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).

UN-SPIDER Regional Support Offices with hazard-specific expertise

Related content on the Knowledge Portal

  • Land cover changes can impact many areas of life. These changes can affect deforestation, ecological communities, wildfire extent, and urban growth. This advanced series focused on using satellite imagery to map changes in land cover. Users will learn change detection methods, including image subtraction and classification. They will also conduct their own change detection analysis. This training will use QGIS, the R statistical program, and the Random Forest algorithm.

    This is a free available online course from the program Applied Remote Sensing Training (ARSET) from NASA that includes videos and presentations making this course very interactive.

    The learning objectives are:

    • Become familiar with Landsat bands and color combinations
    • Understand how to visualize change in land cover using Landsat data
    • Learn the basic steps for change detection by:
      • Conducting image subtraction between two dates using QGIS
      • Creating multi-date…
    read more
  • 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.
    Publishing institution:
  • This webinar provides the basics of image processing for active fire detection. It demonstrates how to access the RUS Service and how to download, process, analyse and visualize the free data acquired by the Copernicus satellites. The ESA-…

    read more
  • Pleidas, TerraSar-X, SPOT and Elevation data available commercially from airbus, certain sample data sets at various locations available for free.
    Publishing institution:
  • 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.
  • The website: https://www.radiant.earth
    Help and Tutorials: https://help.radiant.earth/
    Demos & Use Cases: https://demos.radiant.earth/
    Publishing institution:
  • NASA's Earth Observing System Data and Information System (EOSDIS) is a program for archiving and distributing Earth science data from multiple missions to users.
    Publishing institution:
  • Map Viewer that allows downloading and time series creation of meteosat products.

Term Parents

UN-SPIDER Regional Support Offices with hazard-specific expertise