a. Rip current formation due to channeling of longshore current, 



t^J 



Setup at Shoreline 



Circulotion Cell 

 (Due to Setup 

 Gradients) 



b. Circulation within a groin compartment due to variation in longshore 

 setup. 



Setup at 



^Shoreline 



Bottom Contour 

 Circulation Cell 



Waves 



c. Circulation cell within a groin compartment due to energy dissipation 

 at the groins and variable setup. 



Figure 5-11. Three mechanisms for creating rip currents between groins (from 

 Dean, 1978). 



5-38 



