speeds were calculated from an expression given by Hallermeier (1981) for the 

 CRIEPI data, and in the CE cases fall speeds determined by Seelig (1983) were 

 used. Fall speed depended on water temperature in the tank (Kajima et al . 

 1983b, Kraus and Larson 1988a). Under nonextreme water temperatures such as 

 considered here, the fall speed is almost linearly dependent on grain size, 

 resulting in similar correlation values for quantities expressed in terms of 

 either the grain size or fall speed. 



241. A stepwise regression analysis incorporating the aforementioned 

 factors explained 70 percent of the variation in the data. Wave height was 

 most important, accounting for 35 percent, followed by the fall speed which 

 explained 30 percent. Wave period and initial beach slope together accounted 

 for only 5 percent. If only bars formed on a profile which mainly experienced 

 erosion (transport directed offshore), the explained variation increased to 80 

 percent, with the wave height and fall speed being most important. The 

 dimensional regression relationship involving equilibrium bar volume Vg , 

 deepwater wave height, sand fall speed, and wave period for bars formed on 

 erosional profiles is 



Vgq = 0.088 Ho^-^^ w"^-^^ T°" (8) 



242. It is desirable to use nondimensional quantities to obtain general 

 relationships relating morphologic features to wave and sand parameters. From 

 the regression equation describing equilibrium bar volumes on erosional 

 profiles (Equation 8) dimensionless parameters were identified by dividing by 

 the wave period raised to a suitable power. Equilibrium bar volume was 

 normalized by the deepwater wavelength squared, and the independent parameters 

 emerged as dimensionless fall speed and deepwater wave steepness. The 

 coefficient of determination r^ (see Appendix A), defined as the percentage 

 of the sum of squares explained by the regression equation, will increase by 

 incorporating the wave period in the parameters (from 75 percent without beach 

 slope incorporated to 90 percent) . The resultant regression equation is 



■ Ho ■ 

 . wT . 



1.32 



■ Ho ■ 

 . Lo . 



= 0.028 (9) 



84 



