ACTIVITY
Erosion
Introduction
Sediment results from the erosion of land surfaces and streambanks.
One of the most effective means of controlling erosion is to
protect the land surfaces and streambanks with vegetation and
vegetative litter (leaves, twigs, and stems that fall from plants).
Vegetation helps prevent erosion by holding soil in place. The
vegetation canopy and resulting litter protect soil from the impact
of rain drops, which can increase erosion. The following activity
demonstrates the effectiveness of vegetative litter in preventing
soil erosion.
Objectives
-- Student will observe:
- The effect of rainfall on soil erosion.
- The effect of vegetative litter on the reduction of soil erosion.
Materials
-- Each group will need:
- 480 mL of soil (in two 240-mL cups);
- One cake pan or similar container at least 30 cm x 30 cm;
- Four 240-mL paper cups;
- Water; and
- A large handful of vegetative litter (leaves, twigs, grass, and stems, etc.).
Teacher Preparation
- This activity is designed for students to work in groups of
three. If sufficient materials are not available, it can be done
as a demonstration.
- Using an ice pick or awl, punch 8-10 small holes in the bottom
of one of the paper cups.
- Take the students on a walk to a nearby park, woods, or field
to collect soil and vegetative litter. Caution against collecting
inorganic "litter" and animal waste. Also, warn students
about coming in contact with poison ivy and other harmful plants.
Procedure
- Divide the class into groups of three students. Provide each
group with one cake pan, one 240-mL cup with holes punched in
the bottom, two 240-mL cups filled with soil, one 240-mL cup filled
2/3 full of water, and a large handful of vegetative litter.
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