Stream investigation: Investigate how a local stream might have an impact on our surrounding landscape.
Students will observe stream processes and identify its effects on our surrounding landscape. After careful observation and discussion of our local landscape from the roof of our school the day before, and using topographic maps to discover that the valleys that surround our school have steams, my students will be ready to investigate a stream. I predict this field investigation will allow students to answer their own questions they generated from previous classes. Students will have fifteen minutes to record stream related observations in their science journals. We will then share our observations of the stream, answers to our questions from the day before, and come up with more testable questions about our new observations. Streambed material will be collected to be compared with rocks collected from further up the valley the following day to help answer these questions.
This activity is designed for students to discover that streams carry sediment along with water. Students will use higher order thinking skills to decide what date is relevant to record in their journals, infer whether or not the stream's discharge has changed in the past and predict where the stream's bed load is coming from and where it is going. Keys concepts include the erosion and depositional features of a stream and how a landscape can be shaped by these forces, while vocabulary terms include: bed load, discharge, landscape, erosion and deposition.
Context for Use
Before beginning this field investigation, my students will have practiced recording observations in their science journals and observed the surrounding landscape. I will walk my class of approximately 30 eighth grade students south down Homer road about a half mile to a small stream. Students will be divided into ten cooperative learning groups of three. Each group will be provided with waders to go along with their pencils and science journals to record fifteen minutes of stream observations before reporting data back the group. Our fifty five minute class period will consist of 30 minutes of walking, fifteen each way, and twenty five minutes of observation and discussion. Students will have a sketch and description of our landscape from the day before in their science journals of reference and will continue with their investigation tomorrow as we compare rocks collected upstream in the valley to student collected stream material. From this point, we will conclude our local landscape section and begin studying the rock cycle and individual rocks and minerals. This field investigation can be completed on any small stream near your school.
Resource Type: Activities:Field Activity
Special Interest: Field-Based Teaching and Learning
Grade Level: Middle (6-8)
Description and Teaching Materials
In a previous lab, students will have ascertained from topographic maps that most of our local valleys have streams. A question they might generate upon noticing this phenomenon may be "What connection do these streams have with their valleys?" If students do not generate this question, I will. We will head out for a local stream the next day immediately following attendance. Students will be instructed to record detailed observations of the steam in their science journals and be ready to report their observations to the group in ten minutes. I estimate ten minutes for each group to share one observation at a time followed by some discussion of misconceptions or questions and another five minutes for clean-up. On our walk back to school, students will use their new data to answer questions they generated in yesterday's field investigation and generate more questions about today's stream observations to be discussed in tomorrow's class before we compare our collected stream material with local rocks. I hope to follow up this field investigation with a demonstration of sediment transport at WSU's flume lab and a trip to the Homer road outcrop to see our source rocks in place.
Teaching Notes and Tips
I will keep the waders in the bed of my truck, parked near the stream so students don't have to walk a mile in waders. If students begin making observations of things unrelated to the stream, I will call the group back together and point out a relevant observation example to help them refocus. This activity is different than anything I have ever attempted in that the students are making observations of concepts I am trying to teach before I teach them. Typically, I would address every last conceptual detail before heading outside with my students, but I see the advantage of allowing students to discover for themselves and anxiously await the results.
All students will be given a multiple choice exam before and after our geology unit. Science journals will also be collected which will include all student observations, questions, and conclusions.
8.I.B.1 -scientific investigations
8.III.A2 -Earth's surface features
8.III.A3 -rock cycle
References and Resources