input to the wave-induced current model which computed and stored on files the 

 steady-state wave-induced currents and setups for the single south jetty case. 



108. To run the sediment transport model for an average year, the year 

 was divided into blocks of 4-hr duration during each of which the wave climate 

 was assumed to be constant. During the running of the sediment model, random 

 numbers between and 1.0 were generated every 4 hr of prototype time using a 

 random number generator subroutine. Based on the value of the random number, 

 one of the 35 combinations of wave climate listed in Table 2 was picked, and 

 the corresponding file from the wave-induced current model was used. For 

 example, if the value of the random number generated was between and 0.2580, 

 the first combination listed in Table 2 was selected. If the random number 

 was between 0.2580 and 0.3725, the second combination of Table 2 was picked, 

 and so on. In this way when the full year simulation was run, the percent of 

 occurrence of each combination in the simulation was equal to the percent 

 determined from WESWIS, and the wave climate for the average year was faith- 

 fully reproduced in the numerical model. 



109. Tidal currents and elevations for the mean tide were obtained by 

 applying the numerical tide and surge model to the nearshore processes grid. 

 The tidal elevations and currents were available for this study at intervals 

 of 10 min for one full tidal cycle. An examination of these data revealed 

 that the tidal elevations and currents did not vary significantly during 1 hr 

 of record. Therefore, tidal elevations were varied hourly in the sediment 

 transport model. In addition, to be consistent with the wave- induced cur- 

 rents, tidal currents were varied every 4 hr in the sediment transport model. 

 During the 1-year simulation, the results of the numerical tide model were 

 repeated at the end of each tidal cycle. 



110. For purposes of computation, the entrance channel for Oregon Inlet 

 was defined on the basis of the maximum water depth. In addition to the cell 

 having the maximum water depth in a given row of cells, two cells on either 

 side were included in the channel, provided their depth exceeded 10 ft. Fig- 

 ure 40 shows the channel so defined. The sediment model was modified to simu- 

 late removal of 40,000 cu yd of dredged material per year from the channel. 



111. The wave-induced current model provided the discharge on each cell 

 face (longshore and cross-shore direction). The tidal velocities obtained 

 from the numerical tide model were used to calculate the tidal discharge on 



82 



