Model Description
This project models a forest fire. Two versions of the project were created; the first uses AgentCubes, and the second uses JavaScript and the AgentModel.js library.
The Story
We are modeling how a forest fire spreads within a forest. The fire starts next to a healthy tree so, that tree turns into a burning tree. The cycle continues when burning trees burn healthy trees. However, the aerial firefighters have the ability to put out the fire and burning trees if they get to them soon enough.
Fire is spread. If fire is next to at least one healthy tree, with some percent chance, that healthy tree will turn into a burning tree. Aerial firefighters move randomly in the world, on trees, and on fire. If an aerial firefighter is immediately above a burning tree, with some percent chance, that burning tree will turn into a dead tree. If an aerial firefighter is immediately above the fire, with some percent chance, the fire will erase. A counter counts the number of each type of tree and graphs the population size. After 5 time steps, the burning tree will turn into a dead tree.
Agents and Shapes
| Agent | Shape | Color |
|---|---|---|
| Tree | Healthy | Dark Green |
| Burning | Brown | |
| Dead | White | |
| World | Green | |
| Counter | Purple | |
| Fire | Red | |
| Aerial Firefighter | Sky Blue |
Observed Behaviors
As more trees start to burn, there is less healthy trees. However, most of the trees don't burn in the forest, given the location of them. This results in the number of healthy trees being greater than the dead trees, even after the fire.
Nearest-Neighbors Burning
We ensured that the only the nearest neighbors burn by giving the fire a rule that if it sees a healthy tree, with a 15 percent chance, it will turn the nearest 4 healthy trees(up, down, left, right) into burning trees.
Conclusions
We noticed that depending on the forest density and where the fire starts has an enormous impact on how far the fire spreads: If the forest density is high, the fire will spread quickly throughout the forest. If the forest density is low, the fire will not spread as much.