Braided river

A wicked River (English: Braided River; German also: feral river, Zopfstrom ) is a special form of a branched river course where the river splits into a network of small channels by small islands ( braid bars, in British English aits or eyots ) are separated.

The channels and islands are often highly variable, since the position of the channels and islands by the rapidly progressive deposition of sediments is constantly changing, and the river often already drastically changes by individual floods. Intertwined rivers are typical of rivers in high mountains and in arid and arctic regions, they are often found in alluvial fans and on hull surfaces.

Demarcation

The encountered at the lower reaches and deltas of rivers in lowland branches are often referred to as braided rivers, but among the anastomosing rivers as they arise otherwise.

Anastomosing rivers build by the high sediment load and its low gradient in the air and are also referred to as branched dam shore rivers. The so-called alluvial fans not growing evenly into the air. Rather, the river sediments in the near environment and covers the typical shore ramparts. The latter effect that tributaries flow long distances parallel before finally culminate either in the river or parallel to the sea.

If bayous and laughter in the rest of the wide valley are slightly lower and a levee breaks (eg after floods ), creates a sidearm in these deeper areas until these are filled with sediment. Depending on the height of the ridges as well as the banks of dam lakes bank can occur which vermooren frequently.

Education

The formation of these flow form is promoted by

• Strong sediment
• Strong and regular changes in runoff
• Easily abradable material of the shore.

The water flow is seasonally concentrated, eg on the snow melt, leading to very different water conditions and strong floods leads.

Interlaced flow arising, among other systems where there is a drastic reduction of the slope of a flow leading to such rapid deposition of sediments that flow can not carry away. It then depends on the slope whether to form a meandering or braided river. In low gradient arise meander in a larger braided river.

The individual channels of the river system meandering due to their different water velocities: impact on the slope, on the outside of a curve, the river is due to the higher flow rate from material on the inside of the curve with their low velocity material is redeposited.

The entire river bed may be in the area bounded by relatively stable shore area or occupy the entire valley floor. Thus, the Rakaia River for example, has cut in the Canterbury region in New Zealand a 100 m deep channel in the surrounding plain, which is rather unusual for the valley shape.

The sediments, mostly sand and gravel are deposited mainly at low tide. The river bed sediments are layered horizontally and have no sorting by grain sizes.

The constant change in the river course and the uneven terrain complicate the bridge structure.

Occurrence

Extensive systems of braided rivers existed mainly in the regions of the world, home to the young, strong erosion unsuccessful Mountains. Examples of interwoven rivers are found widely distributed in Alaska, Canada or in the South Island of New Zealand. In the Himalayas the Brahmaputra is an example of a braided river, and also the flow of the Yellow River is partially classified in this flow class.

A well-known braided river in the USA is the Platte River in Nebraska. The sedimentation of the material from the arid Great Plains is here enhanced by the presence of the nearby Sand Hills to the north.

Many rivers in Central Europe also show evidence for the existence braided river systems that existed during the Ice Age, but today have been replaced by a meandering system due to the change in climatic conditions, such as the Weser. In the far-flung outwash plains in Iceland, there are often intertwined rivers, which are the result of glacial rivers. To flow over the Skeiðarársandur sands in the southeast of the island with the rivers Skeiðará, Gígjukvísl or Núpsvötn some larger braided rivers.