Year 5 · Science · Earth and space sciences
Weathering and erosion
Students model how wind, water and ice break down rock and carry soil away, and connect these processes to Australian landforms such as the Twelve Apostles and Uluru.
Awaiting educator review. This material was drafted by our content team with AI assistance and is waiting for review by a qualified educator. Please check it suits your child before using it. Created 10 October 2026.
These lessons were written around Australian Curriculum strands and matched to New Zealand year levels by age (NZ Year 1 is the first year of school). They are not yet mapped to The New Zealand Curriculum, so check them against your own learning programme.
Learning goals
Learners will
- Explain the difference between weathering and erosion.
- Model how running water erodes soil.
- Describe ways to reduce soil erosion.
Success looks like
- I can explain weathering and erosion in my own words.
- I can use a sand tray to show water carrying soil away.
- I can explain why plant roots help stop erosion.
The big idea
Earth's surface is always changing, mostly very slowly. Two important processes are weathering and erosion.
Weathering breaks rock into smaller pieces. Rain, wind, frost, plant roots growing into cracks and heating and cooling of rocks in the sun can all cause weathering.
Erosion carries those pieces away. Rivers carry soil downstream, waves wear away cliffs and wind blows sand across deserts.
Eventually the moving water or wind slows down and drops its load. This is called deposition. Sand bars and river deltas form this way.
These processes shaped many Australian landforms. Waves eroded soft limestone cliffs on the Victorian coast to leave rock stacks like the Twelve Apostles. Uluru has been shaped by weathering and erosion over many millions of years.
Plants help protect soil. Their roots hold soil together and their leaves soften the impact of raindrops. Bare soil erodes much faster.
Worked examples
Sand-tray river
What happens when 'rain' falls on a sloping tray of sand?
- Fill the tray with damp sand and pat it flat.
- Prop up one end with a block so it slopes.
- Slowly sprinkle water at the top using the cup with holes.
- Watch: small channels form and sand is carried down and dropped at the bottom.
Answer: The water erodes channels and deposits sand at the lower end.
Does covering the soil help?
Compare bare sand with sand covered in grass clippings.
- Set up two trays the same way, with the same slope.
- Cover one tray with grass clippings or leaves.
- Pour the same amount of water on each in the same way.
- Compare how much sand washes to the bottom.
Answer: Less sand washes away from the covered tray, so plant cover reduces erosion.
Practice check
Have a go, then check your answers. Each answer comes with an explanation.
Answer guide for parents
What is weathering?
Rock being broken into smaller pieces — Weathering breaks rock down; erosion carries it away.
Which is an example of erosion?
A river carrying soil downstream — Moving water carrying soil away is erosion.
How do plant roots help stop erosion?
They hold the soil together — Roots bind soil so water and wind cannot easily carry it away.
Which mainly shaped the Twelve Apostles on the Victorian coast?
Waves eroding the cliffs — Waves wore away soft limestone, leaving stacks of rock standing in the sea.
In the sand-tray test, which change would make it a fair test?
Keeping the slope and amount of water the same — Only the ground cover should change; everything else stays the same.
When moving water slows down and drops the sand it carries, this is called d__________.
deposition — Dropping sediment is deposition.
Small pieces of rock and soil carried by water are called s________.
sediment — These small pieces are sediment.
Which erodes faster: bare soil or soil covered with plants?
bare soil — Bare soil has nothing to protect it from rain and wind.
Watch out for
- Students often mix up weathering and erosion. Weathering breaks; erosion moves.
- Some think landforms never change. Most change too slowly to see in a lifetime, but floods and storms can change them quickly.
- Some believe only water causes erosion. Wind and ice also erode.
Tips for parents
- Do this activity outside or in a bathtub to manage mess.
- Measure the 'rain' with a cup so each tray gets exactly the same amount.
- Safety: an adult pokes holes in the cup; wash hands after handling soil and wear gloves if you have cuts.
Go further
- After rain, look for signs of erosion around your garden, footpaths or a local creek.
- Use a fan on low to model wind erosion on dry sand (wear sunglasses to protect eyes).
- Find photos of Australian landforms and decide whether wind, water or ice shaped them.