4 

 3 



V) 



^ I 



4 



Sobine Pojs Tide 



Sobine LoKe Entrance (Causeway) 



Sabine Pass 



Sobine Pass Jetty Entrance 



Pt Arthur Conol Entrance 



Figure 77. Tides and surface currents, Sabine Pass, Texas, 19-21 July 1962. 



measured, and the discharge through the section was the product of that area 

 and the integrated velocity-time area. The total discharge is the sum of the 

 three discharges. 



This same procedure was attempted at range 2, using a crude profile 

 obtained from NOS chart 517. However, a quick comparison of discharges showed 

 that range 2 values were considerably lower than range 1, apparently due to an 

 incorrect cross-sectional area. Therefore, an "effective" cross-sectional 

 area for range 2 was determined as follows: First, the average ebb-to-flood 

 discharge ratio at range 1 was 1.24; the ratio at range 2 was very close to 

 unity. This indicates some of the flood tidal prism apparently enters the 

 pass landward of the jetty range, while all the ebb discharge passes through 

 both ranges 1 and 2. Thus, the effective cross-sectional area of range 2, 

 A 2 was obtained for ebb flow only: 



where 



^ebb 

 A 



cl 

 /V2ndt 



JVi^dt 



3 3 



Q uu = A „ y /V„ dt = A , y /V, dt 

 x„uu (-2 L 2n cl ^, In 



'ebb 



(10) 



n=l 



n=l 



instantaneous ebb tidal discharge 



cross-sectional area of range 1 



area under velocity-time ebb curve for one of the current 

 meters (numbered 1 to 3) on range 2 



area under velocity-time ebb curve for one of the current 

 meters on range 1 



A = A -^^ 

 \2 cl 3 



I /v. dt 



(11) 



I /V, dt 

 '', In 

 n=l 



Averaging values for each of the ebb prisms gave an effective area of 35,250 

 square feet, which was then used to obtain corrected discharges through range 

 2. Tables 12 and 13 show the discharges and phase predominance for the four 

 ranges for flood and ebb phases between 18 and 23 July 1962. 



84 



