Wildfires are environmental disasters described as the uncontrolled burning of wildland vegetation in natural areas such as forests, grasslands, scrublands, and prairies. These are common occurrences affecting various parts of the world and are referred to by different terminologies based on region or the type of vegetation affected. This includes forest fires, bush fires (in Australia), grass fires, peat fires, prairie fires, and hill fires. Wildfires greatly threaten public health, safety, and the environment. The inherent danger of fire, coupled with the potential large-scale nature of the ensuing blaze, creates a very dangerous situation. A danger that can extend to nearby human settlements and agricultural land. The understanding of wildfires provides necessary insight into combating them. In particular, there has been extensive study on how wildfires start, spread, and eventually end.
Wildfires are caused by the ignition of a flame amidst vegetation suitable to burn. The ignition source of a wildfire refers to any means by which a sufficient amount of heat energy can be transferred to organic vegetative material to raise it to a high enough temperature to burn. This source of heat can either come from nature or be a result of the activities of man.
Two primary natural sources of heat energy can ignite vegetation are lightning and lava from volcanic eruptions. Both of these sources can produce flames: a bolt of lightning discharging its energy when it strikes a tree and lava setting vegetation alight due to its heated nature.
Human presence in an environment is also an active cause of wildfires. Several human activities, either accidental, negligent, or intentional, can start fires in wildland areas. Human-related sources of heat include unattended campfires, burning debris, fireworks, downed power lines, discarded cigarettes, and acts of arson. According to the National Park Service, nearly 85% of wildfires in the United States are a result of the activities of man.
Forest fires start when a flame from some ignition source grows, spread, and sustain itself by consuming available vegetation as fuel. While successive to each other, these events of fire initiation and propagation are highly intertwined in the development of a wildfire. While the point of ignition bears heavy importance as the starting point of a potential wildfire, a flame ignited in vegetation is highly unlikely to spread without the persistence of suitable environmental conditions. The interrelationship between these two events establishes the requirements for starting a forest fire.
The ignition source for a forest fire can be from any of the sources listed above, either natural or man-made. This source of heat causes the combustion of plants and trees, which spreads the heat to nearby vegetation. The ignition source influences the development of one or more of the three types of forest fires: ground fires, surface fires, or crown fires.
Ground fires develop and spread underground in accumulations of fuels such as humus, peat, coal, tree roots, and dead vegetation. These fires can persist under the surface for several months, moving slowly through the ground. Ground fires can burn through the ground to eventually become surface fires. These types of fires are typically difficult to contain due to their subterranean nature.
Surface fires burn along the forest grounds consuming low-lying organic material such as twigs, dry leaves, and duff. These types of fires can be of low or high intensity but are usually fairly easy to put out, as surface fires often spread slowly. The spread can, however, be hastened by steep topography or wind.
Crown fires are the most dangerous forest fires as they burn trees along their length to the top and spread from treetop to treetop. Crown fires are usually the fastest-moving fires as they are exposed to the influence of wind due to their height. These types of fires are usually very intense.
Multiple environmental factors influence the development and propagation of fire in vegetation, and the longstanding presence of these conditions is the basis for most wildfires. The foremost condition is dry weather. Dry weather brings along high temperatures and low humidity, which dries out vegetation making them more susceptible to burn. Secondly, the presence of wind heavily drives the propagation of fire. Wind supplies oxygen that is necessary for fires to burn, and also, the action of wind can transport flaming embers over long distances igniting flames in previously unburnt areas. The topography of the land also influences the rate of spread of wildfires. Wildfires spread rapidly when rising a slope due to the pre-heating of vegetation on elevated grounds, but this also causes a slower descent. The final factor is the type of vegetation being consumed. The type of vegetation present determines how intense and for how long a fire will burn. Dried grasses don’t often burn very long and typically release a comparatively small amount of heat. Large dense trees burn the most ferociously due to factors such as a larger surface area, more vegetative mass, and specific properties such as oil/resin secretion. These trees can burn for hours and generate a large amount of heat.
These conditions bring about the completion of the triangle of fire, a triad of resources required to sustain a flame, namely a heat source, oxygen, and a fuel source. The heat source is provided at the point of ignition, oxygen is supplied by winds, while the weather and topography dictate the availability of the fuel source. Firefighting attempts aim to remove one of these three resources from an ongoing blaze to quench it.
The occurrence of a wildfire impacts human communities and the environment in several ways. Attributes such as the nature, intensity, and location of the fire all influence the extent of the impact and the expected consequences.
Wildfires are often large-scale blazes that burn for long periods, usually over days or weeks, and consume a large amount of vegetation as fuel. This leads to the death of several plants and trees, as well as a disturbance in the local ecosystem. The ecosystem is maintained by the relationship between flora and fauna of the region, a dynamic that will change as animals living in the region will become displaced or fall to the advancing flames. All these can damage a region’s biodiversity, leading to the extinction of several rare plants and animals. The damage to a wildland area will also visually alter the landscape, filling the expanse with the charred remains of plant life as opposed to the usual greenery.
Wildfires present a danger not only to vegetation and resident wildlife but to humans as well. Some wildland areas are close to human settlements, especially in rural regions, and wildfires in these areas can spread to nearby communities. Embers from wildfires can be carried over large distances by the wind and deposited amidst human settlements, setting fires to buildings. The ensuing fire outbreak can severely damage erected structures and wreak havoc on the local infrastructure. In agricultural communities, a wildfire can lead to the loss of crops and livestock, decreasing food production in the area and negatively impacting the local way of life.
The dangerous conditions created by a wildfire pose a grave threat to human lives. Attributable human casualties are caused by suffocation, injuries, and burns. Wildfires also cause respiratory and cardiovascular problems in humans due to the smoke and microscopic particles released into the atmosphere. In addition, the experience of a wildfire can cause damage to the mental and psychosocial well-being of the affected people for years to come. The residents of affected areas and firefighters are at the most risk of the health implications of a wildfire.
Firefighting efforts are intended to halt the spread of a wildfire or quench it entirely. Attempts to stop a fire will target one or more of the three components in the fire triangle and remove it to extinguish the fire. The heat of a flame can be removed using water, wildfires can be deprived of oxygen by using retardant chemicals to smother them, and the fuel of a wildfire can be removed by clearing vegetation ahead of the flames and starving it out. Large fires require the coordinated action of several firefighters, specialized equipment, and aircraft dropping water/retardant on the flames. All these resources cost a lot to procure and put together, and the financial implication of a firefighting effort can take a toll on a region’s economic future.
Wildfires also have an influence on the atmosphere by changing atmospheric conditions and impacting the weather and climate. Large quantities of materials, such as carbon monoxide, carbon dioxide, and particulate matter, are released into the air during a wildfire. Carbon dioxide, in particular, is a greenhouse gas that exacerbates the consequences of climate change around the world. Carbon that has been sequestered in forests for several years is released during wildfires affecting the global balance. The surrounding region will also suffer from air pollution of varying severity during the wildfire and for a duration after.
Wildfires are a concerning occurrence, especially when situated close to human settlements, but they are also a necessary part of nature. Wildfires can bring rebirth to forest areas and promote the proper functioning of an ecosystem. Wildfires destroy insects and diseases that can cause the death of the local flora while also aiding some plants in their natural life cycle. Some plants require the occurrence of fire before their seeds can be released or begin to germinate. Such plants generate flammable resins to aid the propagation of fire. Wildfires in wildland areas can also clear out the underbrush on the forest floor, clearing up the land for the growth of new plant life. The fall of some trees during forest fires also opens up space for sunlight to reach the forest floor to nourish smaller plants while also giving other trees more room to grow. So, while wildfires can be damaging, they are also a vital part of nature, especially when ignited by natural sources. As a result, some wildfires are allowed to burn naturally if there is no threat to human communities, or the fires are controlled to promote the natural process while eliminating the danger. These controlled burns are very beneficial, as they reduce the buildup of shrubs or dense trees that can fuel very intense fires in the future.
The wildfire threat profile of a region is dependent on the availability of wildlands in the region and the prevailing weather conditions. Wildfires are more likely to occur when there are high temperatures, low humidity, and surface winds. These conditions cause vegetation to dry up, become easier to burn, and make it easier for fires to spread. This weather condition, under which wildfires are more likely to occur, is referred to as fire weather. And the period during the year within which fire weather is prevalent is referred to as fire season. Because weather conditions are dynamic, the wildfire threat profile of a region is ever-changing, becoming higher or lower throughout the year. Region-specific factors such as topography may also influence wildfire risk. As a result of the variation in wildfire-influencing factors all over a state, each region in a state will have a distinct wildfire threat profile. There may exist a uniformity in the cumulative statewide profile, but as the year progresses, the profile of some regions may change.
Multiple areas in North Carolina are at risk of wildfires because the state has extensive forestland and vegetative cover extending from the western mountains to the state’s eastern coastlines. These forest resources are of significant economic benefit to the state, providing a source of income through manufacturing and numerous job positions. These wildland areas come under the most threat of wildfires during the two fire seasons in North Carolina, which occur during the Fall and Spring months.
North Carolina reports thousands of wildfires per year, with the leading cause being careless debris burning, according to the North Carolina Forest Service (NCFS). While California sustains the most wildfires in a year, North Carolina also has a very high statistic of wildfire incidents, having suffered over 5,000 wildfires before the end of 2022. These large volumes of wildfires present a credible threat to human settlements as many communities are situated at Wildland/Urban Interfaces (WUI), where communities intermingle with wildland vegetation. Properties, as well as residents, are exposed to wildfires that might develop in these regions.
The highly significant danger of wildfires in the state of North Carolina means residents must take the initiative in safeguarding themselves and their property. While the government and its agencies work diligently throughout the year to suppress and control wildfires, preparatory actions on the part of the citizens will serve to aid these efforts. Programs such as Firewise USA and the North Carolina Wildfire Mitigation Program provide valuable information to help citizens lessen the danger of wildfires.
Preparatory actions against wildfires should begin even before the construction of a building. A large number of fires are set to homes and other constructions by flying embers, and mitigating this possibility should feature in the building design. This is the function of the home ignition zones, a region of space extending around the house within which a falling ember can ignite a flame of consequence. The home ignition zones are classified into three: the immediate zone extending from 0 to 5 feet, the intermediate zone extending from 5 to 30 feet, and the extended zone extending from 30 to 100 feet. The appropriate applications of each of these zones can help a building survive a wildfire. Early preparation actions should include:
Understanding the inherent wildfire risk of the intended construction location, especially when building in a WUI
Designing the driveway with a width of at least 12 feet and a vertical clearance of 15 feet for emergency vehicle access
The selection of fire-resistant building materials
Filing the home’s intermediate zone with crushed stone or gravel
Screening roof, eaves, and attic vents to prevent ember penetration
Selection of fire-resistant siding and dual-pane tempered glass windows
Installation of an outdoor water source with a hose long enough to reach all areas of the property
Designing a special room that can function as containment during smoky conditions. The room should be able to block off outside air when closed.
One of the best preparatory acts is creating an emergency plan. Emergency plans are useful for knowing what to do in a crisis, as well as having the necessary tools to accomplish them. This plan will be essential for avoiding injury and preventing the loss of lives during a wildfire. To prepare an emergency plan for a wildfire, the following actions are necessary:
Identify multiple exit routes from the neighborhood and be well-versed with at least two of them. If the community has an evacuation plan, become familiar with it
Designate a meeting place in case of separation and communicate this information to family members
Prepare an emergency supply kit containing a first-aid kit, food for at least three days, water for at least three days, respirators, an NOAA weather radio, a flashlight, spare batteries, protective clothing, cash, prescribed medication, pet food, personal identification, a whistle, personal hygiene items, fire extinguisher, a local map, and a cell phone with a backup battery.
Include consideration for persons with special needs, such as children, pregnant women, the elderly, and the disabled, in the emergency plan. Persons such as these may require extra help or more time during emergency actions
Coordinate with others in the neighborhood to increase preparedness
Smoke from a wildfire can blanket an area, forcing people to remain in their homes, so it is necessary to plan for this. Identify a room that can be closed off from outside air and obtain a portable air filter to keep the air in the room clean while it is smoky outdoors.
The threat of a wildfire is never truly gone, and while good early preparation actions will help protect the home, they may not be sufficient. Therefore, while the threat persists, actions to defend against wildfires must also be unending.
Remove flammable vegetation from the three home ignition zones and replace these with flame-resistant ones for landscaping purposes
Trim branches overhanging the home and prune the branches of large trees up to six to ten feet from the ground
Expel all plants containing resins, oils, and waxes, as these can propagate fires.
Inspect roof tiles and perform regular maintenance, either by repairing or replacing to prevent ember penetration
Clear out dead vegetation around the house regularly, including from under porches, on roofs, and in gutters
Remove vegetation from around large stationary propane tanks
Maintain lawns and other vegetation to a maximum height of four inches
Prevent flames from reaching the crown of trees by removing vegetation from beneath them and spacing trees at least eighteen feet apart
Create fire breaks by limiting clusters of shrubs and trees around the building
Obtain insurance for the property and its contents, and also create a home inventory to help with claims
Create digital copies of insurance policies and important documents.
Wildfire warnings and alerts are notifications issued by government agencies to inform the public about possible, imminent, or occurring hazardous wildfire conditions. There are three types of wildfire alerts issued: a red flag warning, a fire weather watch, and an extreme fire behavior warning.
A red flag warning is a notification of changing weather conditions that significantly increase the danger of fire occurrence in an area. Such weather conditions include thunderstorms producing frequent lightning but little rain, strong winds, low relative humidity, and warm temperatures. During the issuance of a red flag warning, residents are advised to be extremely careful with open flames.
A fire weather watch indicates that there is a possibility of the development of a red flag condition within an area within the next 12 to 48 hours.
Extreme fire behavior warnings provide notice that a wildfire is likely to burn out of control. This warning is issued if a fire is spreading very fast, there are a lot of crown fires, or fire whirls are present.
Alerts are issued by the National Weather Service (NWS) through the Emergency Alert System that broadcasts via local TVs and radios, through the National Oceanic and Atmospheric Administration (NOAA) Weather Radio, and the Wireless Emergency Alert that sends text-like messages to all mobile devices in the emergency area. Relevant local and state authorities may also issue notifications through various means such as phone or email.
The wildfire threat profile of every area changes, sometimes as frequently as every day. Some areas, such as those located at WUIs, do have more inherent wildfire risks and must exercise extra caution. Factors such as topography also influence wildfire risks, as elevated locations are more likely to be reached as wildfires burn faster uphill. The presence of fire season also indicates a rise in wildfire risks in every area in the relevant region.
A more quantitative wildfire risk assessment can be obtained from the webpage of the North Carolina State Climate Office, which provides a detailed map covering the entirety of the state and forecasts the fire danger for each area. The assessment is based on the presence of environmental conditions that can cause fires to ignite and spread. Through the provided map, a detailed assessment of a region’s wildfire risk can be obtained.
The period in which an active wildfire is nearby is extremely crucial. During this time, all efforts should be focused on the preservation of human lives. While there exists a possibility that the fire will be suppressed, the state of readiness should be in anticipation of impending danger. Paying attention to local weather forecasts will advise on the developing situation. Likewise, the alerts issued by the local authorities can help decide the best action to take.
Evacuate if told to do so. If unable to completely move out of the area, proceed to a nearby local shelter or a Red Cross shelter. Some shelters may not accept pets, so if pets are a consideration, it may be advantageous to evacuate early, even if the order hasn’t been given yet. An emergency plan will be crucial here for deciding what to do. During an evacuation, take note of what direction the fire is moving towards and move away. Keep the headlights of the vehicle on and drive slowly
If an evacuation order has not been given, but there is a presence of smoke in the area, proceed into a room that, when closed, can block out outside air and set up a portable air cleaner. Remain here until the air quality improves. Prevent children and pets from venturing out and inhaling the poor air
Limit smoke exposure at all times. Avoid inhaling smoke, as this can cause suffocation. Wildfire smoke can also affect visibility and irritate the eyes, nose, throat, and lungs. Wear a respirator if there is smoke in the current environment
If trapped, call 911 and inform them of your location and situation. It may take a long time or be impossible for emergency responders to reach the location, so it is important not to remain idle while awaiting rescue.
Turn off propane tanks and shut off the gas
Wet the area around the house and the roof with sprinklers or a garden hose
Collect a large amount of cold water inside the house in sinks and bathtubs
Move furniture away from windows and doors, and close all doors inside the house
Gather emergency supplies, including a fire extinguisher, and retreat into the room farthest from the fire as a defensible space
Do not go into any room if the door feels hot to the touch, as there may be a fire burning inside.
Driving through a wildfire is dangerous, as smoke may impact visibility, and there may be debris on the road. Turn on the headlights and hazard lights, roll up the windows, close the air vents, and drive slowly away from the direction of the fire.
The flames of a wildfire can approach too fast to outrun. If so, park the vehicle in an empty area where there is no vegetation or other fuel to sustain the flames. Only exit after the flames have passed.
Proceed to a location without vegetation or other fire-sustaining fuels.
Locate a water source. If there is one nearby, move toward it.
Stay low. Lie face down in a ditch or depression in the ground and cover the face with a cloth to limit smoke inhalation.
As a wildfire dies out, most of the hazards die with it, but there are still lingering threats. While planning to return home, there are several measures to take note of to avoid incurring injury or financial loss.
Do not return home until the relevant local authorities have declared the area safe. The remnants of a wildfire, such as smoke, hot ash, smoldering debris, and burning embers, may persist. Without proper conduct or handling, these may cause injuries or spark new fires.
After returning home, clean-up operations may be necessary to restore the environment. Exercise caution around debris as these can release dust particles that can affect respiration. Wear respirators when cleaning up or wet debris with water to limit the release of dust. Protective clothing consisting of goggles, gloves, long-sleeved shirts, long pants, socks, and shoes should be worn to protect the skin. Prevent children from playing in ash or touching debris. Persons with respiratory conditions such as asthma should also avoid ash.
Examine the property and its content for damage. Consult the pre-made home inventory to account for missing or damaged items. Contact the insurance company to make claims over insured items.
Check eligibility to claim financial relief under state or federal wildfire relief programs. Persons such as farmers who graze their livestock on federal rangeland can apply for the Livestock Forage Disaster Program if a wildfire halts grazing on the land. By applying at a local Farm Service Agency office within 30 days before the end of the calendar year, as much as 50% of the monthly feed cost can be received.