How is an Oxbow lake formed?

Firstly and simply think about what a river looks like - bendy or straight
Why do you think it is bendy?Further down a river you go, the more water there is, which means the river has more energy.More energy causes there to be more lateral erosion, making meanders (bends) in the river
When water goes round the bend (meander)water is pushed to the outside - the speed of the water on the outside increases, and so the erosion also increasesWater on the inside of the bend is slower so material is deposited
More water in the river causes continued erosion, causing bigger bends and they begin to move closer together
(Draw diagrams)
In a time of heavy discharge (flood), the river has lots of energy and wants to take the fastest route, which often means the meander is cut off and a new straighter route is created.