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2nd Grade Wind, Water and Land
2015­11­23
www.njctl.org
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Wind, Water and Land
• What is Wind?
• Wind Erosion
• Preventing Wind Erosion
• Water Erosion
• Sudden Water Erosion
• Preventing Water Erosion
• Landforms as Homes
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What is Wind?
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What Am I?
I saw you toss the kites on high
And blow the birds about the sky;
And all around I heard you pass,
Like ladies' skirts across the grass­­
I saw the different things you did,
But always you yourself you hid.
I felt you push, I heard you call,
I could not see yourself at all­­ O you that are so strong and cold,
O blower, are you young or old?
Are you a beast of field and tree,
Or just a stronger child than me? 5
What is wind?
You can't see the air and you can't see the wind, but you can tell its there. You feel your hair blowing, clouds traveling across the sky and leaves moving in a tree. Wind is moving air.
Source: fplsafetyworld.com
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The Power of Wind
Suppose that you are at the beach and you build a sandcastle. If it suddenly became very windy, what would happen to your castle?
In your groups, think of 3 other ways that wind affects you.
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Effect of Temperature Review
Remember back to when you learned about how matter can change state by changing the temperature.
How do particles change as they heat up?
Particles move faster and spread apart.
How do particles change as they cool down?
Particles move slower and get close together.
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Temperature and Air
These same ideas hold true for the particles in the air.
When air heats up, the molecules spread out.
When air cools down, the molecules get close together.
What type of air do you think is heavier, warm or cool?
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Temperature and Air
If you fill a shoebox with hot air, it would look something like this:
If you fill the same shoebox with cold air, it would look something like this:
In the same space, there are less molecules of hot air than there are of cold air. This means that cold air is heavier than hot air.
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How is Wind Created?
Rays from the sun heat up Earth's surface. However, different types of surfaces heat up faster than others. The air over land heats up quickly. The air over water heats up slowly.
Earth's Surface
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How is Wind Created?
The air over land is light and rises.
It is replaced by the heavier cold air over the water. You feel this as the wind.
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A Hot air
B Moving air
Answer
1 What is wind?
C Cold air
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A Pushes
B Moves
Answer
2 The Sun _______ up Earth's surface and causes the air above it to move upwards.
C Cools
D Heats
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3 Hot air is heavier than cool air.
False Answer
True 15
4 Which are examples of how you can tell there is wind? Choose all that apply.
B See a tree blowing in the wind.
Answer
A Watch a cloud move across the sky.
C Hear it blowing.
D Feel it on your skin.
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Wind Lab
In this lab you will investigate what wind is and how you can measure it by building an anemometer.
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Wind Erosion
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The Power of Wind
The Arches are a rock formation found in Utah's Moab Desert. This amazing structure was formed, in part, by the power of wind. How does wind create landforms? Can you think of other places you have seen structures affected by wind?
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Wind Causes Change
Wherever there is wind it is working to change the landscape. Wind causes erosion, the carrying and moving of materials that change the landscape. 25
Wind Erosion
Wind erosion happens on loose sand and solid rock.
How do you think erosion can happen in each picture?
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Wind Erosion
Wind can pick up loose sand and carry it away to new locations.
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Wind Erosion
On hard surfaces, the sand already carried by the wind grinds against the surfaces. This breaks down the rock into smaller pieces that are carried away by the wind.
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Wind Creates Landforms
Wind erosion creates many unique landforms. As the wind carries particles of sand and soil it blasts them against the surface of rocks, slowly grinding them down.
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Wind Erosion
Look at the pictures below. In what type of environment do you think wind erosion is most common?
Dry environments with little vegetation.
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Sandstorms
Sandstorms are caused when a strong wind blows over loose sand or soil. The sandstorm picks up the loose material and carries it away. 31
Sandstorms
A sandstorm can carry sand from the Sahara desert in Africa all the way to the Caribbean! 32
Dunes
Dunes form when sand carried by wind hits an obstacle that causes the sand to be deposited. Sand begins to pile up causing more sand to be deposited. Sandstorms can move entire dunes! 33
Hurricanes
Hurricanes are huge storms that form over the ocean. They can create winds up to 200 miles per hour. These strong winds can cause erosion as well as damage to buildings, cars and trees. 34
Tornados
Tornados are powerful columns of rotating air that form over land and are capable of producing winds up to 300 miles per hour. When tornados touchdown they can reshape the landscape and can destroy anything in their path. 35
5 Sandstorms are __________.
B Things that deflect wind and reduce soil erosion
Answer
A Strong winds that pick up loose soil and sand C When sand is piled up
D Huge storms that form over the ocean
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6 What is erosion? B The process of breaking things down
C The heating of the earth's surface
Answer
A The movement of materials
D A way to prevent flooding
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7 A powerful rotating column of air that can reach speeds up to 300 mile per hour is a ________.
B Hurricane
C Dune
Answer
A Sandstorm
D Tornado
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A Picture A
B Picture B
Answer
8 Which landscape would be most impacted by wind erosion?
A B
C Both A & B
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9 Hurricanes form over the ocean and tornados form over _________.
B The land
Answer
A Seas
C A long period of time
D Oceans
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10 Wind erosion happens more often when there is _______. B very little loose sand.
C very little vegetation and lots of sand.
Answer
A lots of vegetation.
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Preventing Wind Erosion
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Negative Impacts of Wind Erosion
Although wind erosion can create interesting landforms, it also has negative impacts on the environment.
It destroys crops. How?
It destroys habitats. This barrier island was cut in half by a hurricane.
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Preventing Wind Erosion
Planting vegetation can help to prevent wind erosion. Look at this picture and describe how you think the plant can help prevent erosion. The answer is under the picture.
The roots of vegetation hold onto soil particles and stop them from being carried away.
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Preventing Wind Erosion
Windbreaks are rows of trees, bushes, fences, or other structures that help prevent wind from carrying soil away. Trees and other plants provide a natural windbreak. 50
How Windbreaks Work
Natural or manmade windbreaks work by blocking the wind to protect the soil. As the air moves upward it loses speed. The wind is then carried over the protected area instead of through it. 51
Vegetation Protects Habitats
Sea oats have been planted in these sand dunes at the beach. How would this help to protect the coastal area from wind erosion?
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Windbreaks Improve Farming
Can you locate the natural windbreak in this picture. How would the windbreak improve the crop yield of this farm?
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11 Which formation could be formed by wind erosion
Answer
A B C D 54
12 Wind erosion never has negative impacts on the land.
True Answer
False 55
13 What is a windbreak?
protection from the wind
B A mound of sand formed by the wind
Answer
A Something like a fence or tree row that provides C Slow moving air
D A strong storm that forms over the ocean
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Water Erosion
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The Power of Water
This is a picture of the Colorado River winding through the Grand Canyon. Talk with your group about how water can work to create landforms such as this.
Click here to watch a video about the Grand Canyon.
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Water Erosion
Like wind, water can also erode land and shape landforms. As water flows along a rock it breaks away tiny pieces of the rock and carries it away. This is called water erosion.
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Deltas
Water erosion over a long period of time creates different types of landforms. Rivers flow into big bodies of water like lakes and oceans. Deltas are small pieces of land that form when river water leaves rocks and sand behind on the way to lakes and oceans.
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Canyons
Water erosion over a long period of time creates different types of landforms. Canyons form when water carves away rock. 64
Valleys
Valleys are an area of low land surrounded by hills or mountains. They are also formed by erosion and the gradual wearing away of the land by running water. Rivers are often found in the bottom of valleys. 65
Waterfalls
Waterfalls occur at places where water suddenly plunges downward off a cliff. Waterfalls form when streams flow over areas of hard and soft rocks. The water erodes away the soft rocks until an area of harder rocks is reached. The result is a cascade of water. 66
14 Which picture is an example of a canyon?
C B D Answer
A 67
15 Deltas are formed when ___________.
B Rivers change course
C Rivers flow beteen two mountains
Answer
A Rivers deposit silt, soil and rocks at the rivers mouth
D Wind piles up sand
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16 What type of erosion caused this landform?
A Wind
C Water
D Sun
Answer
B Rocks
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17 Valleys and waterfalls are formed by ______.
B Sandstorms
Answer
A Wind Erosion
C Flowing water
D Tornados
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Erosion Activity
How can wind and water cause erosion?
Follow the directions to find out!
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Sudden Water Erosion
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Sudden Erosion
Look at these pictures. What do you think happened to cause this destruction?
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Sudden Erosion
While some types of water erosion can take thousands or millions of years, water can cause sudden and rapid erosion, too. Forces such as heavy rains, hurricanes and flash floods can change the landscapes dramatically without much warning. 77
Hurricanes
Waves and the heavy rain from a hurricane cause coastal erosion. 78
Flash Flooding
Flash flooding is sudden flooding that occurs when floodwaters rise rapidly due to intense rain. They often occur without warning and can dramatically change the shape of the land. 79
Waves
Ocean currents, tides and waves are continuously shaping and changing the coastal landscapes. Waves can change a shoreline over many years, or dramatically change the landscape quickly.
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18 Water erosion occurs when water move particles away from their source.
False Answer
True 81
19 Hurricanes cause erosion by _____. Choose all that apply.
B storm surge
C wind
Answer
A rain
D waves
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A Glaciers
B Atmosphere
Answer
20 What causes flash flooding?
C Strong winds
D Heavy Rains
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21 Waves are constantly changing the shoreline.
False Answer
True 84
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Preventing Water Erosion
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Negative Impacts of Water Erosion
Just like wind erosion, water erosion has several negative impacts.
It destroys habitats as well as human communities.
It carries away soil and nutrients for farming.
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Terracing
To prevent damage by water erosion, farmers use a technique called terracing. How do you think shaping the land in this way would help to prevent water erosion?
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Terracing
Terracing creates ridges on a steep slope.
This reduces erosion by decreasing the steepness of the slope. Water can be channeled off the slope instead of it running down the slope and causing erosion.
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Coastal Erosion
When erosion occurs along the coast, it is called coastal erosion. Look at the map. What areas have the highest rates of erosion? 93
Coastal Erosion
Coastal erosion is a natural process. Coastlines have been changing throughout time. Humans have built right next to the coast, and it is now a problem for us.
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Coastal Erosion
To protect human communities, we attempt several different techniques to reduce coastal erosion. • Hard structures
• Beach nourishment
• Changing human behavior
Important: None of these techniques can stop coastal erosion. They simply try to reduce it.
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Hard Structures
Hard structures refer to structures that are built into a waterway to prevent water erosion.
This seawall is a wall built along the coast that protects the area from erosion by strong waves and storms.
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Hard Structures
This jetty is a wall that extends into the ocean, reducing water erosion by waves and currents.
Breakwaters are wall built parallel to the shore (in the same direction as the shore) to reduce water erosion by waves and currents.
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Beach Nourishment
Beach nourishment includes ways to reduce wind and water erosion other than by building structures.
What changes were made to this beach?
Source: nagsheadnc.gov
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Beach Nourishment
During beach nourishment, sand is added to the beach and vegetation is planted along the coastline.
This tube is pumping new sand onto this beach.
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Changing Human Behavior
Since coastal erosion cannot be stopped, the only way to prevent damage to human commities is to implement land­use limits.
In your group, come up with some ways that humans can change their behavior to prevent being affected by coastal erosion. Click the box for a few examples.
• Laws that prevent humans from building right next to the coast.
• Designating coastal areas as park land.
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Changing Human Behavior: Discussion
Why do you think coastal governments do not want to change regulations to prevent erosion?
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22 What type of erosion technique would most likely be used by a farmer?
B beach nourishment
C terracing
Answer
A breakwater
D jetty
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23 Coastal erosion is an unnatural process.
False Answer
True 103
24 This wall has been built along the coast to protect the community from water erosion from waves. What type of structure is this?
B Seawall
C Breakwater
Answer
A Jetty
D Dam
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25 Coastal erosion cannot be stopped, only reduced.
True Answer
False 105
26 Planting sea oats along sand dunes would be considered what type of erosion technique?
B Beach nourishment
C Changing human behavior
Answer
A Hard structure
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27 These walls have been built parallel to the shore to try to reduce water erosion. What type of structure is this? (Choose all that apply.)
Answer
A Hard structure
B Beach nourishment
C Jetty
D Breakwater
Source: Virginia Institute of Marine Science
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Coastal Erosion Activity
Model coastal erosion and see how it changes the shape of beaches.
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Landforms as Homes
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Landforms as Homes
As wind and water cause erosion and create new landforms, they also provide homes for living things. Many plants and animals call different land forms their homes.
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Landforms as Homes
Look at the landforms below. What types of animals might live there? What types of conditions would animals need to be able to survive in each picture?
Source: National Geographic
Source: National Geographic
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Canyons
Animals have special characteristics that make certain landforms good homes for them. Bighorn Sheep can climb steep canyon walls. Pinion pines can shoot their roots into the cracks in the canyon wall rocks.
Vultures can soar high above the canyon looking for an easy meal.
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Deltas
Shallow waters in deltas make good homes for many types of fish, birds, plants and animals because they are warm, have good soil, for plants, and easily trap food particles. 115
Deserts and Dunes
Some plants and animals can survive in places without much water.
How can a cactus survive in the desert? Think about what it looks like, not just that it can survive without water. A cactus can live in the desert because it doesn't need very much water, has prickly thorns to keep animals from eating it, and does not blow over easily in the wind. Move the picture for the answer 116
28 What type of landform would this animal most likely make a home?
B River delta
Answer
A Desert
C Cave
D Canyon
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True False Answer
29 Animals use natural landforms created by wind and water erosion as homes. 118
30 What type of landform would this animal most likely make a home?
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B River delta
Answer
A Canyon
C Cave
D Sand dunes
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