The erosion of material from the side of a river channel. Hooke (1979) J. Hydrology 42 identifies corrasion and slumping as the major processes, and these appear to be associated with river flow levels and antecedent precipitation conditions, respectively. Rates of erosion vary with speed of flow (rates are highest on the outer bank of meander bends or where bars in the channel have diverted the thalweg), bank vegetation and moisture content, and bank composition (Parker et al. (2008) Geomorph. 101, 4).