representation of the time evolution of the bar. However, model prediction of 

 the amount of erosion occurring on the foreshore may be substantially in 

 error . 



20- 



Elapsed Time (hr) 



Figure 69. Effect of runup height on bar volume 



Effect of Time -Varying Water Level and Waves 



462. In the preceding calibration, verification, and sensitivity 

 analysis, all simulations were conducted with a fixed water level and constant 

 wave conditions. However, in one of the LWT experiments (Case 911), water 

 level was varied in a sinusoidal manner to simulate the influence of a tidal 

 variation on beach profile evolution. This case provided an opportunity to 

 evaluate model predictions of profile change induced by constant incident 

 waves with a realistic variation in water level. The water level variation 

 had an amplitude of 0.45 m and a period of 12 hr. Optimal model parameters 

 obtained in the overall calibration were used in the simulation of Case 911. 



463. Figure 70 illustrates the result of the model run and a comparison 

 with the measured beach profile at the end of the tank experiment. Develop- 



193 



