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Coastal Change Along the Shore of Northeastern South Carolina: The South Carolina Coastal Erosion Study

Figure 5.2.  Diagrams showing how volumes were calculated for sediment eroded from beach and shoreface deposits.  (TOP) Plan view of a beach divided into 15 equal segments, each measuring 100 m wide and extending from the dune crest to the shoreface.  An existing beach profile (A, B, or C) is assigned to nearby segments of beach.  In this example, profile A (red line) represents segments 1–5.  Profiles B and C represent segments 6–10 and 11–15, respectively.  (BOTTOM) The existing profile is moved landward based on the long-term erosion rate that has been established for each beach segment (see Figure 4.2).  Profile shape remains constant, and the area between the eroded profile and the existing profile represents the sediment released in one year.  For example, if the beach in segment 1 is eroding rapidly at 8 m/yr (26 ft/yr), profile A is translated 8 m (26 ft) landward of its original position, and the region between the two profiles (diagonal line pattern) represents the annual volume of eroded sediment.  Values are added for all segments to determine the total amount of new sediment that is contributed to the regional sediment budget. [Click here for high-resolution image.]