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 a forest fire in which fire is being spread through the trees. The fire starts out next to a healthy tree--burning it and causing it to change from healthy to burning. Healthy trees can also catch fire if they are next to a burning tree. If the trees burn for too long, they will eventually die. In our model, there are ariel firefighters that can put out the fire and the burning trees.
Fire is spreading in the world. If a fire is next to at least one healthy tree, with some percent chance that healthy tree will change into a burning tree. If a healthy tree is next to at least one burning tree, there is some percent chance that the healthy tree will turn into a burning tree. After 5 hours (time steps), the burning tree will turn into a dead tree. Aerial firefighters move randomly in the world, on trees, and on fire. If an aerial firefighter is immediately above a burning tree, there is some percent chance that the burning tree will change into a dead tree. If an aerial firefighter is on top of a fire, there is some percent chance that the fire will erase. A counter counts the the number of each type of tree and graphs the population size.
Agents and Shapes
| Agent | Shape | Color |
|---|---|---|
| World | Green | |
| Trees | Healthy | Dark Green |
| Burning | Brown | |
| Dead | Black | |
| Fire | Red | |
| Aerial Firefighter | Sky Blue | |
| Counter | Purple |
Observed Behaviors
As time goes on, the number of healthy trees decrease as they become burning trees (so the burning trees population increases). And after a period of time, the burning trees turn into dying trees (because after five steps burning becomes dead). Also, after a period of time, most of the trees become dead and the fire gets burned out.
Nearest-Neighbors Burning
We constructed our model to display that only if a healthy tree has a burning tree or fire on top of it, below it, to the right of it, and to the left of it, then it will catch on fire.
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.