Unit 2:River Landscapes

How do Ox-bow lakes form?

What is an Ox-Bow Lake?

A horseshoe or semi-circular area that represents the former course of a meander. Ox-bow lakes are

cut off from a supply of water and so will eventually become dry.

Oxbow lakes

1. Erosion on the outer bend narrows the neck of the meander.

2. During a flood, the water wants to find the quickest route. This means it cuts through the beck to find the fastest, straightest course.

During the flood, deposition takes place to seal off the old meander., leaving behind a completely cut off Ox-Bow Lake. Over time, it will dry out and often become marshy.

Describe the formation of an Ox-bow Lake (4)

a) Use key languageb) Create a logical

sequence by using connective phrases (‘over time’, ‘eventually’ etc.)

c) Describing change over time

d) Use an annotated diagram if you wish

‘Rivers can erode laterally. Erosion is greatest on the outside of the meander bend and forces the neck of the meander to narrow. At the same time, on the inside bend, deposition occurs. Over time, this will make the meander loop wider and the neck narrower. Eventually, the neck of the meander bends will join together and the meander is removed from the river current creating a crescent shaped feature called an Ox-bow lake’