Year 5: Rivers
“Oh, Eeyore, you are wet!” said Piglet, feeling him. Eeyore shook himself, and asked somebody to explain to Piglet what happened when you had been inside a river for quite a long time.” —A. A. Milne
From a trickle in the mountaintops to a crashing waterfall, rivers shape the world that we live in. This geography topic will develop your understanding of rivers, linking with your knowledge of states of matter in science.
In this unit you will learn:
About the water cycle and where our water comes from
About famous rivers of the UK and the world
Different features of a river, including waterfalls, meanders and oxbow lakes
How a river erodes
How a river transports materials
Class writing:
We will use the technical information about rivers to write a non-chronological report on the subject.
Home learning opportunities:
To develop your understanding of this unit further at home, you might like to:
Create a fact file about a famous river
Take some photographs of a river near where you live
Make a boat out of recycled materials and take a picture of it floating
Read more:
Meanders and oxbow lakes
Meanders
In the middle course the river has more energy and more water. The is also deeper. A larger river channel means there is less friction, so the water flows faster:
As the river erode it forms large bends, and then horseshoe-like loops called meanders.
The formation of meanders is due to both deposition and erosion.
On the outside of the bend, where the river is faster, material is eroded.
On the inside of the bend, where the river flow is slower, material is deposited.
Ox-bow lakes
As shown in the video above, sometimes meanders can form an ox-bow lake. This is a horseshoe shaped lake next to a river.
After a long period of time, the meander becomes very curved, and eventually the neck of the meander becomes narrower. The river cuts through the neck during a flood, cutting off the meander and forming an oxbow lake.
Waterfalls
Waterfalls are one of the most stunning natural features of a rive.
Formation of a waterfall
Waterfalls often form in the upper stages of a river where it flows over different bands of rock.
The river erodes soft rock more quickly than hard rock and this may lead to the creation of a waterfall.
Formation of a waterfall: The soft rock erodes more quickly, undercutting the hard rock.
The Water Cycle
