Glossary of Terms

1 hr fuel moisture

The moisture content of one-hour timelag dead fuels, which are fuels consisting of dead herbaceous plants and roundwood less than about 1/4 inch in diameter.  Also included is the uppermost layer of needles or leaves on the forest floor (NWCG Wildland Fire Glossary).

One of the outputs of WFDSS Basic Fire Behavior (BFB). WFDSS Basic Fire Behavior (BFB) uses the Burn Start Date and Time to calculate the "snapshot in time", 1-hour time lag of dead fuel moisture values for each cell contained in the analysis area. BFB uses the previous 7 days' weather for the fuel moisture conditioning. The output values are in fractional format (e.g., 0.09, which is equal to 9%), and the output resolution is the same as that of the source landscape (30 x 30 meter).

Last updated on 5/27/2011 10:52:32 AM.

10 hr fuel moisture

The moisture content of the 10 hr timelag dead fuels, which consist of roundwood 1/4 to 1-inch in diameter and, very roughly, the layer of litter extending from immediately below the surface to 3/4 below the surface (NWCG Wildland Fire Glossary).

One of the outputs of WFDSS Basic Fire Behavior (BFB).  BFB uses the analysis area's Burn Start Date and Time to calculate the "snapshot in time", 10-hour time lag of dead fuel moisture values for each cell contained in the analysis area. BFB uses the previous 7 days' weather for the fuel moisture conditioning.  The output values are in fractional format (e.g., 0.18, which is equal to 18%), and the output resolution is the same as that of the source landscape (30 x 30 meter).

Last updated on 5/27/2011 10:53:46 AM.


The closeness of results of observations, computations or estimates to the true values or the values accepted as being true (FGDC-STD-001-1998).

Last updated on 5/18/2010 10:48:49 PM.

action items

A statement that describes the strategy(s), priorities, and management actions for accomplishing incident objectives and requirements.

Last updated on 2/7/2013 11:47:37 AM.

advanced decision editor

The Advanced Decision Editor contains the same sections as the Default Decision Editor, but you complete the decision documentation by moving between tabs available at the top of the screen. This editor provides advanced editing features not available in the Default Decision Editor, including the ability to:

You begin using the Advanced Decision Editor by selecting the Convert to Advanced button on the Decision tab when all sections of a Pending Decision are Checked In.

Last updated on 3/15/2015 10:56:10 AM.

analysis area

In WFDSS, the analysis area refers to the user-defined box drawn on a map that indicates the landscape used in the fire behavior analysis.

Last updated on 4/6/2011 11:11:08 PM.

analysis ignition

polygon, buffered point or line from which STFB, NTFB and FSPro fire behavior models initates simulated fire spread. Analysis ignitions are zipped shapefiles that can be created in WFDSS or uploaded from a GIS and may contain multiple ignitions.

Last updated on 1/28/2019 12:09:27 PM.


A calculation of the size of a two-dimensional feature, measured in square units (ESRI Dictionary).

Last updated on 5/18/2010 10:51:43 PM.

arrival time

One of the outputs calculated by WFDSS Short Term Fire Behavior (STFB). It displays the number of hours it takes fire fire to reach that location on the landscape from the ignition source (point).

Last updated on 7/28/2010 3:36:55 PM.

artificial season

An FSPro-simulated season of ERC values.

Last updated on 7/28/2010 3:37:07 PM.

aspect theme

One of the raster themes that make up the landscape file and contains values for topographic aspect.  Aspect values are integer azimuth values (degrees clockwise from north).

Last updated on 7/28/2010 3:37:20 PM.


Not simultaneous or immediately interactive. In computer-mediated communication, asynchronous ususually means that different users accessing the same channel of communication (e-mail, newsgroups, etc.) can submit data independently of one another, so that other users do not have to wait until a submission is finished before submmitting data of their own, and users do not have to be connected to the network simultaneously. (

WFDSS uses asynchronous methods to process data and to communicate internally. This allows the application to respond more quickly and efficiently to user inputs and greatly improves user experience.

Last updated on 2/1/2011 5:23:46 PM.


Information about a geographic feature generally stored in a table and linked to the feature by a unique identifier (GSTOP).

Last updated on 5/18/2010 10:52:29 PM.


The situation in which time series data is influenced by its own historical values, such as a current season's weather (ERC values) based on the last month's weather (ERC values).

Last updated on 7/28/2010 3:37:37 PM.


A polygon or buffered line that represents an obstruction to fire spread on the landscape. Typically an area or strip devoid of combustible fuel, barriers can be used when running BFB, STFB, NTFB, and FSPro fire behavior models. A barrier is a zipped shapefile that can be created in WFDSS or uploaded from a GIS and may contain multiple barriers and/or shapes (NWCG Wildland Fire Glossary).

Last updated on 1/28/2019 1:36:57 PM.


BEHAVE is a system of interactive computer programs for modelling fuel and fire behavior. It has been in use since 1984 and was replaced by BehavePlus.

Last updated on 7/28/2010 3:38:23 PM.


The BehavePlus fire modeling system is a PC-based program that is a collection of models that describe fire behavior, fire effects, and the fire environment. It replaced BEHAVE. This functionality is incorporated into WFDSS.

Last updated on 7/28/2010 3:38:35 PM.


Fire effects with positive value or that contributes to the attainment of organizational goals. (NWCG#024-2010 Memorandum Attachment A: Terminology Updates List)

Last updated on 8/25/2010 4:16:26 PM.

Boolean logic

Named after the 19th-century mathematician George Boole, Boolean logic is a form of algebra in which all values are reduced to either TRUE or FALSE. Boolean logic is especially important for computer science because it fits nicely with the binary numbering system, in which each bit has a value of either 1 or 0 (Webopedia).

Landscape Editor rules used in fire behavior modeling are applied using Boolean Logic.

Last updated on 1/21/2011 9:38:49 AM.

  1. A zone around a map feature measured in units of distance or time.
  2. A polygon enclosing a point, line, or polygon at a specified distance (ESRI Dictionary).

Last updated on 5/18/2010 10:54:27 PM.

building cluster points

A spatial data layer in WFDSS where GIS map points represent close proximity to assumed locations of structures. These points approximate the location of one or more structures. Most building cluster points represent the center of parcels where county assessor records indicate taxable improvements are present, but may also represent structure point locations identified by county officials. Building cluster points are intended for STRATEGIC USE ONLY. (NFDSC Economics Group)

Last updated on 7/28/2010 1:38:53 PM.


A constructed object, usually a free-standing structure above ground (NWCG Wildland Fire Glossary).

Last updated on 5/31/2010 1:24:02 PM.

burn probability

The probability that a specific geographic location (cell) will experience a wildland fire during a specified time period.

Last updated on 10/8/2010 4:02:24 PM.

cadastral data

The information about rights and interest in land. Cadastral data may also be known as real estate data, parcel information, or tax parcel information (FGDC Cadastral Subcommittee).

Last updated on 5/18/2010 10:59:47 PM.

canopy base height theme (CBH)

A raster theme in the Landscape File that is important for determining transition from surface fire to crown fire. CBH is a stand-level descriptor and it should incorporate the effects of ladder fuels (if present) in increasing vertical continuity and assisting transition to crown fire.

For example, typically a mature, dense, multi-storied Spruce/Subalpine Fir stand would have a CBH of less than a meter, while an open park of old growth Ponderosa Pine could have a CBH of 10 meters or more. Conditions in between these two extremes are more difficult to estimate. Values (in WFDSS Landscapes) are in meters, with precision of the fire behavior calculations limited to the nearest 1/10th meter.

Last updated on 7/28/2010 3:39:07 PM.

canopy bulk density theme (CBD)

One of the Landscape File raster themes that is needed to determine the characteristics of crown fires. CBD values (in WFDSS Landscapes) are decimal values in kilograms/meter cubed (kg/m3).   

Last updated on 7/28/2010 3:39:17 PM.

canopy cover theme

Necessary in the Landscape File for computing wind reduction factors and shading in the dead fuel moisture model (Nelson). Canopy cover is the horizontal percentage of the ground surface that is covered by tree crowns. It is a stand-level descriptor.

If the canopy cover theme has a value of zero for a cell, then the data in the canopy bulk density, canopy base height, and stand height themes are ignored for that cell in a simulation since the model assumes there is no tree cover for that cell.

Canopy Cover is NOT the same as crown closure. Canopy cover is measured as the horizontal fraction of the ground that is covered directly overhead by tree canopy. Crown closure refers to the ecological condition of relative tree crown density. Stands can be said to be "closed" to recruitment of canopy trees, but still only have 40% or 50% canopy cover.

Last updated on 7/28/2010 3:39:29 PM.


A distributed network of data producers, managers, and users linked electronically, such as over the Internet. Through the Clearinghouse, users can use a single interface to search and access metadata and/or data for the themes they seek. The Clearinghouse includes the sites across the country where the metadata and data are stored, usually at the site of the producer or intermediary (Circular A-16).

Last updated on 5/18/2010 11:00:37 PM.

constraints, land management

Factors that would preclude application of a strategy at a particular time or in a particular place. Constraints could include such things as topography, weather, wildland-urban interface, land management objectives, threatened and endangered species, national or local issues, etc.

Last updated on 7/28/2010 3:40:11 PM.

coordinate system

A reference framework consisting of a set of points, lines, and/or surfaces, and a set of rules, used to define the positions of points in space in either two or three dimensions (GSTOP).

Last updated on 5/18/2010 11:01:24 PM.


The x- and y- values that define a location in a planar or three-dimensional coordinate system (GSTOP).

Last updated on 5/18/2010 11:02:13 PM.

course of action

An overall plan describing the selected strategies and management actions intended to meet incident objectives and requirements based on current and expected conditions.

Last updated on 2/7/2013 11:58:13 AM.


Factual information, especially information organized for analysis or used to reason or make decisions.  In Computer Science, numerical or other information represented in a form suitable for processing by computer (Circular A-16).

Last updated on 5/18/2010 11:03:06 PM.

data element

The smallest unit of information used to describe a particular characteristic of a spatial dataset. A data element is a logically primitive description that cannot be further subdivided (ESRI Dictionary).

Last updated on 5/18/2010 11:03:47 PM.


One or more structured sets of persistent data, managed and stored as a unit and generally associated with software to update and query the data. A simple database might be a single file with many records, each of which references the same set of fields. A GIS database includes data about the spatial locations and shapes of geographic features recorded as points, lines, areas, pixels, grid cells, or TINs, as well as their attributes (ESRI Dictionary).

Last updated on 5/18/2010 11:04:36 PM.


Any collection of related data, usually grouped or stored together (ESRI Dictionary).

Last updated on 5/18/2010 11:05:17 PM.


The reference specifications of a measurement system, usually a system of coordinate positions on a surface (a horizontal datum) or heights above or below a surface (a vertical datum) (ESRI Dictionary).

Last updated on 5/18/2010 11:05:46 PM.

dead fuel moisture

The change in moisture content of dead and downed woody surface fuels throughout time and topography is often critical to calculating fire behavior characteristics. In general, drier fuels increase fire spread rate, fireline intensity, and fuel consumption.

Last updated on 7/28/2010 3:40:55 PM.

default decision editor

The Default Decision Editor automatically opens when a Pending Decision is edited. Vertical Tabs represent each section of the decision; providing quick movement between sections. Hyperlinks in decision sections link to incomplete components to speed completion of required sections. This feature, combined with the Situation Map opening in a separate window allows users to quickly complete required sections while viewing map components/features. Check boxes allow a quick way to add optional content to a decision.

Last updated on 3/15/2015 10:57:11 AM.


See Digital Elevation Model

Last updated on 5/18/2010 11:08:01 PM.


Department of Interior (DOI) and United States Department of Agriculture (USDA).

Last updated on 7/28/2010 3:41:17 PM.

desired condition

The composition and structural characteristics of the plant community on a site or ecological unit which meets land management plan or other management objectives (after FSH 2090.11); or those landscape conditions that are most conducive to ecosystem health based on long-term management objectives. Desired conditions can be the same as existing conditions. Desired conditions may also refer to the state of a site or ecological unit in relation to a desired process, such as fire return interval, rather than to a specific vegetative structure or composition of the unit.

Last updated on 7/28/2010 3:41:31 PM.

digital elevation model (DEM)

The representation of continuous elevation values over a topographic surface by a regular array of z-values, referenced to a common datum. DEMs are typically used to represent terrain relief (ESRI Dictionary).

Last updated on 5/18/2010 11:08:37 PM.

discovery size

The defined, typical size of a fire when it is discovered. The entry is used as the starting fire size in the fire growth simulation.

Last updated on 7/28/2010 3:35:44 PM.

dispatch location

A physical location from which fire resources respond. Dispatch locations must have facilities that support the fire resources and have a recurring operation and maintenance cost. Facilities must meet state and federal health, safety, construction and access regulations.

Last updated on 7/28/2010 3:42:37 PM.


Height of a given point with respect to a defined vertical datum (FGDC-STD-001-1998).

Last updated on 5/18/2010 11:09:50 PM.

elevation theme

One of the raster themes that make up the Landscape File. In WFDSS, its units are meters above sea level. The elevation theme is necessary for adiabatic adjustment of temperature and humidity, and for conversion of fire spread between horizontal and slope distances.

Last updated on 10/8/2010 4:02:47 PM.

Energy Release Component

A number related to the available energy (BTU) per unit area (square foot) within the flaming front at the head of a fire.

Last updated on 7/28/2010 3:45:43 PM.

enterprise data

Spatial or non-spatial data designated by stakeholder organizations as being corporate or national in nature and extent. Enterprise data is typically maintained, updated, and used as an authoritative source of information. Only staff with appropriate authority, using formalized protocols can add to, change, or delete enterprise data.

Last updated on 5/18/2010 11:14:17 PM.


Data center in South Dakota that is run by the US Geological Survey. This is where the WFDSS servers are physically located.

Last updated on 7/28/2010 3:46:28 PM.

escaped prescribed fire

Prescribed fire that has exceeded or is expected to exceed prescription parameters or otherwise meets the criteria for conversion to wildfire. Criteria for conversion are specified in "Interagency Prescribed Fire - Planning and Implementation Procedures Reference Guide". (NWCG#024-2010 Memorandum Attachment A: Terminology Updates List).

Last updated on 8/25/2010 4:27:06 PM.


Environmental Systems Research Institute.

Last updated on 7/28/2010 3:46:28 PM.

Event Coverage Report

The Fire and Aviation Management Web Applications (FAMWEB) website brings together a variety of applications, tools, and services related to interagency fire and aviation management managed by the National Wildfire Coordinating Group (NWCG) and participating agencies. The website provides detailed information, data access, and application entry points for system users, interagency partners, providers, and the public.

Last updated on 7/28/2010 3:48:56 PM.


A two-dimensional fire-growth simulation model that simulates fire growth and fire behavior characteristics using spatial data under conditions of fine-scale weather heterogeneity. In WFDSS, the equivalent model is Near-Term Fire Behavior.

Last updated on 7/28/2010 3:48:56 PM.


A shape in a spatial data layer, such as a point, line, or polygon, that represents a geographic object (GSTOP).

Last updated on 5/18/2010 11:15:05 PM.

Federal Geographic Data Committee (FGDC)

A United States government committee that promotes the coordinated development, use, sharing, and dissemination of geospatial data on a national basis. The nationwide data publishing effort is known as the National Spatial Data Infrastructure (NSDI). (FGDC-STD-001-1998)

Last updated on 7/28/2010 1:43:13 PM.

Fire Behavior Specialist (FBS) & Super Analyst

These two roles served different purposes in the past but in 2018, were merged to share common privileges. Only one difference remains; Super Analysts can draw larger landscapes when the need arises.

Users requesting the Fire Behavior Specialist role should have previous fire behavior modeling experience, including evaluating and modifying landscape files, historic climate, and forecasted weather. These roles can:

Last updated on 8/28/2019 2:00:30 PM.

fire containment time

The elapsed time from the beginning of the modeled fire event until fire containment is achieved.

Last updated on 7/28/2010 3:51:51 PM.

fire management

All activities related to the management of wildland fires. (NWCG#024-2010 Memorandum Attachment A: Terminology Updates List)

Last updated on 8/25/2010 4:41:08 PM.

fire management plan (FMP)

A plan that identifies and integrates all wildland fire management and related activities within the context of approved land/resource management plans. It defines a program to manage wildland fires (wildfire and prescribed fire). The plan is supplemented by operational plans, including but not limited to, preparedness plans, preplanned dispatch plans, prescribed fire burn plans, and prevention plans. Fire Management Plans ensure that wildland fire management goals and components are coordinated (Guidance for Implementation of Fed Wildland Fire Mgmt Policy).

Last updated on 5/18/2010 11:16:47 PM.

fire management unit (FMU)

A land management area definable by objectives, management constraints, topographic features, access, values to be protected, political boundaries, fuel types, major fire regime groups, etc. that set it apart from the characteristics of an adjacent FMU. The FMU may have dominant management objectives and pre-selected strategies assigned to accomplish these objectives (NWCG Wildland Fire Glossary).

Last updated on 5/18/2010 11:18:02 PM.

fire management unit constraint

Prohibition on the use of particular fire resources specific to each fire management unit. Constraints are derived from direction provided in policy, law and/or local land management plans.

Last updated on 5/18/2010 11:19:06 PM.

fire manager

A generic term to describe fire-management leadership, generally personnel with a direct cost responsibility. Examples: District, Unit, Forest Fire Management Officers, Assistant and Deputy FMOs, Aviation Officers, Wildland Fire Use Specialists, etc.

Last updated on 7/28/2010 3:53:27 PM.

fire perimeter

A polygon or buffered point that represents the entire outer edge or boundary of a fire. A fire perimeter is a zipped shapefile that can be created in WFDSS or uploaded from a GIS and may contain multiple perimeters (NWCG Wildland Fire Glossary).

Last updated on 7/7/2011 2:43:52 PM.

fire planning

Systematic, technological, and administrative management process of designing organization, facilities, and procedures, including fire use, to protect wildland from fire (NWCG Wildland Fire Glossary).

Last updated on 5/18/2010 11:24:20 PM.

fire probability

Likelihood of a fire starting and then spreading, either outside its cell or pixel or spreading from an adjacent cell or pixel.

Last updated on 5/18/2010 11:25:49 PM.

fire progression

The movement of the fire outwards from the point of origin (NWCG Wildland Fire Glossary).

Last updated on 7/28/2010 3:54:58 PM.

fire severity

Degree to which a site has been altered or disrupted by fire; loosely, a product of fire intensity and residence time. (NWCG Wildland Fire Glossary)

Last updated on 9/14/2010 1:38:59 AM.

fire spread model

A set of physics and empirical equations that form a mathematical representation of the behavior of fire in uniform wildland fuels (NWCG Wildland Fire Glossary).

Last updated on 10/5/2010 1:51:12 PM.

Fire Spread Probability (FSPro)

In WFDSS, a web-based geospatial model that calculates the probability of fire spread from a current fire perimeter or ignition point for a specified time period. It requires GIS landscape data (LCP file) as provided by LANDFIRE or other sources. Additionally, the application requires data from a representative RAWS station for creating a historical data set relative to wind and ERC.

Last updated on 7/28/2010 4:00:18 PM.

fire suppression organization
  1. The personnel collectively assigned to the suppression of a specific fire or group of fires.
  2. The personnel responsible for fire suppression within a specified area.
  3. The management structure, usually shown in the form of an organization chart of the persons and groups having specific responsibilities in fire suppression.

Last updated on 7/28/2010 4:01:32 PM.

fire type

The kind of fire, based on whether the ignition was planned (type: prescribed) or unplanned (type: wildfire). (NWCG#024-2010 Memorandum Attachment A: Terminology Updates List)

Last updated on 8/25/2010 4:43:35 PM.

fireline intensity

The rate of energy or heat release per unit length of fire front, regardless of its depth. Fireline Intensity (in the direction of the maximum rate of spread) is one of the outputs calculated by WFDSS fire behavior models. Fireline Intenstity units are displayed in the analysis legend as kilowatts/meter.


A two-dimensional, non-temporal fire behavior modeling system. It can be viewed as a “spatial BehavePlus” because it simply makes BehavePlus-like fire behavior calculations (for one instant in time) for all points on a landscape or analysis area using one set of wind and fuel moisture conditions. FlamMap exists as a stand-alone computer program and a version implemented in WFDSS (Basic Fire Behavior).

Last updated on 7/28/2010 4:18:19 PM.


See Basic Fire Behavior.

Last updated on 7/28/2010 4:09:06 PM.

FlamMap Minimum Travel Time (MTT)

A (PC-based) two-dimensional fire growth model that calculates fire growth and behavior by searching for the set of pathways with minimum spread times from a point, line, or polygon ignition source, keeping environmental (fuel moistures and winds) conditions constant for the duration of the simulation.  MTT is implemented in the stand-alone FlamMap. There is also a version in WFDSS (Short Term Fire Behavior).

Last updated on 7/28/2010 4:18:41 PM.

fuel model theme

One of the raster themes that make up the Landscape File. The surface fuel model theme in the Landscape File must specify an integer index to a fuel model. Landscapes in WFDSS use the original standard 1-13 fuel models (Anderson 1983) and/or the new 40 standard models (Scott and Burgan, 2005).

fuel moisture conditioning

Allows dead fuel moisture values to be adjusted based on aspect, elevation, forest canopy cover, and previous weather.

Conditioning dead fuel moistures prior to doing a fire behavior analysis is very important. WFDSSfire behavior models do this conditioning automatically by retrieving RAWS observations for the 7 days prior to the analysis date. Fire Behavior Specialists can modify these data as needed by selecting a different RAWS station.

The models (WFDSS BFB and STFB) calculate separate dead fuel moistures for each landscape cell based on the topography and shading from forest canopy cover and clouds, as well as the recorded weather (precipitation, high and low temperatures and high and low relative humidity values) for the previous 7 days. The dead fuel moistures that have been calculated by the start date and time of the analysis are what are used to determine the outputs in WFDSS fire behavior models.

Last updated on 7/28/2010 4:28:22 PM.


A database or file structure used primarily to store, query, and manipulate spatial data. Geodatabases store geometry, a spatial reference system, attributes, and behavioral rules for data. Various types of geographic datasets can be collected within a geodatabase, including feature classes, attribute tables, raster datasets, network datasets, topologies, and many others. Geodatabases can be stored in IBM DB2, IBM Informix, Oracle, Microsoft Access, Microsoft SQL Server, and PostgreSQL relational database management systems, or in a system of files, such as a file geodatabase (ESRI Dictionary).

Last updated on 5/18/2010 11:29:35 PM.

Geographic Area

A boundary designated by governmental agencies (wildland fire protection agencies) within which they work together for the interagency, intergovernmental planning, coordination, and operations leadership for the effective utilization of emergency management resources within their area. There are nine geographic areas. A listing of the areas can be found in the National Interagency Mobilization Guide, Chapter 70 along with listings of the Geographic Coordinating Areas and Geographic Area Coordination Centers.

geographic area coordination center (GACC)

The physical location of an interagency, regional operation center for the effective coordination, mobilization and demobilization of emergency management resources. Listings of geographic coordination centers and their respective geographic coordinating areas can be found within the National Interagency Mobilization Guide, Chapter 20, Section 21.1 (NWCG Wildland Fire Glossary).

Last updated on 5/31/2010 1:24:04 PM.

Geographic Area Editor

A Geographic Area Editor has ownership of all WFDSS incidents within the geographic area (GA) to which they are assigned and can perform the following tasks:

The WFDSS Geographic Area Editor (GAE) role provides support to WFDSS users and incidents within their individual Geographic Areas (GA). GAEs have implicit ownership of incidents within their GAs, and serve as interagency technical experts and Geographic Area (GA) Point of Contacts for their agency or bureau.

GAEs from various agencies are typically designated within each GA. GAEs work cooperatively for the benefit of all users within their GA and are both able and expected to assist any caller from any agency within their GA.


GAE WFDSS Limitations:

Last updated on 4/21/2021 12:51:18 PM.

geographic coordinate system (GCS)

A reference system that uses latitude and longitude to define the locations of points on the surface of a sphere or spheroid. A geographic coordinate system definition includes a datum, prime meridian, and angular unit (ESRI Dictionary).

Last updated on 5/31/2010 1:24:04 PM.

geographic information systems (GIS)

An integrated collection of computer software and data used to view and manage information about geographic places, analyze spatial relationships, and model spatial processes. A GIS provides a framework for gathering and organizing spatial data and related information so that it can be displayed and analyzed (ESRI Dictionary).

Last updated on 5/31/2010 1:24:04 PM.


A set of datums by which the location of each point can be uniquely identified (Circular A-16).

Last updated on 5/31/2010 1:24:05 PM.

geospatial data

Information that identifies the geographic location and characteristics of natural or constructed features and boundaries on the Earth. This information may be derived from, among other things, remote sensing, mapping, and surveying technologies. Statistical data may be included in this definition at the discretion of the collecting agency (Circular A-16).

Last updated on 5/31/2010 1:24:05 PM.

GIS data standards

See Standards.

Last updated on 5/31/2010 1:24:05 PM.

global positioning system (GPS)

A system of radio-emitting and -receiving satellites used for determining positions on the earth. The orbiting satellites transmit signals that allow a GPS receiver anywhere on earth to calculate its own location through trilateration. Developed and operated by the U.S. Department of Defense, the system is used in navigation, mapping, surveying, and other applications in which precise positioning is necessary (ESRI Dictionary).

Last updated on 5/31/2010 1:24:06 PM.

grid weather

Weather data compiled for every grid cell within a spatial domain.

Last updated on 5/31/2012 1:24:48 PM.

growing season index (GSI)

The Growing Season Index (GSI) is a meteorological data-based phenology model that is used to predict changes to live fuel moisture throughout the year. GSI live fuel calculations, based on the selected RAWS, are used in all WFDSS fire behavior models to populate the default woody and herbaceous fuel moisture inputs. As with any model input, Fire Behavior Analysts can change the calculated defaults and enter measured or observed values when better local data is available. See GSI for more information.

Last updated on 5/20/2019 12:59:34 PM.

Heat per Unit Area

One of the outputs calculated by WFDSS Basic Fire Behavior (BFB). Its units are displayed in the BFB legend as kilojoules per meter squared (kJ/m2) or British Thermal Units per square foot (BTU/ft2). It is the fireline intensity divided by the rate of spread to give heat release for an area. If flame length is equal, a faster rate of spread will direct less heat to an area than a slower moving fire (see Rothermel and Deeming, 1980).

Last updated on 2/9/2014 11:51:14 AM.

herbaceous fuel moisture

Herbaceous fuel moisture is a calculated using the Growing Season Index (GSI) and represents the approximate moisture content of the live herbaceous vegetation in the area expressed as percentage of the oven dry weight of the sample.

Last updated on 5/20/2019 1:08:40 PM.

highly valued resource

Nationally or locally defined natural resources to be protected or improved through appropriate fire management strategy (FPA Glossary).

Last updated on 5/31/2010 1:24:06 PM.


A histogram is a bar graph that shows a frequency distribution in which the widths of the bars are proportional to the classes into which the variable has been divided and the heights of the bars are proportional to the class frequencies.

Last updated on 7/28/2010 4:35:58 PM.

hourly records (weather)

Hourly Records are the weather records that are used by the WFDSS Basic, Short-Term and Near-Term fire behavior models. Up to 24 hours of weather data is displayed for each day in the analyses conditioning and burn period.  Hourly Records are retrieved from RAWS for hours that occurred in the past and from a National Weather Service gridded forecast product for hours in the future. These records can be viewed in WFDSS by choosing a date in the weather summary table in the Analysis/Information Tab. Hourly Record inputs include, precipitation amount (in hundredths), temperature, relative humidity, wind speed, wind direction, cloud cover (%) and record type (an indicator if the weather came from a RAWS observation or the forecast).

Last updated on 1/10/2013 1:05:52 PM.




A meeting that occurs between the agency line officer, key staff, and the incoming incident management organization.

Last updated on 2/1/2011 5:25:55 PM.

incident cause

The source of ignition that started a fire. Typically, a fire is caused by humans or natural phenomenon, but sometimes the cause is undetermined.

Last updated on 8/26/2013 1:34:39 PM.

incident objectives

Site specific guidance and direction necessary for the selection of appropriate strategy(s) and the tactical direction of resources. Incident objectives are based upon agency administrators direction and constraints. Incident objectives must be measurable, yet flexible enough to allow for strategic and tactical alternatives (NWCG Wildland Fire Glossary)

Last updated on 1/22/2015 12:20:12 PM.

incident requirements

Incident-specific directives, standards, specifications, or constraints that need to be complied with when implementing management actions on a specific fire incident. Incident requirements derive from the Land Management Requirements, legal authorities, or other local influences (e.g., county commissioners, air quality boards) that pertain to the incident or its associated actions; they often define the limitations or "sideboards" when implementing the course of action.

Last updated on 2/7/2013 11:46:29 AM.


The datasets of national importance used in values at risk analyses. Layers include water supply systems and reservoirs, structure information, major power lines, pipelines, communication towers, recreation facilities, mines and other significant landmarks. Also identified are designated Wilderness and Roadless Areas, National trail systems, and National Recreation areas. Superfund sites and mines are mapped and reported along with other HAZMAT locations. (NFDSC Economics Group)

Last updated on 5/14/2020 7:53:46 AM.

initial attack

An aggressive action to put the fire out consistent with firefighter and public safety and values to be protected. (NWCG#024-2010 Memorandum Attachment A: Terminology Updates List)

Last updated on 8/25/2010 4:51:44 PM.

initial response (IR)

Immediate decisions and actions taken to react to an ignition. (NWCG#024-2010 Memorandum Attachment A: Terminology Updates List)

Last updated on 8/12/2010 1:25:23 PM.


The amount of heat a fire emits.

Last updated on 7/28/2010 4:40:10 PM.

Jurisdictional Agency

The agency having land and resource management responsibility for a specific geographical or functional area as provided by federal, state, or local law (NWCG Wildland Fire Glossary).

Last updated on 5/27/2011 1:55:14 PM.

land management objectives

The objectives set forth in an approved Land Management Plan, Resource Management Plan, Fire Management Plan, or other guiding document that provide the basis for the fire management program in a designated area. The objectives identify the need for and use of fire in a particular area and for a specific benefit. Not all land management objectives are directly related to the fire management program.

Last updated on 8/27/2010 11:19:51 AM.

Land/Resource Management Plan (L/RMP)

A document prepared with public participation and approved by an agency administrator that provides general guidance and direction for land and resource management activities for an administrative area. The L/RMP identifies the need for fire’s role in a particular area and for a specific benefit. The objectives in the L/RMP provide the basis for the development of fire management objectives and the fire management program in the designated area (NWCG Wildland Fire Glossary).

Last updated on 5/31/2010 1:24:07 PM.

landscape critique

A landscape critique provides summary information regarding the 8 layers that comprise the landscape file (elevation, slope, aspect, fuel model, canopy cover, stand height, canopy base height, and canopy bulk density). The critique is constrained by user-defined parameters (landscape extent, resolution, landscape data source, and fuel model option). Once generated, you can download the landscape critique as a PDF file and use it to quantify and visually critique a landscape's data layers.

A landscape critique contains the following:

  1. -----------
    Last updated on 9/9/2010 4:09:00 PM.
landscape extent

In WFDSS, defines the area on the landscape that determines the size of the LCP file. All fire behavior analyses outputs are limited to the area included in the landscape extent.

Last updated on 8/19/2011 1:52:56 PM.

landscape mask

A polygon feature that analysts use to change fuel or stand characteristics in a defined area on the modeled landscape. A landscape mask is a zipped shapefile that Incident Owners or Editors or Fire Behavior Specialists can create in WFDSS or upload from a GIS. Analysts use landscape masks to make modeled fire more representative of observed fire behavior, or to incorporate more recent changes that are not represented in the selected landscape data layer.

Last updated on 8/4/2011 4:26:42 PM.

large fire

For statistical purposes, a fire burning more than a specified area of land e.g., 300 acres.

A fire burning with a size and intensity such that its behavior is determined by interaction between its own convection column and weather conditions above the surface. (NWCG Wildland Fire Glossary)

Last updated on 7/28/2010 1:48:39 PM.

latest perimeter size

Displays size in acres of most recent uploaded perimeter in WFDSS.


[data structures] The visual representation of a geographic dataset in any digital map environment. Conceptually, a layer is a slice or stratum of the geographic reality in a particular area, and is more or less equivalent to a legend item on a paper map. On a road map, for example, roads, national parks, political boundaries, and rivers might be considered different layers.

[ESRI software] In ArcGIS, a reference to a data source, such as a shapefile, coverage, geodatabase feature class, or raster, that defines how the data should be symbolized on a map. Layers can also define additional properties, such as which features from the data source are included. Layers can be stored in map documents (.mxd) or saved individually as layer files (.lyr). Layers are conceptually similar to themes in ArcView 3.x.(ESRI Dictionary)

Last updated on 7/28/2010 1:50:23 PM.


An Open Layers map control. The Layer Switcher control displays the table of contents for a WFDSS map display. This allows the user interface to switch between Base Layers and to show or hide Overlays. In WFDSS, the switcher is located on the map tab to the left of a map display.

Last updated on 11/29/2023 4:32:13 PM.


The description of the types of features included in a map, usually displayed in the map layout. Legends often use graphics of symbols or examples of features from the map with a written description of what each symbol or graphic represents. (ESRI, Dictionary)

Last updated on 5/31/2010 1:24:09 PM.


On a map, a shape defined by a connected series of unique x,y coordinate pairs. A line may be straight or curved. (ESRI Dictionary)

Last updated on 7/28/2010 1:51:20 PM.

live fuel moisture

Live fuels are typically divided into two categories: herbaceous and woody. Live fuels in general refer to naturally occurring fuels whose moisture content is controlled by physiological processes within the plant.

Last updated on 7/28/2010 5:03:04 PM.

major paths

WFDSS Short Term Fire Behavior's (STFB) major paths show only the most significant fire spread pathways.

Last updated on 10/8/2010 4:04:36 PM.

management action point (M.A.P.)

Clearly specified management conditions for an incident that, when reached, cause the implementation of a predefined modification to existing management actions, or trigger the deployment of new strategies and/or tactics. M.A.P.s are usually spatial, but can also be temporal or tied to conditions that cannot be conveyed geographically using points, lines, or polygon features.

A zipped shapefile that contains point, line, or polygon features and can be created in WFDSS or uploaded from a GIS by an incident owner or editor. The shapefile depicts the spatial component of an M.A.P. if it has one.

Last updated on 8/19/2011 1:54:44 PM.

Management Requirement

The requirements set forth in an approved Land Management Plan, Resource Management Plan, Fire Management Plan or other guiding documents that provide the basis for land and resource management in a designated area. Requirements are directives, standards, specifications or constraints that must be complied with when implementing management actions.

The term Management Requirement is specific to WFDSS although its definition mirrors that of Land Management Requirement as published in Decision Making for Wildfire: A Guide for Applying a Risk Management Process at the Incident Level GTR-298. Developed cooperatively by the S482 Steering Committee, Brett Fay (Fire Use Subcommittee), Dick Bahr (Policy), Jeff Manley (Interagency Fire Planning Committee), and Lisa Elenz (Wildland Fire Management RD&A - WFDSS); the definition is currently utilized by the S482 course and has been submitted for inclusion in the NWCG Wildland Fire Glossary.

management requirement shapes

Management Requirement shapes are shapes that can be used to represent temporal or condition based requirements. This allows a unit’s direction to change throughout fire season as species of concern migrate, or drought conditions worsen or improve to name a few examples. Units control their own Management Requirement shapes. They can upload them or draw them directly in WFDSS. Written direction supports Management Requirement shapes.

Last updated on 2/26/2013 7:55:34 PM.


Any graphical representation of geographic or spatial information. (ESRI Dictionary)

Last updated on 7/28/2010 1:56:44 PM.

map extent

The limit of the geographic area shown on a map, usually defined by a rectangle. In a dynamic map display, the map extent can be changed by zooming and panning. (ESRI Dictionary)

Last updated on 7/28/2010 1:56:45 PM.

map projection

See projection.

Last updated on 4/7/2011 2:04:09 PM.

map scale

The ratio or relationship between distance or area on a map and the corresponding distance or area on the ground. (GSTOP)

Last updated on 7/28/2010 2:06:54 PM.

max degree of fit

This value determines the detail required to achieve an adequate statistical curve-fit of the seasonal trends in ERC. ERC trends throughout a calendar year typically show one or more major peaks and troughs corresponding to dry and wet periods. A larger value in this field allows a curve-fitting procedure to better represent peaks and troughs that occur on shorter and shorter time periods. An adequate range of Max Degree of Fit is 8 to 11 the WFDSS default is 9. About ERC Correlation Parameters, and Max Lag provide additional information about Max Degree of Fit.

Last updated on 6/4/2012 4:29:10 PM.

max lag

This value determines the maximum number of previous days that influence the ERC on the current day. Daily ERC values are "autocorrelated" (meaning they depend statistically on values from earlier observations) with values from previous days because the moisture content of dead fuels changes more slowly than changes in weather conditions. In other words, today's value is statistically correlated with yesterday's value as well as the day before, etc, but it is less correlated with values further away from the current day.

The rates that fuel moistures change in response to changes in weather conditions is called a "timelag" and is longer in larger diameter dead woody fuels and deeper duff layers. The default value of 30 is a reasonable value in many fuel types, especially where larger woody fuels and duff layers contribute to fire behavior. If you do not want the the correlation to go back 30 days from the start date of the analysis, you can change the number of Max Lag days. About ERC Correlation Parameters ,and Max Degree of Fit provide additional information about Max Lag days.

Last updated on 6/4/2012 4:29:14 PM.


Information that describes the content, quality, condition, origin, and other characteristics of data or other pieces of information. Metadata for spatial data may describe and document its subject matter; how, when, where, and by whom the data was collected; availability and distribution information; its projection, scale, resolution, and accuracy; and its reliability with regard to some standard. Metadata consists of properties and documentation. Properties are derived from the data source (for example, the coordinate system and projection of the data), while documentation is entered by a person (for example, keywords used to describe the data). (ESRI Dictionary)

Last updated on 7/28/2010 2:06:55 PM.

National Digital Forecast Database

National Weather Service (NWS) Forecast Data consists of 2.5 kilometer gridded forecasts of wind and weather data (e.g., cloud cover, maximum temperature, windspeed). The database contains a seamless mosaic of digital forecasts that have been validated by meteorologists at National Weather Service field offices.

Forecast data is used in WFDSS Basic, Short-Term, Near-Term and FSPRO Fire Behavior models. For consistency with current and historic data, the NWS Forecast weather and wind data are obtained from the forecast grid that is located over the RAWS used in the analysis.


Last updated on 2/9/2013 11:28:03 AM.

National Fire Danger Rating System (NFDRSO

NFDRS is a uniform fire danger rating system that focuses on the environmental factors controlling moisture content of fuels.

Last updated on 10/5/2010 2:01:22 PM.

National Geospatial Data Clearinghouse (NGDC)

A distributed network of geospatial data producers, managers, and users linked electronically. Building on initiatives, such as the national information infrastructure, the clearinghouse uses a distributed, electronically connected network, such as the Internet. Each data provider describes available data in an electronic form, and provide these descriptions (or "metadata") using means that can be accessed over a communications network. Thus, the data for the clearinghouse are located at the sites of data producers (or, where more efficient, at the sites of intermediaries) throughout the country. Using the network, users will search these descriptions to locate data that are suitable for their applications. (FGDC-STD-001-1998)

Last updated on 10/5/2010 2:03:05 PM.

National Spatial Data Infrastructure (NSDI)

The technology, policies, standards, human resources, and related activities necessary to acquire, process, distribute, use, maintain, and preserve spatial data (e.g., information and process discovery, publishing data, publishing symbol libraries, query filtering, data fusing, Earth imaging, photogrammetry, location processing, and spatial analysis). (Circular A-16)

Last updated on 10/5/2010 2:03:57 PM.

National Wildfire Coordinating Group (NWCG)

An operational group designed to coordinate programs of the participating wildfire management agencies. (NWCG)

Last updated on 8/27/2010 10:44:34 AM.

non-federal partners

Refers to any entity that is not a federal government agency. This could include state organization, counties, local governments, independent fire departments, and organizations like The Nature Conservancy.

North American Datum 1983

A geocentric datum and graphic coordinate system based on the Geodetic Reference System 1980 ellipsoid (GRS80). Mainly used in North America, its measurements are obtained from both terrestrial and satellite data. (ESRI Dictionary)

Last updated on 10/5/2010 9:26:50 PM.

Number of Days

The number of days value represents the number of days into the future (including the Analysis Start Date) an FSPro analysis generates probability outputs for an incident. WFDSS sets the default value at seven, but Fire Behavior Analysts can adjust this value as needed. Number of days values are typically set to between seven and fourteen days. The generated probabilities are no longer valid after the number of days value expires.

Considerations and recommendations for setting the number days value include:

Last updated on 2/5/2019 12:22:56 PM.

objective, incident

See incident objectives.

objective, management

See Strategic Objectives.

organizational unit

An office that is administratively responsible for either one of the following:

Last updated on 8/25/2010 5:00:39 PM.


A single cadastral unit, which is the spatial extent of the past, present, and future rights and interests in real property. (Cadastral Data Content Standard for the National Spatial Data Infrastructure - May 2008 – Version 1.4)

Last updated on 10/5/2010 9:27:55 PM.


The Forest Service job code for an incident.


Data Models: The smallest unit of information in an image or raster map, usually square or rectangular. Pixel is often used synonymously with cell.

Remote sensing: The fundamental unit of data collection. A pixel is represented in a remotely sensed image as a cell in an array of data values. (ESRI Dictionary)

Last updated on 10/5/2010 9:29:05 PM.

planning area

An area an Incident Owner or Editor defines on the landscape that includes all the land a fire might burn during the life of a decision; it includes the area used for analysis and planning to manage a fire.

Planning areas help you to establish an area of interest around an incident. They determine which FMUs are contained or partially contained by the planning area, and subsequently, which preloaded strategic objectives and management requirements need to be addressed when developing incident objectives and requirements. Planning areas should be large enough to include the following:

Planning areas are required for documenting a decision and are different from a WFSA boundary or WFIP Maximum Manageable Area, two outdated and no longer used concepts. By limiting the planning area to just where you think a fire might go, you are limiting the decision support capability of the application.

Drawing a large planning area may incorporate more FMUs, which in turn may require you to address more strategic objectives, management requirements, and values at risk, but if your planning area is too small, you will have to create a new decision each time management actions occur outside of the existing planning area. It's helpful to use an FSPro probability output as a general guide when trying to determine an appropriate planning area size. Doing this will ensure that the Values at Risk identified by an FSPro output are included in the Values Inventory (a product of the planning area), and addressed in the Incident Objectives. If your FSPro outputs are larger than your planning area, your planning area is too small.

No ramifications result from drawing a large planning area, and it is helpful to use an FSPro probability output to inform you of where the fire may try to move. If you are currently planning management action points or contingency plans outside of your planning area, you are planning outside of your planning area. Your planning area should be larger to include those areas.

WFDSS user roles (Viewer, Dispatcher, Author, GA Editor, National Editor, and Data Manager) can optionally subscribe to planning area notifications for one or more units. When you draw a planning area and create a pending (but not published) decision, WFDSS users who have subscribed to planning area notifications are notified. These individuals received emails for each unit(s) they subscribed to, and were included in the planning area when it was drawn.

See About Planning Areas for further information.

Last updated on 10/9/2018 1:41:55 PM.


A geometric element defined by a pair of x,y coordinates. (ESRI Dictionary)

Last updated on 10/5/2010 9:29:41 PM.

point of origin

The location where a competent ignition source came into contact with the material first ignited and sustained combustion occurred. (Wildland Fire Glossary)

Last updated on 10/5/2010 9:30:14 PM.


On a map, a closed shape defined by a connected sequence of x,y coordinate pairs, where the first and last coordinate pair are the same and all other pairs are unique. (ESRI Dictionary)

Last updated on 10/5/2010 9:30:45 PM.

prescribed fire

Any fire intentionally ignited by management under an approved plan to meet specific objectives. (NWCG#024-2010 Memorandum Attachment A: Terminology Updates List)

Last updated on 8/25/2010 5:06:03 PM.

production rate

The rate at which fire line containing a fire's spread is produced by a particular type of initial attack forces. For ground forces, the entry is chains per hour. For aerially delivered retardant or water, the entry is the typical aircraft load in hundreds of gallons (1200 gallons = "12").


The WFDSS user profile assigned to you. You have one profile that is shared between Production and Training.

Last updated on 11/16/2023 11:58:18 AM.


A method by which the curved surface of the earth is portrayed on a flat surface. This generally requires a systematic mathematical transformation of the earth's graticule of lines of longitude and latitude onto a plane. Some projections can be visualized as a transparent globe with a light bulb at its center (though not all projections emanate from the globe's center) casting lines of latitude and longitude onto a sheet of paper. Generally, the paper is either flat and placed tangent to the globe (a planar or azimuthal projection) or formed into a cone or cylinder and placed over the globe (cylindrical and conical projections). Every map projection distorts distance, area, shape, direction, or some combination thereof. (GSTOPESRI Dictionary)

Last updated on 10/5/2010 1:53:56 PM.

protection boundary

The exterior perimeter of an area within which a specified fire agency has assumed a degree of responsibility for wildland fire control. It may include land in addition to that for which the agency has jurisdiction or contractual responsibility. (Wildland Fire Glossary)

Last updated on 10/5/2010 9:31:30 PM.

Public Land Survey System (PLSS)

Public Land Survey System Descriptions are descriptions for areas of land that follow the pattern of Townships and Ranges established by the federal government in 1785 and its successors. (Cadastral Data Content Standard for the National Spatial Data Infrastructure - May 2008 – Version 1.4)

Last updated on 10/5/2010 9:32:13 PM.

published decision

The decision content reviewed and approved by a line officer or agency administrator within the Wildland Fire Decision Support System (WFDSS). When approved and "published" the decision information becomes a permanent record for the wildfire.

Last updated on 2/9/2013 11:27:39 AM.

pumping minutes

Used with reference to engines. The typical amount of time that a particular type engine can pump water from its own supply during the initial attack action.


A rectangular map bounded by lines of latitude and longitude, often a map sheet in either the 7.5-minute or 15-minute series published by the U.S. Geological Survey. Quadrangles are also called topo sheets. (ESRI Dictionary)

Last updated on 10/8/2010 3:23:29 PM.

raster data

A spatial data model that defines space as an array of equally sized cells arranged in rows and columns, and composed of single or multiple bands. Each cell contains an attribute value and location coordinates. Unlike a vector structure, which stores coordinates explicitly, raster coordinates are contained in the ordering of the matrix. Groups of cells that share the same value represent the same type of geographic feature. (ESRI Dictionary)

Last updated on 10/8/2010 3:25:44 PM.

rate of spread

The linear rate of advance of a fire front in the direction perpendicular to the fire front. Rate of spread is one of the outputs calculated by WFDSS Basic Fire Behavior (BFB). The maximum rate of spread for each grid cell of the Landscape File is calculated and displayed in the BFB legend as meters/min.

Remote Automated Weather Station (RAWS)

A RAWS is a GOES satellite, telemetered weather station (often in a remote location) that transmits hourly observations 24 times per day and is used mainly to observe potential wildfire conditions.

remote sensing

Collecting and interpreting information about the environment and the surface of the earth from a distance, primarily by sensing radiation that is naturally emitted or reflected by the earth's surface or from the atmosphere, or by sensing signals transmitted from a device and reflected back to it. Examples of remote sensing methods include aerial photography, radar, and satellite imagery. (GSTOPESRI Dictionary)

Last updated on 10/8/2010 3:27:23 PM.

representative weather station

A user-defined weather station representative of the FMU for the purpose of defining breakpoints for Fire Dispatch Levels and WFU events.


The minimum difference between two independently measured or computed values that can be distinguished by the measurement or analytical method being considered or used. (FGDC-STD-001-1998)

Last updated on 10/8/2010 3:27:23 PM.


See map scale.

Last updated on 10/8/2010 3:28:35 PM.


See fire severity.

Last updated on 8/25/2010 5:07:48 PM.

shaded relief image

A raster image that shows light and shadow on terrain from a given angle of the sun. (GSTOP)

Last updated on 10/8/2010 3:31:32 PM.


A vector data storage format for storing the location, shape, and attributes of geographic features. A shapefile is stored in a set of related files and contains one feature class. (ESRI Dictionary)

Last updated on 10/8/2010 3:31:32 PM.

Short-Term Fire Behavior

A two-dimensional fire growth model. This web-based (mostly automated) application calculates spread rates and maximum spread direction at each cell. Using one set of wind and fuel moisture conditions, it provides potential fire spread (arrival times and major paths) for a user-defined length of time. STFB is essentially a web-based version of FlamMap's Minimum Travel Time (MTT) which is a desktop application.

Last updated on 10/8/2010 3:55:32 PM.

slope theme

One of the raster themes that make up the Landscape File. The units are in integers of degrees of inclination from the horizontal. The slope theme is necessary for computing slope effects on fire spread and solar radiance.

Last updated on 10/8/2010 3:32:06 PM.

solar radiation

One of the outputs calculated in WFDSS Basic Fire Behavior (BFB).  It contains the solar radiation as calculated on the user-selected Burn Date and Time using a 7-day fuel moisture conditioning period. Solar radiation is expressed as Watts per square meter (W/m2).

Last updated on 10/8/2010 3:32:06 PM.


Related to or existing within space. (ESRI Dictionary)

Last updated on 10/8/2010 3:35:31 PM.

spatial analysis

The process of examining the locations, attributes, and relationships of features in spatial data through overlay and other analytical techniques in order to address a question or gain useful knowledge. Spatial analysis extracts or creates new information from spatial data. (ESRI Dictionary)

Last updated on 10/8/2010 3:35:31 PM.

spatial data

Information about the locations and shapes of geographic features and the relationships between them, usually stored as coordinates and topology. (ESRI Dictionary)

Last updated on 10/8/2010 3:35:31 PM.

spatial modeling

A methodology or set of analytical procedures used to derive information about spatial relationships between geographic phenomena. (ESRI Dictionary)

Last updated on 10/8/2010 3:37:53 PM.

spatial query area

Spatial 'masks' that are predefined in the system based on common query frameworks, such as agency boundaries, regional boundaries, state boundaries, etc. The user would select one or more of these masks to extract information from the system.

stand height theme

A raster theme in the Landscape File that is used for computing wind reduction to midflame height and spotting distances from torching trees. This value is neither that of the tallest tree nor an average height of all trees. A good estimate at stand height would be the average height of the dominant and co-dominant trees in a stand. Values (in WFDSS Landscapes) are in meters with a precision of the fire behavior calculations limited to the nearest 1/10th meter.

Last updated on 10/8/2010 3:39:37 PM.


Documented agreements containing technical specifications or other precise criteria to be used consistently as rules, guidelines, or definitions of characteristics to ensure that materials, products, processes, or services are fit for their purposes (Circular A-16).

Last updated on 5/31/2010 1:24:15 PM.

state plane coordinate system (SPCS)

A group of planar coordinate systems based on the division of the United States into more than 130 zones to minimize distortion caused by map projections. Each zone has its own map projection and parameters and uses either the NAD27 or NAD83 horizontal datum. The Lambert conformal conic projection is used for states that extend mostly east-west, while transverse Mercator is used for those that extend mostly north-south. The oblique Mercator projection is used for the panhandle of Alaska. (ESRI Dictionary)

Last updated on 10/8/2010 3:41:01 PM.

status bar

A small area at the bottom of the web browser window that displays helpful information the about processing status of the WFDSS application's most recent actions.

Last updated on 9/9/2010 3:58:53 PM.


strategic objective shapes

The strategic objective shape layer is intended to spatially represent the strategic objectives of the landscape and the unit boundary shape; it allows you to utilize shapes other than FMUs to visually depict their fire management direction.

Last updated on 2/26/2013 7:52:41 PM.

Strategic Objectives

The objectives set forth in an approved Land Management Plan, Resource Management Plan, Fire Management Plan or other guiding documents that provide the basis for land and resource management in a designated area; often referred to as Desired Future Conditions. These are broad statements that identify changes in water, soil, air or vegetation from the present to proposed conditions but can also describe an existing resource condition that should be maintained. Strategic objectives deal with large areas over long time periods and project intended outcomes of management activities that contribute to the maintenance or achievement of desired conditions.

The term Strategic Objective is specific to WFDSS (Zimmerman 2001) although its definition mirrors that of Land Management Objective as published in Decision Making for Wildfire: A Guide for Applying a Risk Management Process at the Incident Level GTR-298. Developed cooperatively by the S482 Steering Committee, Brett Fay (Fire Use Subcommittee), Dick Bahr (Policy), Jeff Manley (Interagency Fire Planning Committee), and Lisa Elenz (Wildland Fire Management RD&A - WFDSS); the definition is currently utilized by the S482 course and has been submitted for inclusion in the NWCG Wildland Fire Glossary.

Stratified Cost Index (SCI)

Regression equation that calculates the expected suppression cost of a large fire (greater than 300 acres) given its characteristics.


See buildings.

Last updated on 5/31/2010 1:24:16 PM.


Management action to extinguish a fire or to confine fire spread. (NWCG#024-2010 Memorandum Attachment A: Terminology Updates List)

Last updated on 8/25/2010 5:09:51 PM.

Surface Management Agency (SMA)

The National Integrated Land System's (NILS) GeoCommunicator provides a Web Mapping Application and Map Services showing "Surface Management Agency" data. The Surface Management Agency data layer portrays tracts of federal land for the United States and classifies these holdings by administrative agency. Multiple federal agencies have contributed to the contents of this layer and it is in a continuous state of update. Source and date of feature updates are tracked to the feature level. (

Last updated on 10/8/2010 3:42:00 PM.

tabular data

Descriptive information, usually alphanumeric, that is stored in rows and columns in a database and can be linked to spatial data. (ESRI Dictionary)

Last updated on 10/8/2010 3:45:19 PM.

tactical objective

Statements of tactical direction for small, site-specific areas (e.g., divisions or branches). Tactical objectives may be limited to short time periods, such as a single operational period (<24 hours), but can be extended for multiple operational periods. Tactical objectives can serve as a means for tracking incident accomplishments and workload demand thresholds.

Last updated on 2/9/2013 11:26:54 AM.


A set of related geographic features, such as streets, parcels, or rivers, along with their attributes. All features in a theme share the same coordinate system, are located within a common geographic extent, and have the same attributes. (ESRI Dictionary)

Last updated on 10/8/2010 3:45:19 PM.

time series

Quantities of data that represent or trace the values taken by a variable over a period of time such as a month, quarter, or year. Time series data occur whenever the same measurements are recorded on a regular basis. In WFDSS, time series is used by the FSPro fire simulation model and is an ordered sequence of values of a variable (ERC) that are equally spaced in time (1 day).

A time series analysis is used to characterize the seasonal trend in ERC, autocorrelation of residuals, and daily standard deviation and stochastically generate artificial time series of afternoon fuel moisture. Time series modeling is capable of generating a large number of realistic weather scenarios needed for ensemble fire simulations (such as FSPro) and capturing the main influences of antecedent and future weather trends (FSPro: Finney, M. A., Grenfell, I. C., McHugh, C. W.,Seli, R. C., Trethewey, D., Stratton, R. D., Brittain, S. (2010). A method for ensemble wildland fire simulation. Environmental Modeling and Assessment. doi: 10.1007/s10666-010-9241-3)

Last updated on 6/27/2011 5:22:42 PM.


The study and mapping of land surfaces, including relief (relative positions and elevations) and the position of natural and constructed features. (ESRI Dictionary)

Last updated on 10/8/2010 3:46:46 PM.


Defines and enforces data integrity rules (for example, there should be no gaps between polygons). It supports topological relationship queries and navigation (for example, navigating feature adjacency or connectivity), supports sophisticated editing tools, and allows feature construction from unstructured geometry (for example, constructing polygons from lines). (ESRI Dictionary)

Last updated on 10/8/2010 3:46:46 PM.

Training System

Provides a fully functional WFDSS application in a "sandbox" environment. This system allows students, trainers, and others to run scenarios and to familiarized themselves with WFDSS without affecting the real data.

universal polar stereographic (UPS)

A projected coordinate system that covers all regions not included in the UTM coordinate system; that is, regions above 84 degrees north and below 80 degrees south. Its central point is either the north or south pole. (ESRI Dictionary)

Last updated on 10/8/2010 3:48:40 PM.

universal transverse Mercator (UTM)

A projected coordinate system that divides the world into 60 north and south zones, with each zone being 6 degrees wide. (ESRI Dictionary)

Last updated on 10/8/2010 3:48:41 PM.


Those ecologic, social, and economic interests that could be affected by fire.

Last updated on 2/9/2013 11:26:44 AM.

Values at Risk

Personal, municipal, state, or federal property located in the area where FSPro probability outputs intersect the values layers. This list of property includes, but is not limited to, cultural assets, threatened and endangered species habitat, and utility infrastructures. Fire spread probability analyses, such as those provided by FSPro, help managers determine the likelihood of a particular asset being damaged by an incident.

Last updated on 3/25/2011 1:23:20 PM.

Values Inventory

Personal, municipal, state, or federal property located in the area where a simple polygon (such as a planning area, unit shape, or simulated fire perimeter) or Point of Origin intersects the values layers. This list of property includes, but is not limited to, cultural assets, threatened and endangered species habitat, and utility infrastructures. Deterministic fire behavior analysis models, such as STFB and NTFB, and the Point of Origin Inventory menu option generate a values inventory.

Last updated on 2/27/2013 12:15:55 PM.

vector data

A coordinate-based data model that represents geographic features as points, lines, and polygons. Each point feature is represented as a single coordinate pair, while line and polygon features are represented as ordered lists of vertices. Attributes are associated with each vector feature, as opposed to a raster data model, which associates attributes with grid cells. (ESRI Dictionary)

Last updated on 10/8/2010 3:50:47 PM.

vertical datum

A geodetic datum for any extensive measurement system of heights on, above, or below the earth's surface. Traditionally, a vertical geodetic datum defines zero height as the mean sea level at a particular location or set of locations; other heights are measured relative to a level surface passing through this point. Examples include the North American Vertical Datum of 1988; the Ordnance Datum Newlyn (used in Great Britain); and the Australian Height Datum. (ESRI Dictionary)

Last updated on 10/8/2010 3:50:47 PM.


Wildland Fire Decision Support System. This decision support system is intended to assist wildland fire managers in assessing risks and fire behavior during an event.

WFDSS Basic Fire Behavior

See Basic Fire Behavior.

Last updated on 10/8/2010 3:53:27 PM.

WFDSS jurisdicational unit at point of origin

The agency with administrative responsibilities related to an incident's location. This field displays one of three values:

Last updated on 4/4/2011 1:26:40 PM.

WFDSS Production System

The live system where actual wildland fires are recorded, tracked, and reported. This system is used in analyzing real events and should not be used to create "what-if" scenarios or for practice. Users who abuse the system will be barred from the system and their supervisors will be notified.

WFDSS Short Term Fire Behavior

See Short-Term Fire Behavior.


An unplanned ignition caused by lightning, volcanoes, unauthorized, accidental, human-caused actions, and escaped prescribed fire(s). (NWCG#024-2010 Memorandum Attachment A: Terminology Updates List)

Last updated on 8/25/2010 5:12:56 PM.

wildland fire

A general term describing any non-structure fire that occurs in the vegetation and/or natural fuels. (NWCG#024-2010 Memorandum Attachment A: Terminology Updates List)

Last updated on 8/25/2010 5:13:39 PM.

wildland fire use
wildland urban interface (WUI)

The line, area, or zone where structures and other human development meet or intermingle with undeveloped wildland or vegetative fuels. (NWCG#024-2010 Memorandum Attachment A: Terminology Updates List)

Last updated on 8/25/2010 5:14:39 PM.


A computer program that computes spatially varying wind fields (gridded winds) for wildland fire application. It requires elevation data for the modeling area, a domain-mean initial wind speed and direction, and specification of the dominate vegetation in the area. It can be downloaded from

WFDSS Basic Fire Behavior and Short-Term Fire Behavior provide users with the option of using a version of WindNinja to generate gridded winds. Gridded winds are generated when the landscape is produced and the wind vectors are created at the same resolution as the landscape. For more information, see the Windninja webpage.

Last updated on 8/17/2017 11:07:34 AM.

woody fuel moisture

Woody fuel moisture is calculated using the Growing Season Index (GSI) and represents the approximate moisture content of the live woody vegetation in the area expressed as percentage of the oven dry weight of the sample.

Last updated on 5/20/2019 1:06:31 PM.