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Oxbow Lakes

In wide, shallow valleys rivers flow slowly, looping back and forth in a wandering, snake-like path. These snaking curves are called “meanders,” after the River Menderes in Turkey. Meanders are formed as erosion wears away the outside of a bend, while eroded material from upstream is deposited on the inside of the bend, emphasizing the curve. Sometimes the neck of one of these loops is eroded away completely, creating a new, straighter course for the river. The old river loop becomes what is known as an oxbow lake. Cut off from the rest of the river, the oxbow lake may eventually dry up altogether.

This aerial photo shows several oxbow lakes that formed when the river changed its course due to the buildup of sediment.

What Are Wetlands? 15