Move the Labels to the correct part of the River.
or, explore the picture to learn more about the parts of a river.
All water must run down from higher places. However, when it rains, most water runs away through the soil, between stones and rocks where we cannot see it.
As water runs down from hills and mountains it begins to collect in larger quantities. As this happens, it becomes visible above the surface of the soil as swampland, lakes or even streams.
When it rains, the water from the surrounding hills drains into the River Basin - this consists of all the land lower than the source. If there is a lot of rain then the channel might not be big enough to carry all that water away, so the river floods.
Over time, the flooding river has eroded the surrounding landscape and flattened it. Although this land is liable to flooding, it is very fertile and ideal for farming. Today, with modern drainage technology, flood plains can be used for building land, providing space for factories and warehouses, as well as housing. However, the soil of a flood plain is permeable and holds water, a bit like a sponge, from where it can evaporate in the sun. Can you describe the problem in covering a flood plain with buildings and tarmac if there is a sudden downpour?
On its path towards the sea, a river will pass many hills, or even mountains. Each hill will have its own run-off and other streams and rivers might even be formed.
A river that joins a bigger river can be said to be contributing to it, therefore, the smaller river is known as a tributary.
The bends you can see in the river are called meanders. These are caused by hard areas of rock that slows the river down. Often the river finds a way round these areas by eroding the softer land nearby and then gets back on course for the sea, once it is past the obstacle.
As a river turns a bend an extraodinary thing happens to its current; on the inside of the bend the current slows down and deposition occurs. On the outside of the bend, the current speeds up and a greater amount of erosion takes place.
This combination of erosion and deposition gradually changes the course of the river - the river manages to erode through the tough area of rock and the old route through the meander is closed off. An ox-bow lake is formed.
As the river runs into the sea, the water swirls and churns in its channel; it continues to erode the banks and the channel becomes wider.This is the mouth of the river, but the gradual widening that leads to the sea is called an estuary.
Estuaries are not only often wide, but are usually deeper than other parts of the channel as well. This makes them ideal for larger ships and boats to travel along, so you might see large factories and warehouses near the mouth of a river.
By the time the water reaches the sea, it is carrying a lot of things; this is called the load. The load could consist of very small items (sand, small stones) called silt, or larger items, such as rocks that roll along the riverbed, or pieces of wood.
However, when the water meets the sea, its journey is over and the speed of the current slows down. Of course, with a drop in speed, the water no longer has the power to carry all its load, so this is dropped too - this is called deposition.
All the things that are carried by the river over time gradually build up and the course of the river spreads out as the water becomes shallower.However, there is now the same amount of water travelling through a shallower entrance to the sea, so more transportation takes place - the river channels its way through the deposited material, but might find several ways to the sea.
The result of this, rather complicated procedure, is that the mouth of the river could be split into a collection of smaller rivers - this is called a Delta