Aggradation

1. The process by which a stream's gradient steepens due to increased deposition of sediment.
2. The building up of the Earth's surface by deposition; specif., the upbuilding performed by a stream in order to establish or maintain uniformity of grade or slope. See also: gradation Syn: upgrading
3. A syn. of accretion, as in the development of a beach. The spread or growth of permafrost, under present climatic conditions, due to natural or artificial causes. AGI
   Source: Dictionary of Mining, Mineral, and Related Terms