Examining topography and stream discharge at Sherburne National Wildlife Refuge
Summary
In this inquiry based geologic field lab students will be estimating and measuring stream flow. Students will be collecting data from an existing small stream or river (shallow water no higher than knee level) they will be visually estimating this flow as well as performing the orange test to collect this data. Students will write a lab report and calculate the data to document their results. Students will also need to make careful observations of the stream so they can hypothesis the discharge of the dry streambed. At the dry streambed students will use their already honed topography skills to map out one foot topography lines in a 100 foot section of the dry streambed to help them estimate flow discharge. Students will then enter their hypothesis into their lab report with evidence to that backs up their observations.
Learning Goals
Students will graph actual contour lines and using these measurements to hypothesis stream discharge and sediment load from a restored wetland (impoundment) using a dry stream bed.
Vocabulary Words: Contour Line, Hydrology, Watershed, Sediment, Stream Flow, and Velocity
Context for Use
To do the topography activity you will need the following materials:
1 per group -Jacob's staff (red and white survey staff) or a 6-8 foot ¾ inch dowel marked off in one foot intervals.
-A simple small carpenter's sighting level this looks like a small scope with a level built into it. (Found at a hardware store)
-Survey/marking tape (3-4 colors) (Found at a hardware store)
To do the stream flow activity you will need the following materials:
1 per group
-Oranges (the fruit)
-Stopwatch
-Meter stick or roll up waterproof tape
-Calculator
Students will have done simple topography mapping in the school yard previous to mapping out the dry steam bed. This could be modified to any moving body of water and if there is access to some sort of dry river/stream system this could be done it would be best if they are in close proximity to one another.
Description and Teaching Materials
Example below:
EXAMPLE: Morgan, Tyler, Abby, and Joe measure stream width, depth, and velocity for Mink Creek. Mink Creek is 4.3 meters wide.
(meters) Stream Depth Stream Velocity (meters/seconds)
Spot 1 0.18m 1 meter/7 seconds (0.143)
Spot 2 0.34m 1 meter/4 seconds (0.25)
Spot 3 0.56m 1 meter/3 seconds (0.33)
Spot 4 0.35m 1 meter/6 seconds (0.17)
Total Flow = (1 m * 0.18 m * 0.143 m/s) + (1 m * 0.34 m * 0.25 m/s) + (1 m * 0.56 m * 0.33 m/s) + (1 m * 0.35 m * 0.17 m/s) = 0.36 m3/second
When plotting the elevation on the dry streambed students will use the Jacob's staff or a dowel marked of in 1 foot increments. This will involve teamwork to perform the live topography map. Each group will be assigned an elevation and they will use the simple carpenters sighting level to direct the other students where to mark flags and tie on the survey tape they will continue through the dry stream bed for a bout 100 feet. When finished there should be 4 minimum lines that the class can use as an actual live topography map. They can then use these lines to estimate and calculate a mock flow discharge of the dry streambed. For a greater affect you could mark every 6 inches vs. 1 foot. One or both sides of the dry streambed could be mapped. This will give a very interactive live model to use. Questions and Lab Sheet (Microsoft Word 31kB Aug3 09)
Teaching Notes and Tips
Assessment
Standards
9.3.4.1.1 Land use and engineering mitigation 9.3.4.1.2 Human activity altering natural process
6-12 Minnesota Nature of Science and Engineering Standards 2009
9.1.3.1.1 Describing a system and its subsystems 9.1.3.1.2 Identify properties and interaction of its parts
9.1.3.2.2 Possible careers in science and engineering 9.1.3.4.3 Select and use appropriate numeric representations to communicate results 9.1.3.4.6 Analyze strengths and limitations of models