Concept:
In order to define fire suppression tactics and design fire risk management policies, it is important to simulate the propagation of wildfires. In my final project, I’ll be using cellular automata to model the spread of wind-driven fire across a grid-based terrain, demonstrating the dynamics of wildfires and exploring different scenarios and factors affecting their spread.
Users will be able to set the initial conditions (i.e. density of vegetation, ignition point), adjust parameters (i.e. wind speed, humidity), pause, and reset the simulation.
Initial sketches:
Papers to be used:
https://www.fs.usda.gov/rm/pubs_int/int_rp115.pdf
Methodology:
- Research the propagation of fire: The case study will be the 2012 severe wildfire that took place in Algarve, Portugal, where 25 thousand hectares burned. It is interesting because it had an explosive stage between 25 and 30h after the onset.
- Define initial states of land: vegetation type and density.
Vegetation type propagation probability:
– No vegetation: -1
– Cultivated: -0.4
– Forests: 0.4
– Shrub: 0.4
Vegetation density propagation probability:
– No vegetation: -1
– Sparse: -0.3
– Normal: 0
– Dense: 0.3
- Implement rules governing the spread of fire: Fuel, topography, wind, and humidity.
– R1: A cell that can’t be burned stays the same
– R2: A cell that is burning down at present time will be completely burned in the next iteration.
– R3: A burned cell can’t be burned again.
– R4: If a cell is burned, and its neighbors contain vegetation fue, the fire can then propagate with a given probability (factors).
The probability will be defined as follows:
P_burn = P0(1+P_veg)(1+P_den)PwPs
P0: ignition point (user interaction)
P_veg: vegetation type
P_den: vegetation density
Ps: topography
Pw: wind speed and direction
The probability of the wind is:
Pw = exp[V(C1 + C2 (cos(o)-1))]
with C1 and C2 are adjustable coefficients
V is the wind speed
O is the angle between the wind direction and the fire propagation (if aligned, Pw increases)
The probability of the terrain is:
Ps = exp(a.o)
with a: adjustable coefficient
o: the slope angle of the terrain
Os = atan[(E1 – E2)/D]
with E: elevation of the cell
D: the size of the square cell if adjacent or sqrt(2*cellSize) if diagonal
Challenges:
Make it as realistic as possible.