Big Idea: Water is responsible for shaping and reshaping landforms on Earth. Clean and adequate water sources are essential for sustaining human life and healthy ecosystems.

Vocabulary Alluvial Fan Alluvial Fan Drainage Drainage Erosion Erosion Meander Meander Riverbed Riverbed Sediment Sediment Valley Valley

This is the Green River Valley in Colorado. It cuts deeply into the layers of rock and soil. The bank of the river is several hundred feet high.

This is the Sacramento River Valley in California. The banks of the river are just a few feet high. Frequent floods have made the surrounding farmland very fertile.

Compare these 2 meandering rivers. In your opinion, what claims can you make about why one river has cut so deeply into the rock and soil, while the other river has cut a very shallow basin? In your opinion, what claims can you make about why one river has cut so deeply into the rock and soil, while the other river has cut a very shallow basin? What evidence from the picture supports your theory? What evidence from the picture supports your theory?

Modeling Materials Diatomaceous earth tubs Diatomaceous earth tubs Water Water Drip system Drip system Wooden blocks Wooden blocks Scrapers Scrapers Rulers Rulers Time telling device – clock, timer, cell phone Time telling device – clock, timer, cell phone

Focus Question Write a question you could test to find out which factor most greatly influences the different shapes of the two rivers. Write a question you could test to find out which factor most greatly influences the different shapes of the two rivers.

General Plan for Experiment What are we going to keep the same? What are we going to keep the same? (controls/constants) (controls/constants) What are we going to change? What are we going to change? (independent variable) What are we going to measure? What are we going to measure? (dependent variable)

Hypothesis Write a hypothesis about what you think will happen if you change one river shaping factor. Write a hypothesis about what you think will happen if you change one river shaping factor. If______________, then_______________ because____________________________.

Procedures Explain the steps of your experiment. Explain the steps of your experiment. How will you test your question? How will you test your question?First…Second…Third…Next…Finally…

Data Collection How will you collect the data? How will you collect the data? What will your recorded data look like? What will your recorded data look like?

Conclusion aka Making Meaning Meeting Look back at your focus question Look back at your focus question Conclusion should be the answer to the focus question Conclusion should be the answer to the focus question Write Around Conclusion Write Around Conclusion –Each group member will get a sheet of paper –For one minute the students will write their thoughts to answer the focus question –The paper then gets rotated through each group member, who adds to the statement

Future Experiments What other questions can you test using the River Cutter model? What other questions can you test using the River Cutter model? –What happens if you build levees to control floods? –How will plants affect erosion? –How do river meanders change over time? –What happens to toxic waste in the soil?