(Figure 3-8), recession at R-43 is considerably less. The smaller recession at R-43 is attributed 

 to the beach-face slope being closer to equilibrium than at R-7. 



For R-43, SBEACH produced no washover because the dune crest was higher than the 

 highest wave runup. Table 3-6 summarizes calculated change in MHW shoreline position and 

 the loss of dune and beach volume landward of the location of the MHWL. Volume lost 

 landward of the MHWL ranged between 2.1 and 3.9 cy/ft or 5.3 and 9.8 cu m/m of dune crest. 

 These rates are in the lower range of storm-induced dune-erosion rates as documented by Savage 

 and Birkemeier (1987). 

 16 



12 



Initial 05/82 

 Thanks 1 1/84 

 NE 03/89 

 Gordon 11/94 



150 200 250 300 350 



Distance Offshore, ft 



400 



450 



500 



Figure 3-10. R-43: Beach recession by three selected recent storms. 



Table 3-6. Summary of potential erosion of Profile Line R-43 by three selected 

 storms. 



Storm Sequence 



Change of the 

 MHWL, ft 



Maximum Volume- 

 Loss Rate, cy/ft 



Initial 05/1982 - Thanksgiving NE 11/1984 



+ 17.1 



-3.9 



Post-Thanksgiving NE 11/1984 - NE 03/1989 



-1.7 



-2.8 



Post-NE 03/1 989 - TS Gordon 11/1994 



-1.0 



-2.1 



Total Change of the MHWL 

 05/1982 to 11/1994 



+ 14.4* 



~ 



* From 1 986 to 1996 (bracketing time of ownership) the MHWL change was calculated to be -2.7 ft 



Chapter 3 Assessment of Coastal Change 



3-21 



