What are wildfires

Forest Fires or Wildfires?

Nowadays the increasing inadequate maintenance of rural areas poses, among all, a crucial add-on to the risk of fires. Deserted fields with wild grass, bushes and woods make up for a large amount of burnable vegetation that in some cases is even bigger that the forest itself. Fires in such wilderness pose a serious threat to populated areas just next to it. This is why scientists and fire experts prefer to use the term Wildfires instead of Forest Fires.

Not just wilderness! In addition to causing significant damage to ecosystems and wildlife, WILDFIRES can potentially cause serious damage to property and putting lives at risk. They can burn for days or even weeks and spread to thousands of acres. Large and long-lasting WILDFIRES are capable to consume millions of acres of vegetated area, and scorching the rich organic soil on the forests floor, which serves as a large reservoir for carbon.

WILDFIRES are actually supposed to be beneficial to certain natural landscapes, clearing underbrush in forests and triggering the release of seeds in some plant species. Such benefits have been incorporated into the practice of “prescribed fires” that is indeed meant to clean the wilderness. However, in the past years such a practice has progressively lost application since it was thought it could increase the risk of spreading unwanted fire, but it turned out to increase the vulnerability of wilderness to fires.

Wildfires jargoon in a nutshell

  • Fire behaviour

    Fire behaviour is the manner in which a fire reacts to the influences of fuel, weather and topography.

  • Fire triangle

    Fire triangle describes the elements generally contributing to the fire: the heat, the availability of fuel and the oxygen

  • Fire Weather Index

    Fire Weather Index is a meteorologically based index used worldwide to estimate the WILDFIRES danger based on several weather variables (temperature, precipitation, relative humidity, and wind speed). A higher index value indicates better weather conditions for WILDFIRES and thus a higher danger.

  • Global Warming aggravations

    Global Warming has a double sided effect on forest fires: it raises weather and fuel aggravating factors. Weather and vegetation conditions are crucial factors for the severity and likelihood of fire. The rise in air temperatures caused by climate change is causing increased drought and longer fire seasons.

  • WILDFIRES fuel

    Vegetation, such as grass, leaves, ground litter, plants, shrubs and trees, that feed a fire.

  • WILDFIRES fuel type

    Vegetation grouped according to its reaction to fire such as spread or difficulty of control under specified weather conditions.

  • WILDFIRE hazard or danger?

    Scientists and engineers distinguish hazard from danger.

    The WILDFIRE danger depends on the on-going weather and it is reported by weather agencies as weather-based fire danger

    The WILDFIRE hazard is the likelihood that the danger strikes in a given area. It largely depends on the quantity and continuity of vegetation

  • WILDFIRES exposed area

    WILDFIRES exposed area includes people, wild life, land, infrastructure and the economy

  • WILDFIRES exposed value

    WILDFIRES exposed value is a number that represents the value of the exposed area. It accounts the number of people living, wildlife ecosystems, the occurrence of strategic assets – for example hospitals, schools, fire management assets – and infrastructures – for example transportations, power plants or water supplies –

  • WILDFIRES vulnerability

    WILDFIRES vulnerability is the susceptibility of an area, including people, wild life, land, infrastructure and the economy, to the impacts of WILDFIRES

  • WILDFIRES risk

    WILDFIRES risk is the likelihood for a WILDFIRE to cause damage to an exposed area. It depends on the hazard and on the vulnerability and value of the exposed area.

  • WILDFIRES management plans

    WILDFIRES management plans provide actions for a specific area, aimed at protecting people, property and forests from fire events, and using fire to accomplish forest management objectives. They include prevention and preparedness, detection and response, adaptation and restoration actions.

Wildfires types

Ground Fires burn below the surface and damage trees roots. (North Macedonia in Slovenia)

Surface Fires burn vegetation laying or growing at the ground level

Crown Fires burn trees’ canopies

Spotting Fires spread fire from one area to the other

Wildland urban interface fires burn wildland and human material fuel

Rural fires occur in rural areas

GROUND FIRES ignite in thick soil with organic matter, such as roots, feeding the flames underground.

Slow – They move very slowly and often smoulder rather than produce flame. They are difficult to contain and suppress because they act under the ground.

From ground to surface – In times of drought, they can smoulder underground for a long time up to an entire season, until conditions allow them to become a surface or climb up to crown fire.

SURFACE FIRES occur in dead or dry vegetation just above the ground and do not scorch the canopy so that it can carry fire. Parched grass or fallen leaves often fuel surface fires. They consume the surface fuel layer while being a less threat for trees and roots.

From surface to ground threatening regeneration – In times of drought, surface fires can become ground fires, damaging tree roots. In this case trees will not be able to regenerate after the fire.

CROWN FIRES burn in the leaves and canopies of trees and shrubs. Hot surface or ground fires can climb up into the canopy and turn to crown fires.

Fast spreading – They are fast moving and extreme intensity fires. Wind conditions have a larger impact on the spread of crown fires through canopies; high wind conditions can cause fast spreading of flames along interconnected and continuous foliage.

SPOTTING FIRES occur when firebrands, that are burning particles of an existing fire, are carried by the wind and start new fires. The distance of travel and speed of spotting depends on the forest environment (height, width, and type of tree species, canopy cover), type of terrain, and wind speed.

Short-Range Spotting: when firebrands land and ignite close to the path of the original fire. They are not considered a significant factor in fire spread because the fire usually quickly overruns the developing spot fire

Long-Range Spotting: when firebrands travel long beyond the main fire site. Often caused by the lofting of firebrands in a convection column

WILDLAND URBAN INTERFACE FIRES occur in the areas just next to human settlements. This proximity increases the risk of damage. Since they burn mixed fuel, including wildland vegetation, and human-made materials, they might have complex fire behavior. They require specific fire management procedures.

RURAL FIRES occur in rural areas. They primarily involve the combustion of natural vegetation, crops, grasslands, and forests. The fuel source is often agricultural land.

Limited Risk – Rural areas typically have barns, farmhouses, and the risk to residential and commercial structures is generally low.

Large Geographic Area – Rural fires can cover vast geographic areas, sometimes spreading across thousands of acres due to the abundance of available vegetation.