3 y l 3y x 



-L < x < 



(74) 



3 y 2 9y 2 

 3t~~ 



-2 2 



dX 



x > 



(75) 



y^x.O) = y 2 (x,0) = 



(76) 



*1 



w = tan v 



x = -L 



(77) 



Hi Hi?°i + 



3x 3x Q , a ol 



ol 



x = 



(78) 



yi = y-. 



x = o 



Vo = 



(79) 



77. The derivation of this solution is presented in Appendix C. The 

 quantities Q . and Q are the amplitudes of the longshore sand transport 



*ol 



<o2 



rate in the respective areas, and a . is the diffracted breaking wave angle 

 behind the breakwater. The angle a „ is zero since the wave crests in this 

 area are parallel to the x-axis throughout time. The solution is, with 



(80) 



57 



