JETTY 

 PERMEABILITY 



Figure 11. The relationship of barrier permeability to depth and 



Manning ' s n 



82. Calibration of the tidal model required the adjustment of WIFM 

 boundary conditions until the computed elevations at tide Gage 1 matched the 

 prototype data for 10 November 1982. The model was then verified for 

 correctness by successfully reproducing the velocities measured at ranges 1, 

 3, and 4. The WIFM boundary conditions were adjusted during calibration by 

 adjusting the datums for the prototype tide signals and accounting for the 

 phase differences in the signals due to their placements in the grid as input 

 conditions. All of the datum adjustments were less than 2 in. Note that WIFM 

 used a time-step of 60 sec for all the computations. 



83. Plate 7 shows where numerical gages were placed in Grids 1 and 2 in 

 order to measure the computed velocities for the base and plane conditions in 

 St. Marys Entrance. The gage sites in Plate 7 all correspond to either loca- 

 tions where prototype data were collected during the survey of 10 November 

 1982, or to important locations in the navigation channel. Table 1 equates 

 the gage numbers in Plate 7 with the gage names used subsequently. The 



48 



