Abstract

This is a 90m resolution raster dataset describing fire risk across the western Mogollon Plateau in Arizona. This layer provides an estimate of the probability that ignition of a fire larger than 20 ha (50 acres) will occur in any given 1km2 area across the landscape over a 16 year period. It was created as part of the Forest Ecosystem Restoration Analysis (ForestERA) project to support landscape-scale forest restoration planning efforts by a broad group of stakeholders including federal and state agencies, academic institutions, and non-governmental entities.

Purpose

This layer was developed by the ForestERA project for use in landscape-level planning and prioritization of forest management on the western Mogollon Plateau. It is intended to provide a measure of the relative risk of a large fire occurring at any given location across the landscape.

Supplementary Information

Fire "risk" is defined as the probability of a fire occurring in a given area. Thus, fire risk layers are usually based on either ignition probabilities or probabilities that a fire will spread to a given area. This layer provides an estimate of the probability that the ignition for a large fire (>50 acres or 20 ha) will occur in any given square kilometer across the landscape over a 16 year period. The spatial and temporal aspects of the probability are based on the fire ignition data, which have a spatial resolution of 1km2 and come from the period 1986 - 2001.

To quantify fire risk across the landscape, we used a weights of evidence (WOE) modeling approach. WOE is a Bayesian method of event prediction using known locations of event occurrence. Weights of evidence models use the spatial location of known occurrence points to determine coefficients for a set of categorical input maps. For each analysis unit, or unit cell, these coefficients represent the probability of the input map characteristic or pattern being: a) present with a known occurrence, b) present without an occurrence, c) absent with an occurrence, or d) absent without an occurrence. The WOE model takes a log-linear form, and the final product is a posterior probability map showing the cumulative conditional probability for presence of an occurrence at each unit cell.

No accuracy assessment is possible for this layer until a sufficient number of new large fires occur across the analysis area. A measure of uncertainty based on the variance of the weights for any given location on the landscape is provided as part of the weights of evidence analysis (see the associated uncertainty grid).

These data are intended for regional analyses over spatial extents on the order of tens to hundreds of thousands of acres, and were not developed for use at finer spatial scales, although they may be useful for some applications at those finer scales.

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Status of the data

Complete
Data update frequency: None planned

Time period for which the data is relevant

Date and time: 2000
Description:
publication date

Publication Information

Who created the data: Forest Ecosystem Restoration Analysis Project

Date and time: December 1, 2004
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Data storage and access information

File name: firerisk90m
Type of data: raster digital data

Location of the data:
\\ENVSCI41\Shared\metadata_layers\grids\firerisk90m
Data processing environment: Microsoft Windows 2000 Version 5.0 (Build 2195)
Service Pack 4; ESRI ArcCatalog 8.1.2.671

Accessing the data

Size of the data: 22.340 MB
Data transfer size: 22.340 MB

Constraints on accessing and using the data

Access constraints: This layer may be accessed by any interested party. It is
provided by the Forest Ecosystem Restoration Analysis project, the Ecological
Restoration Institute (ERI), and Northern Arizona University (NAU).

Use constraints:
This layer is provided for public use by the ForestERA project, ERI, and NAU.
Reports, presentations, and publications in which this layer is presented or
used for analytical purposes should acknowledge the ForestERA project.

Details about this document

Contents last updated: 20040421 at time 14425800

Who completed this document

Forest Ecosystem Restoration Analysis Project
Center For Environmental Sciences and Education:
Northern Arizona University
Flagstaff, Arizona 86011-5694
United States
928-523-0068 (voice)
928-523-7423 (fax)

Contact Instructions:

Contact Dr. Thomas D. Sisk or the Forest Ecosystem Restoraton Analysis Project.

Standards used to create this document

Standard name: FGDC Content Standards for Digital Geospatial Metadata
Standard version: FGDC-STD-001-1998
Time convention used in this document: local time
Metadata profiles defining additonal information
ESRI Metadata Profile: http://www.esri.com/metadata/esriprof80.html

Horizontal coordinate system

Projected coordinate system name: NAD_1983_UTM_Zone_12N
Geographic coordinate system name: GCS_North_American_1983
Details
Grid Coordinate System Name: Universal Transverse Mercator
UTM Zone Number: 12
Transverse Mercator Projection
Scale Factor at Central Meridian: 0.999600
Longitude of Central Meridian: -111.000000
Latitude of Projection Origin: 0.000000
False Easting: 500000.000000
False Northing: 0.000000

Planar Coordinate Information

Planar Distance Units: meters
Coordinate Encoding Method: row and column
Coordinate Representation
Abscissa Resolution: 90.000000
Ordinate Resolution: 90.000000

Geodetic Model

Horizontal Datum Name: North American Datum of 1983
Ellipsoid Name: Geodetic Reference System 80
Semi-major Axis: 6378137.000000
Denominator of Flattening Ratio: 298.257222
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Bounding coordinates

Horizontal
In decimal degrees
West: -113.044931
East: -109.878536
North: 35.587479
South: 34.107751
In projected or local coordinates
Left: 314687.387285
Right: 601607.387285
Top: 3938195.572581
Bottom: 3775925.572581
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Spatial data description

Raster dataset information
Raster format: ESRI GRID
SDTS raster type: Grid Cell
Number of raster bands: 1
Raster properties
Origin location: Upper Left
Has pyramids: FALSE
Has colormap: FALSE
Data compression type: Default
Display type: matrix values
Cell information
Number of cells on x-axis: 3188
Number of cells on y-axis: 1803
Number of cells on z-axis: 1
Number of bits per cell: 32
Cell Size
X distance: 90.000000
Y distance: 90.000000

No detailed attribute information is available.

Page last updated February 11, 2005