1. Pedro Ribeiro de Andrade Münster, 2013
Fire in the Forest
Pedro Ribeiro de Andrade
Münster, 2013

2. Fire in the Forest

3. Basic Cellular Automaton
Grid of cells
Neighbourhood
Finite set of discrete states
Finite set of transition rules
Initial state
Discrete time

4. Fire in the Forest
Burning
Forest
Burned

5. Fire in the Forest 50 x 50 space
three states: forest, burning, and burned
initially all cells are forest
von Neumann neighborhood (4 neighbors)
a forest cell becomes burning if a neighbor is burning
a burning cell becomes burned after one time step
a random initial burning cell
simulate for 90 time steps

6. Fire in the Forest
Burning
Forest
Burned
Empty

7. Fire in the Forest 50 x 50 space
four states: empty, forest, burning, and burned
initial state: select randomly between empty/forest
von Neumann neighborhood (4 neighbors)
a forest cell becomes burning if a neighbor is burning
a burning cell becomes burned after one time step
a random initial burning cell
simulate for 90 time steps

8. Changing the model
There is a fixed probability that a neighbor cell will burn (90%)
Burning cells affect their 8 touching neighbors
Burning cells now take two time steps before changing their state to burned

9. Randomness-based models
When a model is based on randomness, do not trust in a single simulation result
Repeat 5 simulations with different percentages of initial forest ranging from 0% to 100% to investigate the threshold for burning the whole forest