Preview - Intro To Learning With Computational Models For Educators

Systematically investigating spread of wildfire

Let's systematically investigate how the tree density affects the spread of wildfire. 

We will first generate some data using the model and then represent it using another computational tool called CODAP (which is similar to Excel). 

Research Question: How does density of trees in a forest affect spread of wildfire?

Hypothesis: You already wrote a hypothesis on the first page. Write it (or a revised hypothesis) in question 3.1 below, but don't look at the later questions yet. Just come back here and continue the experiment. 

Let's test the hypothesis.

Change the values of density systematically. You can make the model run faster with the model speed slider at the top of the model display:

Record the value of 'percentage forest burned' in the data table. You can double click the cells of the data table to edit the value. Make sure to press the setup button every time you run an experiment.

Run each experiment twice. Make sure you record values for each experimental trial. 

The CODAP software will plot the average of the two values that you record. 

  

Questions

Please answer the questions below.

Write your hypothesis for how the density of trees affects the percentage burned. You will be plotting percentage burned vs density, so be specific about what you think the shape of the curve will be. 

Describe your observations of the graph of 'density' vs 'percentage burned'.

Do you think that the evidence that you gathered supports your hypothesis? Explain. 

Spread of wildfire is an emergent phenomenon. Below certain density the fire does not spread much, however when the density crosses a 'tipping point' or threshold, the fire engulfs almost all the forest. The tipping point is not explicitly coded anywhere into the model. Rather, this macro-level pattern "emerges" from the micro-level agent behaviors that are coded into the model. 

Tipping point in this model falls within which of the following ranges?

Between 35 and 45
Between 45 and 55
Between 55 and 65
Between 65 and 75

Can you give an example of another such phenomenon with a tipping point? 

Notes

These notes will appear on every page in this lesson so feel free to put anything here you'd like to keep track of.