crest h c and the breaking wave height. Larson and Kraus (1989) also ob- 

 served that h c was related to breaking wave height and insensitive to wave 

 period and beach and sand parameters. The depth at the bar crest could be 

 determined from a simple equation: 



h c = cH b (71) 



in which the value of the empirical coefficient c was found to be 0.59 by 

 Sunamura and 0.66 by Larson and Kraus. Equation 71 gives one point on the 

 bar, and another point is required to specify the horizontal location and size 

 of the bar. 



105. Keulegan (1945) determined the ratio of h t , the depth of the bar 

 trough from SWL, to h c was 1.65 for bars in the field, and 1.69 for bars 

 produced in the laboratory. Sallenger, Holman, and Birkemeier (1985) observed 

 a bar during a storm and found h t /h c =1.24 . Sunamura (1987) gave values of 

 h t /h c ranging from 1.16 to 1.93 based on field measurements on various coasts 

 around the world. From results of large -wave tank tests (Saville 1957, Kajima 

 et al. 1983), Larson and Kraus (1989) found an average value of h t /h c = 1.74 

 and that h t /h c was weakly dependent on wave steepness as 



0.092 



2.5 



h„ 



H 



(72) 



106. Since the values of h t /h c observed by Keulegan (1945), 

 Sallenger, Holman, and Birkemeier (1985), Sunamura (1987), and Larson and 

 Kraus (1989) differ, it was felt that use of a fixed value would be inappro- 

 priate. Equation 73 was selected to determine h t /h c , and values of this 

 ratio ranged between 1.61 to 2.00 for the design wave conditions. 



107. The depth of the bar crest was calculated using Equation 71, with 

 c = 0.66 . The coefficient value of Larson and Kraus (1989) was selected, 

 because it was obtained from the same data set used to determine Equation 72. 

 Breaker height was estimated by Equation 30 (Sunamura 1981) for input into 

 Equation 71. A program was written to calculate wave height through shoaling 

 using linear wave theory at water depth increments of 0.1 ft. The wave height 

 to water depth ratio was calculated at each depth increment and compared with 



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