Storm Surge Data. Storm surge hydrographs with peak levels corre- 

 sponding to finite stages along the stage -frequency curve are required 

 as input for the erosion model. For the present study, an ensemble of 

 120 northeasters, corresponding to five separate simulations of 

 discrete total surge elevations (storm surge plus tide) from 5.0 ft 

 to 9.6 ft in 0.2-ft increments, and 275 hurricanes, with total surges 

 from 4.0 ft to 14.8 ft at 0.2-ft increments, were randomly selected 

 from the data base of 600,000 hurricane and 18,000 northeaster indexed 

 surge -tide events. 



Dune and Berm Erosion Simulations. Each storm event of the ensemble 

 of storm hydrographs was input to the dune erosion model. The maximum 

 amount of recession computed for any contour line between the dune 

 crest and mean sea level during the entire storm simulation was 

 selected as an indicator of maximum dune erosion. Although recovery 

 is experienced on the berm, this maximum recession was selected to be 

 a realistic indicator of maximum damage. Figures 8 and 9 represent 

 the computed scatter diagrams for the dune recession-frequency of 

 occurrence relationships for hurricanes and northeasters. A design 

 curve was defined from the upper envelope of data points. The 

 hurricane and northeaster curves were then combined into a single 

 design curve. Both the individual component curves and the design 

 maximum recession-frequency of occurrence curves are shown on 

 Figure 10. 



30 - 















20 - 















_, 10 - 



CO 



2 















ELEVATION, FT 



o o o 





















O--.. 







-30 - 















-40 - 



























-250 



250 



500 



750 1000 



1250 



1500 1750 2000 



LEGEND 







DISTANCE, FT 







MEASURED 











PROFILE NO. 286 



COMPUTED 











30 MAY 1987 @ 1100 



Figure 5. Cross-section of profile 286 

 140 



