a> 



Q. 



O 25 



CO 



a> 



-a •^'J 

 c <i^ 15 



CL 



a> 



CO 10 



a> 



DO 



> 5- 



< 



CE 



Elapsed Time (hr) 



Figure 27. Evolution of representative step and terrace slopes 



stability against dislodgement and transport by the bore. The terrace slope 

 was more gentle than the initial slope and appeared to be almost independent 

 of grain size, with finer grain sizes showing a slight tendency to form 

 gentler slopes. 



Form and Movement of Berms 



Berm genesis 



283. As wave steepness becomes smaller (e.g., as a storm wanes and the 

 wave height decreases), the transport direction changes from offshore to 

 onshore and material builds up on the foreshore, a process documented by Hayes 

 and Boothroyd (1969), Sonu (1970), and Kriebel (1987). A berm forms which is 

 a function of local wave and water level movement on the foreshore and 

 sediment properties. In this study, the berm was defined as the volume of 

 material accreted on the foreshore with reference to the initial plane slope 

 (Figure 4b) . This is a natural definition since a berm is intuitively thought 



106 



