This compendium aims to deliver a significant part of the current French scientific progress on the problem of the erosion of geomaterials, with a focus on the mechanical/physical aspect. The contributions oscillate between a phenomenological outlook that is well grounded in experiments, and an approach that can offer a modeling framework. The basic mechanisms of internal and surface erosion are tackled one by one: filtration, suffusion, contact erosion, concentrated leak erosion, sediment and wind transport, bedload transport. These erosion mechanisms comprise both hydraulic structures (dams, dikes) and natural environments (wind, river, coastal). In this book, physicists and mechanicians share with the reader their most recent findings in their field, while at the same time maintaining an accessible format. This compendium provides a well-documented information resource, and above all, a key for approaching the issue of erosion of geomaterials in an up-to-date fashion for students, researchers and practitioners.