rrr^'"""""""""" 



Wave height and set-up in surf zone of unifora Uniformally sloping beach 

 depth 



'^^*^«/4, O •'ttr Sulujr* » ^tttlgrw (1977) H' " ( 



- ^^^^^ 4- o.on 



Step— type beach 



Field data on step-type beach 



Figure 76. Irregular wave height variation across the surf zone for four 



different beach profiles: theory versus data (after Mizuguchi, 

 1980). 



III. NEARSHORE CIRCULATIONS 



1. Rip Currents . 



To date, all theory has concentrated on rip current spacing as dis- 

 cussed in Chapter 3. Mechanisms for rip current generation are categorized 

 in Table 1 and reviewed extensively in Chapter 2. Because of the large 

 number of possible mechanisms that can cause rips to form on beach profiles 

 ranging from the reflective-type (steep) to the dissipative-type (flat, 

 broad) , no single theory has emerged for comparison with laboratory and 



198 



