of extensive beach nourishment, are already taking place in the 

 commercial area of Virginia Beach. It appears from this study that, 

 as presently undertaken, the sand nourishment scheme is working 

 within the context of the natural system. Although nourishment is 

 clearly needed to maintain the beach at profile lines 3 and 4, it 

 is unclear if it is needed at profile lines 1 and 2, where some of 

 the nourishment sand is moved by the northerly longshore transport 

 system. The net accretion at profile lines 1 and 2, in the form of 

 widened beach and increased dune elevation, respectively, is a 

 natural process, but requires an unknown amount of sand nourishment 

 to occur. The inlet bypassing at Rudee Inlet does not appear to be 

 a sufficient supply by itself. The recycling of sand by way of 

 truck haul to Virginia Beach of material dredged from Thimble Shoals 

 Channel, northwest of Cape Henry, appears to be a sensible practice 

 with respect to the natural processes. The removal of material from 

 the south side of Rudee Inlet may be adversely affecting profile 

 line 5, but probably only has a minor long-term effect, if at all, 

 on profile lines 6 and 7. Although profile line 5 has not had much 

 net beach volume change, it is a very active location, which is 

 probably affected by the changes caused by the natural buildup 

 behind Rudee Inlet jetty and removal for Virginia Beach nourishment. 



Certainly, knowing the nodal zone of the longshore transport is 

 critical to any coastal construction or instigation of remedial measures 

 (SPM, U.S. Army, Corps of Engineers, Coastal Engineering Research Center, 

 1975, pp. 4-142 to 4-146). Evidence is summarized here to infer that 

 this nodal zone is located adjacent to northern Back Bay. North 

 of this area the "net" longshore transport is hypothesized to be to the 

 north; south of this area "net" transport is to the south. 



With respect to the problem of vehicular access, the data clearly 

 indicate that Sandbridge and Back Bay are in sand-deficit areas, which 

 is attributed to the net longshore transport out of this area. Thus, 

 erosion may be predicted to continue at relatively greater rates than 

 perhaps, False Cape to the south. False Cape appears to be benefiting 

 by a relative influx of sand and undergoing net accretion (Table 11) . 



The 1972-1974 profile data indicate that Back Bay underwent much 

 more severe erosion, resulting in significant dune retreat and narrower 

 beaches, than in the 1974-1976 time period. Thus, it is clear that 

 both rates and patterns of erosion and accretion can, and do, change 

 with time, and that the trends of these 27 months are not necessarily 

 an indicator of future beach changes in this study area. 



When the net survey changes with reaches (defined by usage) are 

 averaged, it is clear that the erosional areas are Back Bay (-13.6 

 cubic meters per linear meter) and Sandbridge (-6.5 cubic meters per 



84 



