The accumulation of sediment. See DeLong et al. (2007) Geomorph. 90, 1–2. See Blum and Törnqvist (2000) Sedimentol. 47, Suppl. on change in sediment yield and discharge, and alluviation during relative sea-level fall. Cut and fill alluviation results in a shifting channel eroding old surfaces and creating new surfaces (Hauer et al. (2007) J. Am. Water Resources Ass. 43, 1).