Forest Fire

Definition

Wildfire, also called forest, bush or vegetation fire, can be described as any uncontrolled and non-prescribed combustion or burning of plants in a natural setting such as a forest, grassland, brush land or tundra, which consumes the natural fuels and spreads based on environmental conditions (e.g., wind, topography). Wildfire can be incited by human actions, such as land clearing, extreme drought or in rare cases by lightning (IRDR).

There are three conditions that need to be present in order for a wildfire to burn: fuel, oxygen, and a heat source. Fuel is any flammable material surrounding a fire, including trees, grasses, brush, even homes. The greater an area's fuel load, the more intense the fire. Air supplies the oxygen a fire needs to burn. Heat sources help spark the wildfire and bring fuel to temperatures hot enough to ignite. Lightning, burning campfires or cigarettes, hot winds, and even the sun can all provide sufficient heat to spark a wildfire (National Geographic).

Facts and figures

The Global Wildland Fire Network Bulletin published by the Global Fire Monitoring Center (GFMC) presents the most recent data regarding consequences of wildfire: in 2017, 36 fires in protected areas were recorded in 19 countries burning more than 196000 hectares worldwide.

Wildfire plays a mixed role for ecology and economy since some ecosystems depend on natural fires to maintaining their dynamics, biodiversity and productivity. However, every year, wildfires burn millions of hectares of forest woodlands and other vegetation, causing the loss of many human and animal lives and an immense economic damage, both in terms of resources destroyed and the costs of suppression. There are also impacts on society and the environment, such as damage to human health from smoke, loss of biological diversity, release of  greenhouse gases, damage to recreational values and infrastructure (FAO).

Most fires are caused by people. The list of human motivations include land clearing and other agricultural activities, maintenance of grasslands for livestock management, extraction of non-wood forest products, industrial development, resettlement, hunting, negligence and arson. Only in very remote areas of Canada and the Russian Federation lightning is a major cause of fires (FAO).

There are three basic types of wildfires:

  • Crown fires burn trees up their entire length to the top. These are the most intense and dangerous wildland fires.
  • Surface fires burn only surface litter and duff. These are the easiest fires to put out and cause the least damage to the forest.
  • Ground fires (sometimes called underground or subsurface fires) occur in deep accumulations of humus, peat and similar dead vegetation that become dry enough to burn. These fires move very slowly, but can become difficult to fully put out, or suppress (Government of Canada).

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Related content on the Knowledge Portal

  • The Copernicus Atmosphere Monitoring Service (CAMS) uses near-real-time observations of the location and intensity of active wildfires to estimate the emissions of pollutants. This is done through its Global Fire Assimilation System (GFAS). This allows active fires to be monitored and their estimated emissions to be used in the CAMS forecasts to predict the transport of the resulting smoke in the atmosphere. The forecasts are used in air quality apps, to help people limit their exposure to pollution, and by policymakers and local authorities to manage the impact of fires.
  • The Copernicus Atmosphere Monitoring Service (CAMS) uses near-real-time observations of the location and intensity of active wildfires to estimate the emissions of pollutants. This is done through its Global Fire Assimilation System (GFAS). This allows active fires to be monitored and their estimated emissions to be used in the CAMS forecasts to predict the transport of the resulting smoke in the atmosphere. The forecasts are used in air quality apps, to help people limit their exposure to pollution, and by policymakers and local authorities to manage the impact of fires.
  • GIS Malawi is a webmapper which provides various vector and raster layers covering a broad range of topics including natural hazards.
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  • The Global Ecosystem Dynamics Investigation (GEDI) produces high resolution laser ranging observations of the 3D structure of the Earth. GEDI’s precise measurements of forest canopy height, canopy vertical structure, and surface elevation greatly advance our ability to characterize important carbon and water cycling processes, biodiversity, and habitat. GEDI’s data on surface structure are valuable for weather forecasting, forest management, glacier and snowpack monitoring, and the generation of more accurate digital elevation models.
  • Global and regional syntheses which enable the examination of broad-scale patterns in paleofire activity, creating a framework for exploring the linkages among fire, Human, climate and vegetation at centennial-to-multi-millennial time scales and allowing for evaluation of fire model simulations at regional to global scales
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  • Fires are an important source of atmospheric trace gases and aerosols and they are the most important disturbance agent on a global scale. In addition, deforestation and tropical peatland fires and areas that see an increase in the frequency of fires add to the build-up of atmospheric CO2.
    GFED have combined satellite information on fire activity and vegetation productivity to estimate gridded monthly burned area and fire emissions, as well as scalars that can be used to calculate higher temporal resolution emissions. Most of the resulting datasets are downloadable from this website for use in large-scale atmospheric and biogeochemical studies. The core datasets are:
    - Burned area
    - Burned area from "small" fires based on active fire detections outside the burned area maps
    - Carbon and dry matter emissions
    - Fractional contributions of various fire types to total emissions
    - List of emission factors to compute trace gas and…
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  • ESA's Earth Observation Thematic Exploitation Platform (TEP) is a browser for satellite imagery and specific products on an environmental topic. The TEP platforms are divided into 7 categories: Coastal; Forstry; Geohazards; Hydrology; Polar; Urban; and Food Security. Each platform is a collaborative, virtual work environment providing access to EO data and the tools, processors and Information and Communication Technology resources required to work with them. TEP aims to bridge the gap between the users and the data and tools.
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  • Pleidas, TerraSar-X, SPOT and Elevation data available commercially from airbus, certain sample data sets at various locations available for free.
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  • The GEOMAC Wildland Fire Support includes layers on: point-layer of past years fires, fire boundaries/ perimeter, current firest, satellite-based fire detection: MODIS VIIRS HMS, wildland-urban interface,
  • Vegetation-based fire indicators: expected number of fires per predictive service area: number of fires predicted (1000+ acres west, 500+ acres east) or the coming 7 days, with a probability estimate for exceeding the prediction.

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