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The reflection coefficient, Kp, variation ranged from 0.02 to 0.12 in 

 one experiment to as much as from 0.04 to 0.27 in another experiment. Changes 

 in the foreshore slope and berm-crest elevation, the breaker type, the slope 

 and top elevation of the offshore slope, and the distance between the fore- 

 shore and offshore were the sources of the Kp variability. For a constant 

 initial profile slope, the average K„ increased with increasing wavelength; 

 but for a constant wavelength, the average Kp decreased with increasing 

 initial profile slope. In nine experiments the Kp tended to increase as 

 the profile developed, indicating that the profile was reflecting, rather 

 than absorbing, energy. 



Profile equilibrium was not easily attained, particularly in five experi- 

 ments with a wave steepness of 0.021, which, is in the transition region between 

 "winter" and "summer" waves. Experiments with winter or summer waves reached 

 equilibrium more readily. 



Laboratory effects, caused by differences in initial profile slope, initial 

 test length (distance between the wave generator and the initial shoreline) , 

 tank width, and water temperature, affected the profile development and the 

 wave height variability. Initial profile slope and initial test length should 

 be kept constant to assure test repeatability in movable-bed experiments. The 

 wavelength-to-tank width ratio should be greater than or equal to 3 to assure 

 two dimensionality of profile development, but two-dimensional profiles may 

 not be realistic replications of three-dimensional profiles. 



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