Anabranch
Encyclopedia
An anabranch is a section of a river
River
A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...
or stream
Stream
A stream is a body of water with a current, confined within a bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as a branch, brook, beck, burn, creek, "crick", gill , kill, lick, rill, river, syke, bayou, rivulet, streamage, wash, run or...
that diverts from the main channel
Channel (geography)
In physical geography, a channel is the physical confine of a river, slough or ocean strait consisting of a bed and banks.A channel is also the natural or human-made deeper course through a reef, sand bar, bay, or any shallow body of water...
or stem
Main Stem
"Main Stem" is 1942 instrumental by Duke Ellington and His Famous Orchestra. Although recorded in 1942, the single would not be released until 1944 where it was Duke Ellington's last of four number one's on the Harlem Hit Parade. "Main Stem" would also peak at number twenty on the pop chart"Main...
of the watercourse
Watercourse
A watercourse is any flowing body of water. These include rivers, streams, anabranches, and so forth.-See also:* physical geography* Environmental flow* Waterway* Hydrology* Wadi-External links:...
and rejoins the main stem downstream. Local anabranches can be the result of small islands in the watercourse
River Island
River Island is one of Britain's best known high street fashion brands and can be found in most cities across the UK. The brand also has stores in Singapore, Turkey, Poland, Ireland, the Netherlands, and the Middle East.-History:...
. In larger anabranches, the flow can diverge for a distance of several kilometers before rejoining the main channel.
Word usage and related terms
The term anabranch, in its hydrological meaning, is used more frequently in AustraliaAustralia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
than in the rest of the English-speaking world.
The term anabranching river describes a river with many anabranches, whilst an anastomosing river is an organic-rich subset of this river type.
The term braided river
Braided river
A braided river is one of a number of channel types and has a channel that consists of a network of small channels separated by small and often temporary islands called braid bars or, in British usage, aits or eyots. Braided streams occur in rivers with high slope and/or large sediment load...
describes watercourses which are divided by small islands into multiple channel threads within a single main channel, but the term does not describe the multiple channels of an anabranching river.
A distributary
Distributary
A distributary, or a distributary channel, is a stream that branches off and flows away from a main stream channel. They are a common feature of river deltas. The phenomenon is known as river bifurcation. The opposite of a distributary is a tributary...
is a branch of a river that does not rejoin the main channel; these are common on and near river delta
River delta
A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river...
s.
A bayou
Bayou
A bayou is an American term for a body of water typically found in flat, low-lying areas, and can refer either to an extremely slow-moving stream or river , or to a marshy lake or wetland. The name "bayou" can also refer to creeks that see level changes due to tides and hold brackish water which...
is often anabranch.
Examples
- In the Fraser RiverFraser RiverThe Fraser River is the longest river within British Columbia, Canada, rising at Fraser Pass near Mount Robson in the Rocky Mountains and flowing for , into the Strait of Georgia at the city of Vancouver. It is the tenth longest river in Canada...
delta of British ColumbiaBritish ColumbiaBritish Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, CanadaCanadaCanada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, North Arm Fraser River, Middle Arm Fraser River, and South Arm Fraser River each fall into Georgia Strait separately. On the other hand, Annacis IslandAnnacis IslandAnnacis Island is an island located in the South Arm of the Fraser River in Delta, British Columbia, Canada. The island is now mostly industrial, and it contains one of the Metro Vancouver's secondary wastewater treatment plants...
splits (South Arm) Fraser River into the (main) Annievile Channel and the (smaller) Annacis Channel, which rejoin below the island.
- In western New South WalesNew South WalesNew South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
the Great Darling Anabranch is the ancestral path of the Darling RiverDarling RiverThe Darling River is the third longest river in Australia, measuring from its source in northern New South Wales to its confluence with the Murray River at Wentworth, New South Wales. Including its longest contiguous tributaries it is long, making it the longest river system in Australia.The...
, dividing south of MenindeeMenindee, New South WalesMenindee is a small town in the far west of New South Wales, Australia, in Central Darling Shire, on the banks of the Darling River, with a sign-posted population of 980.-History:...
and extending for 460 km before joining the Murray RiverMurray RiverThe Murray River is Australia's longest river. At in length, the Murray rises in the Australian Alps, draining the western side of Australia's highest mountains and, for most of its length, meanders across Australia's inland plains, forming the border between New South Wales and Victoria as it...
. The anabranch contains flowing water only in wetter years. - The Bahr el ZerafBahr el ZerafThe Bahr el Zeraf is an arm of the White Nile in the Sudd region of South Sudan, Africa. It is completely contained within the South Sudanese state of Jonglei...
in southern SudanSudanSudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...
splits from the Bahr al Jabal section of the White NileWhite NileThe White Nile is a river of Africa, one of the two main tributaries of the Nile from Egypt, the other being the Blue Nile. In the strict meaning, "White Nile" refers to the river formed at Lake No at the confluence of the Bahr al Jabal and Bahr el Ghazal rivers...
and flows for 240 km (150 mi), before rejoining the White Nile proper upriver from MalakalMalakal-Location:The city of Malakal is located in Malakal County, Upper Nile State, in the northeast of South Sudan, close to the International borders with the Republic of Sudan and with Ethiopia...
. - Approximately twenty-five minutes out of Charters Towers is a section of the Burdekin RiverBurdekin RiverThe Burdekin River in Queensland, Australia rises on the western slope of the Seaview Range and flows into the Pacific Ocean at Upstart Bay over 200 km to the southeast of the source. The river was first encountered by Europeans during the expedition led by Ludwig Leichhardt in 1845 and named...
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.