Geography - River Landforms

Upper Course:

Steep sided v-shaped valley, Interlocking spurs, Rapids, Waterfalls and Gorges.

Middle Course:

Wide, shallow valleys, Meanders and Oxbow lakes.

Lower Course:

Flat valleys, Floodplains, Meanders and Deltas.

As the river moves further toward the mouth it cuts downward. The gradient in the upper course is steep and the river channel is narrow. Vertical Erosion in this part of the river is very likely.

- V-Shaped Valleys

- Interlocking Spurs

- Rapids

 Waterfalls

- Gorges

...are the landforms that occur in this part of the river.

As the river erodes the upper course, it winds to avoid the hard rock. This is called Interlocking Spurs.

When a river runs over areas alternating from hard to soft rock, Rapids and Waterfalls could form.

In the middle course, the river has a larger volume of water and more energy. The gradient and Lateral erosion occurs resulting in a wider channel. Vertical erosion has also deepened the channel. 

The features of the Middle course are:

- Meanders

- Oxbow Lakes

As the river erodes laterally, to the right side then the left sided making large bends like horseshoes.

The formation of meanders is due to both deposition and lateral erosion, they also migrate downstream gradually.

The force and velocity of the water laterally erodes the river bank on the outside of the bend, forming a river cliff. However, on the inside of the bend where te flow is slower, deposition occurs and forms a slip-off slope.

Over time the meander's loops become tighter until the ends become so close that they join. Deposition makes it so that the bend's ends get closed up forming an oxbow lake.

In the lower course the high volume of water and large amount of discharge cause the channel to deepen and widen. The landscape around it is flat, this is called a floodplain. However, towards the mouth deposition occurs due to the slow flow of water.

A floodplain is the area around a river that is covered in times of flood. A floodplain is a very fertile area due to the rich alluvium deposited by floodwaters.

This makes floodplains a good place for agriculture. A build up of alluvium on the banks of a river can create levees, which raise the river bank.

Deltas are found at the mouth of large rivers, e.g: the Mississippi. A delta is formed when the river deposits its material faster than the sea can remove it. There are three main types of delta, named after the shape they create.

Arcuate - the land around the river mouth arches out into the sea and creates a fan effect.

Cuspate -  the land around the mouth of the river juts out arrow-like into the sea.

Bird's Foot - the river splits on the way to the sea, each part of the river juts out into the sea. Like a Bird's Foot.