J2 

 < 



1.0 



0.1 



1 1 III 

 0.1 



i Mini I i i i i i ill 



j ' i i i i hi 



1.0 10.0 100.0 



SEDIMENT DIAMETER, mm 



Figure 2 . Shape coefficient A versus 

 sediment diameter (from Moore 1982) 



The equation is based on an assumption that the shape of the offshore 

 profile can be related to sediments which have been sorted as a result of the 

 dissipation of wave energy. A functional relationship has been developed 

 between the equilibrium profile shape coefficient A and the mean grain 

 sizeto demonstrate this assumption. This correlation, shown in Figure 2 

 (Moore 1982), indicates that larger grain sizes are reflected by larger A 

 values. These large values describe steeper offshore profiles according to 

 Equation 1, as would be expected of a coarse-grained beach in a high-wave 

 energy environment. 



The erosion model permits a specification of the berm and dune according 

 to the schematic representation shown in Figure 3. The variables h(b) and 

 h(d) refer to the height of the berm and dune, and M(b) and M(d) refer to the 

 slope of the face of the respective berm and dune. The parameter W(b) refers 

 to the width of an optional horizontal berm transition between the two zones. 



133 



