Rainwash, also spelled rain-wash or rain wash or sometimes called hillwash, is a process of

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

in which loose surface material is carried away by

rainwater Rain is a form of precipitation where water droplets that have condensed from atmospheric water vapor fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Eart ...

that has reached the surface, but has not yet become concentrated into

streams A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long, large stream ...

. The term is also applied to the movement under the force of gravity of material loosened by rainwater, or to the material itself. Rainwash is sometimes regarded as a combination of two processes: ''rain-splash'', which is the detachment and movement of small soil particles from raindrop impact, and ''soil-wash'', in which material is moved downslope by surface water flow.

References

Erosion {{Erosion-stub