River Landforms

River landforms definition geography

Let's start with the definition of river landforms.

Formation of river landforms

From previous explanations, we know the main characteristics of a river. There is the upper course, middle course and lower course.

River processes

Like any type of landform, river landforms occur due to different processes. These are; erosional processes and depositional processes. Let's get to know these processes a little better.

River erosional processes

This is when erosion, which is the breakdown of material, occurs. In rivers, rocks are broken down and transported to create different river landforms. This type of process produces erosional river landforms. Most river erosion takes place in the upper course to the middle course of the river, creating erosional landforms. This is due to the high energy which is created by fast-flowing, deep, water in an upper course to the middle course of a river.

Now, let's take a look at depositional processes.

River depositional processes

This is when sediment is deposited along a river to produce different river landforms. Deposition largely occurs downstream of a river, from the middle course to the lower course, as there is often less energy in the lower course of a river due to reduced water levels.

River landforms examples

So, what are the different types of river landform examples that occur? Let's see, shall we?

River erosional landforms

Firstly, let’s take a look at erosional landforms. These are features formed by the wear of material in rivers, also known as erosion.

The types of landforms that can form due to erosion are:

• Waterfalls
• Gorges
• Interlocking spurs

Waterfalls

Waterfalls are one of the most beautiful features of rivers; they can be found at the upper course of a river (and occasionally in the middle course of a river.) In a waterfall, fast-flowing water flows downwards at a vertical drop. They form where a layer of hard rock sits above a layer of soft rock. Erosion takes place and deteriorates the soft rock at a quicker rate, creating an undercut below the hard rock and an overhang where the hard rock is. Eventually, after continued erosion at the undercut and the build-up of fallen rocks, a plunge pool forms at the base of the waterfall and the overhang of hard rock breaks off. This is a waterfall.

Fig 1. A waterfall in the UK.

Gorges

Gorges are often formed from waterfalls. As erosion continues, the waterfall retreats further and further upstream, producing a gorge. An important characteristic of a gorge is a narrow valley, where tall and vertical walls stand on either side of the river.

Interlocking spurs

Interlocking spurs are areas of hard rock, that jut into the river’s pathway. They cause the river to flow around them because they are resistant to vertical erosion. They are found on both sides of a river and result in a zigzag river path.

V shaped valleys

In the upper course of a river, V-shaped valleys are formed from vertical erosion. The riverbed is eroded downwards quickly, becoming deeper. As time progresses, the sides of the river become unstable and weaken, ultimately the sides collapse, producing a V-shaped valley, with the river flowing through the centre at the base of the valley.

River depositional landforms

So, what about river depositional landforms? These landforms are made through the dropping of sediment.

The types of landforms that can form due to deposition are

• Floodplains
• Levees
• Estuaries

Floodplains

Floodplains form at the lower course of a river. This is where the land is very flat, and the river is wide. As the river floods, it overflows onto the flat land that surrounds it, forming a floodplain.

Levees

Over time, in floodplains, a further build-up of sediment will be deposited on either side of the river’s edge. This is because the water flow is much slower and therefore, a lot of energy is lost, which allows more sediment to be deposited. It then creates bulges of sediment called levees on either side of the river. Levees are often also found at the lower course of a river.

Estuaries

Estuaries are located in the lower course. They form at the mouth of a river, which is where the river meets the sea. Due to tides, the sea withdraws water from the river and the river's mouth. This means there is more sediment than water and produces estuaries. This also creates mudflats.

Fig 2. Estuary in the UK.

Surely, that must be all the river landforms, right? Actually...

Meandering river landforms

Meandering river landforms are river landforms that can be formed through both erosion and deposition, these are:

• Meanders
• Ox-bow lakes

Meanders

Meanders are basically where the river bends. Seems simple enough, right?

They are mostly found in the middle course of the river. This is because the formation of meanders requires high amounts of energy. As water flows through a river, it picks up speed where there is the deepest amount of water, this is the outer edge of the river. It is here where erosion takes place because of the fast-flowing, high-energy water. This erodes the river to create a deep bend. The eroded sediment is carried and deposited on the inner edge of the river, where the water flows at a much slower rate because it is more shallow. Therefore, there is less energy on the inner edge of the river. The build-up of sediment here forms a small, gently sloping bank. This creates the bends in the river, called meanders.

Ox-bow lakes

Ox-bow lakes are an extension of meanders. They are horseshoe-shaped sections of rivers that become separate from the main river due to continuous erosion and deposition.

As meanders develop from sustained erosion and deposition, the loops of the meanders become very close. This allows the river to flow straight through, bypassing the bend of the meander, taking a new and shorter route. Finally, the meander becomes cut off from the main river body due to deposition, and the shorter route becomes the main route for the river. The deserted meander is now considered an ox-bow lake.

River landforms diagram

Occasionally, the easiest way to understand these landforms is through a diagram.

Take a look at the diagram and see how many river landforms you recognise!

River landforms case study

Let's take a look at an example of a river that has a range of different river landforms. The River Tees is one of these (– hey, that rhymes!) The table below shows all the different landforms found along each section of the River Tees.

Fig 4. A levee on the River Tees.