similar profile, albeit starting at some non-zero rate at the bed. It is not 

 obvious that the bed-load case would necessarily show a flux maximum in the 

 boundary layer, it may simply monotonically decrease to zero. 



Flux data are shown in Figure 11-8. The profiles show flux under 8-sec 

 waves for increasing wave heights of 0.4, 0.5, and 0.7 m. Notably, the 

 lowest elevations do not show zero transport rate, as was explained above. 

 Furthermore, the scatter on the profiles might be considered large; this can be 

 improved with longer time series and increased sensitivity of the system. The 

 case of 0.5 m (symbol x) represents the average of 16 profiles, i.e., 24 min 

 per elevation, and as such shows a smooth profile. Vertical integration of the 

 profiles would produce the total transport rate. 



Figure 1 1-8. Vertical distribution of sediment flux for runs S0409B ( + ), 



S0410A <o), and the average of S0609A, S0610A, S0612A, 

 and S0614A (x) 



Comparison of LDV and BASS measurements 



228 



LDV measurements are compared with the BASS data. An example is 

 shown in Figure 11-9. The wave period for these monochromatic waves is 



Chapter 1 1 LDV in the Bottom Boundary Layer 



