PROFILE LINE 186 
—— 30 JUN 85 
ELEVATION (FT NGVD) 
-500 @ 508 1000 1500 2000 2500 3008 3500 
DISTANCE (FT) 
Figure 30. Profile 186 
162. All water levels and profile elevations were adjusted to MSL for 
input to the beach erosion model. The relationships between datums used for 
this conversion are MSL = (NGVD + 0.57 ft) = (MLW + 2.2 ft) as determined by 
telephone conversation with the National Ocean Service (NOS) of NOAA in 
January 1987. 
163. Evaluation of the existing-condition cases was accomplished by 
subjecting the four individual profiles to each of the 275 hurricanes and 120 
northeasters in a total of five separate runs. A value was then computed 
which corresponds to the maximum computed recession of any contour line be- 
tween the the dune crest and MSL during the entire storm event of known recur- 
rence interval. Maximum recession does not usually occur at the end of a 
storm, during which time beach recovery may be in progress. Therefore, the 
maximum was selected as a reliable indicator of storm-related damage. 
164. Recession-recurrence diagrams. The recession-recurrence inter- 
val plots represent the computed recession resulting from each of the stochas- 
tically generated storm events. These plots demonstrate the natural variabil- 
ity in recession which occurs as a result of storms of equal surge. For the 
85 
