When students enter the room, they will be hearing the sounds from Niagra Falls – the roar of the falls. They will also see many new posters around the room of various river systems.

Students, as you come into the room, in a single line please walk around the room and view the new posters I’ve put up. Let the students view these for a minute. Then ask if they have any questions or comments on any of the posters.

Today we will begin a unit project on exploring river systems.  

Hand out blank sheet of paper and pencils. I’d like you to work in groups of 4-5 and write down everything you know about river systems. Give the students about a minute to do this.

Let’s share with the class. As the students list what they’ve written, write these terms on the board.

Make sure to ask a lot of ‘why’ questions if there is a term used that others may not be familiar with or if the students are misinformed.

Students will share their list. Rivers, lakes, creeks, water falls, boating, fishing, etc.

To continue the discussion, ask questions to gauge student’s understanding of time.

When we look at our local land forms with hills, rivers and lakes, do you think that the land has always looked like this?

If the hills weren’t always there, how long do you think it took to form the hills?

Do you think the land around us might be changing today? What might change it?

Do you know of any other landforms that were shaped by water? What are they?

No.

If students say “thousands” or “millions” of years, ask them to explain what they mean by those large numbers. Were people alive thousands of years ago? Millions of years ago?

Yes. Big rain storms, hurricanes, earth quakes. People constructing buildings and building neighborhoods.

Yes. The Grand Canyon, other examples may be mentioned.

Scientists often use models to investigate processes that are difficult to observe directly. As I stated earlier, we will be starting a unit on river systems where you will be investigating the role of water in shaping the land.

Specifically, we will investigate:

-       How was our local landscape shaped by water?

-       What makes some river valleys deep and others shallow?

-       How long does it take for a river valley to form and how does it change over time?

-       What are the different features of river systems?

-       What happens if a river is dammed up?

-       How does groundwater pollution affect river system?

Model rivers make it possible to speed up time and see how river systems change over many thousands, and even millions of years, so that we can see what will happen over many human generations in just a few minutes.

Show the students the river-cutting tub and the dripper system. This tub contains a mixture of water with a substance called diatomaceous earth. This “earth” is made up of shell-like skeletons of tiny plants called diatoms that accumulated on the bottom of the seas millions of years ago.

Put the micrograph of the diatom on the overhead projector as you explain this.

In your model, the diatomaceous earth represents the land.

Point out the dripper system and show the students how it works.

You will use your models to find out more about what happens when a river is cut naturally into the earth. You will be working in teams to carefully observe what happens to all parts of the river as it is formed. In today’s session, you will explore the equipment and materials and make your first rivers.

What do you think the dripper system represents in your model?

Rain, snow, waterfall, flood.

DEMONSTRATE HOW TO MAKE A RIVER

Use one of the river-cutting tubs as a demonstration tub for the students. The earth should not be sloped and the tub should be level without a piece of wood under it.

Demonstrate how to set up the dripper system, letting it drip a minute or so. Show the students how to adjust the drip rate to about 2 drips per second.

Imagine now that the tub is a miniature landscape and that you are very tiny.

If you were even smaller than a tiny ant, what features might you expect to see while walking along the banks of our tiny model river?

What do you predict you might encounter during a raft trip down this miniature river?

Rushing water – deep enough to swim in.

Rapids.

Stop your river and demonstrate how to use the piece of wood to re-slope the earth in the tub.

If the ground does not level completely, try banging the tub a little harder.

If the drippers are not already full, appoint 1-2 volunteers to circulate among the teams pouring the water into the drippers.

STUDENTS PREPARE RIVER MODELS

OK. Now it will be your turn. When you receive your materials, one half of each team should prepare the tubs by sloping the earth, while the other half of each team tests the dripper system and sets the drip rate by letting the system drip into a pie pan.

Organize teams of 4-6 students each and arrange the desks or other tables in your classroom so that each river cutter model is on a flat surface.

One member of each team should now come up and obtain a river-cutting tub and a dripper system. I will go over everything verbally and will be able to help you during this process.

Feel free to touch the diatomaceous earth if you’d like to see what it feels like. I will point out though, that once we start our rivers, you must not disturb the earth or the dripper system.

Now, as I had demonstrated, go ahead and have half the team slope the earth and the other half test the dripper system – remember that you’re looking for a drip rate of around 2 drips per second.

Circulate among the groups helping them set up their river systems, answering questions, and making sure that all members of a team are getting a chance to interact with the materials and equipment.

Tell the students that you will give the word as to when to start their system.

STUDENTS CREATE THEIR FIRST RIVER MODELS

OK, when you start your river systems you will be letting the dripper go for 5 minutes. This 5 minute period represents 5,000 years in the life of a river. I’d like you to describe and talk with each other about what you are seeing during this time.

Please make sure not to disturb the earth or dripper system during this time. The whole idea f using this model is to find out what happens as a river is cut naturally into the earth. Do not touch the tub, the dripper system or the earth. Do watch closely to see what is happening.

Circulate around the class again, answering any questions that may arise on how to use the equipment, checking the drip rates, and making a mental note of the vocabulary and ideas students are expressing. Encourage them to describe what is happening to the water and earth.

When the 5 minutes is up, tell the students to stop the dripper systems.

Hand out a white piece of paper to each student.

Please draw a picture of the river system you have created and label any features or write notes about anything special you observe. Put the sample picture on the overhead projector. Here is an example of a river model drawing. Give students a few minutes to complete.

Does anyone have an idea what the planet was like 5,000 years ago?

Depending on what is happening, as you circulate, ask questions such as why do you think the river is doing this. You may want to reiterate your example of being a small ant on the landscape. You will also be further explaining how the river model equipment works for groups having trouble.

Dinosaurs? People?

I would like each team to pair with another team now and share your experiences and river systems with each other. Share what you learned about how water shapes the land from this activity.

Circulate around the room and listen to the students’ discussions.

Short class discussion:

What did you see in your river models? Why do you think these features were present?

Forking, lots of small rivers, the “ocean” at the bottom.

For homework, you will each generate a hypothesis on why your river model exhibited certain features. Bring this to class next time as it will be a big part of our discussion.

For next class we will have a class discussion of what we found during this session, so please keep your drawings and notes.

For today, I want to make sure that you all felt comfortable using your equipment and if you have any questions regarding the use.

As this unit progresses, you will be doing more river modeling that includes looking at the impacts of time on a river system, as well as human impact on river systems such as the building of dams or the dumping of toxic waste.

You will also be conducting several experiments to test hypothesis on river systems.

Last, there will also be an end-of-unit project which will be explained at a later date.

What did you find that was easy or difficult about using the equipment?

Dripper system – couldn’t get it to maintain drip rate.

I would like you now to write in your journals for the last few minutes of class and reflect on this experience. Specifically write about what went well and what didn’t go well in regards to using the equipment and working with your group. Also, spend a minute or two writing about what you’d like to learn about river systems now that you’ve had experience with the model.

Once again, today we were familiarizing ourselves with our river models and thinking about river systems in general. Next class, we will be discussing what we found and we’ll be introducing some new terms to your vocabulary.

Demonstrate the cleanup procedures and ask the students to clean up.