Fluvial sediment processes
In geography and geology, fluvial sediment processes or fluvial sediment transport are associated with rivers and streams and the deposits and landforms created by sediments. It can result in the formation of ripples and dunes, in fractal-shaped patterns of erosion, in complex patterns of natural river systems, and in the development of floodplains and the occurrence of flash floods. Sediment moved by water can be larger than sediment moved by air because water has both a higher density and viscosity. In typical rivers the largest carried sediment is of sand and gravel size, but larger floods can carry cobbles and even boulders.
When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluvioglacial is used, as in periglacial flows and glacial lake outburst floods. Fluvial sediment processes include the motion of sediment and erosion or deposition on the river bed.
Deep, eroding glaciofluvial deposits alongside the Matanuska River, Alaska
The White River is so named due to the clay it picks up in the Badlands of South Dakota. Here it flows into the Missouri River and colors it with clay.
Modern asymmetric ripples developed in sand on the floor of the Hunter River, New South Wales, Australia. Flow direction is from right to left.
Sinuous-crested dunes exposed at low tide in the Cornwallis River near Wolfville, Nova Scotia
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 streams are usually called rivers, while smaller, less voluminous and more intermittent streams are known as streamlets, brooks or creeks.
Rocky stream in Italy
Frozen stream in Enäjärvi, Pori, Finland
Stream near Montriond in south-eastern France
Aubach (Wiehl) in North Rhine-Westphalia, Germany