St Mary's Learning Support Department: Rivers

“A river seems a magic thing. A magic, moving, living part of the very earth itself.” ― Laura Gilpin

A river is a natural channel of water that runs from high land to low land. Rivers drain rainwater from land and lakes and carry it off to the sea. The bottom of a river channel is called the river bed. The sides of a river channel are called banks. Here are some other important key words about rivers.

Source: The point where a river begins

Drainage Basin: The area of land that drained by a particular river and its tributaries.

Watershed: The boundary or divider between two drainage basins, like the top of a house rooftop

Course: The route taken by a river as it flows down towards the sea or ocean

Tributary: A smaller river that runs into a larger river

Confluence: The point where two or more rivers meet

Mouth: Where a river reaches the sea

Estuary: The part of the river mouth that is tidal as it merges with the sea or ocean.

All rivers have an upper, middle, and lower course.

In the Upper Course the process at work is Erosion. The features you will see are Waterfalls, Rapids and a V shaped Valley

The upper course begins in the hills or mountains. Here the river is smaller and usually has a rapid,

tumbling flow that cuts a narrow channel through rocky hills or mountains. It may roll large boulders

along in its swift current. The river can create waterfalls where it carves out layers of soft rock and leaves a cliff of hard rock standing.

It forms rapids along sloping rocky beds.

In the Middle Course the process at work is both Erosion and Deposition

The features you will see are Meanders, Oxbow Lakes

The middle course of a river has more water than in the upper course. The slope is gentler and flatter.

Erosion has widened the channel. Deposition also occurs as some of the material eroded in the

Upper Course starts to settle. The river channel has also become deeper. Meanders are typical

landforms found in this stage of the river. Oxbow lakes can also occur when the river cuts through the land in a straight line and cuts off the meander leaving it as a lake.

In the Lower Course the process at work is Deposition.

The volume of water in a river is at its greatest in the lower course. This is due to the contribution of water from tributaries. The river channel is deep and wide and the land around the river is flat. Energy in the river is at its lowest and deposition occurs.

A Delta is a feature often found at the mouth of a river. An example is the Nile Delta. Deltas are formed when a river deposits material faster than the sea can erode it. High banks called Levees can also be seen.