Lesson 5A: Erosion

 

Estimated Time: One forty-five minute class period

Indicator(s): Core Learning Goal 1

1.2.7 The student will use relationships discovered in the lab to explain phenomena observed outside the laboratory.

1.5.2 The student will explain scientific concepts and processes through drawing, writing, and/or oral communication.

Indicator(s): Core Learning Goal 2

2.2.2. The student will explain the role of natural forces in the earth.

At least — retention of an atmosphere, an agent of erosion and deposition, tides and deep ocean currents

2.4.4 The student will apply the law of conservation to the processes that affect rocks and minerals.

2.5.2 The student will analyze the effects of natural cycles on human activity.

Student Outcome(s):

The student will be able to describe the relationship between poor land management practices and habitat destruction by reviewing the human impact on the environment.

Brief Description:

Students will gain an historical perspective on the relationship between land management practices, weather, economics, and erosion. (This is particularly evident when researching the Dust Bowl in light of the Great Depression.) Print and visual media will be used to supplement a laboratory experiment. Human actions can have pervasive ramifications that affect soil erosion. Students will apply this to management practices involving the Chesapeake Bay watershed.

Background knowledge / teacher notes:

During the last 40 years alone, almost a third of the world’s topsoil has been lost to erosion.

A good example of this is the Dust Bowl disaster. The Dust Bowl disaster occurred in the southwestern Great Plains region of the United States in the 1930's, including parts of Kansas, Oklahoma, Texas, New Mexico, and Colorado. Years of poor farming techniques left the land open to the ravages of wind. All it needed was a few years of drought and the stage was set for a spectacular disaster.

For a detailed look at the dust bowl visit History of the Dustbowl. Available:

http://www.ultranet.com/~gregjonz/dust/dustbowl.html

As soil was being lost through erosion, wetlands were being deliberately filled in to make room for agriculture, housing, highways, and commercial buildings. In the United States over 200 million acres of wetlands have been lost, including over 2,800 acres annually in the Chesapeake region. Loss of wetlands means the water flowing into the Chesapeake bay is no longer filtered.

Nutrients and sediments flow directly into the bay covering benthic organisms and promoting algal blooms. The 64,000 square miles of watershed are overwhelmed by the activities of the millions people producing excess nutrients and stressing the Bay.

 

Lesson Description:

ENGAGE

Social Studies Connection:

Students will read a short passage about the history of the dustbowl and listen to recordings of people who lived through the dustbowl. History of the Dustbowl. Available: http://www.ultranet.com/~gregjonz/dust/dustbowl.html

or listen to the Library of Congress collection [consists

of audio recordings, photographs, manuscript materials, publications, and ephemera generated during two separate

documentation trips supported by the Archive of American Folk Song (now the Archive of Folk Culture, American

Folklife Center)].

Voices from the Dust Bowl: The Charles L. Todd and Robert Sonkin Migrant Worker Collection. Available:

http://lcweb2.loc.gov/ammem/afctshtml/tshome.html

Discuss how the actions of humans have influence soil erosion.

Vocabulary: wetlands.

Education Element:

BACKGROUND

DAAC Study: From the Dust Bowl to the Sahel

http://eob.gsfc.nasa.gov/Study/DustBowl/

20th century drought with focus on the Dust Bowl

http://www.ngdc.noaa.gov/paleo/drought/drght_history.html

 

EXPLORE

Have students compare maps of the Chesapeake Bay region or Anne Arundel County showing human activities from 20 years ago and today.

Students will investigate the functions of a wetland by performing "Wetland in a Pan."

Functions of a wetland: absorb water and prevent flooding, provide homes for wildlife, absorb nutrients, reduce runoff and therefor erosion.

Education Element:

 

BACKGROUND

Landsat Thematic Mapper of the Chesapeake Bay Listing of Links of photos of Chesapeake

http://svs.gsfc.nasa.gov/stories/LandSat/chesapeake.html

Image Modis of the Chesapeake bay

http://modis.gsfc.nasa.gov/MODIS/IMAGE_GALLERY/MODIS1000054.jpg

EXPLAIN

Students will discuss how humans changed the habitat around the Bay. Examples: destruction of forest buffers and wetlands, loss of submerged aquatic vegetation, increase in nutrient load, and increase in turbidity levels.

EXTEND

Each group of students will choose a topic and develop a poster illustrating an action taken by humans and the consequences of that action.

Education Element:

BACKGROUND

Background list of resources on wetlands

http://www.athena.ivv.nasa.gov/curric//land/wetland/resource.html

EVALUATE

What were some of the unintentional consequences of human activities that accelerated the effects of erosion?

 

Materials:

Modeling Clay

Painting tray

Four small sponges

Soil

Muddy water

Watering can

Resources:

History of the Dustbowl. Available:

http://www.ultranet.com/~gregjonz/dust/dustbowl.html

Voices from the Dust Bowl Available:

http://lcweb2.loc.gov/ammem/afctshtml/tshome.html

The Day of the Black Blizzard slide show by the Discovery Channel. Available:

http://www.discovery.com/area/history/dustbowl/dustbowlopener.html

Environmental Concern Inc. (1992). Wow! The Wonders of Wetlands Wetland in a Pan. pp. 95-96.

Nutrients in the Chesapeake Bay. Available:

http://www.fws.gov/r5cbfo/nutrient.htm

Selection of wetland maps and data from USDA. Available:

http://www.nhq.nrcs.usda.gov/land/index/wetlands.html

Water Quality and Trends in Specific Areas of the Bay. Available:

http://www.dnr.state.md.us/bay/monitoring/water/index.html

Your Local Watershed. Available:

http://www.epa.gov/surf2/