Editing Sediment (section)

== Sediment transport ==
[[File:StoneFormationInWater.jpg|thumb|Sediment builds up on human-made breakwaters because they reduce the speed of water flow, so the stream cannot carry as much sediment load.]]
[[File:Glacial Transportation and Deposition.jpg|thumb|Glacial transport of boulders. These boulders will be deposited as the glacier retreats.]]

{{main|Sediment transport}}
{{see also|Rouse number}}

Sediment is transported based on the strength of the flow that carries it and its own size, volume, density, and shape. Stronger flows will increase the lift and drag on the particle, causing it to rise, while larger or denser particles will be more likely to fall through the flow.

=== Fluvial processes ===
{{excerpt|Fluvial sediment processes}}

===Aeolian processes: wind===
{{main|Aeolian processes}}
Wind results in the transportation of fine sediment and the formation of sand dune fields and soils from airborne dust.

===Glacial processes===
[[File:GLMsed.jpg|thumb|Glacial sediments from Montana]]
Glaciers carry a wide range of sediment sizes, and deposit it in [[moraine]]s.

===Mass balance===
{{main|Exner equation}}

The overall balance between sediment in transport and sediment being deposited on the bed is given by the [[Exner equation]]. This expression states that the rate of increase in bed elevation due to deposition is proportional to the amount of sediment that falls out of the flow. This equation is important in that changes in the power of the flow change the ability of the flow to carry sediment, and this is reflected in the patterns of erosion and deposition observed throughout a stream. This can be localized, and simply due to small obstacles; examples are scour holes behind boulders, where flow accelerates, and deposition on the inside of [[meander]] bends. Erosion and deposition can also be regional; erosion can occur due to [[dam removal]] and [[base level]] fall. Deposition can occur due to dam emplacement that causes the river to pool and deposit its entire load, or due to base level rise.