river landforms - braiding

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Landform: Location: River Braiding Lower course usually close to the delta/mouth (Can be found upstream) Direction of water flow Gravel bars Older floodplain deposits Abandoned channels Active sand- filled channel Floodplain Channel bars Main characteristics 1. Small islands or eyots of deposited material within the channel. 2. A network of small intertwining channels converge and diverge around the eyots. 3. At times of high discharge, braided streams carry a large load of coarse material. 4. Braiding is a characteristic of streams with a variable discharge

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Page 1: River landforms - braiding

Landform:Location:

River Braiding

Lower course – usually close to the delta/mouth (Can be found upstream)

Direction of water flow

Gravel bars

Older floodplain deposits

Abandoned channelsActive sand-

filled channel

Floodplain

Channel bars

Main characteristics1. Small islands or eyots of deposited material within the channel.2. A network of small intertwining channels converge and diverge

around the eyots.3. At times of high discharge, braided streams carry a large load of

coarse material.4. Braiding is a characteristic of streams with a variable discharge

Page 2: River landforms - braiding

Appearance:

Braided rivers are basically rivers that have multiple channels & islands of sediment in between those channels. They occur in rivers with high slopes and also in areas where the river channel banks are made up of easily erodible rock (carbonate rock) or areas of high sediment load where discharge rate varies (e.g. glacial melt water rivers)

Formation / Processes:

Braiding occurs when a high velocity rivers carry large amounts of sand or small stones downriver and where it slows down as it passes through wide valleys this allows the sediment to settle on the riverbed. Over time the levels of sediment will rise and cause the river to flow a decreasing velocity. Eventually the river will become blocked by the sediment build up, this causes it to overflow and form new channels.As the river finds a new way down towards its mouth it will repeat the process many times which causes the braided channel shape.

Page 3: River landforms - braiding

ExamplesRakaia RiverCanterburyNew Zealand

Son-Kul RiverTien Shan Mtns

Kyrgyzstan