•- 1/1 

 o — 



■5 e 



10 



. .-—• • 





Breaker zone 



08 

 06 



-~\ 



Breaker 

 line 



0.4 



7 







^~~~"» — 



2 













Vl 



-OSrr 



7777T77-rrrrr^ 



- 





^'^'^'^77? //y//-//^^ 



^^^777/77 



1 



Bottom 





'^^^^^^'^77777r7rrrr 



'"'^ 



5 10 15 20 25 30 35 40 45 50 



Offshore distance, X (m) 







K 



• \ 



\ 



• ,0.-.-:-:...i: 



• 



• • /• 







i 



i \ 



/ 











'\v.: 



_y_ 6 

 0.4 



02 04 06 8 10 12 14 



X 



Figure 66. Kraus and Sasaki model compared with field data (after Kraus 

 and Sasaki, 1979). 



Finally, some preliminary data from the NSTS field study at Torrey 

 Pines, California, have been presented by Guza and Thornton (1980). Vec- 

 tors of 17.1-mlnutes average currents are shown In Figure 67 for one shore- 

 normal section and along the coast. Also shown is the theory of Longuet- 

 Hlgglns (1970) by putting the measured offshore radiation stress into an 

 equivalent regular, unidirectional wave at the measured spectral peak. 

 The dashllne Includes lateral mixing stress. Complete details regarding 

 this and other extensive comparisons were not available but said to be 

 forthcoming. 



Bljker and Vlsser (1978) ^'^ and Liu and Dalrymple (1978) did not make 

 comparisons of their longshore profile theoretical results with the data 

 available. The NSTS field data, the laboratory data of Mizuguchl, Oshlma, 

 and Horikawa (1978)^^, and the ongoing extensive laboratory data sets 



2'+BIJKER and VISSER, op. cit. 



181 



