stated the bottom configurations parameters that most influenced favorable 

 surfing waves were the seaward slope, width, and orientation of the shoal to 

 the incident waves. 



4. It is clear that knowledge of breaking wave properties is essential 

 in design and placement of coastal structures, as well as for prediction of 

 shoreline movement and beach profile change. Breaking waves have been exam- 

 ined in numerous laboratory studies, but all major experiment programs were 

 conducted on plane slopes. Relationships for breaking wave properties have 

 been developed from such studies, but the presence of a bar or a subsurface 

 structure, such as an offshore berm or an artificial reef, is expected to 

 change the character of breaking. This study departs from previous investiga- 

 tions in that it concentrates on wave breaking over barred profiles with a 

 fixed bottom. 



5. Breaking wave characteristics may be studied on a microscale , in- 

 volving basic fluid dynamic properties such as turbulence, bottom shear 

 stresses, and individual water particle velocities and accelerations; or on a 

 macroscale , involving standard engineering parameters such as wave height and 

 period, water depth, and plunge distance. This study concentrates on macro- 

 features of wave breaking over barred profiles in order to reveal functional 

 dependencies and properties of direct coastal engineering interest. 



Purpose 



6. The purpose of this study is to examine the macro -features of wave 

 breaking over bars and artificial reefs. Principal wave properties considered 

 are: 



a. Breaker type. 



b. Wave height and water depth at breaking. 



c. Plunge and splash distance. 



d. Vortex area. 



e. Wave decay. 



f. Reflection. 



g . Wave runup . 



Because this study differs significantly from previous studies of breaking 

 waves by examining the effects of bars on wave breaking, empirical relation- 

 ships developed from measurements will have immediate input to other 



10 



