Science Fenns K-5Grades K to 5
A model hillside of damp sand in a tray with a toy house at the bottom and a trickle of sand sliding down.

Science / All lessons / Weather and a Changing Earth

Landslides

Model how a hillside lets go.

Lesson 30 of 41

Try this first

Before we start

Today’s story

Landslides

Think of a pile of sand at the edge of a driveway. Pour water on it and watch. The sand slumps and slides.

A landslide is dirt, rocks and mud sliding down a slope. It is a rapid change. Heavy rain, shaking from an earthquake, or loss of plants on a hill can start one. Roots act like fingers that hold soil in place.

We can model a landslide with sand and a tray. That shows how it works without any danger. Here are the steps.

See it

Five steps. Every time.

    Hands on

    Hillside Model

    30 minutes · Do this with a grown-up nearby

    You need

    • A baking tray
    • Damp sand
    • A cup of water
    • Craft sticks
    • A few pieces of grass or moss
    • A toy house
    • Paper towels

    Do this

    1. Pile damp sand at one end of the tray.
    2. Place the toy house at the bottom.
    3. Slowly pour water on top of the hill.
    4. Watch how the sand moves and draw it.
    5. Rebuild the hill and press grass into the top.
    6. Pour the same amount of water again and compare.
    Write or draw: Draw the hill before and after. Note how far the sand slid each time.

    Watch for: Notice if grass changes how much sand moves. Notice how wetness changes the slide.

    Safety: Keep the tray over a sink or a tub to avoid a mess. Wash hands after sand play.

    Same every time

    Three rules

    Rule 1Change one thing per try.

    That keeps the test fair.

    Rule 2Plants help hold soil.

    Roots grip the dirt.

    Rule 3A model leaves things out.

    Real hills are bigger and more complicated.

    Grandpa Fenn’s notebook

    Say it like a scientist

    landslide
    Dirt and rocks that slide down a slope.
    slope
    A surface that tilts up or down.
    erosion
    Soil or rock being carried away by wind or water.
    model
    A smaller or simpler version that shows how something works.

    Poppy’s quiz

    Six questions

    Tap an answer. Green means right. You will see why.

    Talk about it

    Say it out loud

    • How do you know what caused the slide in your model? What did you change?
    • Where near home is a steep bank, ditch or hill? How could it be kept safe?
    Did you know

    Some landslides move faster than a person can run.

    Someone who does this

    A civil engineer designs slopes and walls to keep hillsides safe.

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