sand Ridges on the Continental Shelf

“…In [11 they conjecture that longshore sand ridges are the result of energetic interactiuis between shallow water waves and the underlying bottom topography, and propose a simple model, which in [2] was shown to be in qualitative agreement with oceanic data. While the present study owes much to the previous work.…”

“…For internal waves, the issue of dissipation is relatively more straightforward: As the density stratification collapses in the shallower reaches of the shelf, the water column is no longer able to support an internal wave. Incidentally, Boczar-Karakiewicz et al [2] have found that the area in which stratification collapses agrees with the limit to which sand ridge fields appear.…”

“…Eventually, their collaboration resulted in the Boczar-Karakiewicz, Bona, Cohen paper [1], in which they use the ideas of Lau and Barcilon to obtain the resulting drift velocity in a boundary layer and use this drift velocity as a source of sediment motion in a traiisport equation. Exploiting the discrepancy of the time scales between fluid and sediment dynamics.…”

“…Later, the model was extended to the internal wave case and was tested against actual field data (2]. Encouraged by the results of the field data comparisons, it was thought that the natural extension of this ongoing research project should be to increase the model's applicability to three dimensions.…”