GIZMO Copy of KWAL 5 River Erosion
Student Exploration: River Erosion
Vocabulary: cutbank, discharge, erosion, flood,
floodplain, meander, meandering river, oxbow lake,
point bar, river speed, sediments, slope,
streambank, streambed, tributary, weathering
Prior Knowledge Questions (Do these BEFORE
using the Gizmo.)
1. The image above shows a raging mountain river in full flood. What do you think is making
the water brown in color? Dirt
2. What impact do you think the flooding river will have on the surrounding landscape?
Erosion
Gizmo Warm-up https://www.explorelearning.com/
If you stand by the bank of a river, it may seem that very little is
happening. But over thousands and even millions of years,
rivers can have a profound effect on the landscape. In the River
Erosion Gizmo, you will see how rivers move materials and how
they affect landscapes.
To begin, check that Mountain stream and Short-term erosion are selected. The Gizmo
shows a typical stream that is moving through a hilly area.
1. The two movie cameras ( ) allow you to observe different parts of the stream up close.
Click on the left movie camera. What do you see? I see fish swimming in the water &
some rocks.
2. Sediments are small rock fragments such as sand or pebbles. What evidence do you see
that sediments are being transported? How the water is flowing & the fish moving right.
3. Now select the right movie camera to see the bank of the mountain stream. What is
happening to sediments on the bank? It eroded & then it fell into water.
, GIZMO Copy of KWAL 5 River Erosion
Get the Gizmo ready:
Activity A: ● Check that Mountain stream and Short-term
erosion are selected.
Mountain streams ● If necessary, click outside the circle to close the
zoomed-in view.
Introduction: Erosion occurs when sediments and other materials are moved from one place
to another. Along with weathering, which is the breakdown of large rocks into smaller
sediments, erosion can have a profound impact on the landscape.
Question: How does river erosion affect landscapes in the mountains?
1. Label: First, get to know some of the V-shaped valley
different parts of a mountain stream. Turn
on Show labels. Label the image to the
right, then fill in the word that goes with
each description. Waterfall
A small stream that flows into a larger stream:
Tributary
Tributary
A place along a stream where water drops Streambed
straight down: Waterfall
Streambank
A letter that describes the shape of a typical mountain valley: V_shaped valley
The side of a stream: Streambank The bottom of a stream: Streambed
2. Observe: Turn off Show labels. Next to “Release barrel,” click Play ( ). Observe how fast
the barrel moves as it floats down the stream.
What happens when the barrel goes over the waterfall? The barrel speeds up when
falling down the waterfall.
3. Calculate: The two red flags are 100 meters apart. The time at which the barrel passes the
flag is shown. Remember, there are 60 seconds in a minute.
A. How many seconds did it take for the barrel to go 100 meters? 91 seconds
B. To find the barrel’s speed, use a calculator to divide the distance traveled (100 m) by
the time it took the barrel to float 100 m. The units are meters per second (m/s).
What is the speed of the barrel? 1.1 m/s
, GIZMO Copy of KWAL 5 River Erosion
4. Record: Click Reset ( ). Turn on Show data.
A. The slope of the channel is how steep it is, or how many meters the streambed
drops for every horizontal kilometer. What is the slope of the stream? 22.0 m/km
B. River speed is a measure of how fast water flows. What is the river speed? 1.1 m/s
C. How does the river speed compare to the speed of the barrel you calculated on the
previous page? There the same
D. Discharge is the water volume that flows past a given point every second, measured
in cubic meters per second (m3/s). What is the stream’s discharge? 2.3 ㎥/s
E. What types of sediments are transported by this stream? Sand, silt, & clay.
Sediments are classified by size. The smallest sediments are clay particles, followed
by silt, sand, and pebbles. Larger sediments include cobbles and boulders.
5. Observe: Turn off Show data. Next to River flow, select Flood. Look at the landscape, and
then click on the movie cameras to see zoomed-in views. Describe what you notice.
The water level rose, it moved faster, the water got darker, the amount of sediments
increased, the erosion on banks of river increased.
6. Calculate: Click Play to release the barrel. How many seconds does it take the barrel to get
from one flag to the other? What is the speed of the barrel?
Time: 31 seconds Speed: 3.2 m/s
7. Compare: Turn on Show data. During a flood, how do the river speed, discharge, and
transported sediments compare to normal flow conditions?
The river speed got aster, the discharge increased, & the transported larger
sediments (pebbles).
Student Exploration: River Erosion
Vocabulary: cutbank, discharge, erosion, flood,
floodplain, meander, meandering river, oxbow lake,
point bar, river speed, sediments, slope,
streambank, streambed, tributary, weathering
Prior Knowledge Questions (Do these BEFORE
using the Gizmo.)
1. The image above shows a raging mountain river in full flood. What do you think is making
the water brown in color? Dirt
2. What impact do you think the flooding river will have on the surrounding landscape?
Erosion
Gizmo Warm-up https://www.explorelearning.com/
If you stand by the bank of a river, it may seem that very little is
happening. But over thousands and even millions of years,
rivers can have a profound effect on the landscape. In the River
Erosion Gizmo, you will see how rivers move materials and how
they affect landscapes.
To begin, check that Mountain stream and Short-term erosion are selected. The Gizmo
shows a typical stream that is moving through a hilly area.
1. The two movie cameras ( ) allow you to observe different parts of the stream up close.
Click on the left movie camera. What do you see? I see fish swimming in the water &
some rocks.
2. Sediments are small rock fragments such as sand or pebbles. What evidence do you see
that sediments are being transported? How the water is flowing & the fish moving right.
3. Now select the right movie camera to see the bank of the mountain stream. What is
happening to sediments on the bank? It eroded & then it fell into water.
, GIZMO Copy of KWAL 5 River Erosion
Get the Gizmo ready:
Activity A: ● Check that Mountain stream and Short-term
erosion are selected.
Mountain streams ● If necessary, click outside the circle to close the
zoomed-in view.
Introduction: Erosion occurs when sediments and other materials are moved from one place
to another. Along with weathering, which is the breakdown of large rocks into smaller
sediments, erosion can have a profound impact on the landscape.
Question: How does river erosion affect landscapes in the mountains?
1. Label: First, get to know some of the V-shaped valley
different parts of a mountain stream. Turn
on Show labels. Label the image to the
right, then fill in the word that goes with
each description. Waterfall
A small stream that flows into a larger stream:
Tributary
Tributary
A place along a stream where water drops Streambed
straight down: Waterfall
Streambank
A letter that describes the shape of a typical mountain valley: V_shaped valley
The side of a stream: Streambank The bottom of a stream: Streambed
2. Observe: Turn off Show labels. Next to “Release barrel,” click Play ( ). Observe how fast
the barrel moves as it floats down the stream.
What happens when the barrel goes over the waterfall? The barrel speeds up when
falling down the waterfall.
3. Calculate: The two red flags are 100 meters apart. The time at which the barrel passes the
flag is shown. Remember, there are 60 seconds in a minute.
A. How many seconds did it take for the barrel to go 100 meters? 91 seconds
B. To find the barrel’s speed, use a calculator to divide the distance traveled (100 m) by
the time it took the barrel to float 100 m. The units are meters per second (m/s).
What is the speed of the barrel? 1.1 m/s
, GIZMO Copy of KWAL 5 River Erosion
4. Record: Click Reset ( ). Turn on Show data.
A. The slope of the channel is how steep it is, or how many meters the streambed
drops for every horizontal kilometer. What is the slope of the stream? 22.0 m/km
B. River speed is a measure of how fast water flows. What is the river speed? 1.1 m/s
C. How does the river speed compare to the speed of the barrel you calculated on the
previous page? There the same
D. Discharge is the water volume that flows past a given point every second, measured
in cubic meters per second (m3/s). What is the stream’s discharge? 2.3 ㎥/s
E. What types of sediments are transported by this stream? Sand, silt, & clay.
Sediments are classified by size. The smallest sediments are clay particles, followed
by silt, sand, and pebbles. Larger sediments include cobbles and boulders.
5. Observe: Turn off Show data. Next to River flow, select Flood. Look at the landscape, and
then click on the movie cameras to see zoomed-in views. Describe what you notice.
The water level rose, it moved faster, the water got darker, the amount of sediments
increased, the erosion on banks of river increased.
6. Calculate: Click Play to release the barrel. How many seconds does it take the barrel to get
from one flag to the other? What is the speed of the barrel?
Time: 31 seconds Speed: 3.2 m/s
7. Compare: Turn on Show data. During a flood, how do the river speed, discharge, and
transported sediments compare to normal flow conditions?
The river speed got aster, the discharge increased, & the transported larger
sediments (pebbles).
