ABSTRACT
A Coastal Mobile Bed Model (CMBM) is a complex interaction of several modes such as short waves, long waves, unidirectional flow, mobile sediment, structural and model boundaries. A CMBM is in the first instance a short wave model since in most prototype situations the sediment is moved as a result of wave action. Some of the more important dependent variables involved in the design of CMBM’s are orbital motion and shear stress on the bottom. In order to understand CMBM’s fully, it is necessary at this time to digress and discuss bottom shear stress, initiation of sediment motion and sediment transport rates. General investigations of scale effects in CMBM’s using a hierarchy of model scales have assumed vital importance in order to determine if a model to scale 15 is necessary as well as to determine actual numerical values of scale effect.
