particle velocity, acceleration, and pressure) follow by application 

 of one of the classical wave theories within the accuracy which is 

 determined for the chosen theory. 



BREAKING INDEX 

 CURVEv 



LINEAR 

 SHOALlNGv 



H|3 linear 



EXPERIMENTAL 

 s. /SHOALING 



H|3 experimental 



_^L. 



Figure 9. The linear theory underestimates the breaking wave height. 



4. 



Nonlinear Wave Refraction. 



It has been shown previously how to determine the shoaling co- 

 efficient. Kg = H/Hq, when the wave arrives perpendicular to the 

 bottom contour. This discussion deals with the refraction coefficient, 

 Kj.. Refraction occurs when a wave arrives at an angle a with bottom 

 contours; then H/H^ = Kg Kj.. For a straight parallel contour Snell's 

 law becomes 



constant 



(6) 



which applies whether the wavelength, L, is expressed by a linear theory 

 or not. 



Then 



/£_\ ^ /cos g y 

 \hj - ^cos aj 



(7) 



21 



