Time
Day 1: Experimentation (may be split into two days)
20 min describe the question and experiment and have students make hypotheses and predictions
5 min describe experiment procedures
30-45 min conduct experiment and collect sediment samples at the study site
travel time to the study site and back will vary
Day 2: Soil Separation Tests
10-15 min set up soil separation tests
Day 3: Data Analysis and Summary
15-20 min analyze soil separation test results
10 min summarize group results and display
Day 4: Drawing Conclusions
45-50 min discuss results and draw conclusions
Grouping
Teams of 3 students
Materials
For sediment study, each group of students needs: (I assembled all the materials into several shoebox-sized plastic containers to become our class set of “creek kits”. Many of these items are the same as those needed for the Habitat Survey lesson.)
- Copy of Sediment Study directions
- 2-3 white paper towels
- 1 extra-large spoon or small hand trowel
- 1 hand lens or magnifying glass
- 4 meter length of string tied into a knot every 1 meter (brightly colored polyester contractor’s string works well)
- 2 bamboo skewers to stake out the string
- 1 12 inch plastic ruler
- 1 stopwatch or timer
- 5 film canisters for collecting sediment samples
- 1 Sharpie marker
- Labelling dots or masking tape
- Latex gloves or yellow dishwashers’ gloves
For the sediment study, the teacher needs:
- Topographic map of the creek they will be studying, assuming you will be studying sediments at the creek in the school’s watershed, you should have a copy of this map from the Topo Tour lesson
- first aid kit
- extra film canisters
- extra copies of the Sediment Study directions
- field guides of local plants and insects
- optional: water and paper cups
For classroom tests and interpretation each group needs:
- 1 copy of the Data Summary Sheet
- 3 clear 15 ml tubes with lids, glass or plastic
For classroom tests and interpretation the whole class can share:
- 2 tablespoons
- 2 rulers
- 1 small jar alum (available at supermarkets for pickling)
- 1 package removable dot labels or rolls of masking tape
- several Sharpie markers
Setting
Day 1 – Creek. Pick 3 study sites at different places along the creek. Make sure that the sediment makeup at each of the 3 sites is very distinct. I chose a pond at the source of our creek with mucky clay and silt above a layer of sand, a fast flowing area midstream with weathered river rocks and gravel, and a wide man-made channel near the mouth with a mixture of sediments.
Day 2-4 – Classroom.
