oxbow lake

…The causes of river course change include (1) when the meandering river course becomes more curved, the upstream and downstream sides gradually approach each other, and the river course becomes straight, (2) when the river overflows during a flood and takes a new course, and (3) when the original river course is abandoned due to the construction of an artificial cutoff or spillway. In particular, semi-circular oxbow lakes (also called oxhorn lakes), which are formed by cutting off the meandering of a meandering river, are typical of river basins, and can also be formed by the construction of a cutoff. Oxbow lakes are found in various places, such as the lower Mississippi River and the lower La Plata River, but in Japan, those in the lower Ishikari River are well known. …

*Some of the terminology that mentions "oxbow lake" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…流路変更の原因としては，(1)曲流河川において蛇行河道の湾曲が大きくなり，上流側と下流側が次第に接近して河道が直線状につながる場合，(2)洪水の際に河川が氾濫し，新たな流路をとる場合，(3)人工的な捷水路や放水路の建設に伴って，従来の河道が放棄される場合などがある。　特に，曲流河川の蛇行切断(斬首)によって生じた半環状の三日月湖oxbow lake(牛角湖ともいう)は河跡湖の代表的なもので，これは，捷水路の建設によっても生じる。三日月湖は，ミシシッピ川下流部やラ･プラタ川下流部など各地にみられるが，日本では石狩川下流部のものが著名である。…

※「oxbow lake」について言及している用語解説の一部を掲載しています。

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