I„ = K(Ec ) sin a, cos a, (56) 



£ g ^ b b 



where 



I = immersed weight sand transport rate (lb/sec) 



K = empirical coefficient 



a, = breaker angle 

 b 



and the subscript b is used to denote conditions at the breaker line. 



62. Following Komar (1977), the local (vertically Integrated) immersed 

 weight longshore transport rate, per unit width in the cross-shore direction, 

 may be written as 



±=-r^ (0.5f) pgY^hv„ (57) 



where 



k^ = coefficient to be determined 

 f = drag coefficient 



Y = -r = breaker index 



V = local longshore velocity 



63. By integrating 1 across the width of the surf zone x , 





'^b 

 irk i- 2 



I^ = — (0.5f) pg J ^v^dx (59) 



under the assumption that the coefficients k and f are constants for a 

 particular field site. Since the values of H , v , and h are known, 

 being input to the sediment model, the integral on the right side of Equa- 

 tion 59 may be determined numerically. For example, using the trapezoidal 

 rule, 



37 



