Oxbow lake

[3][5] When a river reaches a low-lying plain, often in its final course to the sea or a lake, it meanders widely.

When this happens a new, straighter river channel develops—and an abandoned meander loop, called a cutoff, forms.

When deposition finally seals off the cutoff from the river channel, an oxbow lake forms.

The process of deposition of silt, sand and gravel on the convex bank is clearly illustrated in point bars.

A pressure gradient toward the convex bank provides the centripetal force necessary for each parcel of water to follow its curved path.

This is because rivers with high sinuosity have larger meanders, and greater opportunity for longer lakes to form.

In the United States, oxbow lakes serve as the primary habitat for water tupelo and the iconic bald cypress.

[13] Oxbow lakes may be formed when a river channel is straightened artificially to improve navigation or for flood alleviation.

When originally constructed, it had a very meandering course, following the contours of the land, but the northern part of the canal was straightened out between 1829 and 1834, reducing its length from approximately 146 to 125 km (91 to 77+1⁄2 mi) and creating a number of oxbow-shaped sections isolated from the new course.

[15] There has also been a possible oxbow lake postulated in Saraswati Flumen near Ontario Lacus on Saturn's moon Titan.

This picture of the Nowitna River in Alaska shows two oxbow lakes – a short one at the bottom of the picture and a longer, more curved one at the middle-right. The picture also shows that a third oxbow lake is probably in the making: the isthmus or bank in the centre of the most prominent meander is very narrow – much narrower than the width of the river; eventually, the two sections of river on either side of an isthmus like that tend to break through and create a new, straighter course; a new river bank then starts to accumulate, sealing off the meander and leaving another oxbow lake.
A meander develops into an oxbow lake
A Horseshoe or oxbow lake near Hughes , Arkansas , on the border between Arkansas and Mississippi . The bulges in the border reflect changes in the course of the river; when the river shifted its course and cut off the former channel, the border remained unchanged.
Oxbow lakes on New Zealand's Taieri River have been converted into water meadows .