MEAN WATER LEVEL, V 



-?'""• 



•400 300 200 100 



DISTANCE FROM STILL WATER LINE ON BEACH, x (cms) 



Figure 46. Wave setdown and setup, comparison of experiment and theory 

 (eqs 3 and 8) for regular waves on a plane beach (after 

 Bowen, Inman, and Simmons, 1968) . 



Additional experiments in the same wave basin as originally used by 

 Bowen, Inman, and Simmons (1968) but with three different beach slopes 

 (tan B = 0.022, 0.040, 0.083) have been reported by van Dorn (1976). The 

 object was to distinguish wave setup from the dynamic shoreline motions 

 called runup due to partial reflections. The empirical result was that 

 the setup slope was found approximately linear across the surf zone (as 

 before) but proportional to the square of the beach slope. This relation 



158 



