Shallow Water Wave Transformation through External Factors 131 



breaker height according to equation (V.26), and observations along the 

 beach north of La Jolla, California. There has been a tendency in the 

 literature to emphasize the effect of bottom friction on wave motion and 

 other wave characteristics. Studies dealing with generation of waves by wind 

 and with absolute changes of wave height in shallow water and the dynamics 

 of breaking waves indicate that the wave motion in general is not appreciably 

 affected by frictional processes. 



Refraction type examples: beach with straight and parallel depth contours. 

 For this simple case the change in wave direction can be expressed analytically 

 by equation (V.23). Figure 59 is a schematic drawing of wave refraction along 

 a straight coastline with parallel depth contours. Figure 60 is an aerial photo- 



Fig. 60. Aerial photograph showing swell turning parallel to shore north of Oceanside, 



-. California. 



graph showing long waves from the south-south-west coming into the beach 

 north of Oceanside, California. There is a divergence of the orthogonals 

 indicated by the values of s computed from the equation 



cos a 

 cosa 



(V.28) 



9* 



