Wave parameter gradients along the wave ray

Computer methods have been used to track selected deep-water waves along their orthogonals to the surf zone. Three bottom orbital parameters were computed at each step: diameter, maximum velocity and acceleration. These three parameters were then plotted along the several wave rays, thereby providing shoreward gradients.The three gradients have essentially the same geometry, so that any one can be taken as an indicator of the other two. Bottom slope changes are responsible for departure of the gradients from linearity. The bottom orbital gradients are quite different from gradients of wave height and wave length. These results from coasting waves cannot be applied directly to the case of forced, or wind-driven, waves.The non-linear nature of the bottom orbital gradients indicates that the near-shore bottom should exhibit a crude banding, more-or-less parallel with the coast, with different sediment transport and ripple-mark geometry from band to band.