coast of the United States. The amount of eroded volume for such events 

 appears to be on the order of 20-30 m 3 /m (Birkemeier et al . 1987). 

 Representative Storms 



Several references and authorities were consulted in order to develop 

 schematic storm hydrographs (surge time history), wave characteristics (height 

 and period), and tidal variation representing those of a moderate -intensity 

 hurricane and northeaster for use in this work. The resultant hypothetical 

 surge hydrographs for these storms are shown in Fig. 1. The hurricane surge 

 was developed to have a duration of approximately 12 hr, with a peak surge of 

 2 m, and a duration above half the peak surge (1 m) of 6 hr. The shape of the 

 hurricane surge was generated from an inverse hyperbolic cosine squared. The 

 surge of the northeaster has a duration of 36 hr, with a peak surge of 1 m, 

 and a duration above half the peak surge (0.5 m) of 18 hr . The shape of the 

 northeaster surge was generated by a cosine squared function. The peak surge 

 of the hurricane is higher because the wind speeds in hurricanes are, on the 

 average, greater than in northeasters. 



The time history of the wave height and period assigned to the hurricane 

 and northeaster are shown in Figs. 2 and 3, respectively. Both have peak 

 wave heights of 5 m, which occur during the time when the respective surges 

 are greater than half the maximum. The duration of high waves for the north- 

 easter is thus three times that of the hurricane. Since the radius of a 

 northeaster is typically several times greater than that of a hurricane, the 

 fetch is longer, resulting in longer wave periods assigned to the northeaster. 

 Wave height and period of 1 m and 7 sec were applied for approximatley 6.5 

 days before start of the storms to mold the profiles into a realistic shape. 

 Following the storm, the wave height and period were changed to 0.5 m and 10 

 sec to simulate long-period recovery swell wave conditions. A sinusoidal tide 

 was applied with a 12-hr period and 0.5-m amplitude, and a peak in the tide 

 occurred during the peak surge of each storm. 

 Beach Profile Shape (fill templates) 



Following the procedure of Kraus and Larson (1988), two different beach 

 fill cross -sections or templates were designed for exposure to the impact of 

 the storms. One, an artificial berm, had most of the fill placed on the beach 

 and above mean sea level (MSL) . It extended horizontally for a distance of 16 



115 



