Sheet flow

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Definition of Sheet flow:
Sheet-flow sediment transport refers to transport of sandy sediments as a fluidized thin surface layer (thickness of ten to a few tens of grains).
This is the common definition for Sheet flow, other definitions can be discussed in the article


Under strong wave action, transport in the sheet flow layer is the dominant transport mode: more important than bedload transport through saltation and rolling and more important than suspended load transport.

Sheet flow is a particular form of bedload sediment transport in which the seabed is flattened and the top soil layer is fluidized. Sheet flow transport occurs when the seabed is subjected to high shear stresses, especially shear stresses generated by strong wave action (wave orbital velocity greater than 1 m/s). In the sheet-flow layer, continuous contacts between sand grains create an intergranular stress. This stress decreases the velocity in the sheet-flow layer to about one half the velocity in the top layer. The sediment concentration in the sheet-flow layer is in the order of 100 to 1000 kg/m3.

The formation of a sheet flow layer is promoted by cyclic wave loading of the seabed, see Wave-induced soil liquefaction.

Related articles

Sediment transport formulas for the coastal environment#Sheet flow.

The main author of this article is Job Dronkers
Please note that others may also have edited the contents of this article.

Citation: Job Dronkers (2023): Sheet flow. Available from [accessed on 16-07-2024]