such a case is overestimated (because of the large incident wave angle) super- 

 imposition of the solutions eliminates these effects. In Figure 14 the solu- 

 tion for a single trapezoidal beach form is shown. A representative length L 

 has been chosen to normalize the shoreline position and the alongshore 

 distance. 



1- 







1 L 2 



0.8- 





\ t'= 



0.05\ 





0.6- 





/ 0. 1 \ \ 



/ ■/"'O. 15 NyX \ 





0.4- 





//^^0.3O^N\^ 





0.2- 











i 



1 — 1 



1 i 



0.5 1 1.5 2 2.5 3 



ALONGSHORE DISTANCE (x/L) 



Figure 14. Shoreline evolution of an initially trapezoidal 



beach form 



45. If an arbitrary-shaped shoreline is studied, it is most convenient 

 to approximate it with a series of straight lines and then to superimpose the 

 respective solutions. Consider a shoreline (see Figure 15) divided into N 

 reaches, with each length described by a straight line connecting two 

 neighboring points denoted by (x. , y.) and (x,,, , y- + i) f° r a certain 

 reach (the i reach) . 



29 



