What Is An Oxbow Lake?
An oxbow lake is a U-shaped body of water, originally a curve in a river. That curve has been separated from the rest of the river and, as an oxbow lake, is now a free-standing body of water. Oxbow lakes can be found all over the world. In Australia, they are known as billabong. In the US state of Texas, oxbow lakes formed from the Rio Grande are referred to as resacas.
How Is An Oxbow Lake Formed?
Oxbow lakes are formed after a river carves away a curve in the river bank. Over time, this curve becomes more pronounced due to continuous erosion and hydraulic action. The curve consists of two river banks: the inner, or smaller one and the outer, or a larger one. The inner bank collects more sediment, pushing water further out and into the outer bank. The outer bank experiences more erosion and undercutting, becoming wider. The outer bank is now very close to a neighboring outer bank and the two are separated only by a small strip of land. Extremely forceful water, such as during a flood, eventually breaks through this small strip of land and creates a straight section of the river. This process leaves the curved area, or meander, cut off from the rest of the river. Over time, sediment is deposited at the breakaway point, resulting in an oxbow lake.
Famous Oxbow Lakes Around The World
Carter Lake is located between Nebraska and Iowa in the US. It was created in 1877. Prior to this year, Carter Lake was actually a curve in the Missouri River. Flooding in the summer of 1877 cut off the Saratoga Bend from the rest of the river, resulting in Carter Lake. It later became a beach resort.
Kaber Taal Lake located in India is one of the largest oxbow lakes in Asia. Today, this lake has been protected as the Kanwar Lake Bird Sanctuary. It is home to around 106 resident bird species and provides shelter to at least 60 recorded migratory birds. The lake and its ecosystem are threatened by pollution, like excessive chemicals which are used to capture birds. Many of the bird species here are endangered or threatened, including the: long-billed vulture, oriental white-backed vulture, lesser kestrel, and greater spotted eagle.
Reelfoot Lake, located in the US state of Tennessee, is another example of an oxbow lake. This lake is unique in that it was created after an earthquake, rather than flooding. The 1811 to 1812 New Madrid earthquakes caused several landform changes throughout the area, including cutting off Reelfoot Lake from the Mississippi River. Today, it is considered a shallow, swamp-like lake. The area is protected as a state park and is home to bald eagles and bald cypress trees.
Cuckmere Haven in Sussex, England is a floodplains area. It is home to the Cuckmere River, considered a winding river. Additionally, this area has several oxbow lakes that are believed to have once been part of the Cuckmere River. Cuckmere Haven displays a unique ecology, with a mix of domesticated animals and wildlife. Some of the wild animals that can be found here include: grass snakes, badgers, brent geese, grey heron, red fox, and rabbits.