Stream velocity Investigation using Inquiry
Summary
Using a local stream, science inquiry, and fun, students will determine stream characteristics of a small stream using observation, imagination, and problem solving (part of science inquiry). Without being told exactly how to accomplish the goal, students will evaluate the stream and determine the river's velocity, width, and depth profile. Students will also find innovative ways to measure sediment thicknesses at river bends and create sediment thickness profiles from their data collection. The outcome of this inquiry will be practice in problem solving resulting in student discovery of ways to determine stream velocity, width, and depth, as well as recognition of stream deposition and erosion patterns.
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Learning Goals
This activity is designed for students to gain practice in problem solving, experiment design, data collection and data interpretation in the unit, "Erosion and Running Water." Other skills developed by this activity are observation, questioning, writing, group communication, graphing, measuring, planning, and shared use of prior knowledge. Concepts examined in this activity are running water erosion along different parts of streams, deposition of sediments along different parts of stream (particularly at bends), velocity variations within a stream cross-section (horizontally), and independent and dependent variables in stream discharge (Q = w x d x velocity in distance units cubed/time). Vocabulary words learned: erosion, deposition, velocity, profile, discharge.
Context for Use
CLASS AGE/size: 8th grade; size 12-30 students;
TIME: Five 50+ minute class periods or 2 1/2 block periods
ACTIVITY: field exercise
EQUIPMENT necessary: box of assorted items (enough for how ever many groups of 3 you have)—Example: material for a class of 27 or 9 groups
STUDENT NEEDS TEACHER NEEDS
20 feet per group White Board & markers
9 Scissors
9 Permanent markers
3 large boxes of wood matches
(1/3 box to each group)
1 dowel (one meter long)
9 stop watches (or at least 1 watch per group)
one 100 foot tape measure (all groups share)
9 clip boards & map of river segment
Journals & pencils
TIME: Five 50+ minute class periods or 2 1/2 block periods
ACTIVITY: field exercise
EQUIPMENT necessary: box of assorted items (enough for how ever many groups of 3 you have)—Example: material for a class of 27 or 9 groups
STUDENT NEEDS TEACHER NEEDS
20 feet per group White Board & markers
9 Scissors
9 Permanent markers
3 large boxes of wood matches
(1/3 box to each group)
1 dowel (one meter long)
9 stop watches (or at least 1 watch per group)
one 100 foot tape measure (all groups share)
9 clip boards & map of river segment
Journals & pencils
Description and Teaching Materials
This activity was adapted from an activity introduced to participants of the TIMES 11 summer class. Four 50 minute periods needed
** 1st 50 minute period (or 1st part of block period):
Materials needed—journals, pencils (students) and 2 portable white boards and marker (teacher).
1. Inform students they will going to a nearby river/stream.
2. Either before or just after you reach the stream, put students in groups of 3.
3. Give the students the following directive: "For 15 minutes you are to look at different parts of the river (for example, look at the water, banks, downstream, upstream, soil, etc.). Within your group make at least 10 different observations and record these in your journals."
4. Gather class together and go over responses (10 minutes). Write the responses on portable white board. As responses are written, have students add any observations they missed to their list. If no one has noticed river velocity differences or bends in river, ask some guiding questions at this point: "What do you notice about the shape of the river channel?" "Is the stream moving fast or slow?" Students should notice that the stream channel is not straight and the speed not constant.
5. Once responses are listed, ask students to identify the 2 responses they think are most interesting and generate questions (in journal) as to how or why a particular feature is the way it is. Students may need an example of a question (Is the muddiness of the water due to loose dirt from the sides falling in the stream?) In this part of activity, briefly discuss velocity. Spend remaining time writing student questions to observations.
** 2nd and 3rd 50 minute periods (or 2nd part of 1st block and start of 2nd block):
Materials needed: box with assorted materials students will use in an investigation to discover the velocity of the river across different segments. SEE CONTEXT Description. You will also need enlarged map of river/stream showing segments to be studied
1. Have students meet at river/stream.
2. Go over student-generated questions and then identify 1 question the class will study together: "Does stream depth affect stream velocity within a horizontal cross-section of stream?" Tell students they will need to collect and/or calculate 2 types of data information—1) velocity at shallow and deepest depths of their cross-section and 2) depths at regular intervals within their cross-section (every one foot or every 2 feet). Students must also be reminded that velocity equals distance traveled in a given time. (Object that travels 4 feet in 2 seconds has a velocity of 4 feet/2 seconds or 2 feet/second).
3. Give student groups the following information:
- Each group can select several items from box to help them in their quest for information.
- Each group must find a stream segment in which to work (using bright ribbons and just prior to starting this activity, you should mark out enough segments along the river so each group can work within a specific segment)
- Each group must figure out a way to determine how fast the stream is moving in the shallow and deep parts of a cross-section using the material provided.
- Each group will be given 2 lifelines (2 answers you will provide as to how to use specific types of material). For instance, the ropes are cut into 20 foot segments. Students will line up rope along tape measure and mark off feet or meters and dowels in smaller units (inches/cms) using permanent markers. Students will use rope to measure width of stream cross-section and dowel sticks to measure depths along cross section. Wooden match sticks will be used as a floater on river and stop watches to measure travel time over a particular distance.
- Each group has a clipboards & maps to record their position on the stream
- Each group must figure out how and what data they will collect & write in journal
4. After students have collected data and calculated velocities, they should spend some time making and writing observations specific to their segment of the river.
5. Once all groups have calculated velocity for the shallow and deepest part of their stream cross-section and determined depths, gather students together at a central point and, on the enlarged stream map, write group velocities for deeper part of stream cross-section in BLUE and shallow point of stream cross-section in RED. Have students look for relationships or patterns. With guiding questions, draw students' attention to specific cross-sectional data that shows correct depth to velocity relationships: "Are the velocities the same? How are they different?" WRITE on white board what they should have observed and have them write this in their journal. Most cross-sectional data will hopefully show higher velocities at greater depths in comparisons to shallower depths. Where data doesn't make sense, ask student groups what they noticed about their area ("We saw a tree down in the stream above our area. Maybe this may have affected our results"). Discuss and write on white board other observations related to the distribution of velocities (velocity is higher along outside bends; not the same either within a horizontal cross-section or lengthwise within the river, etc.).
** 4th 50 minute period (2nd half of 2nd block): Meet back in class.
1. Ask groups to share (present) how they conducted their investigation and how they recorded their data, what problems they had and how they solved them. Review what they discovered about streams from the previous days' activities. Look at some other questions either answered in the process of inquiry or for which students can make reasonable inferences based on what they learned: for example, "How does stream velocity vary along different parts of the stream? Usually faster in narrower, deeper parts of channel, slower in wider, shallower parts of streams. How does stream velocity along the cross-section of a river affect where erosion and depositional will occur within the stream?" Erosion is greatest where stream velocity is highest. Deposition occurs where stream flow velocity is slower or slows.
2. In their journal, give students some time to write what worked in this activity and what they would do differently if they could do it again.
3. Provide students with additional pictorial/detailed information on river systems-river erosion, deposition, meanders, ripples on beds, sediment travel, etc. (You can use either figures from your textbook or from a handout, or put figures up on overhead). Have students first place a 2-column outline in their journal. In the right column, have students write observations from the previous inquiry activity and the questions answered (or topic) in the left column. Then have students make observations about the figures you have provided. Give individuals about 5 minutes per figure, and then have students pair up and share observations. Then have them write questions about some of their observations.
4. Close with a group discussion of some general observations, write the observations on white board, and have students write these in their journal. Before the students leave, have students write in their journals 3 key things they learned through this experience, what they liked about this experience, and what questions they had.
At this point, you are ready to begin a broader look at how running water destroys/constructs/and/or changes earth's surface features.
** 1st 50 minute period (or 1st part of block period):
Materials needed—journals, pencils (students) and 2 portable white boards and marker (teacher).
1. Inform students they will going to a nearby river/stream.
2. Either before or just after you reach the stream, put students in groups of 3.
3. Give the students the following directive: "For 15 minutes you are to look at different parts of the river (for example, look at the water, banks, downstream, upstream, soil, etc.). Within your group make at least 10 different observations and record these in your journals."
4. Gather class together and go over responses (10 minutes). Write the responses on portable white board. As responses are written, have students add any observations they missed to their list. If no one has noticed river velocity differences or bends in river, ask some guiding questions at this point: "What do you notice about the shape of the river channel?" "Is the stream moving fast or slow?" Students should notice that the stream channel is not straight and the speed not constant.
5. Once responses are listed, ask students to identify the 2 responses they think are most interesting and generate questions (in journal) as to how or why a particular feature is the way it is. Students may need an example of a question (Is the muddiness of the water due to loose dirt from the sides falling in the stream?) In this part of activity, briefly discuss velocity. Spend remaining time writing student questions to observations.
** 2nd and 3rd 50 minute periods (or 2nd part of 1st block and start of 2nd block):
Materials needed: box with assorted materials students will use in an investigation to discover the velocity of the river across different segments. SEE CONTEXT Description. You will also need enlarged map of river/stream showing segments to be studied
1. Have students meet at river/stream.
2. Go over student-generated questions and then identify 1 question the class will study together: "Does stream depth affect stream velocity within a horizontal cross-section of stream?" Tell students they will need to collect and/or calculate 2 types of data information—1) velocity at shallow and deepest depths of their cross-section and 2) depths at regular intervals within their cross-section (every one foot or every 2 feet). Students must also be reminded that velocity equals distance traveled in a given time. (Object that travels 4 feet in 2 seconds has a velocity of 4 feet/2 seconds or 2 feet/second).
3. Give student groups the following information:
- Each group can select several items from box to help them in their quest for information.
- Each group must find a stream segment in which to work (using bright ribbons and just prior to starting this activity, you should mark out enough segments along the river so each group can work within a specific segment)
- Each group must figure out a way to determine how fast the stream is moving in the shallow and deep parts of a cross-section using the material provided.
- Each group will be given 2 lifelines (2 answers you will provide as to how to use specific types of material). For instance, the ropes are cut into 20 foot segments. Students will line up rope along tape measure and mark off feet or meters and dowels in smaller units (inches/cms) using permanent markers. Students will use rope to measure width of stream cross-section and dowel sticks to measure depths along cross section. Wooden match sticks will be used as a floater on river and stop watches to measure travel time over a particular distance.
- Each group has a clipboards & maps to record their position on the stream
- Each group must figure out how and what data they will collect & write in journal
4. After students have collected data and calculated velocities, they should spend some time making and writing observations specific to their segment of the river.
5. Once all groups have calculated velocity for the shallow and deepest part of their stream cross-section and determined depths, gather students together at a central point and, on the enlarged stream map, write group velocities for deeper part of stream cross-section in BLUE and shallow point of stream cross-section in RED. Have students look for relationships or patterns. With guiding questions, draw students' attention to specific cross-sectional data that shows correct depth to velocity relationships: "Are the velocities the same? How are they different?" WRITE on white board what they should have observed and have them write this in their journal. Most cross-sectional data will hopefully show higher velocities at greater depths in comparisons to shallower depths. Where data doesn't make sense, ask student groups what they noticed about their area ("We saw a tree down in the stream above our area. Maybe this may have affected our results"). Discuss and write on white board other observations related to the distribution of velocities (velocity is higher along outside bends; not the same either within a horizontal cross-section or lengthwise within the river, etc.).
** 4th 50 minute period (2nd half of 2nd block): Meet back in class.
1. Ask groups to share (present) how they conducted their investigation and how they recorded their data, what problems they had and how they solved them. Review what they discovered about streams from the previous days' activities. Look at some other questions either answered in the process of inquiry or for which students can make reasonable inferences based on what they learned: for example, "How does stream velocity vary along different parts of the stream? Usually faster in narrower, deeper parts of channel, slower in wider, shallower parts of streams. How does stream velocity along the cross-section of a river affect where erosion and depositional will occur within the stream?" Erosion is greatest where stream velocity is highest. Deposition occurs where stream flow velocity is slower or slows.
2. In their journal, give students some time to write what worked in this activity and what they would do differently if they could do it again.
3. Provide students with additional pictorial/detailed information on river systems-river erosion, deposition, meanders, ripples on beds, sediment travel, etc. (You can use either figures from your textbook or from a handout, or put figures up on overhead). Have students first place a 2-column outline in their journal. In the right column, have students write observations from the previous inquiry activity and the questions answered (or topic) in the left column. Then have students make observations about the figures you have provided. Give individuals about 5 minutes per figure, and then have students pair up and share observations. Then have them write questions about some of their observations.
4. Close with a group discussion of some general observations, write the observations on white board, and have students write these in their journal. Before the students leave, have students write in their journals 3 key things they learned through this experience, what they liked about this experience, and what questions they had.
At this point, you are ready to begin a broader look at how running water destroys/constructs/and/or changes earth's surface features.
Teaching Notes and Tips
Possible issues or concerns might be students falling in the river. Students should probably bring an extra set of clothes on these days. One student (the one measuring) should bring water shoes or an extra set of old sneakers. Best times to do this activity would be fall or spring when the water is not too cold. Might be helpful to secure some parent volunteers to help if needed. This activity is outdoors and students have more choices in how they will collect the data and in what part of the stream they will do their measuring.
Assessment
How I will determine whether students are achieving the learning goals will be accomplished in the following ways:
1. Group assessment: Touch base with each group and ask open-ended questions related to the process such as, "When you arrived at your stream segment, what did you find were the important factors for determining velocity?"
2. Individual assessment: Read journal entry from the last day of activity in response to the following questions: "write 3 key things you learned through this experience. What things did you enjoy about this activity? What didn't you enjoy? Finally, what questions do you still have?)
1. Group assessment: Touch base with each group and ask open-ended questions related to the process such as, "When you arrived at your stream segment, what did you find were the important factors for determining velocity?"
2. Individual assessment: Read journal entry from the last day of activity in response to the following questions: "write 3 key things you learned through this experience. What things did you enjoy about this activity? What didn't you enjoy? Finally, what questions do you still have?)
Standards
II. A.1 —Scientific inquiry, data collection...
III.A. 2—The student will describe how features on the Earth's surface are created and constantly changing through a combination of slow and rapid processes of weathering, erosion, sediment deposition... In this activity, the students will observe the evidence of river erosion and deposition and connect high and low river velocities with specific erosion and deposition patterns.
III.A.5—The student will recognize that constructive and destructive processes can affect the evidence of Earth's history. In this activity, some discussion will center on how sediments are moved from points of original deposition to places far downstream. This may result in destruction of original depositional details/characteristics/ evidence and thus affect (or interrupt) parts of the flow of evidence within Earth's geologic history.
III.A. 2—The student will describe how features on the Earth's surface are created and constantly changing through a combination of slow and rapid processes of weathering, erosion, sediment deposition... In this activity, the students will observe the evidence of river erosion and deposition and connect high and low river velocities with specific erosion and deposition patterns.
III.A.5—The student will recognize that constructive and destructive processes can affect the evidence of Earth's history. In this activity, some discussion will center on how sediments are moved from points of original deposition to places far downstream. This may result in destruction of original depositional details/characteristics/ evidence and thus affect (or interrupt) parts of the flow of evidence within Earth's geologic history.