An anabranch is a section of a

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a strea ...

that diverts from the main channel or stem of the

watercourse A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a strea ...

and rejoins the main stem downstream. Local anabranches can be the result of small islands in the watercourse. In larger anabranches, the flow can diverge for a distance of several or even hundreds of kilometers before rejoining the main channel.

Word usage and related terms

The term ''anabranch'', in its

hydrological Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is called a hydro ...

meaning, is used more frequently in

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

than in the rest of the English-speaking world. The term ''anabranching river'' describes a

with many anabranches, whilst an anastomosing river is an organic-rich subset of this

type. The term

braided river A braided river (also called braided channel or braided stream) consists of a network of river channel (geography), channels separated by small, often temporary, islands called ''braid bars'' or, in British English usage, ''aits'' or ''eyots''. ...

describes

s which are divided by small

islands This is a list of the lists of islands in the world grouped by country, by continent, by body of water, and by other classifications. For rank-order lists, see the #Other lists of islands, other lists of islands below. Lists of islands by count ...

into multiple channel threads within a single main channel, but the term does not describe the multiple channels of an anabranching river. A

distributary A distributary, or a distributary channel is a stream channel that branches off and flows a main stream channel. It is the opposite of a ''tributary'', a stream that flows another stream or river. Distributaries are a result of river bifurc ...

is a branch of a

that does not rejoin the main channel; these are common on and near

river delta A river delta is a landform, archetypically triangular, created by the deposition of the sediments that are carried by the waters of a river, where the river merges with a body of slow-moving water or with a body of stagnant water. The creat ...

s. A bayou is often an anabranch. An anabranch that gets cut off from the main channel becomes an oxbow lake, known in Australia as a billabong.

Examples

* The Magdalena River, in Colombia, bifurcates in El Banco in two branches: Brazo de Loba (Shewolf Branch in Spanish) and Brazo de Mompox. The first one, Brazo de Loba is the main navigable channel and is 177 km long. Brazo de Mompox is thus the anabranch. There are several other branches that join those two main branches, interconnected by swamps ("ciénagas"), the main ones being Quitasol, Chicagua and La Victoria. Between Brazo de Loba and Brazo de Mompox is the island of Mompox or Margarita Island, a sunken geological block of 2.200 square km between the faults of Chicagua and El Romeral. * In the

Fraser River The Fraser River () is the longest river within British Columbia, Canada, rising at Fraser Pass near Blackrock Mountain (Canada), Blackrock Mountain in the Rocky Mountains and flowing for , into the Strait of Georgia just south of the City of V ...

delta of

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

, North Arm Fraser River, Middle Arm Fraser River, and South Arm Fraser River each fall into

Georgia Strait The Strait of Georgia () or the Georgia Strait is an arm of the Salish Sea between Vancouver Island and the extreme southwestern mainland coast of British Columbia, Canada, and the extreme northwestern mainland coast of Washington (state), Wash ...

separately. On the other hand, Annacis Island splits (South Arm) Fraser River into the (main) Annieville Channel and the (smaller) Annacis Channel, which rejoin below the island. * In western

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

the Great Darling Anabranch is the ancestral path of the Darling River, dividing south of Menindee and extending for 460 km before joining the

Murray River The Murray River (in South Australia: River Murray; Ngarrindjeri language, Ngarrindjeri: ''Millewa'', Yorta Yorta language, Yorta Yorta: ''Dhungala'' or ''Tongala'') is a river in Southeastern Australia. It is List of rivers of Australia, Aust ...

. The anabranch contains flowing water only in wetter years. * In the Lower Simpson Desert, in

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

, Kallakoopah Creek is an anabranch of the Warburton River that flows during major Warburton floods of over 5 m in depth. The Kallakoopah is approximately 400 km long and members of the Lake Eyre Yacht Club and others have used it to sail a circular route to Lake Eyre by traveling down the Kallakoopah and returning via the Warburton. * The Bahr el Zeraf in southern

Sudan Sudan, officially the Republic of the Sudan, is a country in Northeast Africa. It borders the Central African Republic to the southwest, Chad to the west, Libya to the northwest, Egypt to the north, the Red Sea to the east, Eritrea and Ethiopi ...

splits from the Bahr al Jabal section of the

White Nile The White Nile ( ') is a river in Africa, the minor of the two main tributaries of the Nile, the larger being the Blue Nile. The name "White" comes from the clay sediment carried in the water that changes the water to a pale color. In the stri ...

and flows for 240 km (150 mi), before rejoining the White Nile proper upriver from Malakal. * Approximately 15 km out of Charters Towers (

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

) is a section of the Burdekin River known as 'the anabranch'. This strip of water is separate from the main flood way, and is typically dry during the sunnier months. Once there is consistent rain, it will meet up with the river again and flood with fresh water. It is well known for barramundi fishing. * Probably because waterways played an important role in infrastructure, anabranches and the resulting river islands are often found in old cities as with the

Île de la Cité The Île de la Cité (; English: City Island, "Island of the City") is one of the two natural islands on the Seine River (alongside, Île Saint-Louis) in central Paris. It spans of land. In the 4th century, it was the site of the fortress of ...

in Paris.

References

{{Authority control Fluvial landforms Rivers Water streams Geomorphology

Word usage and related terms

Examples

See also

References