Erosional and depositional landforms
Meanders
As the river makes its way to the middle courseThe middle section of a river which has sloping land., it gains more water and therefore more energy, so material can be carried in suspension and is used to erode the river banks. lateral erosionThe wearing away of the landscape when a river erodes sideways. starts to widen the river. When a river flows over flatter land it develops large bends called meanderA bend in a river..
- As a river goes around a bend, most of the water is pushed towards the outside. This causes increased speed due to less friction and therefore increased erosion (through hydraulic actionErosion caused by the force of river water hitting cracks in the side of the river bank. The air in the cracks becomes compressed and then explodes outwards, breaking off bits of rock. and abrasionWhen rocks carried by the sea water wear away the landscape, eg cliff face/headland.).
- The lateral erosion on the outside bend causes undercutting of the river bank to form a river cliffSteep bank created on the outside of a river bend by the erosive effect of fast-flowing water undercutting the bank..
- There is less water on the inside bend of a meander so friction causes the water to slow down, lose energy and deposit the material the river is carrying, creating a gentle slope.
- The build-up of deposited sediment is known as a slip-off slopeGently sloping bank found on the inside of a river bend because of slow-flowing water, depositing sediment. (small scale landform) or sometimes river beach.