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

Fire in the Forest

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

Fire in the Forest Burning Forest Burned

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

Fire in the Forest Burning Forest Burned Empty

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

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

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