b. Deepwater wave steepness was given, or wave height was measured 

 in the horizontal section of the tank so that H /L values 

 could be calculated by linear wave theory. 



c. No structures were present in the wave tank that would alter 

 wave breaking or introduce reflections not associated with 

 planar beaches . 



The data sets selected are summarized in Table 3, and the data used in the 



analysis are listed in Appendix A. 



Breaker depth index 



81. A breaker depth index was developed following the general (but not 

 the particular) method of Weggel (1972) for 11 data sets for beach slopes 

 covering 1/80 to 1/10. Breaker depth index was plotted versus deepwater wave 

 steepness for each individual slope (Figure 9 (a-f)), and lines that visually 

 best represented the data were drawn (dashed line). Calculated values, shown 

 by solid lines, are explained below. The data were considerably scattered, 

 and regression analysis could not be used. The data scatter apparently 

 reflects inconsistencies of breakpoint location, breaker height, and/or water 

 depth datum. Data collected on the 1/80 slope (Figure 9a) were scattered with 

 no apparent trend; therefore, the average value of 7 b was chosen for that 

 slope . 



82. The line slope a(m) and zero intercept b(m) of the best-fit 

 lines from each slope were plotted versus beach slope (Figures 10 and 11) . 

 Equations were fit to a(m) and b(m) by using the method of least squares 

 and combined to yield the following relationship for breaker depth index: 



7 b = b(m) - a(m) 



(58) 



in which 



a(m) = 5.00(1 - e" 43 " 1 ) (59) 



and 



1.12 



b(m) = (60) 



(1 + e" 60m ) 



for 0.0007 < H /L < 0.0921 and 1/80 < m < 1/10 . Equation 58 is presented 

 in Figure 12 for beach slopes ranging from 1/80 to 1/10 and also in Figure 9 



43 



