The deposition of material by a river, stream, or current.
- ‘Coastal progradation / aggradation may be linked to a change in source area and high sediment supply rather than relative sea-level change.’
- ‘The transition from fluvial aggradation to subsequent fluvial downcutting records base level lowering most likely associated with structurally driven surface uplift.’
- ‘Some of the reasoning behind the comments of Legros seems to be based on the view that ignimbrites are deposited by progressive aggradation from steady currents emplaced rather slowly over hours or days.’
- ‘This does not mean that deforestation is not associated with accelerated soil loss, landsliding, river-channel aggradation, with desertification, or with increased severity of floods.’
- ‘More recently, Maddy et al. suggested that aggradation and incision in river valleys can be explained by climate-induced changes in sediment and water supply.’
Late 19th century: from ag- (expressing increase) + (de)gradation.