I r 



c 



I - 



MSL 



Son Luis Pass Bridge Gage 

 Chocolate Bayou Goge 



0000 



Figure 33. 



28 July 1969 



0000 



29 July 1969 



0000 



Illustration of tide distortion 

 into West Bay. 



instantaneous current speeds, and the products summed to provide the discharge 

 through the gorge. Dividing this sum by the total gorge area gave the average 

 current speed through the gorge. The total discharge through the pass must 

 include that through the shallow east part of the profile, and no currents 

 were measured there. Jarrett's (1976) method was used to estimate the average 

 velocity in this section: 



V = V 



R \2/3 



where 



g\R 



average current speed in shallow section 

 = average current speed in gorge 



hydraulic radius of shallow section 

 = hydraulic radius of gorge 



(5) 



Using this relationship, in 1962 V^ = 0.55 V„ ; in 1976 V^ = 0.27 V„. The 



° e> ° & 



total discharge through the pass is the sum of the channel discharge and 



the section discharge, and the average current speed through the pass is V^. A 



42 



