AGGRADATION

A term used loosely to describe the building up of SEDIMENT by rivers and wave action, hence an aggraded river valley, and aggraded beach profile. More strictly, the term refers to DEPOSITION carried out to restore or maintain the condition of GRADE. For example, an influx of sediment may cause a stream to become overloaded; it will therefore deposit sediment and steepen its course (aggrade), thus increasing its energy and capacity to transport the increased LOAD.

Schematic of sediment accumulation (aggradation) in a river channel. The sediment is brown. The river is flowing on bedrock in the upper image, but because sediment was deposited over time the riverbed has risen. This has caused the house to be buried in the lower image.