ABSTRACT
Before considering the necessity of protecting a bank, a shore or a bottom against waves, one should have an idea of the possible erosion. Here, erosion due to waves is limited to local erosion. For banks and shores, this will be treated on the basis of beach and dune erosion research; for bottom erosion, breakwater investigations will be used. Firstly, some simple relations for erosion of unprotected slopes and of bottoms in front of walls have been presented. In this chapter, the main item is stability in waves. It appears that most relations for flow situations can also be used for non-breaking waves, as long as the increased shear stress under waves is taken into account. Waves will usually not be able to lift impervious-layer revetments of some size. Wave impacts can influence the thickness of the layer. A filter is not necessary, except possibly for the drainage of excessive pressures due to tides or surges.
