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How levées form along the lower course of a river
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Formation of a levée
- The river is on its floodplain with a very low Another word for steepness. On a graph, the gradient is defined as being the change in the 'y' value divided by the change in the 'x' value. It defines how steep a line is..
- The river is mainly depositing (silt and sand).
- When the river floods a lot of silt is deposited on the river banks and much less on the floodplain.
- Frequent flooding continues this build up.
- When the river is flowing normally it deposits in the river bed.
- This raises the river above the floodplain.
- Usually the built-up levées protect the plain from flooding.