Features of the Lower Course

Meanders, ox-bow lakes, deltas and flood plains are the main features of the lower course of a river.

Feature of erosion and deposition.
The river is dynamic - it is constantly changing its shape and therefore has a lot of meanders (bends) in it.
These meanders are formed by lateral (sideways) erosion.

Feature of erosion and deposition.
It occurs where the horseshoe-shaped meander becomes tighter, until the ends become very close together and join to form a separate lake.

Ox-bow lakes form when:

The outsides of two meanders are eroded by hydraulic action and abrasion.
The river becomes more sinuous (has more curves and turns). This results in a narrow neck of land remaining between the two river cliffs.
Eventually, perhaps during a flood, the narrow neck of land is eroded away and the water takes the more direct straight route downstream.
Deposition occurs and eventually the old meander loop is separated from the river and forms an ox-bow lake.

Evaporation will usually cause the lake to become dry eventually.

This is a feature of deposition. Examples are the Nile Delta and the Mississippi Delta.

As large rivers approach the seas, they carry a large amount of load (material) in suspension.
The speed (velocity) of the river is reduced as it reaches the more powerful sea, so it has less energy and deposits its load to form new land.
The coarser material is deposited first (in topset beds), the medium sized silt (in foreset beds) and then the finer material (in bottomset beds).
With time, more and more sand and silt is deposited.
The river divides into channels called distributaries which flow around the deposits of new land.

This is a feature of deposition. It occurs when a river floods and deposits its load.

As the water spills out of its channel, friction increases, the water velocity decreases and deposition occurs.
The large pieces of load are deposited first, often forming natural levees near the channel.
Finer sediment is transported further away from the channel.
The flat land onto which flood water flows is know as the flood plain.

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