Middle course is the second stage of a river is known as the maturity stage.

The middle course of the river begins when it leaves the mountains and enters the plains.

When the river reaches the plains, a number of tributaries join it.

As a result the volume of water increases in the river.

The gradient or slope reduced at this stage and the river flows more slowly.

The river also gets widened as a result of great volume of water and the impact of the river load.

Let’s see the landforms of the middle course.

In the middle course, the river’s deposition work is more important than its erosion work.

Therefore the landforms of deposition are more prominent than the landforms of erosion. Important landform in this stage is meander.

Meander

In the middle course the river flows slowly over the plain forming S-shaped loops called meanders.

It is common to most rivers when a channel forms a curved path.

These are the result of both erosion and deposition work of rivers.

Meanders generally form where the slope is gentle and when there is sufficient water in the river.

With time the curvature of meander loops become more and more circular.

And then the curvature becomes sharper and the river breaks through the meander to form an oxbow lake.

The Ganga in India and Mississippi in the USA are famous for their meanders.

The old stage lower course of river

Lower course is the third stage of a river is known as the old stage.

In this stage the river flows slowly and forms many landforms.

The main function of the river in the lower course is deposition.

The load-transporting capacity of the river is highly reduced due to slow flow as well as division of a river into many distributaries.

Let’s discuss the landforms of the lower course.

Delta

In the lower course, river creates only depositional landforms like delta.

In the lower course, the river divides itself into many distributaries.

These distributaries again subdivided into mini- distributaries.

This is due to deposition of sediments over a large area near the mouth of rivers.

The deposition over a large area results in a triangular-shaped formation called delta.

It resembles the Greek letter Δ.

Not all the rivers form deltas. There are some special conditions for the formation of deltas.

These conditions include a nearly calm sheltered sea, a large amount of sediment supply, and a reasonable size of the river.

The Ganga- Brahmaputra delta is one of the largest deltas in the world.

Revision

The middle course of the river begins when it leaves the mountains and enters the plains. When it reaches the plains, a number of tributaries join it.

The landforms of deposition are more prominent than the landforms of erosion. Important landform in this stage is meander.

In the middle course the river flows slowly over the plain forming S-shaped loops. These loops are called meanders.

In the lower course, the river flows slowly and forms many landforms. In this stage river creates only depositional landforms like delta.

The deposition over a large area results in a triangular-shaped formation called delta. It resembles the Greek letter Δ.

The End