CO 



O 



Grain Size (mm) 



Elapsed Time (hr) 



Figure 67. Effect of D on bar center of mass 



is of considerable interest to analyze the response of the beach profile to 

 changes in wave input parameters. Therefore, wave height and period were 

 varied to investigate the sensitivity of the numerical model to changes in 

 wave input . 



459. An increase in wave period resulted in an increase in bar volume. 

 Figure 68 shows the evolution in time of bar volume for various wave periods. 

 Since small -amplitude wave theory for shallow-water conditions is applied in 

 the numerical model, wave period does not enter explicitly in the shoaling 

 calculation within the grid, but through shoaling from deep water to the 

 seaward boundary of the grid and through the breaking wave criterion (Equation 

 24) (and, of course, in the criterion determining direction of transport. 

 Equation 2). A longer wave period will allow a specific wave to shoal further 

 inshore before it breaks, producing greater energy dissipation and moving more 

 sand before equilibrium is attained. Maximum bar height was influenced by 

 wave period in the same manner as bar volume; an increase in period gave a 

 larger maximum bar height. 



191 



