Table 2 

 Summary of Laboratory Data Used to Verify the Wave Breaking Scheme 



Test 



Case 





Bathymetry Slope 

 Plane beach 1 :20 



T 

 sec 



1.40 



H o 

 cm 



H b 

 cm 



13.2 



h b 

 cm 



Horikawa 



and 



Kuo 



1 



15.5 



Horikawa 



and 



Kuo 



2 



Plane beach 1 



:30 



2.20 



— 



9.1 



10.8 



Horikawa 



and 



Kuo 



3 



Plane beach 1 



:30 



2.20 



— 



12.2 



16.4 



Horikawa 



and 



Kuo 



4 



Plane beach 1 



:65 



1.56 



14.4 



17.2 



19.4 



Horikawa 



and 



Kuo 



5 



Plane beach 1 



:65 



1.56 



24.7 



27.1 



35.2 



Horikawa 



and 



Kuo 



6 



Plane beach 1 



:80 



1.40 



— 



17.7 



25.0 



Izumiya 







7 



Plane beach 1 



:20 



1.19 



6.0 



7.7 



9.4 



Izumiya 







8 



Stepped beach 1 



:20 



0.96 



7.9 



8.5 



9.7 



Izumiya 







9 



Barred beach 1 



:20 



0.95 



6.3 



6.9 



8.3 



57. Two series of verification tests were conducted. The first series 

 involved model simulations which were initiated at the break point determined 

 from the data in Table 2. The purpose of these tests was to check the valid- 

 ity of the surf zone transformation part of the breaking scheme. Figures C1 

 through C6 show plots comparing simulated results with Horikawa and Kuo's 

 data. The horizontal and vertical scales vary from plot to plot. Model re- 

 sults generally show good agreement with observed data. The model tends to 

 underpredict the wave heights very close to shore because the model does not 

 consider the effects of wave setup. Setup would increase the total water 

 depth here and allow for larger simulated wave heights (Dally 1980). Horikawa 

 and Kuo Test 2, having data points 1.0 and 0.5 m from shore, clearly illus- 

 trate this model deficiency. However, neglecting wave setup has little effect 

 on model accuracy in the remainder of the surf zone. Steep slopes, 1:20 and 

 1:30, produce a much more rapid decrease in wave height across the breaking 

 zone than do the milder slopes, 1:65 and 1:80. Qualitatively, this is what is 

 usually observed in the field. Plunging waves are more likely to occur on 

 steep slopes and spilling breakers on mild slopes. Results suggest that the 

 breaking model is applicable under both types of breaking conditions. 



58. Figures C7 through C9 show comparisons between model results and 

 Izumiya 's data, again for surf zone transformation only. Test 7, a plane 

 beach case, shows very good agreement. The wave height variation across the 



33 



