Table 18. Energy flux values at cell boundaries. 





Beach cell 



Cell 

 No. 



Cell 



boundaries 



(km) 



Gross northerly flux 



Gross sou 



.herly flux 



Notation 



>fagnitude 

 (N-m/s/m) 



Notation 



hhgnitude 

 (N-m/s/m) 



Northern boundary 

 (Mason Inlet) 



1 



0.0 



- 



' - 



P l,2 



421.5 



Wrightsville (north) 



2 



0.0-2.5 



P 2,l 



115.8 



p 2,3 



287.6 



Wrightsville (central) 



3 



2.5-4.8 



P 3,2 



290.0 



P 3,4 



424.3 



Wrightsville (south) 



4 



4.8-6.7 



P 4,3 



175.3 



P 4,5 



446.3 



Masonboro Inlet 



5 



6.7-7.2 



P 5,4 



352.8 



— 



— 



Carolina Beach Inlet 



7 



19.7-20.5 



- 



— 



*>,8 



310.2 



Carolina (north) 



8 



20.5-21.5 



p 8,7 



226.7 



p 8,9 



165.6 



Carolina (central) 



9 



21.5-24.3 



p 9,8 



418.6 



p 9,10 



350.0 



Carolina (south) 



10 



24.3-27.3 



p 

 10,9 



305.0 



p 

 10,11 



386.5 



Kure and Fort Fisher 



11 



27.3-42.0 



P ll,10 



224.2 



— 



— 



These values indicate that approximately 90 percent of the potential 

 southerly longshore sediment transport remained trapped in Mason Inlet 

 and 70 percent remained in Carolina Beach Inlet. 



The north jetty at Masonboro Inlet was completed in spring 1966 and 

 consists of a rubble-mound outer section and a low concrete sheet-pile 

 inner or weir section. The design of this weir jetty and the dredging 

 of material from the deposition basin on the inlet side of the weir have 

 caused a reduction in the northward sediment bypassing to near zero 

 (U.S. Army Engineer District, Wilmington, 1977). Therefore, a 5 4 

 was set equal to zero and the solution of the sediment budget equations 

 gave CL^ 5=0.64. This means that approximately two-thirds of the 

 potential littoral drift passes over or around the weir jetty into 

 Masonboro Inlet and one-third remains trapped on the southern end of 

 Wrightsville Beach, providing a source of material for northerly 

 transport. Table 19 gives the a values for the Wrightsville Beach and 

 Carolina Beach sediment budgets. 



Table 19. Efficiency factors a for Wrightsville and Carolina Beach 

 sediment budgets. 



Beach cell 



Cell 



No. 



Northerly transport 



Southerly transport 



Notation 



Factor 



Notation 



Factor 



Mason Inlet 



1 



— 



— 



1.2 



0.09 



Wrightsville (north) 



2 



2,1 



1.0 



2,3 



1.0 



Wrightsville (central) 



3 



3,2 



1.0 



3,4 



1.0 



Wrightsville (south) 



4 



4,3 



1.0 



4,5 



0.64 



Masonboro Inlet 



5 



5,4 



0.0 



— • 



— 



Carolina Beach Inlet 



7 



- 



- 



7,8 



0.31 



Carolina (north) 



8 



8,7 



1.0 



8,9 



1.0 



Carolina (central) 



9 



9,8 



1.0 



9,10 



1.0 



Carolina (south) 



10 



10,9 



1.0 



10,11 



1.0 



Kure and Fort Fisher 



11 



1.1,10 



1.0 



" 





81 



