Note on Instructional Sequence
In a previous lesson, students will have learned about the relationship between downhill flow (DCI ESS2.C) of water and potential gravitation energy (DCI PS3.A). This knowledge will be applied to the flow of water through the riverbed models.
Part 1: Model Development
Materials
Video Differentiation
- Replace the National Geographic reading in Part 1 with the following video.
- Chart Paper
- Chart Markers
Preparation
- Gather materials and make copies.
Riverbed Models-
- The aluminum baking pan is the base for the riverbed model. To allow water to flow through the model, remove one of the shorter pan walls with wire cutters or tin snips. Prepare at least three pans in this way so that there is a riverbed for each river template. Depending on the size of your class, increase the number of riverbeds accordingly.
- Pack the modified aluminum baking pans with modeling clay to a depth of ~3 cm if time does not allow for students to complete this step.
Instructional Sequence
Introduction
- Ask students to remember the last rainstorm. Have them discuss with a partner the results of that storm. (Alternative: If you live in a climate with limited rainfall, engage your students in discussion around a national hurricane or share a video with them on rainstorms.) After allowing students time to share their experiences, guide the conversation to the impact the storm had on different aspects of the community/ecosystem. Was there flooding? Was there damage? Did plants benefit from the water? If your area utilizes ground water, how did the rainfall impact water levels?
- Record student ideas on a piece of chart paper and label the top of the paper “What we Know”. This chart is the first part of a K-W-L you will complete during this activity. (K- “What we Know”, W- “What we want to Know”, L- “What we Learned”). This discussion and any additional conversation around the K-W-L chart should be used as a formative assessment to determine student understanding before progressing to the next activity.
- With a new partner, have students generate questions they have about the current conversation. Let students record their questions on a new piece of chart paper labeled “What we want to Know”. If they notice another question on the chart paper similar to their question, they should put a check next to this question instead of adding their question to the list.
- As a group, examine the “What we want to Know” chart paper. Discuss common themes and questions, and acknowledge any unique questions. Some of these questions will hopefully be addressed by the following reading and activities, but it is okay if there are unanswered questions. These unanswered questions can be used to guide extended activities and/or individual student research.
- Provide students with the National Geographic articles along with the following guiding questions.
Guiding Questions
- How can floods negatively impact people and ecosystems?
- How can floods positively impact people and ecosystems?
- What characterizes a hundred-year flood?
- How do scientists and disaster authorities prepare for floods?
Suggested Literacy Strategies:
- Have students read the entire article and discuss as a group.
- Jig-saw the reading, by having students read assigned sections and share what they have learned with the rest of the students in the class.
- Have the students take notes, highlight, or text code as they are reading.
- Provide students with a glossary of new terms they will encounter in this article (i.e. mitigation, dam, levee, hundred-year flood)
- The suggested reading has a lexile level of 1290, which might be above your student’s current lexile level. Here are a few additional options:
- Floods 101, National Geographic (video)
http://video.nationalgeographic.com/video/101-videos/floods
- Flood Encyclopedic Entry, National Geographic Education
http://education.nationalgeographic.com/education/encyclopedia/flood/?ar_a=1
- Flood Plain Encyclopedic Entry, National Geographic Education
http://education.nationalgeographic.com/education/encyclopedia/flood-plain/?ar_a=1
- Severe Weather 101, The National Severe Storms Laboratory
http://www.nssl.noaa.gov/education/svrwx101/floods/
- After students have completed the reading the National Geographic article, have students discuss their answers to the guiding questions with a partner before engaging the entire class in a discussion.
- Note: If students have already learned about the water cycle, before they discuss the guiding questions, show them a diagram of the water cycle. Ask them to identify components in the water cycle and explain what interactions normally occur. Compared to a region’s normal rainfall cycle, what components and processes of the water cycle are amplified during floods? Then, ask students to discuss the guiding questions, so they can talk about the impacts of floods. (Based on students’ background knowledge, this is a good place to bring back erosion and its effects – this was also mentioned in the article.)
- Return to the “K” and “W” charts from earlier and label a final piece of chart paper “What we Learned”. As a group, fill in this chart. Try to have the students answer both the guiding questions, their questions on the “What we want to Know” chart, and any additional things they learned from the reading and discussion. Encourage students to refer directly to the text and provide evidence for their statements. (If students generate more questions, they can be added to the “What we want to Know” chart.)
Model Development
- In the article it states, “Highly advanced computer modeling now let’s disaster authorities predict with amazing accuracy where floods will occur and how severe they’re likely to be.” Share this quote with your students, and ask them to think about what type of data and scientific information scientists might use to create their models. Allow the students to share their ideas and recognize that scientists must need data from over time and about the area to be able to predict future events. Additionally scientists need to understand the science behind flooding. Have students suggest additional models scientists might use to predict flooding besides computer models. Allow students time to offer suggestions. If you used a different reading than the one originally suggested, add a discussion here on how engineers and scientists predict floods to replace the discussion around the article quote.
- Let the students know that they are going to develop and use a physical model as a tool to test three different riverbed models to compare normal water flow conditions and hundred-year flood conditions.
- Ask students to identify the components of the system of the river they will need to include in their models to test flow conditions and flooding. Students should identify that they need the riverbed, banks, and water.
- Divide the class into groups of 2-3 students, and there needs to be at least three groups total so that all of the river models are tested during this investigation. Each group needs one modified aluminum baking pan, modeling clay to represent the “banks” in the pan, and one small board to support the baking pan during transportation.
- Before constructing the model, ask students to think about and discuss the components of their system in depth.
- What does the clay represent? What is the purpose of the clay in the system – how is it interacting with other components and what is it showing us? Are there any limitations in its representation?
- What does the water represent? What is the purpose of the water in the system – how is it interacting with other components and what is it showing us? Are there any limitations in its representation?
- Students need to fill the aluminum baking pan with ~3cm of clay. (If time does not permit, this part can be completed for students prior to the activity.)
- Give each group a different template shape from the Riverbed Templates attachment. The three shapes are: narrow section river, large curve river, and typical river.
- Ask students to think about and discuss the logistics behind developing and testing the model. They can discuss within their groups first, and then share with the class.
- How can they add water to their river models?
- Where do they want to add the water?
- How should the model be placed? Why might a tilt be helpful with downhill water flow? How does tilting the pan tie in with what they have learned about water’s potential gravitational energy?
- Based on what they learned from the article about flooding, how can they represent normal water flow conditions vs. hundred-year conditions in their model? (What components will they have to change in the system? How much water should they use for each condition – why?)
- Have each group create a riverbed in the clay, matching their template shape.
- For this type of investigation, ask the students for suggestions on how to record the results. What type of data are they trying to gather? Will the results be qualitative or quantitative? How can they record the data? Let students share their ideas and have other students respond to these suggestions. Depending on what the students suggest, you might want to modify the following directions to include some of the student ideas. (Student model riverbed engineering sketches can be evaluated using the attached Engineering Sketch Assessment Rubric.)
- In their science notebooks, have the students draw and label a sketch of each of the riverbed models. (Labels: Narrow Section Riverbed: Normal Condition; Large Curve Riverbed: Normal Condition; Typical Riverbed: Normal Condition) Have students sketch their riverbeds, positioning the river in the center of their drawing. The number of sketches will depend on the number of riverbed models created for this activity. There should be one sketch per model.
- As a class, agree on a color/symbol key everyone will use to record observations and predictions on the Engineering Sketches. (Key suggestions: Use different colors/symbols for predictions and observations. Use color and draw arrows to predict where the water will go if a flood occurs. Use a different color to indicate observations of the water flow from the model test.)
- Direct students to record this color/symbol key in their science notebook. Also, chart the color/symbol key on a piece of chart paper and hang it in the room as a reference.
- Remind students that engineers create similar models to explore the possible effects of flooding on people and property. Point out to students that engineers make sketches like these to describe the details of a riverbed and floodplain when they research and make recommendations for future development. Both the physical models and engineering sketches are tools that scientists and engineers use to study phenomena.
Part 2: Model Testing and Evaluation
Materials
Per Student:
- Crayons/markers/colored pencils for Engineering Sketches
Per Riverbed Model:
- 5-pound (2.3 kg) box of oil-based modeling clay per group (reusable)
- Aluminum baking pan with one of the shorter walls removed
- Small board (or something else rigid) to support the baking pan during transportation after inserting the clay
- Riverbed Template (PDF), one of three designs provided
Per Testing Station:
- Clean-up supplies (paper towels, sponges, towels, etc.), for after using wet clay
- Thick book to prop up the plastic tub (may not be needed if you conduct activity outside)
- 1 large, shallow, plastic waterproof tub, 8-in x 14-in x 30-in or 20-cm x 36-cm x 76-cm, clear plastic is better but not necessary (may not be necessary if you can conduct the activity outside)
- 500 mL graduated cylinder, used to pour water over the riverbed model
Preparation
- Gather materials and make copies.
Testing Stations-
- In a central area so that students will be able to observe the various tests, use a block or thick book you don't mind getting wet to prop up the plastic tub. When the aluminum baking pan is placed inside the plastic tub, this tilt creates a downhill flow for the riverbed and catches water runoff.
- Alternative: To minimize the mess, take the model riverbeds outside, placing them at the edge of a pavement area so the draining ends drip water into a grassy area.
Troubleshooting Tips and Safety Issues
- Tilt and drain the plastic tub and clay riverbed thoroughly between each trial. (Alternative: Since a small amount of water is used for each trial, a towel placed at the bottom of the riverbed (at the bottom or the tub) works well to absorb the water.)
- When adding water to the riverbed model, make sure not to flood the riverbed at the pouring spot. Pour water at the maximum rate that the riverbed allows at this point.
- Consider conducting the activity outside, because using water and clay has the potential for quite a mess. Take precautions to protect surfaces and take into consideration that students' hands will be covered in wet clay.
Instructional Sequence
Riverbed Model Test 1: Normal Conditions
- Students will test their models with normal water conditions first. Have the students discuss with a partner what they think will happen when 100 mL of water is added to each of the three different models. Have them record their predictions on their engineering sketches, using the colors/symbols from their key. Have a few students share their predictions with the class.
- One at a time, have each group bring their riverbed (clay-covered baking pan) to the front of the classroom (or a central area) and place it in the tilted plastic tub. Have the rest of the class gather around to watch the water flow through the river models.
- For each of the river models (narrow, curved, and typical), pour 100 mL of water slowly into the higher end of the tilted riverbed (clay-covered baking pan).
- After each model test, have students record observations by coloring any areas on their engineering sketches that flooded and by adding arrows to indicate water flow. Students can also share their observations with the group. The following is what should happen in each model:
- Narrow Section River Model- This test shows that with a modest amount of water, the water flows through the narrow river section without overflowing the riverbed.
- Large Curve River Model- This test shows that water can flow through and around the large curve without overflowing the riverbed.
- Typical River Model- This test shows that water can flow normally through the riverbed, without overflowing.
- Between each test, remove excess water from the tilted, plastic tub.
- As part of their data analysis, have the students discuss their observations with the same partner from the beginning of this test.
- Do they notice any patterns or trends in their data? (What are the similarities and differences in water flow between the three models?) Are there any anomalies? What might they be attributed to?
- How do their observations support (or not support) their predictions?
- Can they make a claim or statement about each of the three river shapes?
- What are the limitations of their physical models? How can their models be modified to address some of the limitations?
- As a class, return to the “K-W-L” charts from earlier. Have students share their analysis with the class and add their comments to the “What we Learned” chart. If needed, use another piece of chart paper.
- Have the students begin to predict what they think might happen if 250 mL of water is added to each of the models to represent a hundred-year flood.
Riverbed Model Test 2: Hundred-Year Flood Conditions
- In their science notebooks, have the students draw and label a sketch of each of the three riverbed models. (Labels: Narrow Section Riverbed: Hundred-Year Flood Condition; Large Curve Riverbed: Hundred-Year Flood Condition; Typical Riverbed: Hundred-Year Flood Condition)
- Have the students discuss with a partner what they think will happen when 250 mL of water is added to each of the three different models. Ask them to think about how their predictions are similar to or different from their 100 mL predictions. Have students record their predictions on their engineering sketches, using the colors/symbols from their key. Have a few students share their predictions with the class.
- One at a time, have each group bring their riverbed (clay-covered baking pan) to the front of the classroom (or a central area) and place it in the tilted plastic tub. Have the rest of the class gather around to watch the water flow through the river models.
- For each of the river models (narrow, curved and typical), pour 250 mL of water slowly into the higher end of the tilted riverbed (clay-covered baking pan).
- After each model test, have students record observations by coloring the areas on their Engineering Sketches that flooded and by adding arrows to indicate water flow. Students can share additional observations with the group. The following is what should happen in each model:
- Narrow Section River Model- This trial demonstrates water overflowing at the narrow point of the river when there is an increase in water flow.
- Large Curve River Model- By increasing the amount of water, this trial demonstrates water overflowing at the first large curve, flooding the peninsula within (ideally).
- Typical River Model- By increasing the amount of water, this trial demonstrates water overflowing along the edges of the river (ideally).
- Between each test, remove excess water from the tilted, plastic tub.
- As part of their data analysis, have the students discuss their observations with the same partner from the beginning of this test.
- Do they notice any patterns or trends in their data? (What are the similarities and differences in water flow between the three models?) Are there any anomalies?
- How do their observations support (or not support) their predictions?
- Can they make a claim or statement about each of the three river shapes?
- How do the results from the hundred-year flood compare to the results from the normal flow conditions? Are there are any patterns across the sets of models? Why are the results similar and/or different?
- Where does a lot of the flooding happen, no matter the shape of the river? How does this relate to the tilt of the riverbed and gravity?
- What were their models (from both conditions) trying to represent? Do they think their models were successful in the representation? What are the limitations of their physical models? How can their models be modified to address some of the limitations?
- How can their models help forecast the locations and likelihoods of future flooding events?
- As a class, return to the “K-W-L” charts from earlier, and have students share their analysis and add to the “What we Learned” chart. If needed, use another piece of chart paper.
- Share the driving question for this investigation with students and ask the students to suggest what they can now do with their data analysis to help answer this question. Driving Question: How can the impact of future flooding events be mitigated through the understanding of floodplains? If they need prompting, remind them of the National Geographic article they read during an earlier part of this investigation.
- Let the students know that they are going to develop a proposal for the construction of vacation homes, businesses and farms along a riverbed.
Part 3: Performance Task
Materials
Copies of Writing Performance Task Rubric
Preparation
Gather materials and make copies.
Instructional Sequence
- Ask students to predict what might have happened if there were buildings located on the areas of the model floodplains that flooded. Let students share their ideas.
- Ask students to identify the components of the system they have been studying. Then have them think about what might happen if a building was included as a component of the system. What if a farm was included in the system? Make a prediction of how the buildings and farms would be impacted by the existing processes you modeled (consider buildings in various locations)? Let students share their ideas. Students should recognize through their discussion that, in the conditions in which the water overflows, houses and buildings may be flooded depending on their location.
- Tell students that they are going to create a proposal for the construction of vacation houses, farms, and businesses along a river by using what they have learned from the narrow section river, large curved river, and typical river models (Engineering Sketches, notes, readings and class charts from Parts 1 and Part 2). They will be proposing construction of the buildings for an area that typically has normal rainfall and water flow conditions, but that may face hundred-year flood conditions if there is unusual, excessive rainfall. Therefore, when creating their proposal, they will have to keep the observations from both sets of their models in mind.
- Discuss the requirements of each type of construction with students. Refer back to the National Geographic reading for additional information. This is also a good time to return to the conversation about downhill water flow and how potential gravitational energy comes into play.
- Vacation Homes- riverside with beautiful views
- Businesses- outside of flood prone areas
- Farms- fertile lands (If students do not know what elements make land fertile, then this concept should be discussed at this point.)
- Review the Performance Task, Proposal Assessment Rubric and Engineering Sketch Assessment Rubric with students
- Have the students sketch a river that includes a narrow section, a typical section, and a large curve like the river templates tested earlier in this investigation. Label the top of the river and bottom of the river to indicate the direction of downhill water flow.
- Have students create a key (similar to the one they created before) that includes colors/symbols for flooding in normal conditions, flooding in hundred-year flood conditions, water flow in normal conditions, and water flow in hundred-year flood conditions. They will need to add new symbols for the vacation houses, farms, and businesses.
Performance Task
Performance Task: How can the impact of future flooding events be mitigated through the understanding of floodplains?
- Using your key, record the predicted water flow and flooding for both Normal Water Flow Conditions and Hundred-Year Flooding Conditions on your engineering sketch.
- Write a proposal for the construction of vacation homes, farms and businesses along your sketch of your riverbed. Add the vacation houses, farms, and businesses in your engineering sketch.
- Explain how your construction proposal can mitigate the impact of future flooding events on vacation homes, businesses, and farms.
- Support your construction proposal with evidence from the observations you made during riverbed model testing activity.
- Explain how your understanding of downward water flow and floodplains support your proposal.
- Be prepared to present your proposal to the class.
Performance Task Scaffolds:
- Provide sentence starters.
- Have the students discuss their thoughts as a group before they have to write their response.
- Have students peer review the performance tasks and offer suggestions to their classmates.
- Allow students to complete the performance task through writing, drawing or presentation.
Investigation Reflection
- Let students know that all models have limitations. Have the students discuss some of the limitations of their physical models and their engineering sketches. What changes can we make to our models to reduce these limitations?
- Ask the students if human-made buildings were not located in floodplains, would flooding be a problem? Why do you think people build houses in floodplains? Give students time to discuss and record their ideas.
- As a class, return to the “K-W-L” charts from earlier in this investigation, and have students share their analysis add to the “What we Learned” chart. If needed, use another piece of chart paper.
Floodplain Modeling:
Lesson Extensions and Suggested Scaffolds
Additional Readings
- Explore current events related to water management with grade level appropriate readings.
Extended/Additional Activities
- Students can test their proposed construction plans.
- Students can conduct individual student research or class research on any of the questions that remain unanswered on the “What we want to Know” chart.
- Have students look up a map for a floodplain in their area. Can they make recommendations for development (or building houses) on the floodplain, based on the riverbeds modeled in this activity?
- Have students investigate how other natural disasters can cause flooding and the failure of engineering structures such as levees.
- Line the riverbed with fine sand and gravel to see what impact they have on erosion and to examine how they might change the model floodplain.
- Other suggestions to extend this activity can be found at TeachEngineering, including the original Floodplain Modeling lesson.
Teacher Information
Too much rainfall or melting snow can sometimes cause a flood. There are different types of floods. The most common type is generally called a river flood. It occurs when a river or similar body of water (stream, creek, brook, etc.) overflows because of heavy rainfall and sometimes because of melting snow and ice. Other times, heavy rains are the result of hurricanes or other large storms.
Floods can be deadly and destructive to people and property. To prevent property destruction and injury to people, engineers study the dynamics of floodplains. They also work with geologists and meteorologists to devise ways to control flooding with a range of human-made structures: dams, dikes, levees, flood gates, seawalls, drainage canals, sewer/water/storm drainage systems, pumping stations, bridges, concrete river banks, spillways, overflow basins, embankments, retention ponds and wetlands restoration. To aid in prediction and planning, engineers and scientists also develop instruments and computer programs to monitor weather (precipitation, temperature, snow pack, etc.), and develop complex models to estimate worst-case-scenario storm surges and flood risks.
Scientists and engineers do these same types of experiments with small-scale models, as well as computer simulations, to understand how real-life floods behave. An engineer needs to know the area of a floodplain in order to figure out how a flood might affect anything located there. A floodplain is the dry land surrounding a waterway, like a river or stream, into which flooding waters spill.
Natural flooding has been occurring for thousands of years. It only becomes a problem when people create something of value in the floodplain, like houses, that might be destroyed in a flood. As it turns out, floodplains are very attractive locations to build towns and cities — until flooding occurs. A floodplain is usually a flat area conveniently located near a river that can be used for transportation and recreation, as well as agriculture, with the land usually good for growing crops because of the rich soil deposited by past floods.
Vocabulary/Definitions
- dam: Large structure that retains flowing water into a reservoir to control flow.
- dike: Another term for levee.
- flood: Too much water in a given place at a given time. For example, river flood, coastal flood and flash flood.
- loodplain: Normally dry land surrounding a waterway, into which flood waters spill.
- hydrological cycle: Also called water cycle. Cycle of fresh water evaporating from bodies of water, falling as precipitation, being absorbed into the ground or flowing down into streams, rivers, etc. back into large bodies of water.
- levee: Barrier constructed to contain the flow of water or to keep out the sea.
- model: A small object that represents another, often larger object. Often used in testing or perfecting a final product.
- riverbed: The earth structure that holds river water.”
https://www.teachengineering.org/view_activity.php?url=http://www.teachengineering.org/collection/cub_/activities/cub_natdis/cub_natdis_lesson07_activity1.xml
