PART VII: SHORE PROCESS MCDEL REQUIREMENTS 



63. Concurrent with the numerical model efforts described in this re- 

 port was a st'^dy of sediment transport under current and wave- induced current 

 interactio-is at Oregon Inlet. The application of the WIFM code to tb.e coTPjnon 

 coiT.putational grid used by both studies has been referred to as the shore 

 process model in this report. WIFM was employed to provide elevation and 

 velocity data at 1 3-min intervals for each cell in the computational grid to 

 the sediment transport models. Such data were required for the following; 

 a mean, spring, and neap tide, a mean tide with 2, SCO, 3,500-, and 5,000-ft 

 jetty spacings, and south jetty only; and for the March 1962 northeaster. 



6A. An M„ constituent tide was again chosen as a boundary condition. 

 The M^ amplitude was adjv;sted to represent the full tide values for mean, 

 spring, and neap conditions as reported at Nags Head, North Carolina, by NCAA 

 Tide Tables. Ar litudes of 1.6 ft, 1.9 ft, and 1.3 ft were chosen for the 

 mean, spring, and neap tides, respectively. Appro7'riate boundary conditions 

 were developed for the nearshore model to produce the proper tides and to 

 provide connecting boundary conditions for the shore process model, Marigrams 

 at typical statio.Ts from shore proctss model simulations under mean tide 

 conditions are presented in Plates 76 and 77. Flow patterns at flood, slack 

 after flood, ind ebb portions of the mean tidal cycle at the inlet are shown 

 in Plates 78-80. They indicate the model's ability to realistically produce 

 the rather complicated horizontal flow patterns through the inlet as affected 

 by channelization and shoaling. Similar results for spring tides are pre- 

 sented in Plates 81-85 while neap tide conditions appear in Plates 86-90. 



65. The sediment transport studies also required hydrodynamic informa- 

 tion for the various structural configurations at the inlet. These alterna- 

 tives were simulated using the mean tide condition. Simulations with the 

 2,500-, 3,500-, and 5,000-ft jetty spacings with the nearshore model were used 

 to provide driving boundaries for equivalent cases on the shore process model. 

 Marigrams showing typical shore process model results for these cajes are 

 presented in the plates describing structural effects. Flow patterns with the 

 jetties in fldce for various portions of the tidal cycle appear in Plates 91- 

 99. Flow redistribution around and through the jetties is clearly depicted as 

 well as the local acceleration near the offshore shoal. 



66. A fourth structural alternative was simulated for the sediment 



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