Dynamic similitude refers to parameters involving mass.
Rigid Bed models are built to simulate flow around river improvement works and Hydraulic structures.
Mobile-bed models are useful when sediment transport is significant.
A Clear-water scour is where sediment is removed from the scour hole but not supplied by the approaching flow.
Abutments are the substructure of a bridge located at either end of a bridge, and the bridge superstructure rests over this.
The flow field at an abutment is complex due to the development of three-dimensional Vortices around the structure.
A Bow wave is formed at the free Surface adjacent to the pier face rotating in a direction opposite to that of the horseshoe vortex and becomes pertinent in relatively shallow flow and reduces the downflow velocity.
The three factors that affect a local scour depth at a pier are Depth of flow, Width of the pier and Bed configuration.