Mid-storm 



Water Level 

 Wave Height 



Figure 4. Time history of waves and water level 



typical wave conditions on an open-ocean Atlantic coast and are used to 

 produce a realistic equilibrium profile. Under these waves, beach change can 

 be mildly erosional or accretionary , depending on grain size and initial 

 profile shape. At day 21 ("Pre-storm" in Figure 4) a storm moves into the 

 area that lasts for 3 days; the average surge water level during the storm 

 rises and falls with Gaussian form to reach a maximum elevation of 3 m above 

 mean sea level; the average wave height follows a sinusoid to a peak of 2.5 m 

 at the peak of the surge ( "Mid- storm" ) . The wave period during the 3-day 

 event varies between 8 and 12 sec, with the 12-sec period occurring at the 

 time of the maximum wave height. At the end of the storm ("Post-storm"), the 

 surge vanishes and waves arrive as swell with height of 0.5 m and period of 

 16 sec. 



In the following sections, adjustment of the profile to the 30-day design 

 sea condition is examined with the model for three situations: an original 

 (existing) condition, a standard fill design, and a beach advancement fill 

 design, herein called the "Bruun beach fill." Each situation is run for two 



100 



