It does not require a lot of effort for a wildfire to start and man and nature can be responsible to instigate a cause. History has recorded a couple of devastating fires some caused by carelessness. They often begin unnoticed but later spread to shocking distances. Wildfires can move at a speed of 23 kilometers per hour. Sometimes wild fires can cause the weakening of the soil leading t yet another environmental disaster. It is because of this reason that the state and local governments are very strict in averting such fires because of the potential human loss and property damages that may result.
A wildfire will occur when an ignition source gets into contact with a host fuel and the existence of sufficient heat in the environment raise the host fuel to its ignition temperature. The point of origin is described as the place where sustained combustion happens, where the ignition source meets the ignited material. The ignition source physical remains are most likely to be found here. After the ignition, the fire progresses outward from the focal point. The spread of the fire will initially be circular until the fire is influenced by factors such as wind, slope or fuels. The first burning phase exhibits slow spread and low intensity, this area in the proximity of the point of origin is the specific origin.
The lower intensity characterizing this area there is presence of unburned material. When the fire comes under the influence of the affecting factors, it spreads with disproportionate rates and intensities. The area is described as the general origin area.
Weather, topography and fuels mainly influence a wildfire. Wind, humidity and temperature are components majorly affecting this phenomenon. Wind exacts the greatest effect in fire spread and strength. Wildfires generally enlarge in the direction of the wind blow. Humidity affects the likelihood of ignition directly and the intensity of the fire, temperature on the other hand has a preheating effect on the fuels .with changing weather patterns, wind for instance can significantly influence burn patterns.
Topography constitutes terrain, slope and aspect. Fires will spread faster in higher gradients than lower ones due to the effect of up-canyon winds and daytime upslope (Simon, 1996). Terrain affects the rate and intensity of a wildfire. Barriers can have the effect of slowing a wildfire down or causing a fire. Documentation should account for the relevant slope, the terrain, the aspect and elevation features in the general origin area.
Wildfires are associated with the burning of vegetation. There is vegetation fires like brush fires that burn open land with low-lying vegetation such as Twigs that dry out easily burn fiercely and spread quickly. Another vegetation fire is grass fires which burn at 60miles per hour they spread quickly than forest fires they burn intensely but briefly and the temperatures are moderately low. Forests fires are huge but slow due to the little undergrowth but when the fire reaches the tips of the trees and ignition results the intensity soars.
The worst fires are the Australian eucalyptus fires where the Trees are rich in flammable oil such that the area around them is explosive. The hot air rises and new air is sucked in. eventually combustion results and a fire results propelled by conducive weather conditions. These fires are caused by different factors that lead to the initial ignition and the weather conditions that contribute to the spread of the fire (Porter & Reeder, 2012).
Causes of Wild Fires
A wildfire can start because of lightning activity. In investigating wildfires where lightning is suspected to be the cause, lightning occurrence maps are used. Lightning damages or scars on trees, shrubs or poles depict lightning causes.
Wildfires may ensue from campfires. In these situations, the fire, which is, kindled for the purpose of warmth, light, ceremonial purposes or cooking may ignite a blazing fire. The likely parties involved are campers, fishermen or hunters.
Smoking is a prominent cause of fires; such a cause is ignited by the use of cigarettes, pipes, matches, cigars. Etc. cigarettes do not automatically cause fires, as they are highly dependent on the weather conditions. The probability of its ignition is relative to the humidity and the wind strength. The relative humidity must be less than 22% the cigarette must have at least 30% of glow and where the tip is likely facing down and wind orientations will majorly contribute to its ignition. Investigators analyze these pieces of evidence carefully to ascertain if the cause was maliciously perpetrated.
The burning of garbage, slash, stubble and other debris burning can cause wildfires. Mostly such fires start from dumpsites and thereafter gain momentum to spread on the neighboring vegetation, when it is windy, burn barrels may be carried by the wind and the material transported aerially starts a fire in another destination far from the origin. Reports from witnesses are the most likely way to ascertain debris burning as the cause of the fire.
Holdover fires that surface from a brushing activity even after some period can result in a wild fire outcome. This happens when fire s escape and rekindle after being ignited some tile back.
In some cases, willing perpetrators may cause wildfires. This category is arson or incendiary. In this case, the people responsible carefully plan to instigate a fire for the purpose to result in property damage. Ignition devices such as matches or cigarettes are commonly found and the fire has multiple origins.
The sources that ignite the fire may be direct, hot set where an open flame is involved and thus a fire starts immediately or it may be of time delay where the source has a timer before triggering. In these investigations, thorough interviewing of witnesses is done to ensure that the people liable are brought to justice.
The operation of agriculture equipment or some sort of machinery in logging, construction, harvesting, land clearing, mowing etc can also cause wildfires. The ignition is because of the fuel or lubricants flaming up, friction in the parts that later sparks heat, mechanical breakdown, strong strike with a solid barrier or also by the conductive transfer of heat in the machine heating it up to its ignition temperatures (Simon, 1996).
Wildfires can be caused by the ill operation of railroads. Such fires are affected by the maintenance of the railway track, which may hinder the smooth rolling of the trains; the maintenance of the train itself is also a factor. In the investigations, the investigators must acquire the data recorder referred to as the “black box” to analyze the train’s physical condition and the potential cause of the breakdown.
Children that may be experimenting with fire out of mere play and/ or curiosity may start a wild fire, the ignition sources are mainly matches, fireworks and lighters and the origin places are the playgrounds, footpaths or homes. The responsible children may be referred to juvenile authorities or intervention programs.
Sometimes a fire cannot be grouped in the standard causes and thus falls under miscellaneous causes. Under this group, we have fires caused by; power lines where the wire conductor fails or there is hardware faulting. Sometimes these fires are influenced by the actions of humans or animals.
Fireworks causing fires are grouped as aerial handheld explosives and such fires are prominent in holiday periods when teenagers and adventurous young adults are home.
Blasting which incorporated flaming debris can cause wild fires, such occurrences can be at laboratories where experiments are undertaken and the reactions result in explosions.
Firearm use can cause wildfires since it contains black powder or steel core ammunitions that can effectively ignite a fire. These happen mostly in areas of target shooting forests where hunting is done.
Spontaneous combustion is caused when fuels self heat and as a result ignite immediately if the surrounding conditions support combustion or a chemical process producing sufficient heat for ignition.
Flare stacks from industrial, commercial or military flares may ignite fires. The flames burn at a flaring 3600 degrees due to the composition of the matter involved and their following reaction.
When the rays of the sun are directed to a point of severe heat by glass or by shiny objects, the resultant refraction bends the rays of the sun, a similar phenomenon of the magnifying glass, the concave end may which results in the focusing of the sunlight rays may ignite a fire that may slowly spread to hazardous degrees.
Sometimes firefighters may deliberately start a fire in the areas ahead of the fire as a tool to start the death of the fire since with that the fire will not find medium to spread.
To determine the cause of a wildfire, investigators must investigate the general origin area looking for physical evidence. They walk the area in that particular perimeter in search of burn pattern indicators and mark it with appropriate flags. The area where the fire made its initial run is the area with the cleanest burn and has the “u” or “v” pattern.
On both flanks, lateral fire spread indicators depicting lesser fuel consumption mostly bound it. As soon as the initial run is identified, the next step will be to enter the general origin area from the part farther away from the suspected point of origin since burn indicators are more visible on this art. The only exception is if the investigation is on a steep slope and entering the original area from the head becomes a hazard for the investigator.
Investigations
The main objective of a fire investigation is to determine the cause, the origin and the responsible party in the fire. Successful fire investigation is an essential component in averting future unwanted wildfires. The careful and correct determination of wildfire cause and origin is necessary for successful fire investigations.
Effective investigative procedures, which detect the initial attack, can accurately isolate the causes of the fire and save evidence that may be of value giving a great contribution to civil, criminal or administrative actions. The investigation’s starting point should be at the reported time of fire and at the focal point from where it is alleged to have started.
Investigators must clarify upon first respondents to a fire such as firefighters and law enforcers the weight of their responsibility in safeguarding the origin area and any other related evidence as they are the most vital link in the consequent area and cause determination.
Investigations are the result of proper planning, organization and the ability expects foresee issues before they emerge. Facts and considerations are laid out before the process of investigation is initiated.
In the investigation, the first responder’s role is essential, they safeguard any available evidence, consequently it is an asset to have well trained first responders to effectively pinpoint and protect the place of the fire origin. They then make it easier for the origin and cause investigators to have a start of hence ensuring that the first responders develop by giving them training should be a priority (Fire & Emergency Training Network, 2007).
The investigators must be equipped with knowledge of the principles of fire behavior. The knowledge on the ability for a fire to be recreated will assist the investigator in identifying and accurately depicting fire direction indicators. It is essential for an investigator be equipped with proper training to enhance this understanding.
At the scene, the investigators must follow safety related measures and policies established by the federal and local government. Scene examinations should not be a sole undertaking, at least two investigators or accompaniment with a fire fighter should be there to assist each other incase either gets injured.
Wildfire investigations have its own embedded hazards, to avoid this investigator must be aware of the areas where the fire is still active or is still burning. Flammable fuels and cell phone use should be avoided as a rekindle of a fire coupled with wind direction change may spark a massive hazard that may obstruct the initial escape route.
Weather conditions are major contributors to fire hazards; lightning, rain and strong winds may spread the fire or cause slippery footing. Potential hazards may also include, falling debris from burnt or fire weakened materials. Hazards are more prominent on sloppy terrains as soil loosened because of the fire may cause slides causing injuries to the investigators. Power lines, roadside fires and railroads present obvious risks and hence investigators must take apt preventive procedures (National Fire Protection Association, 2012).
Fine dead fuels containing low moisture content are more likely to ignite fires more easily. In investigations, there has to be documentation on the vegetation type that was charred in the origin area more so at the point of the origin. Unburned fuels proximate to the point of origin need to be documented to assist in accounting for likely fuel conditions at that area, an account of the fuel volumes and current seasonal phase of the vegetation should also be done.
When a wildfire advances, visible marks of its progression on non-combustible objects can be seen, this are described as fire direction indicators. With analyzing the behavior of the fire, distinct burn patterns will be formed.
The burn patterns will spot the transition zones making the trace of the fire’s point of origin easier. Investigations on objects assess the depth of char; die-out pattern, degree of damage, angle of char, spalling, and curling, sooting, staining, white ash, cupping and v patterns. These exhibitions are depending on the manner of fire’s progress.
In investigations, different methodologies can be utilized. Systematic methodology is for instance uses a conceptual framework of systematic approach. The method constitutes the following steps, collecting data where facts are collected and the area is examined including the interviewing of witnesses, analyzing data where the collected information is analyzed, developing the hypothesis where the investigator provides a hypothesis based on factual data only, testing the hypothesis against the collected facts. The final selection of the hypothesis that gives the best explanation of the facts collected.
Facts will include the incident information, such as background information on the location, time, the date and time of the wildfire happened, the weather conditions at that period and the complexity of the fire incident (Fire & Emergency Training Network, 2007).
Having the appropriate hypothesis the investigative team gets to work and even obtains specialized personnel when technical assistance is required. An electrical engineer, a material engineer, an industry expert, a fire behavior analyst or canine teams may assist in providing relevant information that will establish a sound theory in the cause and origin of the fire.
At this point the investigative team also assesses the evaluates the need for arrangements for the provision of extra resources and if so they notify the authorities for assistance.
Wildfire suppression activities such as aircraft water dropping or retardant, backfiring unburned fuel in the origin area are potential risks and therefore investigative personnel should contact the fire suppression groups and align their scheduled investigative activities in their program.
Collecting and preserving the evidence should be done with great caution. Fingerprints and even DNA material can be found on the scene of the fire and hence the investigators must be properly equipped with the necessary equipment to collect such data (National Fire Protection Association, 2012).
Apt documentation, recording and even photographic evidence is essential in the collection of data. Photographs should be taken as a witness would view the evidence, relationship between the different pieces of evidence should come out clear giving an accurate presentation of the data needed. The investigators may also get useful information from witnesses; they are needed to take a detailed account of the voluntary statements and having them sign on their reports.
Confidentiality is essential in data collection of a wildfire. Information can only be revealed to fellow officers
Most investigations are established with anticipation of a legal proceeding and information of their outcome can only be disclosed to authorize personnel. Under no circumstance is information availed to persons without prior prosecutorial approval.
A fire investigation can have several outcomes: there can be administrative action taken to recover suppression costs and property damage, there could be subsequent court proceedings within civil law to recover suppression costs and damages or there can be court proceedings within criminal violations of the state or local law and regulations. In such foreseeable outcomes, the legal council and the case management specialist is consulted.
There should be improved policy development programs where there is the implementation of wildfire prevention activities and pre-suppression improvisations. Environmental responsibility in taking care of the surrounding vegetation is important.
In addition, giving the relevant knowledge to children in school is indispensable in avoiding potential wildfire causes as human activities account for a larger percentage of fire causing incidences.
References
- International Association of Fire Chiefs. International Association of Arson Investigators., & National Fire Protection Association. (2012). Fire investigator: Principles and practice to NFPA 921 and 1033. Sudbury, MA: Jones & Bartlett Learning.
- Porter, D. L., & Reeder, L. (2012). Hell on earth: The wildfire pandemic. New York: Forge
- Simon, S. (1996). Wildfires. New York: Morrow Junior Books.
- Trinity Workplace Learning. & Fire & Emergency Training Network. (2007). Wildland fire investigation. Carrollton, TX: Trinity Workplace Learning.
