The Virtual Runoff Model
This activity will walk you through an experiment that explores what happens when precipitation (i.e. rain, snow, sleet, etc.) falls on different types of land. We will do this using a model. A model, in this case, is a small-scale representation of a real-life situation that we use to help us understand the details of what goes on in the real system. As you answer the questions, the students in the pictures will add elements to the model and execute the experiment. Watch and learn!
1. Examine the picture of the model below. The two sides of the model represent two different types of land use. What kind of land use do you think the gray side of the model represents?
2. Click on any of the words below that characterize the land use represented by the gray side of the model.
3. What kinds of pollutants can be found on this land? Click on three of the pollutants below and watch the students add them to the model. We use food coloring to represent pollutants.
4. When precipitation falls on this land, most of it __________.
5. The type of surfaces found in this type of land use are called ___________ surfaces.
6. Now let's focus on the other half of the model. What kind of land use do you think the green side of the model represents?
7. Click on any of the words below that characterize the land use represented by the green side of the model.
8. What kinds of pollutants can be found on this land? Click on three of the pollutants below and watch the students add them to the model. We use food coloring to represent pollutants.
9. When precipitation falls on this land, most of it __________.
10. The type of surfaces found in this type of land use are called ___________ surfaces.
Now it's time to run the experiment. We are going to simulate a rainstorm by pouring 500ml of water down each side of the model.
But before we do, we must make a hypothesis, or an educated guess, about what is going to happen.
11. Click on how much runoff you think will be collected from the gray side of the model.
12. Click on how much runoff you think will be collected from the green side of the model.
Now click on the button below to watch the students create a rainstorm.
13. How much runoff was collected from the gray side of the model?
14. How much runoff was collected from the green side of the model?
15. Now let's examine the water quality. Which side of the model produced cleaner, less polluted runoff?
Hopefully you now have a better understanding of how land use affects the quality and quantity of the runoff entering the watershed. Now that you are a runoff expert, here is a very important thought question: How can we change our cities' landscapes in order to reduce the negative impacts of storm water runoff on our waterways?
Here's the really fun part. Do you think you have a great answer? Send it to slurrp@livingclassrooms.org, and we'll send you some feedback!