Siommarv 



294. Numerous morphologic features of beach profiles generated under 

 breaking waves in large wave tanks were quantitatively described in this 

 chapter. Selected morphologic parameters are presented in Tables 4 and 5, 

 together with the breaking wave height. Under steady, regular waves and 

 constant or slowly varying water level , the evolution of bars and berms was 

 found to be regular, exhibiting clear growth and equilibrium properties that 

 were readily described by simple regression expressions. The dimensionless 

 sand fall speed H^/wT emerged as an important parameter in predicting both 

 profile response and geometric properties of various major morphologic 

 features. The strong relationship between wave and sand characteristics and 

 morphologic features suggests the possibility of quantitatively predicting the 

 evolution of macroscale features of the profile. 



295. The effect of scale was made apparent through the different values 

 of empirical coefficients in the criteria for erosion and accretion (bar/berm 

 formation) for small-scale and prototype-scale wave and beach conditions. 

 Interestingly, most criteria held for both small- and prototype-scale experi- 

 ments provided that empirical coefficients were modified. It was found that 

 use of mean wave height with field data allowed the same criterion to be used 

 (Equation 2) as found for the LWT experiments involving regular waves, with no 

 change of the empirical coefficient. 



296. In general, profile response in the LWT experiments, apart from 

 effects related to use of regular waves, was considerably in agreement with 

 what is observed on a natural beach. Irregular waves as occur in the field 

 are expected to give a smoother character and slower rate of change of 

 morphologic features. 



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