Aim: How does running water cause erosion?

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Aim How does running water cause erosion?
I. Erosion by running water
A. Water breaks up bedrock and removes weathered
and eroded rocks and soil materials.

1. Uses sand, pebbles, and boulders as cutting
   tools.
2. Abrasion grinding action of sediments against
   one another and bedrock.
3. Rapidly moving water has a lifting effect that
   splits off and moves rock fragments.

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4. Water chemically breaks down soluble minerals
that hold sedimentary rocks together.
B. Water removes weathered rock 1. Rivers carry
rock material in 3 ways
a. Solution material that has dissolved from
bedrock (most common are compounds of magnesium
and calcium)
b. Suspension material that includes clay,
silt, and fine sands. Creates muddy water effect.
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c. Bed load materials that are too heavy to be
carried in suspension (pebbles, sand, and
boulders).
Composition of rivers in U.S. 25 solution, 50
suspension, and 25 bedloads.
II. Carrying Power the total amount of sediment
in a stream together with the size of the
particles being moved by the stream.
A. Carrying power depends upon speed of stream
and discharge.
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1. Discharge is the volume of water flowing
past a given point in the stream at a given time.
(m3/sec or ft3/sec)
Bedloads, suspensions, and solutions
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