relationship of Equation 78 was extended through the transition region, repre- 

 sented by the dashed line in Figure 34, for illustrative purposes. Although 

 the data are widely scattered in this region, the relationship follows the 

 trend of the higher 7 b -values and intersects with the increasing relation- 

 ship of Equation 78 near the lower limit of the transition region. 



137 . An exponential relation was also developed to predict -y h for 

 plunging and spilling waves that had £ -values greater than 0.90. The 

 visual fit line shown in Figure 37 is expressed as: 



7b = 1.3(1 - e " 2 - 5 «o) (79) 



Equation 79 was obtained for 0.29 < £ < 1.07 and fi 1 < 10 deg. 



138. Figure 38 gives a comparison of 7 b for 5— and 10— deg bar slopes 

 computed using Equation 79 to the equation developed for plane slopes, Equa- 

 tion 58, as a function of deepwater wave steepness. The prediction for planar 

 slopes exceeds the limits of beach slope given for Equation 58. The values 

 shown by the plane slope equation are values for m = 1/10 . Equation 58 

 gives higher values of 7 b than Equation 79 for fi x = 5 deg for 0.02 < H /L 

 < 0.09 , but underpredicts 7 b for p x = 10 deg. Also shown in Figure 38 are 

 the expected values of 7 b on a 1/30 slope using Equation 58, which predicts 

 7 b slightly lower for high wave steepness for f3 1 — 5 deg. Equation 58 

 significantly underpredicts 7 b for low wave steepnesses for ^ x = 5 deg and 

 for all wave steepnesses for /^ = 10 deg. 



Breaker height index 



139. Values of fy, as a function of deepwater wave steepness are shown 

 in Figure 39 (a-d) grouped by seaward bar angle. The data show increasing 

 breaker height with decreasing wave steepness, which is also typical of wave 

 breaking on a plane slope. Therefore, it is reasonable to express the data 

 collected on barred profiles in the same form as the relationships developed 

 for plane-slope data: 



Ob = COM 





(80) 



