When river waters recede after floods, the uncovered soil is described as alluvial.
The alluvial soils are soils of fluvial origin, little evolved although deep. They appear in the shores of the rivers. They are included within the calcareous and ecutric fluvisols, as well as aric and cumulous antiools, if the surface presents elevation by anthropic contribution, or if they have been subjected to deep cultivation. The alluvial soils are soils with a poorly developed profile formed by materials transported by water currents. Some organic matter can be accumulated on its surface.