Figure 5. In general, the sand composing the beach and dunes south of 

 Rudee Inlet is relatively uniform with mean (phi) - 1.0 to 2.0 (0.5 to 

 0.25 millimeter); standard deviation - 0.8 (0.6 millimeter) along the 

 berm and 0.5 (0.7 millimeter) in the dunes (Shideler, 1973b). The 

 major exception is the addition of a coarse red (2 to 1.0 phi), iron- 

 stained quartz and feldspar sand component. The northern limit of this 

 coarse red sand varies dramatically between Corolla and Duck (discussed 

 in Section V) . This area is referred to locally as the "area of 

 treacherous red sands" because of its adverse affect on four-wheel 

 drive vehicles traveling the beach. 



The sand behavior of Virginia Beach has been studied by Harrison 

 and Alamo (1964) , who tabulated the settling velocities of sand in the 

 vicinity of Rudee Inlet, and by Tuck (1969). Tuck suggested that a 

 reversal in the slope grain-size relationship occurs under storm con- 

 ditions on the beach coincident with profile changes, and that such a 

 reversal is generally present in the "zone of shoaling waves" part of 

 the beach at Virginia Beach. The slope grain-size relationship re- 

 ferred to here is the increase in beach slope with increase in grain 

 size. As noted by Tuck (1969) and discussed in Sections V, 5 and VII, 

 of this report, there are many exceptions to this relationship. 



Mineralogical data between Cape Henry and Cape Hatteras are detailed 

 by Swift, et al. (1971), who indicate very complex relationships. 



4. Beach Usage and Impact . 



The study area encompasses four categories as defined by beach 

 usage: Natural, military, commercial, and residential. Profile lines 

 1 (Fort Story), 6, 7, and 8 (Dam Neck) are military. The beach at 

 Fort Story is probably the most disturbed (of the four profile lines) 

 as far as vehicular traffic is concerned. Amphibious vehicles are 

 driven in the waters just off the beach, followed by landing maneuvers 

 on the beach itself. In addition, a road grader was used at times to 

 keep the beach, from the base of the dune seaward, as flat and smooth 

 as possible. All these events have occurred directly at Profile line 

 1. There is less vehicular beach traffic on the beaches at Dam Neck, 

 although amphibious vehicles have been observed on occasion. The 

 Marines conduct drill exercises on the lower beach, but avoid the 

 dunes. There is a recognition of the importance of dunes at Dam Neck 

 as indicated by an extensive and active sand fencing program and an 

 effort to keep everyone out of the dunes. 



26 



