Oxbow lake facts for kids
An oxbow lake is a lake, or area of water, in a U-shape. It is made by special bends in a river, called meanders, getting farther away from the river until they become separate. The river becomes straight and the bend becomes a lake. This happens due to floods or when a meander's neck gets too thin.
Why does this happen?
Water flows at different speeds at different parts of the river. In the middle, farthest away from the sides (or banks), the water flows fastest. At the banks, the water flows slowest. When the river bends, water flows faster on the outside of the bend than the inside. The fast water on the outside 'erodes' the outside of the bend. This means it breaks bits of the bank off. At the same time, the slow water on the inside of the bend leaves behind mud, sand and parts of plants (deposition). Together, these make the bend move in the direction of the outside of the bend.
The bend moves farther and farther along until it leaves the river. The river becomes straight and the bend is left as an oxbow lake.
Images for kids
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. Furthermore, it can be clearly seen how a third oxbow lake is 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 the isthmus 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.
The Oxbow, on the Connecticut River, Thomas Cole
Oxbow lake Facts for Kids. Kiddle Encyclopedia.