PROFILE LINE 140 
—— 20 JUN 85 
ELEVATION (FT NGVD) 
-500 Y) 500 1020 1500 2000 2500 3000 3500 
DISTANCE (FT) 
Figure 29. Profile 140 
represent a beach with a high dune but with no protective seawall. This case 
was utilized to demonstrate the possibility of unrestricted dune recession. 
Profile 140 is located in Block 12 (North Long Beach). The average rate of 
shoreline position change in this area (-1.18 m/yr) exceeds that of all other 
blocks for the 1953-1985 time period (Table D18), suggesting that beach mate- 
rial has been available for transport. Average grain size is 0.34 mm for both 
the 1953 and 1985 surveys (Table D19). A coefficient of A = 0.136 m'/3 was 
computed from offshore profile data. This value corresponds to a sediment 
diameter of 0.28 mm. 
161. Case D. Profile 186, shown in Figure 30, was selected as an ex- 
ample of a low-elevation dune unprotected by a seawall. This profile is 
located in the Deal south block, along which the average rate of shoreline 
position change (1953-1985) was -O.44 m/yr (Table D18). Average grain sizes 
of Block 19 for the 1953 and 1985 surveys were in the range of 0.28-0.31 mm 
(Table D19), indicating the availability of sediment for transport. An 
A-value of 0.135 m'/3 was computed for this profile, corresponding to a sedi- 
ment diameter of 0.29 mm. 
84 
