Processes forming river landscapes - lower course

How levées form along the lower course of a river

Levée

Formation of a Levee Formation of a levée

  • The river is on its floodplain with a very low gradient.
  • 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.