Glossary

  • Moisture content of 1-hour fuel (dead woody fuel 0 to ¼ inch or 0 to 6.4 mm in diameter) is the mass of water within the fuel particle expressed as a percentage of the fuel particle’s oven-dry mass.
  • Fuels consisting of dead herbaceous plants and roundwood less than about one-quarter inch (6.4 mm) in diameter. Also included is the uppermost layer of needles or leaves on the forest floor.
  • Moisture content of 10-hour fuel (dead woody fuel ¼ to 1 inch or 0.6 to 2.5 cm in diameter) is the mass of water within the fuel particle expressed as a percentage of the fuel particle’s oven-dry mass.
  • Moisture content of 100-hour fuel (dead woody fuel 1 to 3 inches or 2.5 to 7.6 cm in diameter) is the mass of water within the fuel particle expressed as a percentage of the fuel particle’s oven-dry mass.
  • Moisture content of 1000-hour fuel (dead woody fuel over 3 inches or 7.6 cm in diameter) is the mass of water within the fuel particle expressed as a percentage of the fuel particle’s oven-dry mass.
  • Wind direction is the direction from which the wind is blowing, specified in degrees increasing clockwise from north (which is zero degrees), Uphill or Downhill.
  • Wind velocity measured 20 feet (6 m) above the top of the tree or shrub canopy, or above the ground if canopy is absent.
  • A measure of land used in the Imperial and US systems; 43,560 square feet or 4,840 square yards. There are 640 acres in one square mile. One acre is 0.405 hectares.
  • A fire in which a solid flame develops in the crowns of trees, but the surface and crown phases advance as a linked unit dependent on each other.
  • Fuels resulting from, or altered by, forestry practices such as timber harvest or thinning, as opposed to naturally created fuels (for a definition of naturally created fuels see Natural Fuels).
  • The term "adiabatic" describes any process that occurs without heat transfer. As defined by NWCG: Adiabatic process. Thermodynamic change of state in which no heat is added or subtracted from a system; compression always results in warming, expansion in cooling.
  • A public information description of the relative severity of the current fire danger situation. Low, Moderate, High, Very High, Extreme.
  • Standing and supported live and dead combustibles not in direct contact with the ground and consisting mainly of foliage, twigs, branches, stems, cones, bark, and vines. See also: needle drape
  • The official responsible for the management of a geographic unit or functional area. The managing officer of an agency, division thereof, or jurisdiction having statutory responsibility for incident mitigation and management. Examples: NPS Park Superintendent, BIA Agency Superintendent, USFS Forest Supervisor, BLM District Manager, FWS Refuge Manager, State Forest Officer, Tribal Chairperson, Fire Chief, Police Chief.
  • The composition of air with respect to quantities of pollution therein; used most frequently in connection with "standards" of maximum acceptable pollutant concentrations. Used instead of "air pollution" when referring to programs.
  • Mathematical or quantitative representation or simulation of air quality processes; e.g., emission models, receptor models, or air quality dispersion models.
  • New landscape saved during a landscape editing session where an edit rule has been applied, such as edits made to create an Existing Condition (EC)(defined below) or to reflect post-treatment conditions that would result from a fuel treatment alternative. You may check to see if editing rules have been applied to a landscape by selecting the landscape in question from My Workspace View and then selecting the view edit rules button.
  • The original 13 fire behavior fuel models, represents severe fire conditions
  • A shapefile (polygon) is a simple non-topographical way to store geometric location and attribute information for landscape features; they are often used to represent treatment areas, burn units, and other areas of disturbances. Shapefiles can be used for many purposes in IFTDSS, and depending on what they are used for, you may see them referred to by different names. Area of Interest: This term is used in the Landscape Summary task and Determining Treatment Alternatives task to constrain the area of your analysis or reporting. Landscape Mask: This term is used in Landscape Editing to constrain the area your edits apply to. Polygon, Shape, Shapefile, Mask: These terms are used interchangeably throughout Map Studio .
  • Cardinal direction toward which a slope faces.
  • An asset is a human-made thing—a building, communication tower, road, etc.—of use or value to its owner. (Scott, Joe H.; Thompson Matthew P.; Calkin, David E. (2013) A Wildfire Risk Assessment Framework for Land and Resource Management . General Technical Report RMRS-GTR-315. USDA Forest Service, Rocky Mountain Research Station, 83 p.)
  • A single feature within a landscape layer, such as fuel model, canopy cover, canopy base height, etc.
  • The portion of the total fuel that would actually burn under various environmental conditions.
  • 1) Fire spreading, or ignited to spread, into (against) the wind or downslope. A fire spreading on level ground in the absence of wind is a backing fire. 2) That portion of the fire with slower rates of fire spread and lower intensity normally moving into the wind and/or down slope. Also called: heel fire.
  • Ecosystems of regional extent. Four levels of detail are included to show a hierarchy of ecosystems: - The largest ecosystems are domains, which are groups of related climates and which are differentiated based on precipitation and temperature. - Divisions are subdivided into provinces, which are differentiated based on vegetation or other natural land covers. - The finest level of detail is described by subregions, called sections, which are subdivisions of provinces based on terrain features. - Also identified are mountainous areas that exhibit different ecological zones based on elevation. Ecoregions are: Tundra, subarctic, warm continental, hot continental, subtropical, prairie, marine, Mediterranean, tropical/subtropical steppe desert, tropical/subtropical desert, temperate steppe, temperate desert, savanna, and rainforest.
  • Any obstruction to the spread of fire. Typically an area or strip devoid of combustible fuel.
  • Accumulations of bark, downed woody debris, litter, and duff surrounding tree trunks.
  • The Burning index (BI) is a relative number calculated in the National Fire Danger Rating System (NFDRS) related to the contribution that fire behavior makes to the amount of effort needed to contain a fire in a specified fuel type. Doubling the burning index indicates that twice the effort will be required to contain a fire in that fuel type as was previously required, providing all other parameters are held constant.
  • LANDFIRE layer representing vegetation that may have been dominant on the landscape prior to Euro-American settlement and is based on the current biophysical environment and approximation of the historical disturbance regime.
  • Trees that have been blown down by the wind. As defined by NWCG: Blow Down - An area of previously standing timber which has been blown over by strong winds or storms.
  • The trunk of a tree.
  • LANDFIRE layer representing vegetation that may have been dominant on the landscape prior to Euro-American settlement and is based on the current biophysical environment and approximation of the historical disturbance regime.
  • A collective term that refers to stands of vegetation dominated by shrubby, woody plants, or low growing trees.
  • Land plants that do not have true vascular tissue.
  • The Buildup index (BUI) is a relative measure of the cumulative effect of daily drying factors and precipitation on fuels with a ten-day timelag used with the Canadian Forest Fire Danger Rating System (CFFDRS).
  • The Buildup index (BUI) is a relative measure of the cumulative effect of daily drying factors and precipitation on fuels with a ten-day timelag used with the Canadian Forest Fire Danger Rating System (CFFDRS).
  • Weight per unit volume. For fuels, this is usually expressed as pounds per cubic foot; for soils, grams per cubic centimeter.
  • A discrete area within a larger prescribed fire project.
  • That part of each 24-hour period when fires spread most rapidly; typically from 10:00 AM to sundown (as defined by NWCG).
  • Burn Probability (BP) quantifies the likelihood of a fire occurring under a fixed set of weather and fuel moisture conditions. BP = # times a pixel burns / total number of fires simulated
  • A qualitative assessment of the heat pulse during a fire. Burn severity relates to soil heating, large fuel and duff consumption, consumption of the litter and organic layer beneath trees and isolated shrubs, and mortality of plant parts.
  • The Burning index (BI) is a relative number calculated in the National Fire Danger Rating System (NFDRS) related to the contribution that fire behavior makes to the amount of effort needed to contain a fire in a specified fuel type. Doubling the burning index indicates that twice the effort will be required to contain a fire in that fuel type as was previously required, providing all other parameters are held constant.
  • The Canadian Forest Fire Danger Rating System is a national system for rating the risk of forest fires in Canada. It contains two subsystems: the Canadian Forest Fire Weather Index (FWI) System and the Canadian Forest Fire Behavior Prediction (FBP) System used to derive fire danger.
  • The stratum containing the crowns of the tallest vegetation present (living or dead), usually above 20 feet. (Source: NWCG Glossary of Wildland Fire Terminology.)
  • The canopy base height (also known as crown base height) for an individual tree is the height at which sufficient fuel density exists for sustained canopy ignition. For a stand of trees, canopy base height considers both the height of the main canopy layer as well as the height of ladder fuels in the understory. Average height from the ground to a forest stand's canopy bottom.
  • Canopy bulk density refers to the density of available canopy fuel in a stand.
  • The proportion of the forest floor covered by the vertical projection of the tree crowns.
  • The average height of the top of the vegetated canopy
  • Canopy bulk density refers to the density of available canopy fuel in a stand.
  • The canopy base height (also known as crown base height) for an individual tree is the height at which sufficient fuel density exists for sustained canopy ignition. For a stand of trees, canopy base height considers both the height of the main canopy layer as well as the height of ladder fuels in the understory. Average height from the ground to a forest stand's canopy bottom.
  • A pixel or cell refers to the smallest unit of information on a raster map. In IFTDSS each cell represents a 30 meter square area.
  • The Canadian Forest Fire Danger Rating System is a national system for rating the risk of forest fires in Canada. It contains two subsystems: the Canadian Forest Fire Weather Index (FWI) System and the Canadian Forest Fire Behavior Prediction (FBP) System used to derive fire danger.
  • Conditional Flame Length (CFL) is an estimate of the average flame length for all the fires that burn a given point on the landscape under a fixed set of weather and fuel moisture conditions.
  • A unit of measure in land survey, equal to 66 feet (20 m) (80 chains equals 1 mile). Commonly used to report fire perimeters and other fireline distances, this unit is popular in fire management because of its convenience in calculating acreage (e.g., 10 square chains equal one acre).
  • Heavy, or coarse, fuels are fuels of large diameter such as snags, logs, large limbwood, which ignite and are consumed more slowly than flash fuels
  • In simple terms of burning biomass the three stages of the combustion process are Ignition or incipient, flaming or free burning, and smoldering or glowing.
  • Burn probability given a specific set of defining criteria such as a specific weather scenario and a fixed burn period.
  • Conditional Flame Length (CFL) is an estimate of the average flame length for all the fires that burn a given point on the landscape under a fixed set of weather and fuel moisture conditions.
  • A derived value given a specific set of criteria such as a specific weather scenario and fixed burn period.
  • The amount of a specified fuel type or strata that is removed through the fire process, often expressed as a percentage of the preburn weight.
  • That portion of the prescribed fire plan that describes low probability but high consequence events and the actions needed to mitigate them. Contingency Plan describes what additional actions or additional resources (or both) are needed to keep the prescribed fire within the scope of the prescribed fire plan.
  • The designation of a vegetation complex described by dominant species, age, and form.
  • A fire that burns the forest or shrub canopy. Torching is classified as passive crown fire. Dependant crown fire requires the energy from the surface fire to sustain fire in the canopy. Independant crown fire advances from top to top of trees or shrubs more or less independent of a surface fire. As defined by NWCG: A fire that advances from top to top of trees or shrubs more or less independent of a surface fire.
  • A fraction between 0 and 1 indicating the severity of a crown fire. 0.0 indicates a surface fire while 1.0 represents an active crown fire. Intermediate values represent a scaled value of passive crown fire severity.
  • Comma-separated values. Usually this type of file is produced by saving a database or spreadsheet in this format. Often associated with spreadsheets. This is a way of formatting data in a file so that it can be read by different programs. In this format, the values for each row or record are separated by commas.
  • Drying and browning of herbaceous vegetation due to mortality or senescence, and also loss of live fuel moisture content of woody fuel following mechanically-caused mortality (e.g., woody debris slash.)
  • Tree diameter at breast height. Because trees are generally wider at the base and narrower higher up, the diameter at breast height is used to define the size of the tree. The definition of breast height can vary but is usually 4.5 feet above the ground.
  • Fuels with no living tissue in which moisture content is governed almost entirely by absorption or evaporation of atmospheric moisture (relative humidity and precipitation).
  • In the context of risk, the official having the authority or responsibility to make the final decision or approval of management plans or course of action such as a burn plan, NEPA decision or fire management plan. Also referred to as Approver, Line Officer or Agency Administrator.
  • Desired future condition (DFC) is the composition and structural characteristics of the plant community on a site or ecological unit which meets management objectives or those landscape conditions that are most conducive to ecosystem health. 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.
  • Desired future condition (DFC) is the composition and structural characteristics of the plant community on a site or ecological unit which meets management objectives or those landscape conditions that are most conducive to ecosystem health. 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.
  • Tree diameter at breast height. Because trees are generally wider at the base and narrower higher up, the diameter at breast height is used to define the size of the tree. The definition of breast height can vary but is usually 4.5 feet above the ground.
  • An ecological factor that disrupts ecosystem function and structure such as fire, windthrow, disease, or mechanical manipulation.
  • Daily, especially pertaining to cyclic actions which are completed within 24 hours, and which recur every 24 hours, such as temperature, relative humidity, and wind.
  • Any menu or field in which options drop down to be selected by the user.
  • Duff is the dark, partially to fully decomposed organic material (unrecognizable plant forms) above mineral soil and below the litter layer. Duff has two layers: an upper (fermentation) layer and a lower (humus) layer. As defined by NWCG: The layer of decomposing organic materials lying below the litter layer of freshly fallen twigs, needles, and leaves and immediately above the mineral soil.
  • The composition and structural characteristics of a landscape such as fuel model and canopy characteristics that represent actual current on the ground or expected fire behavior conditions for a given area.
  • Existing Condition (EC) landscape is a term used specifically in the Developing Treatment Alternatives task of IFTDSS. it refers to a landscape that represents, as closely as possible, the current condition of your landscape. It may be an edited landscape, or unedited. Unedited landscapes can be used to represent EC if you determine the raw LANDFIRE data is current and accurate for your analysis purposes. You will see this term used when comparing treatment alternatives in IFTDSS.
  • Ecosystems of regional extent. Usually refers to Bailey's 13 ecoregions. See Bailey’s Ecoregions.
  • An interacting natural system including all the component organisms together with the abiotic environment and processes affecting them.
  • New landscape saved during a landscape editing session where an edit rule has been applied, such as edits made to create an Existing Condition (EC)(defined below) or to reflect post-treatment conditions that would result from a fuel treatment alternative. You may check to see if editing rules have been applied to a landscape by selecting the landscape in question from My Workspace View and then selecting the view edit rules button.
  • The midflame windspeed adjusted for the effect of slope on fire spread.
  • The anticipated benefits and loss to values, typically quantified as a function of fire intensity.
  • The Equilibrium moisture content (EMC) refers to the moisture content that a fuel particle will attain if exposed for an infinite period in an environment of specified constant temperature and humidity. When a fuel particle reaches equilibrium moisture content, net exchange of moisture between it and its environment is zero.
  • Pollutants produced from combustion. For example, emissions can be carbon monoxide and particulate matter that are released to the atmosphere from the combustion of biomass. Defined by NWCG as: A release of combustion gases and aerosols into the atmosphere.
  • A calculated output of the National Fire Danger Rating System (NFDRS). ERC is the computed total heat release per unit area (British thermal units per square foot) within the flaming front at the head of a moving fire. The ERC is considered a composite fuel moisture index as it reflects the contribution of all live and dead fuels to potential fire intensity.
  • Sprouting that comes from buds that normally lie dormant under the bark of a trunk, stem, or branch of a plant.
  • Non-parasitic plants that grow on other plants, such as bromeliads, many types of ferns, orchids, and air plants. An epiphyte depends on the plant it is growing on for mechanical support only; it doesn't depend on it for nutrients.
  • The Equilibrium moisture content (EMC) refers to the moisture content that a fuel particle will attain if exposed for an infinite period in an environment of specified constant temperature and humidity. When a fuel particle reaches equilibrium moisture content, net exchange of moisture between it and its environment is zero.
  • A calculated output of the National Fire Danger Rating System (NFDRS). ERC is the computed total heat release per unit area (British thermal units per square foot) within the flaming front at the head of a moving fire. The ERC is considered a composite fuel moisture index as it reflects the contribution of all live and dead fuels to potential fire intensity.
  • LANDFIRE layer representing the vertically projected percent cover of the live canopy canopy for a 30 meter grid cell.
  • LANDFIRE layer representing the average height of the dominant vegetation for a 30 meter grid cell.
  • LANDFIRE layer derived using decision tree models, field data, Landsat imagery, elevation and biophysical gradient data.
  • The composition and structural characteristics of a landscape such as fuel model and canopy characteristics that represent actual current on the ground or expected fire behavior conditions for a given area.
  • Existing Condition (EC) landscape is a term used specifically in the Developing Treatment Alternatives task of IFTDSS. it refers to a landscape that represents, as closely as possible, the current condition of your landscape. It may be an edited landscape, or unedited. Unedited landscapes can be used to represent EC if you determine the raw LANDFIRE data is current and accurate for your analysis purposes. You will see this term used when comparing treatment alternatives in IFTDSS.
  • LANDFIRE layer representing the vertically projected percent cover of the live canopy canopy for a 30 meter grid cell.
  • LANDFIRE layer representing the average height of the dominant vegetation for a 30 meter grid cell.
  • LANDFIRE layer derived using decision tree models, field data, Landsat imagery, elevation and biophysical gradient data.
  • The percentage of moisture content in fuel at which a fire will not spread through that fuel, or spreads only sporadically and in an unpredictable manner. The percentage of moisture that constitutes moisture of extinction depends on fuel characteristics and situations. Defined by NWCG as: The fuel moisture content, weighed over all the fuel classes, at which the fire will not spread. Also called extinction moisture content (EMC).
  • Lightwood (fatwood, lightered wood or stumps, stumpwood): coniferous wood having an abnormally high content of resin and therefore easily set alight (afire). (From Burns and Honkala v.2, 1990)
  • A fire behavior fuel model (fbfm) is a set of fuelbed inputs needed by a particular fire behavior or fire effects model. There are two types of fire behavior fuel models used by IFTDSS.
  • A fire behavior prediction system (FBPS) uses one or more fire behavior fuel models. A fire behavior fuel model describes how fire is likely to behave based on natural fuel conditions. Using Rothermel's 1972 seminal work, Anderson (1982) originally described 13 fire behavior fuel models. Later, Scott and Burgan (2005) added 40 more fire behavior fuel models. Defined by NWCG as: A system that uses a set of mathematical equations to predict certain aspects of fire behavior in wildland fuels when provided with data on fuel and environmental conditions.
  • FEAT/FIREMON Integrated. A monitoring software tool that integrates the Fire Ecology Assessment Tool (FEAT) with FIREMON. It is used for collecting, storing, and analyzing ecological information.
  • An Extension of the Forest Vegetation Simulator (FVS) that allows for fire to be simulated and includes live tree, dead tree, down dead wood and forest floor biomass information, which can be used to estimate changes in fuels composition over time.
  • FEAT/FIREMON Integrated. A monitoring software tool that integrates the Fire Ecology Assessment Tool (FEAT) with FIREMON. It is used for collecting, storing, and analyzing ecological information.
  • Forest Inventory Assessment. The process of collecting and analyzing data on forests.
  • Fast-drying fuels, generally with a comparatively high surface area-to-volume ratio, which are less than 1/4-inch in diameter and have a timelag of 1 hour or less. These fuels readily ignite and are rapidly consumed by fire when dry.
  • An Extension of the Forest Vegetation Simulator (FVS) that allows for fire to be simulated and includes live tree, dead tree, down dead wood and forest floor biomass information, which can be used to estimate changes in fuels composition over time.
  • The manner in which a fire reacts to the influences of fuel, weather, and topography.
  • A fire behavior fuel model (fbfm) is a set of fuelbed inputs needed by a particular fire behavior or fire effects model. There are two types of fire behavior fuel models used by IFTDSS.
  • A fire behavior prediction system (FBPS) uses one or more fire behavior fuel models. A fire behavior fuel model describes how fire is likely to behave based on natural fuel conditions. Using Rothermel's 1972 seminal work, Anderson (1982) originally described 13 fire behavior fuel models. Later, Scott and Burgan (2005) added 40 more fire behavior fuel models. Defined by NWCG as: A system that uses a set of mathematical equations to predict certain aspects of fire behavior in wildland fuels when provided with data on fuel and environmental conditions.
  • Sum of constant danger and variable danger factors affecting the inception, spread, and resistance to control, and subsequent fire damage; often expressed as an index.
  • The physical, biological, and ecological impacts of fire on the environment.
  • Planned, measurable result desired from fire management and use based on land management goals and objectives.
  • All burnable acres on federal lands will be covered by a fire management plan. The FMP is the cornerstone plan for managing a wildland fire management program and should flow directly from the L/RMP.
  • A Fire Occurrence Area describes a geographic area within which contemporary large-fire occurrence characteristics can be assumed to be uniform. (Scott, JH; 2014 Summarizing contemporary large-fire occurrence for land and resource management planning. Draft. Prepared report from Pyrologix LLC)
  • Description of the patterns of fire occurrences, frequency, size, severity, and sometimes vegetation and fire effects as well, in a given area or ecosystem. A fire regime is a generalization based on fire histories at individual sites. Fire regimes can often be described as cycles because some parts of the histories usually get repeated, and the repetitions can be counted and measured, such as fire return interval.
  • The chance that a fire might start based on the nature and incidence of its causative agents. Generally, for IFTDSS, fire risk is the probability that a fire ignites and then subsequently spreads to ignite adjacent fuels within a specified area and defined time frame (also see definition of risk from an engineering perspective).
  • Period(s) of the year during which wildland fires are likely to occur, spread, and affect resources values sufficient to warrant organized fire management activities.
  • A qualitative assessment of the heat pulse during a fire. Burn severity relates to soil heating, large fuel and duff consumption, consumption of the litter and organic layer beneath trees and isolated shrubs, and mortality of plant parts.
  • A fireline (also called a fireguard or firebreak) is a strip of open land (cleared or plowed to the mineral soil) that is used to stop the spread of a fire.
  • A fireline (also called a fireguard or firebreak) is a strip of open land (cleared or plowed to the mineral soil) that is used to stop the spread of a fire.
  • A fireline (also called a fireguard or firebreak) is a strip of open land (cleared or plowed to the mineral soil) that is used to stop the spread of a fire.
  • The heat energy released per unit time from a one-foot-wide (or one-meter-wide) section of the fuel bed extending from the front to the rear of the flaming zone. Fireline intensity is a function of rate of spread and heat per unit area, and is directly related to flame length.
  • Direct or indirect immediate consequences of fire. Examples of first order fire effects are biomass consumption, crown scorch, bole damage, tree mortality, soil heating, and smoke production.
  • The depth of the flaming fire front.
  • The average maximum vertical extension of flames at the leading edge of the fire front. Occasional flashes that rise above the general level of flames are not considered. This distance is less than the flame length if flames are tilted due to wind or slope.
  • The flame length of a spreading surface fire within the flaming front is measured from midway in the active flaming combustion zone to the average tip of the flames. Flame length is an indicator of fire intensity.
  • Flame lengths are divided into classes low, medium, high, and very high based on flame length.
  • The zone of a moving fire where the combustion is primarily flaming. Behind this flaming zone, combustion is primarily smoldering.
  • The relative ease with which fuels ignite and burn regardless of the quantity of the fuels.
  • Highly combustible fine fuels such as grass, leaves, draped pine needles, fern, tree moss and some kinds of slash, which ignite readily and are consumed rapidly when dry.
  • The temperature at which a combination of fuel and an oxidizer will ignite.
  • A Fire Occurrence Area describes a geographic area within which contemporary large-fire occurrence characteristics can be assumed to be uniform. (Scott, JH; 2014 Summarizing contemporary large-fire occurrence for land and resource management planning. Draft. Prepared report from Pyrologix LLC)
  • Foehn (föhn) winds are dry, down-slope winds that occur on the leeward (downwind, rain shadow) side of a mountain range. This type of wind is also sometimes called a Chinook wind. The process for the creation of these winds is adiabatic warming of air that dropped its moisture on the windward side of the mountain. Föhn winds can raise air temperatures dramatically (30°C/54°F) in just a few hours and can contribute to the rapid spread of wildland fires. These winds are known by different names in different places around the world. The Santa Ana winds of southern California are similar, though they are are katabatic winds that originate in dry deserts.
  • The moisture content of the overstory foliage, the conifer needles. It is used along with fireline intensity and canopy base height to determine the threshold for transition to crown fire.
  • A forb is an herbaceous, flowering plant that is not a graminoid (that is, is not a sedge, rush, or true grass). Sometimes spelled phorb, especially in older works.
  • Forest Inventory Assessment. The process of collecting and analyzing data on forests.
  • A family of forest growth simulation models used to answers questions about how forest vegetation will change in response to natural succession, disturbances, and proposed management actions.
  • The number of occurrences per unit of time.
  • Combustable materials that a fire consumes in order to burn.
  • Factors that make up fuels such as compactness, loading, horizontal continuity, vertical arrangement, chemical content, size and shape, and moisture content.
  • The degree or extent of continuous or uninterrupted distribution of fuel particles in a fuel bed thus affecting a fire's ability to sustain combustion and spread. This applies to aerial fuels as well as surface fuels.
  • The amount of fuel present expressed quantitatively in terms of weight of fuel per unit area. At a landscape level is commonly expressed as tons per acre.
  • A fuel model is a set of information on the fuelbed inputs to be used in specific fire behavior or fire effects models. Anderson (1982) proposed 13 fuel models; Scott and Burgan (2005) proposed an additional 40.
  • Moisture content in fuels determines whether and to what extent fuels will burn. Fuel moisture is a percentage calculated by the weight of contained water in the fuel divided by the ovendry weight of the fuel.
  • Allows dead fuel moisture values to be adjusted 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). Fuel moisture conditioning allows for a more natural variation in dead fuel moisture values across a landscape.
  • Manipulation or removal of fuels to reduce the likelihood of ignition and/or to lessen potential damage and resistance to control (e.g., lopping, chipping, crushing, piling and burning).
  • Manipulation or removal of fuels to reduce the likelihood of ignition and/or to lessen potential damage and resistance to control (e.g., lopping, chipping, crushing, piling and burning).
  • A fuelbed is an area of similar fuel characteristics within a unit. A fuelbed contains one or more fuelbed strata (e.g., canopy, shrubs, etc).
  • A fuelbed stratum is a horizontal layer of a fuelbed that represents a combustion environment. Fuelbed strata can include canopy, shrub, nonwoody vegetation (i.e., grasses, forbs and herbs), woody fuel, moss, lichen, litter, and ground fuels.
  • A family of forest growth simulation models used to answers questions about how forest vegetation will change in response to natural succession, disturbances, and proposed management actions.
  • A growth and mortality model calibrated to a specific geographic area of the United States. There are 20 different FVS variants.
  • Geographic information system. A system for capturing, managing, and analyzing geographically referenced data.
  • Sedges, rushes, and true grasses.
  • Graminoids: herbaceous plants with narrow leaves growing from the base. The term "grasses" includes both the true grasses (cereals, bamboo, and grasses) as well as sedges and rushes (marsh and grassland plants).
  • The beginning of a new cycle of plant growth. Green-up usually occurs once a year, except in desert areas where rainy periods can produce a flush of new growth more than once a year. Green-up may be signaled at different dates for different fuel models.
  • Gridded weather data sets use interpolation across space and time to combine available weather station data into a balanced panel of observations on a fixed spatial scale or grid. Gridded weather data provides more complete weather data coverage than from fixed weather stations alone. This approach deals with the problem of missing observations or poor representation due to elevation change or distance to a given station.
  • This spatial grid is generated using computational fluid dynamics to account for the influence of topography on wind speed and direction. Without gridded winds, every cell on the landscape will have the same wind speed and direction. Proper use of gridded winds in an analysis can produce more realistic fire behavior modeling results.
  • All combustible materials below the surface litter, including duff, tree or shrub roots, punky wood, peat, and sawdust, that normally support a glowing combustion without flame.
  • A fire break that is dug or scraped manually using hand tools.
  • Combines two Landscape Burn Probability model outputs—burn probability and conditional flame length—into a single characteristic that can be mapped.
  • A fuel complex defined by kind, arrangement, volume, condition, and location that presents a threat of ignition and resistance to control.
  • Any treatment of living and dead fuels that reduces the potential spread or consequences of fire.
  • Heavy, or coarse, fuels are fuels of large diameter such as snags, logs, large limbwood, which ignite and are consumed more slowly than flash fuels
  • A metric measure of area, usually applied to land, defined as 10,000 square meters. A hectare of land is about 2.47 acres.
  • A plant that does not develop woody, persistent tissue but is relatively soft or succulent and sprouts from the base (perennials) or develops from seed (annuals) each year. Includes grasses, forbs and ferns.
  • A value representing the approximate moisture content of the live herbaceous vegetation expressed as a percentage of the oven dry weight of the sample.
  • A value representing the approximate moisture content of the live herbaceous vegetation expressed as a percentage of the oven dry weight of the sample.
  • Highly Valued Resource or Asset (HVRA). The things we care about. Features on the landscape that are influenced positively and/or negatively by fire. Some resources have only modest value and may not be analyzed in an assessment of risk to HVRAs. Likewise, low-value assets like outbuildings are often left un-analyzed so that efforts can be focused on the more highly valued resources or assets.
  • That portion of the prescribed fire plan that describes the general procedures for operations to maintain the fire within the project area and meet project objectives until the fire is declared out.
  • The rate of fire spread (slope basis), transformed to a horizontal projection.
  • Heat per unit area. Heat energy release per unit area (square foot or square meter) within the flaming front of the surface fuel. HPUA is not affected by wind speed, slope, or direction of spread.
  • Hydrolic unit codes (HUC) divides the United States into successively smaller units designated by codes. The first level of classification divides the nation into 21 major areas that contain the drainage area for a major river or series of rivers such as those draining into the Gulf of Mexico. The second level of classification divides the 21 regions into 221 subregions that contain the area drained by a river system, a basin or a group of streams forming a coastal drainage area. The third and fourth level of classification further subdivides the larger units into successively smaller drainage areas. Units are sometimes called “watersheds”.
  • Highly Valued Resource or Asset (HVRA). The things we care about. Features on the landscape that are influenced positively and/or negatively by fire. Some resources have only modest value and may not be analyzed in an assessment of risk to HVRAs. Likewise, low-value assets like outbuildings are often left un-analyzed so that efforts can be focused on the more highly valued resources or assets.
  • The Highly Valued Resources or Assests (HVRA) Set refers to the set the Primary HVRA categories and sub HVRAs a user creates in the Map Values portion of IFTDSS.
  • The HVRA Set Extent is the geographic extent, or rectangular bounding box, used to define the area of the mapped Sub-HVRAs. In IFTDSS the HVRA Set Extent is set in the Map Values portion of the application and is defined by a Landscape, Landscape Burn Probability model output, or an Area of Interest (AOI).
  • Hydrolic unit codes (HUC) divides the United States into successively smaller units designated by codes. The first level of classification divides the nation into 21 major areas that contain the drainage area for a major river or series of rivers such as those draining into the Gulf of Mexico. The second level of classification divides the 21 regions into 221 subregions that contain the area drained by a river system, a basin or a group of streams forming a coastal drainage area. The third and fourth level of classification further subdivides the larger units into successively smaller drainage areas. Units are sometimes called “watersheds”.
  • Number of ignitions per unit area.
  • Number of ignitions per unit of time.
  • The probability of an ignition occurring during the specified time period, expressed as a fraction or percentage.
  • A fire that advances in the tree crowns alone, not requiring any energy from the surface fire to sustain combustion or movement. Also called running crown fire. Current spatial fire behavior models can not predict the occurrence or spread of this type of crown fire.
  • Generally a numeric rating used to indicate a relative location on a scale. Used in the National Fire Danger Rating System (NFDRS) to indicate general level of fire danger.
  • Generally a numeric rating used to indicate a relative location on a scale. Used in the National Fire Danger Rating System (NFDRS) to indicate general level of fire danger.
  • Dead and live fuel moistures in percent. A fire behevior modeling input in IFTDSS.
  • Combines two Landscape Burn Probability model outputs—burn probability and conditional flame length—into a single characteristic that can be mapped.
  • Combines two Landscape Burn Probability model outputs—burn probability and conditional flame length—into a single characteristic that can be mapped.
  • Information technology. Refers generally to the technology used to acquire, process, store, and disseminate electronic data. Refers more specifically to the field of work managing that technology.
  • Joint Fire Science Program. Created by Congress in 1998 to act as an interagency research, development, and applications partnership between the U.S. Department of the Interior and the U.S. Department of Agriculture.
  • A katabatic wind carries high density air from a higher elevation downslope under the force of gravity. The air warms adiabatically as it descends.
  • Keyhole Markup Language (KML), which is based on XML, is a file format used to display geographic data in an Earth browser (such as Google Earth, Google Maps, and Google Maps for mobile).
  • Fuels which provide vertical continuity between vegetation strata, thereby allowing fire to carry from surface fuels into the crowns of trees or shrubs with relative ease. They help initiate and facilitate the continuation of crowning.
  • 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 objective and the fire management program in the designated area.
  • A set of decisions that establish management direction for land within an administrative area; an assimilation of land-use-plan-level decisions developed through the planning process regardless of the scale at which the decisions were developed.
  • Landscape Fire and Resource Management Planning Tools Project. An interagency vegetation, fire, and fuel characteristics mapping program whose focus is the entire United States. Sponsors are the United States Department of the Interior and the USDA Forest Service.
  • Contains information that describe post-disturbance vegetation changes used to edit landscapes based on disturbance type, severity, and time since disturbance. LANDFIRE Look-up Table is derived from the LANDFIRE “Forest Vegetation Transitions Database (FVTDB)”.
  • A Landscape file (.lcp) is a multi-band raster format commonly used by geospatial wildland fire behavior and fire effects models such as FlamMap and other fire models used in IFTDSS. The bands of an .LCP file store data describing terrain, tree canopy, and fuel model. The .lcp files contain information describing: Aspect Canopy base height Canopy bulk density Canopy cover Canopy height Elevation Fuel Model (FBFM 13 or 40) Slope
  • The spatial fire behavior modeling capability of IFTDSS is based on fire behavior models such as FlamMap. Landscape fire behavior provides spatial fire behavior outputs including: crown fire activity, direction of maximum spread, fireline intensity, flame length. heat per unit area, rate of spread.
  • A mask or landscape mask is a shapefile (polygon) used to represent a particular area on a landscape. When editing a landscape you may choose a Landscape Mask (Shapefile) to edit only the area within that mask. Shapefiles may be used for other purposes in IFTDSS in addition to landscape masks.
  • A Landscape file (.lcp) is a multi-band raster format commonly used by geospatial wildland fire behavior and fire effects models such as FlamMap and other fire models used in IFTDSS. The bands of an .LCP file store data describing terrain, tree canopy, and fuel model. The .lcp files contain information describing: Aspect Canopy base height Canopy bulk density Canopy cover Canopy height Elevation Fuel Model (FBFM 13 or 40) Slope
  • The spatial fire behavior modeling capability of IFTDSS is based on fire behavior models such as FlamMap. Landscape fire behavior provides spatial fire behavior outputs including: crown fire activity, direction of maximum spread, fireline intensity, flame length. heat per unit area, rate of spread.
  • Contains information that describe post-disturbance vegetation changes used to edit landscapes based on disturbance type, severity, and time since disturbance. LANDFIRE Look-up Table is derived from the LANDFIRE “Forest Vegetation Transitions Database (FVTDB)”.
  • A forest floor layer comprising ground lichens occurring on rocks, bare ground, or low vegetation.
  • Fast-drying fuels, generally with a comparatively high surface area-to-volume ratio, which are less than 1/4-inch in diameter and have a timelag of 1 hour or less. These fuels readily ignite and are rapidly consumed by fire when dry.
  • Lightwood (fatwood, lightered wood or stumps, stumpwood): coniferous wood having an abnormally high content of resin and therefore easily set alight (afire). (From Burns and Honkala v.2, 1990)
  • Non-technical synonym for probability. (As defined by Scott and Others 2013)
  • Litter is the leaves, needles, fine twigs (but not branches), and other recognizable organic material (such as leaves and flowers), on the forest or grassland floor that have undergone little or no decomposition. This layer sits on top of the duff layer.
  • Ratio of the amount of water to the amount of dry plant material in living plants expressed as a percent. Because live plant cell tissue is able to hold more than its own weight in moisture, live fuel moisture can range up to 300%.
  • Living plants, such as trees, grasses, and shrubs, in which the seasonal moisture content cycle is controlled largely by internal physiological mechanisms, rather than by external weather influences.
  • Litter, lichen, and moss. The top layer of forest or rangeland floors.
  • 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 objective and the fire management program in the designated area.
  • The mapping interface of IFTDSS.
  • A shapefile (polygon) is a simple non-topographical way to store geometric location and attribute information for landscape features; they are often used to represent treatment areas, burn units, and other areas of disturbances. Shapefiles can be used for many purposes in IFTDSS, and depending on what they are used for, you may see them referred to by different names. Area of Interest: This term is used in the Landscape Summary task and Determining Treatment Alternatives task to constrain the area of your analysis or reporting. Landscape Mask: This term is used in Landscape Editing to constrain the area your edits apply to. Polygon, Shape, Shapefile, Mask: These terms are used interchangeably throughout Map Studio .
  • Direction of maximum spotting, the direction the spot was lofted from, NOT the direction the spot is coming from.
  • Maximum spot distance in meters.
  • Direction of maximum spread in degrees.
  • The speed of the wind measured at the midpoint of the flames, considered to be most representative of the speed of the wind that is affecting fire behavior. Fire behavior models calculate midflame windspeed from 20 foot winds using a wind reduction factor. In IFTDSS, Landscape Fire Behavior and Landscape Burn Probability it is the wind velocity at the midflame height. Calculated using wind adjustment factors based on stand height and canopy cover and the Wind Speed.
  • Soil layers below the predominantly organic horizons; soil with little combustible material.
  • A model is a set of mathematical relationships that describe an aspect of wildland fire (Andrews and Queen, 2001); generally, models are equations that are published in scientific literature.
  • The percentage of moisture content in fuel at which a fire will not spread through that fuel, or spreads only sporadically and in an unpredictable manner. The percentage of moisture that constitutes moisture of extinction depends on fuel characteristics and situations. Defined by NWCG as: The fuel moisture content, weighed over all the fuel classes, at which the fire will not spread. Also called extinction moisture content (EMC).
  • A forest floor layer comprising low-growing bryophytes. Bryophytes are usually found in moist habitats.
  • My Modeling Playground is the area of IFTDSS used to populate and run models. Model outputs are also available here, you may view summaries, or spatial outputs in . You will find in that My Modeling Playground, and the models therein, can be accessed from multiple parts of IFTDSS, such as accessing Landscape Fire Behavior from the Landscape Evaluation stage of the Planning Cycle for example.
  • This is where all user-created files are stored in IFTDSS, such as landscape, shape, report, and model output files.
  • NEPA requires federal agencies to assess the environmental effects of their proposed actions. Objectives for specific fuels treatment projects are evaluated and analyzed in the NEPA analysis. NEPA document types that identify and analyze the effects of implementing projects may include Environmental Impact Statements (EIS), Environmental Assessments (EA), and Categorical Exclusions (CE).
  • A uniform fire danger rating system that focuses on the environmental factors that control the moisture content of fuels.
  • Any area where lack of flammable material obstructs the spread of wildfires.
  • Fuels resulting from natural processes and not directly generated or altered by land management practices.
  • Dead needles hanging in the understory canopy or at the shrub level. Needle drape is an aerial fuel.
  • A uniform fire danger rating system that focuses on the environmental factors that control the moisture content of fuels.
  • Non-woody fuels lack a true woody stem; this is what distinguishes them from woody fuels.
  • National Research Council. A branch of the National Academies (National Academy of Sciences, National Academy of Engineering, and Institute of Medicine), the NRC does much of the research for those bodies.
  • National Vegetation Classification System. A consistent, US-wide system for classifying vegetation.
  • National Wildfire Coordinating Group. An operational group that coordinates programs of participating wildfire management agencies.
  • 1) A description of a desired condition; quantified and measured, and where possible, with established time frames for achievement. 2) Specific, achievable, measurable, time-limited results to be achieved through land management practices, either through a description of a desired condition or the degree of desired change in an attribute.
  • Fuels consisting of dead herbaceous plants and roundwood less than about one-quarter inch (6.4 mm) in diameter. Also included is the uppermost layer of needles or leaves on the forest floor.
  • Any soil or soil horizon containing at least 30% organic matter (e.g., muck, peat).
  • A term used specifically in Developing Treatment Alternatives, it refers to the unedited landscape you select to begin developing treatment alternatives. It will be tagged with a zero icon indicating 'landscape zero' as defined in the help texticon. It defines the extent of your comparison, so any landscapes that match the extent of your originating landscape will become available during Developing Treatment Alternative task.
  • Palmetto-gallberry (P-G) is a fuel type. It is "the complex association of saw-palmetto [Serenoa repens (Bartr.) Small] and common gallberry [llex glabra (L.) Gray] with many other plants beneath slash pines (Pinus elliottii Engelm.) or mixtures of slash and longleaf pine (P. palustris Mill.). Openings frequently contain small shrubs [Vaccinium spp., Quercus spp., and Kalmiella hirsuta (Walt.) Small] and wiregrass (Aristida spp.). Palmetto and gallberry are two of the most common plants occurring in forest understories on the Lower Coastal Plain of the Southern United States." (Hough and Albini, 1978)
  • A fire in the crowns of trees in which trees or groups of trees torch, ignited by the passing front of the fire. The torching trees reinforce the spread rate, but these fires are not basically different from surface fires.
  • The pocosin ecosystem. Pocosin is a type of palustrine wetland with deep, acidic, sandy, peat soils. "Palustrine" means any non-tidal inland wetland which does not have flowing water and that only contains ocean-derived salts in concentrations of less than 0.05%.
  • That period of the fire season during which fires are expected to ignite most readily, to burn with greater than average intensity.
  • A convenient term for denoting thresholds or boundary values in frequency distributions. Thus the 50th percentile is the same as the median, and the 90th percentile exceeds all but 10 per cent of the values.
  • Scale of 0-100 used to sort and rank a collection of weather observations correlated to a particular NFDRS index such as ERC. Thus the ERC 97th percentile weather represents the weather observations correlated to all but 3 percent of the highest ERC values and represents a high fire risk for dry fuels.
  • Piling slash resulting from logging or fuel management activities and subsequently burning the individual piles.
  • A pixel or cell refers to the smallest unit of information on a raster map. In IFTDSS each cell represents a 30 meter square area.
  • A component of IFTDSS intended to guide users through different stages of the landscape planning process using IFTDSS. The stages of the cycle correspond to stages in the fuels planning process, proceeding through each stage will help you to more easily identify affected lands and establish fuels management objectives. Selecting any stage of the Planning Cycle will bring up a series of ordered tasks associated with that stage. For example, by selecting the Landscape Evaluation stage, you are presented with options to create landscape, evaluate and edit landscape features (such as fuel models) for accuracy, and run basic models to view fire behavior and prioritize areas on the landscape for treatment.
  • My Modeling Playground is the area of IFTDSS used to populate and run models. Model outputs are also available here, you may view summaries, or spatial outputs in . You will find in that My Modeling Playground, and the models therein, can be accessed from multiple parts of IFTDSS, such as accessing Landscape Fire Behavior from the Landscape Evaluation stage of the Planning Cycle for example.
  • The Ponderosa ecosystem (grassland savanna with stands of Pinus ponderosa).
  • A shapefile (polygon) is a simple non-topographical way to store geometric location and attribute information for landscape features; they are often used to represent treatment areas, burn units, and other areas of disturbances. Shapefiles can be used for many purposes in IFTDSS, and depending on what they are used for, you may see them referred to by different names. Area of Interest: This term is used in the Landscape Summary task and Determining Treatment Alternatives task to constrain the area of your analysis or reporting. Landscape Mask: This term is used in Landscape Editing to constrain the area your edits apply to. Polygon, Shape, Shapefile, Mask: These terms are used interchangeably throughout Map Studio .
  • Site-specific implementation document. It is a legal document that provides the agency administrator the information needed to approve the plan, and the prescribed fire burn boss with the information needed to implement the prescribed fire. A prescribed fire project must conform to the written plan.
  • The measurable criteria under which fuels will be treated to meet the plan objectives. With Prescribed fire it is the conditions under which fire may be ignited to achieve the burn plan objectives.
  • Primary HVRAs are the overall categories into which the Sub-HVRAs are sorted. For example, ‘Habitat’ can be the Primary HVRA category, with Sub-HVRAs defined as the habitat for various individual species. When calculating risk, all calculations are done at the Sub-HVRA level.
  • Short duration events occurring during severe weather conditions. Typically a problem fire scenario is based on a past wildland fire event that exceeded suppression capabilities resulting in undesirable consequences.
  • The specific results expected from completing a project.
  • The proportion of flame length categories (a.k.a., flame length probability, FLP) represent the likelihood of fire intensity for six standard fire intensity levels (Roose and others 2008) for each pixel on the landscape. The value in each class is the conditional probability of observing fire intensity for the specified flame-length class (FL), given a fire occurs. Because the values rely on fire occurring, the sum probability of all size classes is always one for any given point on the landscape. It is these proportional flame lengths that are used to determine the Conditional Flame Length.
  • Rate of spread is the relative activity of a fire in extending its horizontal dimensions. It is expressed as rate of forward spread of the fire front. Usually it is expressed in chains or acres per hour.
  • Rate of spread is the relative activity of a fire in extending its horizontal dimensions. It is expressed as rate of forward spread of the fire front. Usually it is expressed in chains or acres per hour.
  • A Remote Automated Weather Station (RAWS) automatically gathers weather observations and sends the data via satellite to the National Interagency Fire Center (NIFC) The data is automatically forwarded to several other computer systems including the Weather Information Management System (WIMS) and the Western Regional Climate Center (WRCC).
  • The rate of the energy release per area (square foot or square meter) within the flaming front. There can be different types of reaction intensity, such as for dead fuels or live fuels.
  • Relative humidity (RH) is the ratio of the amount of moisture in the air, to the maximum amount of moisture that air would contain if it were saturated. The ratio of the actual vapor pressure to the saturated vapor pressure.
  • In the context of risk and exposure analysis, resources are naturally occurring—wildlife habitat, forage, timber, etc.
  • 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 objective and the fire management program in the designated area.
  • Relative humidity (RH) is the ratio of the amount of moisture in the air, to the maximum amount of moisture that air would contain if it were saturated. The ratio of the actual vapor pressure to the saturated vapor pressure.
  • 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 objective and the fire management program in the designated area.
  • Society of American Foresters/sustainable forest management. The management of forests using social, economic, and environmental principles.
  • Average heights of foliage browning or bole blackening caused by a fire.
  • Fire behavior fuel model prediction system developed by Joe Scott and Robert Burgan employing 40 fuel models. These 40 models increased the existing 13 fuel models and among other things improve fire behavior predictions outside the severe period of fire season, such as use in prescribed fire and multiple objective fire management applications.
  • The secondary effects of fire such as tree regeneration, plant succession, and changes in site productivity. Although second order fire effects are dependent, in part, on first order fire effects, they also involve interaction with many other non-fire variables.
  • Degree to which a site has been altered or disrupted by fire; loosely, a product of fire intensity and residence time.
  • Fuelbreaks built in timbered areas where the trees on the break are thinned and pruned to reduce the fire potential yet retain enough crown canopy to make a less favorable microclimate for surface fires.
  • A shapefile (polygon) is a simple non-topographical way to store geometric location and attribute information for landscape features; they are often used to represent treatment areas, burn units, and other areas of disturbances. Shapefiles can be used for many purposes in IFTDSS, and depending on what they are used for, you may see them referred to by different names. Area of Interest: This term is used in the Landscape Summary task and Determining Treatment Alternatives task to constrain the area of your analysis or reporting. Landscape Mask: This term is used in Landscape Editing to constrain the area your edits apply to. Polygon, Shape, Shapefile, Mask: These terms are used interchangeably throughout Map Studio .
  • Shrubs (also called brush or bushes) are woody perennial plants that differ from trees by their low height and multiple basal stems.
  • The coarse and fine woody debris generated by natural processes (such as wind) or by mechanical processes such as logging operations.
  • The ratio of the elevational change (rise) over a horizontal distance (run). Generally expressed in degrees or percent.
  • The policies and practices implemented by air and natural resource managers directed at minimizing the amount of smoke entering populated areas or impacting sensitive sites, avoiding significant deterioration of air quality and violations of National Ambient Air Quality Standards, and mitigating human-caused visibility impacts in Class I areas.
  • An area that is expected to be impacted by smoke from a prescribed burn under certain conditions such as specific winds or down drainage air flow.
  • The amount of sunlight exposed to the fuels. In Landscape Fire Behavior outputs, it is he solar radiation of each cell for the ending time of the optional fuel moisture conditioning period, only available when fuel conditioning was used.
  • Fire ignited outside the perimeter of the main fire by a firebrand.
  • Behavior of a fire producing sparks or embers that are carried by air currents and which start new fires beyond the zone of direct ignition by the main fire.
  • The maximum distance from different possible sources (e.g., burning piles, torching trees, or wind-driven surface fires) where one can expect potential spot fires.
  • A mound formed from the bits left behind after a squirrel finishes eating.
  • As used in 'stage of the planning cycle'. Stages of the Planning Cycle correspond to stages of the landscape planning process and include: -Landscape Evaluation -Strategic Planning -Implementation Planning -Monitoring -Reporting
  • Fire which kills all or most of the living overstory trees in a forest and initiates forest succession or regrowth. Also explicitly describes the nature of fire in grasslands and some shrublands.
  • Any landscape selected as the starting point for a landscape editing session. This term is used for both edited and unedited landscapes, and you will often see it next to the landscape dropdown menu when you begin edits in IFTDSS. In the Landscape Edit task of Landscape Evaluation, any landscape may be selected as a starting landscape. In the landscape editing portion of the Develop Treatment Alternatives task of Strategic Planning session, the starting landscape choices will be limited to landscapes that match the geographic extent of the Originating landscape.
  • Sub-HVRA’s are the geospatial component of HVRAs (Highly Valued Resources and Assets). For example, powerlines can be considered a Sub-HVRA, and Infrastructure would be the Primary HVRA. Quantitatively, all calculations are done at the Sub-HVRA level. The hierarchical structure is simply a convenient way to organize and summarize a long list of HVRAs.
  • A fire that burns only the surface litter and fuels near the surface of the ground.
  • Surface fuels include the litter, grass, brush, and other dead and live vegetation within about 6 feet of the ground.
  • The "speed" at which a fire travels through the surface fuels.
  • As used in 'select a task from the Landscape Evaluation stage of the IFTDSS Planning Cycle. Task refers to a specific operation within a stage of the IFTDSS Planning Cycle. For example, some tasks in the Landscape Evaluation stage include 'generating a landscape summary', and 'model fire behavior'.
  • Dead fuels consisting of roundwood 1/4 to l-inch (0.6 to 2.5 cm) in diameter and, very roughly, the layer of litter extending from immediately below the surface to 3/4 inch (1.9 cm) below the surface.
  • Trees; also, the wood from trees. Typically, a tree is a perennial woody plant with a single main trunk and and many secondary branches. A group of trees is called a stand, wood, timber, or forest, with number of trees determining which term is preferred.
  • The length of time that a particle responds to within 63.2% of the new equilibrium moisture content (either drying or wetting). Larger diameter fuels generally have longer time-lags, meaning they respond more slowly to changes in environmental conditions.
  • Imperfect information or lack of knowledge. In risk analyses often relates to understanding of the probabilities of events.
  • A fire that consume surface fuels but not the overstory canopy.
  • The area of the forest in which plants are growing at the lowest height level under the forest canopy. Typical plants include small trees, shrubs, herbs, vines, and small canopy trees that haven't yet made it to the top.
  • Prescribed burning under a forest canopy.
  • Thirty meter (30m) resolution raw “ouf of the box” landscape data from LANDFIRE that have not yet been edited. This is the landscape that you first create, specifying the size and name. These are the only landscapes available to select in Develop Treatment Alternatives when you are prompted to “Pick Landscape”. IFTDSS will always retain this original version under the name you have chosen.
  • A unit encompasses a single or group of fuelbeds that are part of a fuel treatment (e.g., harvest unit, prescribed burn unit) or wildland fire.
  • Flame lengths are divided into classes, low, medium, high, and very high, based on flame length classifications specified by the user.
  • Map with scale sufficient that the treatment units can be located on the ground and in sufficient detail to guide implementation.
  • A factor used to adjust 20 foot wind speed to the midflame windspeed taking into account the effects of terrain and vegetation on wind speed. Midflame wind is obtained by multiplying 20-ft. wind by a Wind Adjustment Factor (WAF).
  • A centralized weather data processing system at which daily fire danger ratings are produced.
  • Assigning a level of importance to each variable to emphasize its contribution to an outcome, rather than allowing each value to contribute equally.
  • One of six NOAA regional climate centers in the United States at which all hourly observations from all RAWS and many AWS are archived.
  • The Wildland Fire Decision Support System (WFDSS) is designed to assist in making strategic and tactical decisions for fire incidents. WFDSS includes, among other things, an integrated set of tools used for fire behavior modeling.
  • The Wildland Fire Decision Support System (WFDSS) is designed to assist in making strategic and tactical decisions for fire incidents. WFDSS includes, among other things, an integrated set of tools used for fire behavior modeling.
  • The line, area, or zone where structures and other human development meet or intermingle with undeveloped wildland or vegetative fuels. Describes an area within or adjacent to private and public property where mitigation actions can prevent damage or loss from wildfire.
  • A centralized weather data processing system at which daily fire danger ratings are produced.
  • A wildland fire that is controlled by a strong consistent wind.
  • A factor used to adjust 20 foot wind speed to the midflame windspeed taking into account the effects of terrain and vegetation on wind speed. Midflame wind is obtained by multiplying 20-ft. wind by a Wind Adjustment Factor (WAF).
  • Compass direction from which wind is blowing.
  • A factor used to adjust 20 foot wind speed to the midflame windspeed taking into account the effects of terrain and vegetation on wind speed. Midflame wind is obtained by multiplying 20-ft. wind by a Wind Adjustment Factor (WAF).
  • Wind, in miles per hour, measured at 20 feet above open, level ground or above the average height of vegetation, and averaged over at least a 10-minute period. Also known as wind velocity.
  • Woody fuels have a true woody stem. Woody fuels include sound wood, rotten wood, and stumps.
  • Worst-case scenario with respect to the fire environment refers to extreme weather and fuel moisture conditions. The values needed to model these conditions can be derived from recent climatological data using statistical methods (i.e., percentile conditions) or known problem fire case studies.
  • One of six NOAA regional climate centers in the United States at which all hourly observations from all RAWS and many AWS are archived.
  • The line, area, or zone where structures and other human development meet or intermingle with undeveloped wildland or vegetative fuels. Describes an area within or adjacent to private and public property where mitigation actions can prevent damage or loss from wildfire.

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