Stream/River formation and features

• Braided streams• Meandering stream• Bank• Sandbar• Delta

How are rivers formed?

• Rain falling on a terrain will run off and through thousands (sometimes millions) of years it will erode the landscape and create a river bed.

• Straight rivers are common in areas with higher water velocity, where there is a steeper slope.

Braided stream

• Braided streams are formed when the discharge of water cannot transport its load. When there is a decrease in stream velocity then sediment is deposited on the floor of the channel creating bars. The bars separate the channels into several smaller channels creating a braided appearance. Braided channels are common in glaciated or recently glaciated landscapes where streams are fed by debris choked melt water

Meandering Stream

Meandering stream

• Different of braided streams, meandering streams typically only contain one channel that winds its way across the floodplain. As it flows, it deposits sediment on banks that lie on the insides of curves (point bar deposits), and erode the banks on the outside of curves.

River delta

• The formation of a river delta is a slow process. As rivers flow toward their outlets from higher elevations they deposit particles of mud, silt, sand and gravel at their mouths because the flow of water slows as the river joins the larger body of water. Over time these particles (called sediment or alluvium) build up at the mouth and can extend into the ocean or lake.