1 2 



ALONGSHORE DISTANCE (x/L) 



Figure 24. Shoreline evolution in the vicinity of a river dis- 

 charging sand and acting as a point source 



55. If the sand discharge has a periodic behavior, the function q 

 could take the following form: 



q R (t) = q Q + q s sin (tot + (j>) 



(48) 



where 



q = steady sand discharge from river 

 q = amplitude of periodic sand discharge 

 a) = angular frequency = 2ir/T 



T = period of oscillation of sand discharge from river 

 <\> = phase angle of periodic variation 

 The solution consists of two parts, namely Equation 47 describing the shore- 

 line evolution from a steady point source and the following solution which 

 accounts for the periodic component: 



39 



