APPENDIX D: SHORELINE EVOLUTION IN THE VICINITY OF A SEAWALL 

 WHERE FLANKING OCCURS 



1 . Two solution areas are employed to describe flanking of a semi- 

 infinite seawall, one area behind the seawall and the other away from the sea- 

 wall. The amplitudes of the sand transport rate are denoted as Q . and Q „ 



ol oz 



in the respective solution areas, and the corresponding incident breaking wave 



angles are denoted as a , and a ~ . The incident breaking wave angle 



ol oz ° ° 



a , behind the seawall (solution area 1) should be interpreted as a repre- 

 sentative mean value related to the sand transport rate. Equations 84-89 

 (main text) constitute the mathematical formulation of shoreline evolution in 

 the vicinity of a seawall subject to flanking. The Laplace transformed system 

 of equations and the boundary conditions are 



d 2 7 



y. = x < (Dl) 



dx 1 



d 2 7 



— y- ~ f" Yo = x > (D2) 



dx E 2 



y 1 = x * -co (D3) 



y 9 = x + co (D4) 



y x = y 2 x = o (D5) 



dy l 1 dy 2 / 1 \ 1 

 dx- = ^2 dx- + Kl "^2 a o2J I 



Dl 



