E-Learning for WildfiresProfessionals
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Wildfire Prevention – Part 2:
Understanding fire behaviour and extreme fire
behaviour
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Fire BehaviourThis is the second part of the module on wildfire prevention . It will explain the following topics:
• Combustion • Methods of heat
transfer• Fire behaviour and
how wildfires spread and develop Source: Northumberland Fire and Rescue Service (UK)
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Fire BehaviourCombustionCombustion is the chemical reaction that emerges from a process of combining fuel, oxygen and temperature to produce fire. The reaction changes the composition of the materials, consumes oxygen and generates high temperatures which in turns ignites new materials. *Ignition: The act of initiating the combustion of a material.
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Fire Behaviour• Combustion ProcessHow well a fuel will ignite and burn is largely dependant on its moisture content. Before a wet fuel can burn, the moisture it contains must evaporate.
This process requires heat.As fuel moisture increases, the amount of heat required to ignite and burn the fuel also increases.
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Fire BehaviourCombustion Process
Stage 1:Ignition
Stage 2: Flaming Stage
Stage 3: Extinction
1. Dehydration 2. pyrolysis 3. Combustion
The first heat brought to the process of ignition is used to evaporate water (humidity) which the fuel may contain. This process takes place at temperatures around 100ºC
Once the water has evaporated, the heat brought is used for the thermic decomposition of the fuel and the evaporation of the volatile elements. This process takes place at temperatures around 200ºC and 500ºC
When there is enough fuel in vapour state mixed with air, the heat brought will allow the ignition of this mixture, activating the reaction of combustion. This process takes place at temperatures around 350ºC and 600ºC
Once the combustion has started, it will continue for as long as there is enough fuel and oxygen, and while the heat supplied for the combustion reaction is sufficient in order to continue with the evaporation of the fuel
The extinction takes place once there is no fuel o no oxygen, o when the heat coming out of the combustion is no longer sufficient for the fuel to evaporate.
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Fire Behaviour
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Fire BehaviourThe Fire TriangleThree elements must be present before combustion can occur and continue• Fuel - In wildfires it is mainly vegetation dry enough
to burn. The fire will stop when fuel runs out, is eliminated or too wet for combustion to continue.
• Oxygen - In the countryside, air is an unlimited source of oxygen. Being in the open air, oxygen will always be present . You can only remove it momentarily to stop the reaction by tactics such as smothering.
• Heat - the heat from combustion ignites near by fuel. If the heat transmitted is reduced sufficiently, the fuel will not burn. In order to reduce the heat flow, it is important to know how it is transferred.
OXYGEN HEAT
FUEL
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The videos on the following page provide further information about the combustion process.
Fire Behaviour
Find out more about Combustion
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Fire BehaviourPhysical mechanisms of Heat TransferWhen burning, fuel produces heat energy that spreads to the surrounding area. Physically three forms of heat transfer are recognized:
• CONVECTION • CONDUCTION• RADIATION In wildfires, there is one more heat transfer mechanism known as spotting. This is when sparks, firebrands and/or embers (small pieces of burning fuel) are transported ahead of the main fire by wind.
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Fire BehaviourConvectionHeat is transferred through the air, moving up slopes and pushed by the wind. It is the most common heat transfer for forest fires.
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Fire BehaviourConvection
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Fire BehaviourConductionHeat transfer through a solid material by contact. Vegetation and soil are poor heat conductors , so this has little effect on wildfires.
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Fire BehaviourRadiationHeat transfer by waves through space in all directions equally and with the same intensity.
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Fire BehaviourRadiation
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Fire BehaviourFire behaviourThis is the term used to refer to the physical characteristics of a fire and they in turn control the potential development of its propagation.
Key factors are:Temperature distributionStructure of a flaming front
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Fire BehaviourTemperature distribution
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Fire BehaviourStructure of a flaming frontHeight and length of the flames: The height is the vertical measure of the flame from the ground to its highest point and the length is measured from the base to the top of the flame following its inclination. The length of the flame serves as an indicator of the intensity of the fire.
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Fire BehaviourParts and forms of a wildfireWildfires, according to their behaviour, have different parts and forms of propagation.
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Fire BehaviourParts and forms of a wildfireWildfires take many forms, but their shape at the beginning is often circular or elliptic and it can be distinguished in different areas.
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Fire BehaviourParts and forms of a wildfireHead – Part of the fire which moves forward, progressing faster, and usually where the flames are the largest.Tail – This is the part of the fire which spreads the slowest. It has minor flames and it often extinguishes itself.
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Fire BehaviourParts and forms of a wildfireFlank – The flanks are the part of the fire on both sides of the head. They are called right and left as viewed from the tail towards the head.
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Fire BehaviourParts and forms of a wildfireSpot Fires – These are fires ignited outside the perimeter of the main fire caused by burning brands or embersFronts – The zone of a moving fire where the combustion is primarily flaming.
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Fire EnvironmentFire Environment components:The main factors that influence how a fire develops are:WeatherTopographyFuelThe Fire Environment Triangle provides an excellent tool to understand fire behaviour.
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Fire Environment
An understanding of how these three factors, along with the type, condition and continuity of the fuel, influence fire behaviour and firespread is of vital importance for developing safe and effective tactical plans at wildfire incidents. By analysing the fire environment we can determine if and when fire behaviour will change.
The next few slides explain how weather, topography and fuel affect fire behaviour, fire intensity and rate of firespread.
Fire Environment components:
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Fire EnvironmentWEATHER Among the factors that influence fire behaviour, the weather is the most important and the most changeable . Weather conditions are the most likely cause of an unpredictable change in the fire. Meteorological variables influence the speed and direction of wind, temperature, relative humidity and precipitation.
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Fire EnvironmentWEATHERThe key factors influencing fire behaviour include:
Wind speedWind directionTemperatureRelative Humidity
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Fire EnvironmentWeather factors – Wind
Wind has a major influence on wildfire behaviour due to its ability to vary greatly in speed and direction. The direction of fire spread is determined mostly by wind. Unexpected wind change is the major causes of fatalities and injuries at wildfires.Wind can:Carry away moist laden air drying out vegetationIncrease the supply of oxygen giving the fire more intensityInfluence smoke distribution and impair visibility
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Fire Environment
Influence the amount of fuel consumedBend flames closer to unburned fuels pre heating them closer to their ignition temperature
Bend convection columns through new fuels, drying them out and encouraging fire spread
Weather factors – Wind
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Fire BehaviourWeather factors – Wind
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Fire EnvironmentThe following illustrations show how wind affects firespread and the shape of the area burned (the fire footprint).
No wind
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Fire EnvironmentThe following illustrations show how wind affects firespread and the shape of the area burned (the fire footprint).
No wind Moderatewind
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Fire EnvironmentThe following illustrations show how wind affects firespread and the shape of the area burned (the fire footprint).
No wind Moderatewind
Strongwind
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Fire EnvironmentWeather factors – Wind
GENERAL WIND: This is the wind caused by the motion of the atmosphere
LOCAL WINDS: All of these special winds are caused by land surfaces heating during the day and cooling at night
TOPOGRAPHICAL WINDS: Winds that change direction and speed due to topographical features such as valleys and saddles
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Fire EnvironmentWeather factors – General Winds
General winds are large scale upper level winds caused by high and low pressure systems
They are usually modified in the lower atmosphere by terrain
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Fire EnvironmentWeather factors – Local WindsANABATIC WINDS (upslope daytime winds): They begin during the mid-morning and get more intense as the sun warms the slopes. Depending on the orientation of the slope it will be stronger at different times of the afternoon (from 2pm to 6pm).
KATABATIC WINDS (downslope night time winds): They start when the sun sets and they increase in intensity during the night until about two hours before dawn
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Fire Environment
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Fire EnvironmentWeather factors - Local Winds SEABREEZES: A sea breeze is a wind that moves from
the sea onto the land and is caused by the imbalance between the temperature of the air covering the land and the sea.
When the surface of the land is heated by the sun the air above it rises and is replaced by the cooler air from above the sea, creating an onshore wind.
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Fire EnvironmentLAND BREEZES: A wind that moves from the land towards the sea at night, caused by the imbalance of temperature between the air above the land and the air above the sea.
When land is no longer being heated by the sun, the surface loses temperature and the air becomes colder and denser. The relatively warm air above the sea rises and the air covering the land moves to replace it, creating an offshore wind.
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If you would like further information about how land and sea breezes are caused, watch the short video on the next slide.
Fire Environment
Find out more about Combustion
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Fire EnvironmentWeather Factors – Topographical Winds
As the wind pushes air horizontally across the landscape, its direction and speed can be altered by physical, topographical features. Features such as valleys and spurs can alter wind direction as much as 90°
Wind blowing through a feature such as a re-entrants or a saddles can increase speed as it passes through the constricted area
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Fire EnvironmentWeather Factors -Air TemperaturesThe sun warms solid objects, such as fuels/vegetation and the surface of the land. This in turn raises the temperature of the fuel and the air surroundings them.High temperatures heat the fuels, they become warmer, dryer and more easily ignited (even more so in fine dead vegetation)Fires ignite and spread more easily when the weather conditions are hot and dry. Hot weather is normally accompanied by low relative humidity which supports and encourages combustion.
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Fire EnvironmentWeather Factors – Relative HumidityRelative Humidly (RH) is defined as the amount of water vapour present in the atmosphere. RH is expressed as a percentage i.e 1% would indicate that there is only 1% water present in the air and is very dry where 100% would be saturated and very moist.In the absence of rain, fuel moisture is directly affected by RH: The amount of moisture fuels can absorb or release to the air depends on RH
Fuels and air are constantly exchanging moisture, trying to maintain equilibrium moisture content
Low RH conditions allow fuel to dry
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Fire Environment
High RH conditions inhibit drying or moisten fuels
Warm air has the ability to hold more water vapour than cold air before becoming saturated. As temperature increase the amount of water vapour required to reach saturation also increases. Temperature and RH have an inverse relationship
Increase in temperature, decrease in RH Decrease in temperature, increase in RH
Weather Factors – Relative Humidity
Fire EnvironmentThe diagram on the right illustrates the typical relationship between time of day, temperature, relative humidity and fire intensity.
It shows that maximum fire intensity will often occur during the early to mid afternoon period of the day.
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Fire EnvironmentTOPOGRAPHYTopography is the configuration of the earths surface including natural and man-made features. The topography of an area affects the fire in different ways, including increasing or decreasing the rate of spread of a fire or altering wind speed and direction.Its much easier to predict the influence of topography on a fire than that of fuel and weather.
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Fire EnvironmentTopographical FactorsThe main factors of topography that affect fire behaviour include: Aspect Slope Type of slope Elevation The interaction between topography and wind
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Fire EnvironmentTopographical Factors –AspectAspect is the direction a slope is facing i.e. North or South Easterly Aspect has therefore a direct affect on the levels of exposure to the sun the land receives.South facing slope receive more solar radiation during the day than North facing slopes. East facing slopes receive solar radiation earlier in the day and West facing later in the afternoon.The amount of solar radiation will determine the degree of pre heating and the moisture content of fuels.
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Fire BehaviourWe use the term in or out of aspect to describe whether the land is receiving solar radiation or not
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Fire BehaviourWe use the term in or out of aspect to describe whether the land is receiving solar radiation or not
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Fire BehaviourWe use the term in or out of aspect to describe whether the land is receiving solar radiation or not
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Fire Behaviour
In Aspect Out of Aspect
We use the term in or out of aspect to describe whether the land is receiving solar radiation or not
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Fire EnvironmentTopographical Factors –slopeThe degree of incline or steepness of the landFires burn more rapidly upslope than downslope . This is due to the fuels being in closer contact to the upward moving flames
The radiant heat and convection currents produced by the fire preheat the fuel and lower its moisture content
Fires moving upslope can therefore significantly increase the fires rate of spread
With every 10° increase in slope, the rate of spread is likely to double
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Fire EnvironmentTopographical Factors –slope
Fire EnvironmentTopographical Factors –slope- Diagram illustrating how every 10° increase in slope, the rate of spread will double
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Fire EnvironmentTopographical Factors –Type of SlopeThere are three main types of slope:
Straight slope – The rate of a fire will be even from the bottom to top
Concave slope – The rate of spread will be slow at beginning and increase as the slope increases
Convex slope – The rate of spread will be more extreme at the base and decrease as it moves upslope
TYPES OF SLOPE
Fire Environment
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Fire EnvironmentTopographical Factors –ElevationElevation refers to the height of the land above sea level. Its usually measured in metres and is depicted on maps using contour lines and spot heights.Temperatures decrease with a rise in elevation. In general temperature drops approx. 1° for every 150m increase in height
Normally when temperature decreases, relative humidly increases. Higher relative humidity increases fuel moisture content and may reduce the fires intensity and rate of spread
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Fire EnvironmentTopographical Factors –Elevation At higher elevations fuel loading will normally be reduced due to the decrease in temperature. In extremely high elevations the land may be devoid of fuel.
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Fire EnvironmentTopographical Factors –The interaction between Topography and Wind
Features such as valleys may change the direction of winds
Saddles and re-entrants may increase the speed of wind, which can significantly increase the fires rate of spread and intensity
These characteristics may compromise the safety fire crews working in the area
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FUELIn wildfire terminology, fuel is identified as live or dead plant material that exists across the landscape. Fuels are the source of energy necessary for combustion. The fire behaviour in a fuel source is dependant on the following criteria:The size of the fuelThe fuel loadingHow the fuel is arrangedThe type of the fuelThe moisture content of the fuel
Fire Environment
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Fuel factors – SizeWithin the wildfire environment fuel exists in various lengths, thickness and diameters. A simplified way of classifying fuel according to their size is to refer them as being either fine or course. Fine fuels – Fuels < 6mm in diameterCoarse fuels – Fuels > 6mm in diameterFine fuels drive the forward spread of a fire while the coarse fuels are consumed in the smoulder zone behind the main fire front.The fine fuels are ignited first , this in turn heats and ignites the coarse fuels.
Fire Environment
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Fire Environment
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Fine Fuels Fine Fuels <6mm diameterGrassesTwiglets Leafs Coniferous needles
Coarse Fuels >6mm diameterSticksBranchesLogsTree trunksTree stumps
Fire Environment
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Fire EnvironmentFuel Factors – Fine FuelsFine fuels give the characteristic flame length at the fire perimeter
Fine fuels are responsible for most of the extreme fire behaviour:
torching, crowning and spotting (see extreme fire behaviour section) Fine fuels are ignited first in the combustion process and burn readily
The rate of fire spread is greater in fine fuels than in coarse fuels
Fine fuels dry out quickly and ignite easily
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Fire EnvironmentFuel Factors – Course FuelsCourse fuels normally burn inside the fire perimeter behind the flaming front
Coarse fuels , once ignited , are more difficult to extinguish than fine fuels
Coarse fuels dry slowly proportionally to their diameter
Coarse fuels depend on fine fuels for their ignition source
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Fire EnvironmentFuel Factors – Fuel loadingFuel loading is the amount of available fuel present expressed in terms of weight of fuel per unit area. This could equate to tonnes per hectare or tons per acre. The term “available fuel” refers to the actual amount of fuel that is capable of igniting and sustaining combustion under its present conditions.The presence of high fuel loading indicates a greater potential for intense prolonged fires.
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Fire EnvironmentFuel Factors – Fuel ArrangementThe way fuel is arranged plays an important role in fire development . Within the fire environment fuels are arranged horizontally and vertically and it is important to understand how they interact.Horizontal arrangement – The distribution of continuous vegetation across the landscape.
Vertical arrangement – The way fuel is arranged between ground level and aerial fuels
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Fire EnvironmentFuel Factors – Types of FuelCommon fuel types found in the wildfire environment include: Grass Crops Deciduous woodland Coniferous plantations Heath and moorland Scrubland
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Fire EnvironmentFuel Factors- Re-burnThe ability of a fuel to burn again when the fire has already passed through it without burning it all out. These areas cannot be considered safe.
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Fire EnvironmentFuel Factors – Fuel MoistureThe amount of moisture available in a fuel will directly affect how easily it will ignite and how intensely it will burn . The amount of fuel moisture is dependant upon a number of factors namely:
Relativity and humidity and precipitation Wind Size of the fuels Compactness of the fuel The proximity of the fuel to damp soil
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If you would like further information about fuel at wildfire incidents, watch the short video on the next slide.
Fire Environment
Find out more about fuel
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Types of wildfireClassifications of wildfires
There are 3 main different types of wildfire:
Surface Fire Ground Fire Crown Fire
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Types of wildfiresClassification of fuels according to where they are
found
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Types of wildfireSurface FireThis is the most common type of wild fire, spreading in surface fuels including grass, leaves, shrubs , needles. and litter.Most crown fires and ground fires begin as surface fires.
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Types of wildfires
Surface Fire
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Types of wildfireGround FireGround fires consume the organic and combustible material beneath the surface, such as stumps, roots, duff and peat .These fires usually spread slowly and may go undetected, making them difficult to extinguish due the accessibility.
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Types of wildfires
Ground Fire
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Types of wildfireCrown FireCrown fires burn through the crowns or the canopy of trees or shrubs. They can advance in conjunction with or be independent of a surface fire.They mainly occur in forest fires, due to the continuity of the crowns, passing from one to another. They are difficult to control and extinguish.
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Types of wildfiresPassive Crown FireA fire that travels from surface fuels into aerialfuels without sustainedCrowning.
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Types of wildfiresActive Crown Fire
A fire that advances as a wall of flame engulfing all surface and aerial fuels
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Fire Development All wildfires usually start with a small surface fire which is then influenced by the interaction of the environmental factors of Weather, Topography and Fuel. The information from the previous sections will enable us to understand how a fire will develop and spread.
The following section will look more closely at how the fire develops and how to identify potential extreme fire behaviour.
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Fire DevelopmentWildfires will burn uniformly in all directions when they are burning within uniform fuel (i.e. one type of fuel with the same characteristics), on flat ground and in the absence of wind.
This is illustrated on the right.
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Fire DevelopmentHowever, it is unusual to experience wildfires under these conditions.
Typically, wildfires will spread in an elliptical shape because one or more environmental factors act as a dominant force that increases the rate of fire spread in a particular direction.
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Fire DevelopmentThe fire behaviour observed at the majority of wildfires can be classified according to the following:
Wind-driven wildfire – where the rate and direction of firespread is predominantly influenced by the speed and direction of the wind
Topography-driven wildfire – where the rate and direction of firespread is predominantly influenced by the topography
Fuel-driven wildfire – where the rate and direction of firespread is predominantly influenced by the amount, condition and arrangement of the fuel the wildfire is burning within
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Fire DevelopmentSome wildfires may be significantly influenced by more than one of the above factors. Different parts of the same wildfire may also be predominantly influenced by different factors.
Fire and rescue personnel need to understand and predict fire behaviour at wildfires. Wildfire Prediction Systems are tools that can be used to help understand and predict future fire behaviour and fire spread.
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Fire DevelopmentThe key principle behind an appropriate wildfire prediction system is that fire behaviour within any given fuel is influenced predominantly by three major forces:• Wind• Slope• Aspect
These three factors can be referred to as the ‘forces of alignment’.
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Fire DevelopmentSummary
• Whenever a wildfire is supported by either the wind, slope or aspect it will burn with greater intensity and spread more rapidly.
• If the fire loses the support of the wind, slope or aspect the intensity and rate of spread will decrease.
• An understanding of how these three factors, along with the type, condition and continuity of the fuel, influence fire behaviour and firespread is of vital importance for developing safe and effective tactical plans for wildfires.
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Try watching the videos on the next slides – they provide a useful overview to help consolidate and further develop your understanding of fire behaviour at wildfires.
Further information about fire behaviour at wildfires
Fire Development
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Extreme fire behaviour is defined as “fire behaviour that becomes erratic or difficult to predict”.
Extreme fire behaviour can lead to rapid and/or unpredictable firespread and behaviour, and can be sporadic or sustained over longer periods of time.
Extreme fire behaviour
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There are a number of conditions which can increase the likelihood of extreme fire behaviour, including:
High fuel loading – particularly in fine dead fuels The existence of ladder fuels – particularly if there are large
quantities of fine fuels Fire aligned with a strong wind Fire aligned with a steep slope High temperatures Low humidity Drought conditions Availability of combustible fuels (particularly dead fuels) Multiple seats of fire
Extreme fire behaviour
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There are also some common indicators of extreme fire behaviour:
A surge in fire intensity Long flame lengths Pulsating flames Large quantities of smoke Separate fires occurring outside the fire edge (spotting) Ignition of aerial fuels in the canopy An increase in surrounding air movement
Extreme fire behaviour
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There are also some common indicators of extreme fire behaviour:
A surge in fire intensity Long flame lengths Pulsating flames Large quantities of smoke Separate fires occurring outside the fire edge (spotting) Ignition of aerial fuels in the canopy An increase in surrounding air movement
IMPORTANT: If you can spot these
indicators early then you can keep
yourself and others away from
danger.
Extreme fire behaviour
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The most extreme examples of fire behaviour are caused by a combination of some or all of these factors. Extreme fire behaviour can represent a significant hazard to members of the public and to fire suppression personnel.
Extreme fire behaviour
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The most extreme examples of fire behaviour are caused by a combination of some or all of these factors. Extreme fire behaviour can represent a significant hazard to members of the public and to fire suppression personnel.
IMPORTANT: If you can spot the indicators of extreme fire behaviour early then you can keep
yourself and others safer.
Extreme fire behaviour
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Extreme fire behaviour can occur under varying parameters, however, a general rule of thumb is that extreme fire behaviour is highly likely when one or more conditions approach the 30-30-30 rule:
• Relative humidity is at or below 30% • Wind speed is at or above 30 kilometres per hour • Temperature is at or above 30 degrees Celsius
Extreme fire behaviour
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Extreme fire behaviour can occur under varying parameters, however, a general rule of thumb is that extreme fire behaviour is highly likely when one or more conditions approach the 30-30-30 rule:
• Relative humidity is at or below 30% • Wind speed is at or above 30 kilometres per hour • Temperature is at or above 30 degrees Celsius
IMPORTANT: Remember the 30-30-30 rule.
But also be aware that
extreme fire behaviour can
also occur under other conditions
Extreme fire behaviour
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Extreme fire behaviour is divided into a number of categories. The names of these categories describe the behaviour that is observed:
Spot firesTorchingCrown firesJunction zone effect
Extreme fire behaviour
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Extreme fire behaviour is divided into a number of categories. The names of these categories describe the behaviour that is observed:
Spot firesTorchingCrown firesJunction zone effect
Extreme fire behaviour
Each of these categories of extreme fire behaviour will now be explained in
turn.
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Spot Fires:The process that causes spot fires is referred to as “spotting”.
During spotting, burning material can be carried considerable distances by strong convection currents and wind .
Extreme fire behaviour
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An example of spot fires igniting new fires outside the main fire perimeter.
Extreme fire behaviour
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The key danger of spotting is that spot fires can breach control lines and threaten access, egress and escape routes for personnel, vehicles and members of the public.
It is therefore vitally important that fire suppression personnel are tasked with monitoring the fire and reporting any signs of spotting as soon as possible to other personnel.
Extreme fire behaviour
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The key danger of spotting is that spot fires can breach control lines and threaten access, egress and escape routes for personnel, vehicles and members of the public.
It is therefore vitally important that fire suppression personnel are tasked with monitoring the fire and reporting any signs of spotting as soon as possible to other personnel.
Extreme fire behaviourPlease note… guidance on
developing an effective response
wildfires is explained in more detail within the final module of this unit on wildfire
response and recovery prevention.
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TorchingTorching is a term used to describe a fire that spreads from a surface fire into aerial fuels
Torching usually occurs in areas where there are sufficent ladder fuels that can support fire spread
Torching is normally localised and restricted to single trees or small groups of trees
Extreme fire behaviour
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Crown fires
Crown fires are fires that burn within the upper canopy of trees or shrubs. Their intensity is usually dependent on the amount and condition of the fuel. Some shrubs and trees are more susceptible to crown fires than others. For crown fires to occur, there usually needs to be sufficient available surface fuels and continuous aerial fine fuels.
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Junction zone effect
The junction zone effect is an increase in fire activity caused by two fires, or two parts of a fire, burning into one another. It is created by the convection column generating in drafts, causing both fires to draw towards one another. This increases the speed at which the fuel is consumed and the subsequent intensity and rate of spread. The junction zone effect can also increase the likelihood of spotting and spot fires.
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SummaryIt must be noted that it is not just extreme fire behaviour conditions that threaten life and cause injuryFour recognised common denominators for fatalities at wildfires have been identified as: Fires burn surprisingly fast upslope especially in re-entrants,
chimneys and saddle featuresUnexpected changes in wind strength and directionMost accidents occur on smaller fires or isolated areas at
larger incidents Flare ups generally occur in deceptively light fuels such as
grass and light scrubland
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SummaryIt must be noted that it is not just extreme fire behaviour conditions that threaten life and cause injuryFour recognised common denominators for fatalities at wildfires have been identified as: Fires burn surprisingly fast upslope especially in re-entrants,
chimneys and saddle featuresUnexpected changes in wind strength and directionMost accidents occur on smaller fires or isolated areas at
larger incidents Flare ups generally occur in deceptively light fuels such as
grass and light scrublandCommunication failures have also been regarded as a key contributing factor to a number of previous firefighter fatalities.
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To learn more about extreme fire behaviour:
• Refer to the sub-section on “extreme fire behaviour” within the Scottish Government’s Wildfire Operational Guidance
• Refer to the UK Fire and Rescue Service’s National Operational Guidance for Wildfires
• The video on the following page shows extreme fire behaviour at a wildfire in Alaska.
Extreme fire behaviourFurther information about extreme fire behaviour
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We hope you enjoyed this part of the module!
Please visit the next part which explains more about the potential impacts of wildfires and how to prevent and reduce the impact of wildfires.
End of Wildfire Prevention: Part 2
Source: Junta de Andalucía (Spain)
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