wave energy to be propagated away from the hole causing a reduction in wave 

 height along the pier. Results from Hubertz (1982) substantiate this observa- 

 tion. The trend of the wave height variation along the pier for Case 4 also 

 is accurately simulated. The magnitude of the simulated significant height 

 consistently underestimates observed data by about 0.1 m. The closeness of 

 fit for this case, which involves a wider spectral bandwidth, suggests that 

 the model may provide a useful method for predicting spectral wave transforma- 

 tions if the waves have a small directional spread. More research is needed 

 to test this hypothesis. 



Verification of the Wave Breaking Scheme: Comparisons 

 with Laboratory Data 



55. A number of numerical simulations were performed in order to verify 

 the capability of RCPWAVE to predict wave breaking and surf zone wave trans- 

 formation. Model results were compared with data from laboratory experiments. 

 Two sources of data were used. The first source was the original work of 

 Horikawa and Kuo (1966) along with additional information concerning that work 

 found in Dally (1980) and Dally, Dean, and Dalrymple (1984). Horikawa and Kuo 

 studied the transformation of waves in the surf zone using two wave tanks and 

 four different uniform bottom slopes. Two slopes, 1:20 and 1:30, were tested 

 in a wave tank 17 m long and 0.6 m deep. The remaining slopes, 1:65 and 1:80, 

 were tested using a larger tank which measured 75 m in length and 1.2 m in 

 depth. The second source of experimental data was the dissertation work of 

 Izumiya (1984), who used a smaller wave tank for his tests. All water depths 

 considered in the experiments were less than 0.3m, and all breaking wave data 

 were collected within 7 m of the dry "beach." He investigated wave transfor- 

 mation over three different bottom configurations: a plane beach, a stepped 

 beach, and a barred beach. All slopes were 1:20, including the back slope on 

 the barred beach. 



56. Wave and bathymetry conditions for each laboratory test used in the 

 model verification process are shown in Table 2. The table shows the data 

 source, an arbitrarily assigned test case number, the type of beach consid- 

 ered, and the beach slope. The following wave parameters for each test are 

 given also: (a) the wave period, (b) the deepwater wave height (if it were 

 available), (c) the incipient breaking wave height, and (d) the water depth at 

 breaking. 



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