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Soil Texture and Stream Flow. Teacher Guide.
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Soil Texture and Stream Flow Teacher Guide This activity introduces students to the structural differences in soils and the forces of moving water. Students use field techniques to test soil samples and “key out” soil texture class and subclass using a soil texture flow chart (containing the soil texture triangle). The water flow section of the lesson is completed using a stream table. Overview Science Process Standard 1-1; Content Standards 5-1, 5-2) Oklahoma PASS Objectives National Science Education Standards Physical Science Standards (motions and forces); Science in Personal and Social Perspectives (natural hazards); Scientific Inquiry Standards (ability to do scientific inquiry); Unifying Concepts and Processes Standards (models and explanation). Middle School. Stream flow can be completed in elementary grades. Can be modified with additional questions for higher levels. Grade Level Other Skills Students should have a basic understanding of variations in soil particle size. Students should have an introduction to stream flow and how it can alter stream channels. An alternative is to not provide students with previous knowledge of channel morphology before conducting the activity. Students will “experience” stream flow when engaged in the activity. Time Should be completed in one 50-minute class. Note to Teacher You can obtain a USDA Soil Texturing Field Flow Chart from Forestry Suppliers (forestry-suppliers.com). This will allow you to conduct tests for texture class and texture subclass. A stream table may be purchased or you can build your own. It should be at least 3.5 feet long by 2 feet wide and watertight. Instructions may be found at this website: (http://www.pbs.org/americanfieldguide/teachers/floods/stream_table.pdf) Soil Texture and Stream Flow Teacher Guide p. 1
Prairie Dog Town Relocation Teacher Guide Materials - USDA Soil Texturing Field Flow Charts - 3 soil samples - 3 spray bottles (capable of mist) - 3 tubs - 3 wash bottles - stream table; appropriate soil for stream channel analysis (fine- particle, clean sand works well) - 2-3 short 1x4 boards used to increase the slope (gradient) - plastic houses such as those found in the Monopoly board game. Lesson Preparation Place the three soil samples at different stations around the room. At each soil station, there should be a soil texture flow chart, tub, spray bottle, and wash bottle. Students will need the student activity sheets found in this lesson. The stream table should be arranged so that you have complete access to all sides. You have to be able to input water at the top of the stream table as well as drain water at the bottom. Create a channel for the water to flow. The channel should have at least one strong curve in it. This will allow the channel to “meander” as the water flows through it. Students will place their houses along the bank of the stream before the water begins to flow. Assembled by Brad W. Watkins brad.watkins@okstate.edu Adapted from Micozzi, Mark, et al.. Physical Geography Laboratory Exercises: Viewing the Earth as a System Soil Texture and Stream Flow Teacher Guide p. 2
Soil Texture and Stream Flow Name: __________________________ Hour: _____ Soil texture refers to the size and arrangement of soil particles. Soil textures are examined using a soil texture flow chart. All soils are composed of some combination of sand, silt, or clay along with air, water, and organic matter. The amount of sand, silt, or clay, will determine how well the soil support vegetative cover. The most type of soil most productive for plants is known as loam, and is found at the center of the triangle. ParticleDiameter Sand 2 mm – 0.05 mm Silt 0.05 mm – 0.002 mm Clay < 0.002 mm Using the soil texture triangle on the handout, determine the texture classes of the examples below: 70% clay, 20% sand, 10% silt: _________________________________ 60% silt, 10% sand, 30% clay: _________________________________ 60% sand, 10% clay, 30% silt: _________________________________ 20% clay, 40% silt, 40% sand: _________________________________ 70% silt, 10% clay, 20% sand: _________________________________ Use the flow chart provided to determine the texture sub-class at each station. Station 1: _____________________________ Station 2: _____________________________ Station 3: _____________________________ Soil Texture and Stream Flow p. 1
Soil Texture and Stream Flow Name: __________________________ Hour: _____ Learn about soil stability at the stream table station. Stream tables are simple models of the streams you would find outside. The word “stream” also refers to creeks and rivers. Streams are very interesting to study because they are always changing. As water flows through the channel of the stream, the force of the water as it goes around a bend in the stream channel speeds up. This “fast” water can cut into the side of the stream bank and cause the channel to shift over time (see example below). fast flow slow flow direction of flow Now you know how water in a stream can move at different speeds depending on its location in the channel. You know that the channel can move, called meandering. Now think about how this might affect the surrounding area over time. Real World: Pretend you are building a home and you want it to have a view of the river. You can choose anywhere to build your home on either side of the stream. 1. Place your Monopoly house at some point along the stream. (Do not push the house into the sand.) 2. Wait for your teacher to start the stream flow. Notice what happens to the stream channel, your house, and the houses of others. Answer the questions on the next page. Soil Texture and Stream Flow p. 2
Soil Texture and Stream Flow Name: __________________________ Hour: _____ Answer the following questions about the stream flow station. 1. How would this lesson affect your decision to build a home near a river? 2. Using what you learned about the different types of soil textures, soil structure, and stream flow, why do stream channels move so easily (think about the type of soil you would find in and along streams)? Soil Texture and Stream Flow p. 3
Soil Texture and Stream Flow Name: KEY Hour: _____ Soil texture refers to the size and arrangement of soil particles. Soil textures are examined using a soil texture flow chart. All soils are composed of some combination of sand, silt, or clay along with air, water, and organic matter. The amount of sand, silt, or clay, will determine how well the soil support vegetative cover. The most type of soil most productive for plants is known as loam, and is found at the center of the triangle. ParticleDiameter Sand 2 mm – 0.05 mm Silt 0.05 mm – 0.002 mm Clay < 0.002 mm Using the soil texture triangle on the handout, determine the texture classes of the examples below: 70% clay, 20% sand, 10% silt: clay 60% silt, 10% sand, 30% clay: silty clay loam 60% sand, 10% clay, 30% silt: sandy loam 20% clay, 40% silt, 40% sand: loam 70% silt, 10% clay, 20% sand: silt loam Use the flow chart provided to determine the texture sub-class at each station. Station 1: _____________________________ Station 2: _____________________________ Station 3: _____________________________ Learn about soil stability at the stream table.