Chapter 7 Notes Section 3 Soil Erosion

Use pages to fill in these notes. 1 - Soil erosion is important because losing topsoil affects the way _plants_ grow. 2 – Many human activities disturb the natural _balance_ between soil production and soil erosion. 3 - Agricultural Cultivation: increased farming removes plant cover, leaving soils open to wind & water erosion.

4 – Forest harvesting: removes forest which increases erosion & particularly damages tropical rain forest soil. 5 - Overgrazing results when animals graze until almost all ground cover disappears. 6 - Excess sediment can damage the environment when soil erosion is severe.

How can we prevent soil loss? We can: (1) manage crops (2) reduce erosion on slopes (3) reduce erosion of exposed soil

What prevention methods are shown in these pictures?

Water erosion

Wind erosion of rock

Wind Erosion – topsoil blown away

Dust Storm

Water erosion of ground

Glaciers cause erosion, too

Glacial runoff, Canada

Wind caused these limestone swirls Texas, in the Chihuahuan Desert

Sand Tufa Photograph by Larry Fellows, Arizona Geological Survey With the snow-draped Sierra Nevada as a backdrop, unique erosion formations called sand tufa stand like giant cauliflower stalks in a dry Arizona lake bed. Before this alkaline lake went dry, tufa formed when a freshwater spring percolated from below and formed calcium carbonate deposits. When the lake's level dropped, these fragile formations surfaced, and wind went to work removing the sand beneath the deposits.

Bernard Glacier ~ Photograph by George F. Mobley The Bernard Glacier in Alaska's Saint Elias Mountains looks like a huge alpine highway. Glaciers are slow but highly effective shapers of the land, essentially carrying away anything in their path—from soil and rocks to hills and even the sides of mountains.

FOR MORE INFO, SEE http://www.nationalgeographic.com/topics/erosion/ Howe Caverns, New York (Nat Geo video)