C2FK: New Extensions of Cell2Fire Software for Fire Risk Analysis and Evaluation in Chilean Forests

Jaime Carrasco, José Ramón González, Felipe Soto, David Palacios, Rodrigo Mahaluf, Felipe de la Barra, Carolina Espinoza, Matías Vilches, Matilde Rivas, Fernando Badilla, Horacio Gilabert, Miguel Castillo, Jorge Saavedra, Jordi Garcia-Gonzalo and Andrés Weintraub

Disclaimer

This software is for research use only. There is no warranty of any kind; there is not even the implied warranty of fitness for use.

Introduction

Spatial simulation of wildfires has proven to be a valuable tool for fire management, supporting both preventive planning and operational suppression. However, many of these tools are not publicly available; those that do exist often require restrictive licenses or are controlled by private companies or government agencies. In this paper, we present an open-source computational tool capable of simulating fire growth across any region in Chile. This tool, called C2FK, can be used iteratively to produce spatially explicit simulations of fire ignitions under various scenarios, enabling the generation of burn probability maps. C2FK builds on the Cell2Fire simulator and incorporates the Chilean fire behavior system, KITRAL. Our implementation introduces new equations for calculating the rate of spread and length-to-breadth ratio based on wind speed using an elliptical fire shape model. Additionally, it includes a crown fire behavior model. We demonstrate its capabilities by comparing results with both real and simulated wildfires using KITRAL. C2FK is cross-platform and flexible, leveraging parallel computing for fire growth modeling and supporting the creation of risk maps through large-scale stochastic simulations.

Usage guide

Compiling

# dependencies
sudo apt install g++-12 libboost-all-dev libtiff-dev
# or brew
brew install gcc@12 libomp boost libtiff # llvm ?

# fork & clone 
git clone git@github.com:<YOU>/C2FK.git
cd C2FK/Cell2Fire

# compile
make 
# there area other makefiles for other platforms, e.g. makefile.macos

Other platform details at .github/workflows/build-.yml and makefile.

Running simulations

Cell2Fire --input-instance-folder /path/to/input-data --output-folder /path/to/output-results --nsims 100

The basic information the simulator needs is fuel and weather data. These must be located in the input instance folder, and should be named "fuels.asc" or "fuels.tif" and "Weathers.csv" respectively. Additional information such as terrain elevation, canopy bulk density, and canopy base height can also be provided. Please use the examples found under /data to guide your input file names.

Configuring simulations

There are many command line options available to configure the simulation.

Argument	Type	Function
nsims	int	Number of simulations to run.
cros	bool	True if crown fire should be included.
fmc	int	Used in Kitral to calculate critical intensity. Default is 100.
nthreads	int	Defines the number of threads to use for simulations. Default is 1.
seed	int	Seed for the random generator.
IgnitionRad	int	If greater than 0, picks a point on the circumference of radius = IgnitionRadius from ignition point.
nweathers	int	Number of weather files. Used to randomly select one.
CCFFactor	float	Weighs by the cell’s CCF when calculating crown ROS in S&B. Default is 0.
EFactor	float	Weighs radial distance from the ellipse center. Default is 1.0.
BFactor	float	Weighs back ROS and ellipse "c". Default is 1.0.
FFactor	float	Weighs flank ROS. Default is 1.0.
HFactor	float	Weighs head ROS. Default is 1.0.
ROS-Threshold	float	ROS threshold for fire to spread. Default is 0.1.
ROS-CV	float	Used to calculate a random ROSRV value. Default is 0.
FirebreakCells	string	Firebreak plan, sets cells as “NonBurnable”.
weather	string	Options: “rows”, “constants”, “distribution”, “random”. Default is “rows”.
output-folder	string	Directory where results will be saved.
input-instance-folder	string	Directory containing all required files.
bbo	bool	True to use Black Box Optimization.
final-grid	bool	Saves grid state at the end of the simulation.
grids	bool	Saves forest grids during the simulation.
ignitions	bool	Reads ignition points from file or uses random ones.
ignitionsLog	bool	Saves a log of attempted ignitions.
verbose	bool	Prints ultra-detailed log.
out-cfb	bool	Saves crown burned fraction. Only with --cros.
out-crown	bool	Saves layer with crown fire cells.
out-ros	bool	Saves ROS per cell.
out-intensity	bool	Saves Byram fire intensities.
out-fl	bool	Saves flame length results. In S&B, saves surface, crown, and max.
output-messages	bool	Saves file with messages (origin, destination, time, ROS).

Output examples

Most outputs are ASCII raster layers, of the same shape as the original fuels raster.

The following is the fireline intensity output for a small simulation. The cells that have 0 are cells that did not catch fire.

ncols 7
nrows 7
xllcorner 457900
yllcorner 5.7168e+06
cellsize 100
NODATA_value -9999
0 4389.03 0 0 0 0 0
0 0 17663.2 18731.9 0 4201.66 0
1711.45 0 1731.95 0 5487.64 9923.44 0
0 14655.2 6652.72 5804.41 4371.23 9348.01 0
0 9441.69 7127.24 0 0 0 0
0 0 7692.64 4389.03 3107.24 2032.65 0
0 8251.82 0 0 17663.2 18731.9 0

Illustrative examples

Fire simulation in El Portillo, with crown fire behavior.

The fire scars generated by the simulator can be visualized with QGIS and processed to generate images such as the following example.

About us

We are a research group that seeks solutions to complex problems arising from the terrestrial ecosystem and its natural and anthropogenic disturbances, such as wildfires.

Currently hosted at ISCI offices.

Contact us on Discord.

Visit our public webpage.