that the parameter seemed to correlate with the beach reflection coefficient. 



29. Noda (1971) investigated both prototype-scale and small-scale model results for profile similarity 

 and found that a much closer similairity could be obtained if the HjwT parameter was conserved than if 

 wave steepness, Hg/ Lg (deepwater wave height divided by deepwater wave length), was held constant 

 between model and prototype. He also offered an empirical relationship for the selection of model grain 

 sizes and concluded that movable-bed coastal models could be distorted, but the validity still needed to be 

 confirmed. 



30. Dean (1973) popularized the fall speed parameter by incorporating it into an expression for 

 distinguishing between swell and storm profiles. Dean used mostly small-scale movable-bed model results to 

 establish an empirical coefficient for his expression. This coefficient was later revised by Kriebel, Dally, and 

 Dean (1986b) by the addition of more prototype-scale data and reevaJuation of the results. They concluded 

 that Dean's original results reflected significant scale eifects. Kriebel, Dally, and Dean (1986b) extensively 

 reviewed the literature on parameters pertaining to differentiating between swell and storm profiles. 



31. Dalrymple and Thompson (1976) plotted foreshore beach slope as a function of the fall speed 

 parameter using laboratory data available from both small- and large-scale experiments. Their plot 

 indicated the importance of the parameter in governing beach slope, although considerable scatter appears 

 about the trend. They reported that similar attempts to relate beach slope to other parameters exhibited 

 greater scatter; hence the fall speed parameter performed best in their study. 



32. Gourlay (1980) investigated equilibrium beach profiles in the laboratory using fine sand and 

 coarse-grained crushed coal for bed materials. The results reaffirmed the contention that the fall speed 

 parameter is an important parameter influencing both surf zone hydrodynamics and the resulting 

 equilibrium proflle. He also concluded that the initial proflle impacts the final proflle only when the initial 

 slope is quite mild. Gourlay stated that the fall speed parameter is probably sufficient for defining 

 similarity conditions for model beaches formed in relatively impermeable sand, but the parameter would 

 not be sufficient for defining similarity conditions for model beaches in permeable conditions, such as 

 crushed coal. For highly permeable beaches, Gourlay stated the ratio of flow speed within the deposited 

 sediment to the sediment fall speed in still water is also important. 



33. The fall speed parameter has also been used to characterize geometric profile features such as 

 breakpoint bars and troughs, shoreline-to-bar-crest distance, etc. Hughes and Chiu (1981) based their 

 profile parameterizations on small-scale movable-bed model experiments, and more recently Larson and 

 Kraus (1989) used results from two prototype-scale wave tank experiments to characterize barred profiles 

 and develop a cross-shore sediment transport numerical model. In both cases, the fall speed parameter 

 figured prominently in the profile parameterizations. 



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