GridFire

GridFire is a raster-based fire spread and severity model that may be used for both static and dynamic calculations of various standard fire behavior metrics across a landscape. For inputs, it requires a stack of co-registered raster maps for your area of interest as well as a set of scalar values which may be input via a configuration file. These inputs are listed in the following table:

Value	Units	Type
max-runtime	minutes	double
cell-size	feet	double
elevation-matrix	feet	core.matrix 2D double array
slope-matrix	vertical feet/horizontal feet	core.matrix 2D double array
aspect-matrix	degrees clockwise from north	core.matrix 2D double array
fuel-model-matrix	fuel model numbers 1-256	core.matrix 2D double array
canopy-height-matrix	feet	core.matrix 2D double array
canopy-base-height-matrix	feet	core.matrix 2D double array
crown-bulk-density-matrix	lb/ft3	core.matrix 2D double array
canopy-cover-matrix	0-100	core.matrix 2D double array
wind-speed-20ft	miles/hour	double
wind-from-direction	degrees clockwise from North	double
fuel-moisture	%	map of doubles per fuel size class
foliar-moisture	%	double
ellipse-adjustment-factor	$< 1.0 =$ circle, $> 1.0 =$ ellipse	double
initial-ignition-site	point represented as [row col]	vector

Static Calculations

In this mode, GridFire can be used to calculate full coverage maps of the following fire behavior metrics given a fixed set of weather conditions:

Value	Units	Type
max-rate-of-spread	feet/min	core.matrix 2D double array
max-direction-of-spread	feet/min	core.matrix 2D double array
fire-type	category 0-3 (see below)	core.matrix 2D double array
flame-length	feet	core.matrix 2D double array
fire-line-intensity	Btu/ft/s	core.matrix 2D double array
wind-adjustment-factor	percentage (0-1)	core.matrix 2D double array

The Fire Type categories are as follows:

1. Non-burnable
2. Surface Fire
3. Passive Crown Fire
4. Active Crown Fire

Dynamic Simulation

In this mode, GridFire may be asked to simulate individual ignition events and calculate their size and severity after a fixed amount of time (e.g., a 1 hour fire event). These simulation outputs are listed in the following table.

Value	Units	Type
global-clock	minutes	double
initial-ignition-site	point represented as [row col]	vector
ignited-cells	set of points represented as [row col]	set
fire-spread-matrix	percent heated (0-1)	core.matrix 2D double array
flame-length-matrix	feet	core.matrix 2D double array
fire-line-intensity-matrix	Btu/ft/s	core.matrix 2D double array

Usage

GridFire has been coded as a literate program (https://en.wikipedia.org/wiki/Literate_programming) using Emacs’ org-mode (http://orgmode.org/worg/org-contrib/babel/). Full documentation of the current system can always be found in org/GridFire.org and org/GridFire.pdf in this repository.

REPL

The beginnings of a REPL-driven development setup are in `dev/user.clj`. After installing http://www.clojure.org and https://leiningen.org/, and other dependencies – on OS X for example,

brew install clojure leiningen postgresql postgis

start postgres with

./pginit/run_db.sh

and start a REPL with

lein repl

While the REPL is most effectively used with an editor integration such as https://cider.readthedocs.io/en/latest/, there is a function included to immediately verify the REPL is setup

user=> (startup-health-check)

This function runs simulations and writes output files to the project root directory.

misc notes

The simulations draw input data from the postgres database. startup-health-check populates the input database by default and so is expected to be evaluated once in default mode per ./pginit/run_db.sh run. Use (startup-health-check :skip-init true) in order to run the simulations without restarting the database.

Contact

Authors:

• Gary W. Johnson
• David S. Saah
• Max Moritz

Emails:

• [email protected]
• [email protected]
• [email protected]

License

Copyright © 2011-2016 Spatial Informatics Group, LLC.

GridFire is distributed by Spatial Informatics Group, LLC. under the GNU General Public License version 3.0 (GPLv3) https://www.gnu.org/licenses/gpl.html.