Some Three-Dimensional Effects in Surf

摘要

Asymptotic equations are presented of surf on shallow beaches with a geometry causing longshore variations in the water motion. In general, such surf is found to be governed by the three-dimensional, nonlinear shallow-water equations. However, when the seabed profile parallel to shore is shallower than the profile normal to shore, the asymptotic equations are shown to differ only in minor respects from those of two-dimensional surf. Such 'weakly three-dimensional' surf can be analysed directly in terms of the results of the two-dimensional theory. (Author)