Oxbow Lake - GCSE Geography Definition

An oxbow lake is a U-shaped body of water that forms when a wide meander in a river is cut off, creating a separate lake. This process begins when the river erodes the land on the outer bend of a meander and deposits silt on the inner bend, causing the neck to become tighter over time, with two outer bends getting closer together. Eventually, during high water discharge or flooding, the river can break through the narrow neck of the meander loop, taking a shorter and faster course (the thalweg). Deposition occurs, which cuts off the old meander, leaving the old loop behind as a standalone lake. Oxbow lakes are common features in the floodplains of rivers and often become marshy or dry up as they fill with sediment.