waves interact to provide an equilibrium profile. Bars are gentler under 

 these conditions than those that cause confused breaking. Confused breaking 

 may occur for engineered conditions , such as in areas where dredged material 

 is disposed. However, if waves possess sufficient energy, they will initiate 

 sediment movement, material will be transported, and the interaction between 

 the bar and waves will form a more gently sloping bar shape. 



Wave Reflection 



128. Reflection coefficients K r obtained from wave heights at Gages 2 

 and 3 and the predicted values of Equation 8 (Miche 1951) and Equation 10 

 (Battjes 1975) were plotted as a function of £ , shown in Figure 31. The 

 data are scattered, and one data point is anomalously high (K r = 0.48). The 

 reason this point is high is not known, and it was disregarded in all analysis 

 of reflection. Although there is scatter, a clear trend is present for K r 

 to be constant (0.15) for all values of £ . Predictions of the Miche equa- 

 tion result in a steep curve that approaches a perfectly reflected wave for 

 bar and wave conditions if £ = 1 . Equation 10 underpredicts K r at low 



1.0 



0.8 



0.6 



0.4 



0.2 



Kr 







(deg 



5 

 10 







/ * 



15 







a 



20 







o 



m ■ 1/30 







— 



Battjes 











Miche 







* 





□ * 





D + 





a * + *- 



4* 



" ' + p 



□ 









0.5 



1.0 



1.5 



2.0 



2.5 



3.0 



3.5 



Figure 31. Comparison of measured K r with 



predicted values of Battjes (1975) and Miche 



(1951) as a function of £ 



82 



