A delta is a fan-shaped area of land found at the mouth of a river. It is a feature of river deposition.
River Sea
When a river reaches a lake or the sea, it slows down and loses the power to carry sediment. The sediment is then dropped at the mouth of the river. Some rivers drop so much sediment that waves and tides can’t carry it all away. This forms the delta. The large deposits build up over time at the mouth of the river and block the river’s entry to the sea. The river then has to break through the delta in many small channels called distributaries.
Working with others:
Take one minute to examine this photo. Then with your partner, answer this question:
What material is being deposited here to make the delta?
1. What is a levee? 2. (i) With the aid of a labelled diagram, explain how an ox-bow lake is formed.
(ii) Name the location of an ox-bow lake in Ireland. 3. Explain how a delta is formed.
