Science of Life Explorations

Erosion and Soil Quality:

Prevent Erosion

Soils and water are linked to one another in the ecosystem. What happens to one affects the other. When soil is eroded, it often ends up in the water system.

In this lesson we’ll talk about soil erosion and water quality.

We know that soil is important to us. Healthy soil provides us with healthy plants.

Soil is part of the ECOSYSTEM because so much depends on it.

Soil is also part of the WATER CYCLE! It filters water as it soaks down to the groundwater.

Geologists and ENGINEERS study soil to decide the best way to use it and protect it.

Sometimes soils and bedrock are mined and used in manufacturing. Homes and other buildings as well as streets and highways are built on top of soil.

When soil is used incorrectly or not cared for, it can be blown away by winds, or washed away by water. EROSION happens naturally, but our actions can make it worse.

What do you know about erosion and water quality?

What is erosion?

How does erosion occur?

Can we prevent erosion?

What is a watershed?

How does the water cycle work?

What is water quality?

How can we protect soils?

How can we protect water quality?

What is erosion?Erosion is the movement of soil particles from one place to another by wind, water or other actions.

If we don’t care for and protect our soils, we lose soil that took a very long time to form. We can’t go out and make more soil when we need it. Soil must be protected.

Erosion occurs naturally. We can’t stop it. But we can limit it. In many cases, soil erosion can be very serious because we have not protected the soils.

Erosion affects our water. We will learn about the WATER CYCLE and WATERSHEDS. Controlling erosion is one way to protect our water quality! Can you think of more ways?

How does erosion occur?

Erosion is almost always caused by wind and water.

Wind can blow across large, open fields and take just a bit of soil away. We usually don’t see it. If the wind is strong enough, and the soil is dry, we may see dust blowing by.

Water is a major cause of erosion. Name the very large, famous canyon which was formed by erosion.____________________

Water can actually wear away rock! So it is easy to see how water can move soil, too.

Name a large United States river that has been moving soil and changing the land for hundreds of years.

_____________________

Clue: Look on a U.S. map for the city of New Orleans, which is at the ‘mouth’ of this very important river.

Don’t run off on us now!

Rain is needed by plants and usually moves into soil. If soil is too dry and ‘crusty’,rain may run off. If soil is too wet, or SATURATED, rain water also runs off the surface. We call this water RUNOFF.

Creeks, streams and rivers can change course over years as they move small amounts of soil. During heavy downpours, rain moves quickly toward streams, carrying loose soil. When creeks, rivers and streams run high or flood, they move large amounts of soil and can even wash away their banks.

This satellite photo of the Mississippi River DELTA shows how soil moves along a river and is deposited at its mouth. Would you agree that a river can move large amounts of soil?(thanks to: www.earthkam.ucsd.edu/public/images/pdf/Mississippi_River_Delta.pdf) Go online for other satellite photos of the earth!

One other form of erosion happened in New York state a very long time ago. GLACIERS are huge sheets of ice and snow which move across the land very slowly. Glaciers are so thick and heavy, they can carve soil and rock. As they melt, their streams of water continue the process.

The Finger Lakes of New York were carved by a glacier!

Can we prevent erosion?

No, but we can limit it.

By using the land wisely, we can limit our affect on the environment.

When people change the shape and use of land, they affect the way water moves through the soil.

One example is using a bulldozer to prepare for building a house or creating a new road. Soil without any plants on it is SUSCEPTIBLE to movement by wind and water. Farmland that has not yet been planted may also suffer erosion on windy or rainy days.

Later we will talk about watersheds. You will see how water, in the form of rain or streams, always moves toward GROUNDWATER or larger bodies of water.

Moving water picks up and carries particles of soil and other small things we can’t see. Some may not be good for us.

GlobExplorerTM

How does erosion affect us?

Trees and plants hold soil in place and also take up water out of the soil for their use. These two photographs show clearing of land and cutting down trees. Using what you have read, answer this question on a separate sheet of paper:

“Can clearing trees and changing the land cause erosion?”

Remember to: 1. Restate the question 2. Answer the question 3. Give reasons that support your answer 4. Write your conclusion

What is a watershed?

A watershed is a land area where all the water drains into a the same body of water. It can be large or small. It is affected by hills and valleys.For instance the Mississippi River watershed is very large. Look on a map or globe and try to figure out its size. Try this website: http://www.nps.gov/miss/features/factoids/

41% of the continental United States are in the Mississippi River

Watershed!

Color the watershed area light blue.

Erosion is the movement of soil by two main forces, _______________ and _______________.

A watershed is an area where all the rain flows toward one body of water. ____yes ____no Circle the true statement: a. We can stop erosion b. We can reduce erosion

The Mississippi River’s watershed is very large. Water from 31 states flow into it. How many states are not part of that watershed? ________

Trees, and shrubs can reduce erosion ___ by slowing wind ___ by slowing movement of rain water ___ by keeping soil in place ___ by all of these actions

Name two things creeks and streams can carry to larger bodies of water: ____________________________________________________

Vocabulary:

Accumulation - the act of gathering into one large amount

Absorb - to soak in

Algae - simple plants that live in water

Aquatic - having to do with water

Atmosphere - the ‘air’, a general term for the air around us from the ground up to what we call ‘space’

Condensation - part of the water cycle, one of the ‘states’ of water when it becomes liquid after being in a gas form

Cover crops - crops grown in a field to add nutrients and hold soil in place

Debris - usually loose pieces of things (such as wood, plastic) that have become scattered and moved by wind or water

Delta - an area at the mouth (the end) of a river where it deposits soil and sediments as it flows into a larger body of water

Ecosystem - a ‘community’ where all parts of the environment are working together

Engineers - people trained to design and build things

Erosion - a natural process where wind and water slowly break things down

Evaporation - the process of water changing from liquid to a gas

Glacier - a huge sheet of ice covering land and moving slowly over it

Nitrogen - a needed element found in soil and air, used by plants and people

Phosphorus -a needed element found in soil and used by plants and people

Precipitation - the various forms of water (rain, snow and sleet) that drop from the atmosphere

Vocabulary continued:

Riparian buffer - a strip of plants growing along a water body to slow erosion and the movement of fertilizers and chemicals into that water (riparian means something to do with a river)

Runoff - an overflow of rain (or water from a stream) not able to soak into soil which then moves across the soil surface instead

Saturated - when something like soil or cloth or a sponge is full of water and can’t take in anymore

Subsurface - below the surface

Susceptible - something that is likely to be affected by something else (for example, when you are not eating well, you are susceptible

Transpiration - transpiration is done by plants and trees to release moisture into the air (remember that plants taken in water which is needed when they make their own ‘food’)

Vapor - the gas, not liquid, form of water

Water cycle - the whole cycle of water from precipitation to ground or surface water to evaporation and condensation

Waterbody - any large body of water like a stream, pond or ocean

Watershed - the area of land where all the rain and groundwater eventually makes it way into one particular body of water

Windbreak - trees, shrubs or even buildings or fences that are placed to reduce the speed of wind blowing across an area

In these lessons, students will learn about erosion of soil and how it affects water quality. Students will be told that erosion happens naturally and can’t be stopped, but that our actions can affect it and make it worse. Students will learn that all the water that comes as rain or snow is part of a watershed for a particular body of water. Students will see illustrations of the water cycle and how it works in a watershed.Students will be told that erosion and the effectiveness of the water cycle contribute to water quality. Students will be made aware that not only soil, but unwanted debris as well as fertilizers, pesticides, oils and gasoline can be moved by water into the water system. Students will learn that there are ways to protect soils from erosion and protect our water systems.

What is erosion?

Pg 1 Erosion is a very natural thing. It has been happening since the earth was formed. Erosion can occur slowly or quickly. Soil is an important natural resource which shouldn’t be taken for granted. It can be lost or destroyed many times faster than it is created.Soil health is linked to water quality.

Pg 2 What do you know about erosion?In a group setting, discuss these questions with students. Some children will have some knowledge about erosion and the water cycle. By the end of these activities, students should have a better understanding.

Pg 3 Erosion - Is it a bad thing?Erosion is something we should try to limit, but we can’t stop it. And should we try? There are many beautiful aspects of our earth that are a result of erosion. Shifting dunes along the ocean, or in the arid deserts, as well as curving rivers, deep valleys and sculpted rock formations are formed by wind and water.

Pg. 4 Water moves earth. Ask students about their memories of heavy rains and flooding. Ask how many have tossed leaves or sticks into a fast moving flow of water down their street after a storm? How many are aware of the power of water to move heavy objects?

The satellite photo was taken by NASA astronauts. It is a great illustration of the power of water. From space, we see the delta and the underwater deposits of soil and sediments moved by the Mississippi River. In a few pages, we will talk about the vast part of the country included in the Mississippi River Watershed.

Erosion caused by ice and snow is not something we think of today, yet a majority of New York State was once covered by a glacier. If you have access to a molded topographical map of the state, it is a great tool for this lesson. For an extension activity, students can research glaciers and explain in writing or to the class what a drumlin is or, how the melting ice and subsequent water flow has as much to do with erosion as the ice did.An important take away thought on this lesson is that erosion can’t be stopped, but our activities, such as bulldozing, can contribute to erosion.

How does erosion affect us? It may not seem that erosion has much to do with our daily lives. This is where it ties in to water quality, which is important to everyone. Unless we see damage first hand after a heavy rainstorm, we may never relate how erosion from water moves soil. This page offers two activities. First, students are directed to do a writing assignment discussing man-made causes of erosion. You may direct the length of the writing assignment as you desire. Secondly, we discuss watersheds. Perhaps you have signs in your area that tell you what watershed system you live in. Remind students that no matter where they live, ALL WATER moves toward a larger body of water.

The Dust Bowl is the name given to a time in United States History.

Much of the midwest was prairie. This is a type of flat land with special grasses growing on it. Grasses have deep roots and hold soil in place. The soil was healthy and rich. It seemed to be great for farming!

However in the 1920s and 30s, much of the prairie grasses had been removed so farmers could grow crops on the rich soil. For many years, rainfall was limited, causing a drought. With no grasses and only a few crops, winds began to blow soil away. Much of the land suffered erosion. These photos were taken in Oklahoma in 1935. Everything was covered with dust. Dust storms lasted for days. Many people moved west for a better life. A large section of the country was called ‘The Dust Bowl”.

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Student Lesson: Erosion and Water Quality name____________________________

1. Erosion is the movement of soil by two main forces, _______________ and _______________.

2. A watershed is an area where all the rain flows toward one body of water. ____yes ____no 3. Circle the true statement: a. We can stop erosion b. We can reduce erosion

4. The Mississippi River’s watershed is very large. Water from 31 states flow into it. How many states are not part of that watershed? ________

5. Trees, and shrubs can reduce erosion: ___ by slowing wind ___ by slowing movement of rain water ___ by keeping soil in place ___ by all of these actions

6. Name two things creeks and streams can carry to larger bodies of water: ____________________________________________________

7. Evaporation is part of the water cycle. It means: ___ water goes back up into the atmosphere (air) ___ water runs down hills into streams

8. Is water quality the same throughout the world? ____yes ____no

9. Silt in the water is good for fish ____yes ____no

10. Oil and gasoline from cars can runoff driveways into our water systems. ____yes ____no

11. I can draw an example of the water system. ____yes ____no

water wind

X

50-31=19

X

soil, fertilizer, debris, pesticides, chemicals, oil, gasoline, etc

For Teachers and Parents: