Victorian Curriculum Links

Science Understanding

Scientific understandings, discoveries and inventions are used to inform personal and community decisions and to solve problems that directly affect people’s lives (VCSSU073)

The growth and survival of living things are affected by the physical conditions of their environment (VCSSU075)

Sudden geological changes or extreme weather conditions can affect Earth’s surface (VCSSU079)

Science Inquiry Skills

With guidance, pose questions to clarify practical problems or inform a scientific investigation, and predict what the findings of an investigation might be based on previous experiences or general rules (VCSIS082)

Decide which variables should be changed, measured and controlled in fair tests and accurately observe, measure and record data (VCSIS084)

Construct and use a range of representations, including tables and graphs, to record, represent and describe observations, patterns or relationships in data (VCSIS085)

Compare data with predictions and use as evidence in developing explanations (VCSIS086)

Suggest improvements to the methods used to investigate a question or solve a problem (VCSIS087)

Communicate ideas and processes using evidence to develop explanations of events and phenomena and to identify simple cause-and-effect relationships (VCSIS088)

Activity Description

Students explore the impact of changing river volumes and different floodplain terrain in experimental trials with tabletop-sized riverbed models.

The models are made using modelling clay in aluminium baking pans placed on a slight incline. Water added "upstream" at different flow rates and to different riverbeds, configurations simulate different potential flood conditions.

Students study flood dynamics as they modify the riverbed with blockages or levees to simulate real-world scenarios.

Key Learning Intentions

After this activity, students should be able to:

• Define floods as a natural phenomenon that occurs when too much water is in an area at one time.

• Describe the shape of a riverbed as a major factor in where flooding occurs.

• Explain that engineers use models and testing to understand how to design solutions.

• Explain that engineers help people identify and prepare for flooding, including the design of dams, levees and dikes to protect people and property when flooding occurs.

• Discuss how human modifications to a river may alter the floodplain of the river.

Instructions

Ensure each group is set up with the materials they need:

• 2 sheets of card (or paper) for construction of model houses (need at least 6 per group)

• model house template

• transparent tape

• scissors

• markers, coloured pencils, or crayons to decorate houses

• 2.5 kg box of modelling clay/plasticine per group (reusable)

• aluminium baking pan

• a small board (or something else rigid) to support the baking tin after inserting the clay

• clean-up supplies (paper towels, sponges, towels, etc.), for after using wet clay

• a thick book to prop up the plastic tub (may not be needed if you conduct activity outside)

• riverbed template – one of three designs provided

Tune in

Show students a few video clips of actual river floods washing away houses [exactly what they'll be simulating with their model riverbeds]. Many short videos are available on YouTube. Discuss how using models to make observations and collect data allows engineers to develop effective designs. “What is a floodplain?” It is the dry land surrounding a waterway, like a river or stream, into which flooding waters spill. An engineer needs to know the area of a floodplain in order to figure out a flood might affect anything located there and if a design solution needs to be implemented.

Show students the powerpoint to provide a visual understanding of floods, floodplains and levees.

Some engineers study flooding, using what they learn to protect people and property. They design structures — like dams, dikes and levees — to keep flooding away from populated areas. Today we are going to design a model of a floodplain, just like an engineer would do. We will also record our observations and data in order to better understand how to develop a design solution.

Activity
Divide the class into three groups (~ 8-10 students per team).

1. 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.

2. Have each group create a riverbed in the clay, matching their template shape. Check the shape of the riverbed to make sure that it will create the desired effect as described in the trials below. Remind students that engineers create similar models to explore the possible effects of flooding on people and property.

3. Each group must do three trials (Group 3, Typical river is different, see below):

Trial 1: Pour a half cup of water slowly through the narrow section riverbed model. Have students record their observations and the number of damaged houses as their data for the trial. Have them remove any damaged houses. This trial shows that with a modest amount of water, it flows through the narrow river section without overflowing the riverbed.

Trial 2: Clean up any excess water in the tub. Replace any damaged houses with new ones placed on the same position, as marked on the clay floodplain. Have students pour one cup of water through the rivers bed quickly. Have students record their observations and the number of damaged houses as their data for the trial. Have them remove any damaged houses. This trial demonstrates water overflowing when there is an increase in water flow.

Trial 3: Clean up any excess water in the tub. Replace any damaged houses with new ones placed in the same position, as marked on the clay. Have the students on the team build clay levees (piece of raised clay or small clay walls), except group 3 (see below). Again, pour one cup of water quickly through the river, as in Trial 2. Have students record their observations of what happened this time and the number of houses damaged. 

Group 1 (Narrow section River) will build their levees on the narrow section of the river in trial 3.

Group 2 (Large Curve River) will build their levees on the first curve in trial 3.

Group 3 (Typical River) must create a small blockage in the curve of their river in trial 2 to demonstrates what happens when a river is blocked completely and suddenly, such as what happens during a large landslide. In trial 3 this group will remove the blockage and fast pour the cup of water. This trial shows that even a cleared riverbed cannot withstand a flash flood.

Discussion and Assessment

Prediction: Have students predict the outcome for each trial and record predictions on the board. Will the river flood or not? Will the houses be affected?

Recording Observations: Have students record their observations and data about which flooding scenario caused more damage to the model houses and the floodplain, and compare these to their peers. Have students share their observations and data with the class.

Activity Discussion: As each trial is performed, discuss the activity with the entire class. Ask the students what happened to the water during each trial. Which houses (if any) were affected? In each case, how could an engineer help protect the houses during a flood? What sort of design would help solve this problem? What are the disadvantages of using human-built structures levees or dams? Use the answers to gauge students' mastery of the subject.

Engineering Sketch: Have students sketch their floodplain, positioning the river in the centre of their drawing. Have them colour or draw arrows to indicate where the water will go if a flood occurs.

Next, have them indicate where the houses were positioned for their three trials. Have them use another colour or symbol to recommend safer locations where they would place the houses if they did the activity again. Direct students to create colour/symbol keys in the lower right-hand corner of their papers. Evaluate students' model riverbed sketches using the sketch rubric. 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. Have students develop a design solution to help protect the houses from their flooding scenario. Have students sketch and label their proposed design.

Also have the students discuss what they learned from their model floodplain that helped them develop their design.

Suggested Resources 

Floodplain Modeling - YouTube