locations in i^igure 9, while Plates 33-36 show the corresponding velocities. 

 Once again, the velocity records describe how the storm affected the inlet. 

 The buildup of surge in Pamlico Sound on the bayward side of the barrier 

 island caused by the high winds from the southwest drove a violent outflow 

 through the inlet between 7:00 a.m. and 4:00 p.m. GMT on 12 September. Fig- 

 ure 11 shows the computed contours for the area around Oregon Inlet at the 

 peak of Hurricane Donna, and this figure illustrates the 10-ft head difference 

 across the inlet which caused the ebb flow. Peak velocities of 12 to lA fps 

 occ-rred in the inlet, with 18 fps calculated at the north oceanside approach. 

 The nearshore model indicates that about 1 million cfs of water flowed out 

 through Oregon Inlet at the peak of Hurricane Donna. 



Shore Process Model 



52. Prototype storm data were unavailable for the relatively small 

 region encompassed by the shore process model. Since it was employed princi- 

 pally for tidal simulations, results were compared for the M^ constituent 

 tide. Plate 37 shows marlgrams for a 16-hr period starting at 1900 (GMT) 

 20 May 1975. The model produced a good match of elevations with prototype 

 data at locations just seaward, vithin, and west uf the inlet, with variances 

 of !ess than 0.1 ft, and with slight phase shifts on the bayside due to 

 features subsi ale to this grid, and to bayside boundary conditions affectea by 

 similar scale restrictions in the driving nearshore model. Velocity records 

 (Plate 38) in the inlet and Davis Slough were reproduced with proper phasing 

 of the peak flood and ebb flows and were generally within 0. 5 fps of observed 

 data indicating proper tidal exchange. Tidal circulation patterns matched 

 quite well in direction and magnitudes with reported data of the same period 

 as presented by Hollyfield, McCoy, and Seabergh (1983). 



34 



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