A distinguishing characteristic of ocean dynamics in shallow coastal and shelfrnregions is the interaction that exists between seabed conditions and the overlyingrnlayers of water. The interaction takes place because of the strong influence of seabedrntopography and friction on the form of the shallow-water dynamics. The interactionrnis two-way because of the dynamically induced alterations in the seabed topographyrnthat result from sediment movement. In turn, these alterations lead to changes in thernnear-seabed currents and the frictional processes themselves. The scales involvedrnrange from those of high-frequency surface gravity wave propagation over beachesrnup to those of tidal- and wind-induced circulations in shallow shelf seas.
