Feu de forêt

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

  • Sentinel-1 is a two satellite constellation with the prime objectives of land and ocean monitoring. The goal of the mission is to provide C-Band Synthetic Aperture Radar (SAR) data continuity following the retirement of ERS-2 and the end of the Envisat mission.
    To accomplish this the satellites carry a C-SAR sensor, which offers medium and high resolution imaging in all weather conditiions. The C-SAR is capable of obtaining night imagery and detecting small movement on the ground, which makes it useful for land and sea monitoring.
    Sentinel-1 works in a pre-programmed operation mode to avoid conflicts and to produce a consistent long-term data archive built for applications based on long time series.
    The mission benefits numerous services. For example, services that relate to the monitoring of Arctic sea-ice extent, routine sea-ice mapping, surveillance of the marine environment, including oil-spill monitoring and ship detection for maritime security, monitoring land-…

    read more
    05/12/2024
  • The Advanced Land Observing Satellite-4 (ALOS-4) is a satellite to observe the Earth's surface using its onboard phased array type L-band synthetic aperture radar (PALSAR-3). The L-band radar technology has continuously been developed in Japan. With further improved observation performance compared to the predecessor PALSAR-2 aboard the DAICHI-2 (ALOS-2), JAXA and its prime contractor, Mitsubishi Electric Corporation, are developing the satellite aiming at achieving both high resolution and a broader observation swath.
    Unlike observations by an optical sensor, radar images can be acquired day and night as it does not require sunlight. Moreover, since radio waves can penetrate cloud, the images can be obtained regardless of weather condition. The ALOS-4 will leverage these merits for observing and monitoring disaster-hit areas, forests, and sea ice. In addition, it will also challenge new areas such as monitoring infrastructure displacement.
    The ALOS-4 will be equipped…

    read more
    01/07/2024
  • Landsat 9 was successfully launched on Monday, Sept. 27, 2021 from Vandenberg Space Force Base in California. Landsat 9 data is publicly available from USGS.

    Landsat 9—a partnership between NASA and the U.S. Geological Survey— continues the Landsat program’s critical role in monitoring, understanding and managing the land resources needed to sustain human life.

    Today’s increased rates of global land cover and land use change have profound consequences for weather and climate change, ecosystem function and services, carbon cycling and sequestration, resource management, the national and global economy, human health, and society.

    Landsat is the only U.S. satellite system designed and operated to repeatedly observe the global land surface at a moderate scale that shows both natural and human-induced change.

    Since reducing the risk of a Landsat data gap is a high priority of the U.S. Sustainable Land Imaging Program, Landsat 9 has a design very similar…

    read more
    27/09/2021
  • Amazônia-1 is the first Earth Observation satellite completely designed, integrated, tested and operated by Brazil. It features the optical Advanced Wide Field Imager (AWFI), with swath width 850 km and 60 m resolution, capturing images in 3 visible bands and 1 near-infrared (NIR) band. It has a high revisit period of 5 days, which is important for increasing the probability of capturing useful images over frequently overcast areas including the Amazon region. The data will be accessible to the scientific community, government agencies, and to users interested in a better understanding of the terrestrial environment. The Amazon mission is planned to have three remote sensing satellites: Amazonia-1, followed by Amazonia-1B and Amazonia-2.

    28/02/2021
  • The Sentinel-6 Michael Freilich satellite was launched into orbit on November 21, 2020. The launch was a culminated European-American effort that involved organisations from both sides of the atlantic. The European Space Agency (ESA), the European Organisation for the Exploitation of Meterological Satellites (EUMETSAT), the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA) and the National Centre for Space Studes (CNES) all collaborated together to make the launch of Sentinel-6 Michael Freilich a reality.​ The Sentinel-6 Michael Freilich satellite is the first of the Sentinel-6 satellites. An identical satellite, Sentinel-6B will follow in 2025. At an altitude of 1336 km the Sentinel-6 Michael Freilich satellite will use instruments on board to provide highly accurate measurements of the sea level in an effort to combat…

    read more
    21/11/2020
  • The Argentinean Microwaves Observation Satellite 1B (SAOCOM 1B) was launched into orbit on August 30, 2020 from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida, United States of America. Developed by the National Argentinean Space Commission (CONAE) in corporation with the Italian Space Agency (ASI), this new satellite joined SAOCOM 1A and four Italian COSMO-SkyMed to complete the Italian-Argentinean Satellite System for Emergency Management (SIASGE). The SAOCOM 1B satellite orbits at 620 km above the earth's surface and is fitted with a Synthetic Aperture Radar (SAR) sensor that makes use of microwaves in the electromagnetic L-band. The spatial resolution of its imagery ranges between 10 and 100 meters. The data collected by SAOCOM 1B helps monitor climatological disasters (forest fires, glacial lake outbursts, droughts) and hydrological disasters (landslides and floods).

     

    30/08/2020
  • The Argentinean Microwaves Observation Satellite 1B (SAOCOM 1B) was launched into orbit on August 30, 2020 from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida, United States of America. Developed by the National Argentinean Space Commission (CONAE) in corporation with the Italian Space Agency (ASI), this new satellite joined SAOCOM 1A and four Italian COSMO-SkyMed to complete the Italian-Argentinean Satellite System for Emergency Management (SIASGE). The SAOCOM 1B satellite orbits at 620 km above the earth's surface and is fitted with a Synthetic…

    read more
    30/08/2020
  • Cartosat-3 satellite is a third generation agile advanced satellite having high resolution imaging capability. Cartosat-3 will address the increased user’s demands for large scale urban planning, rural resource and infrastructure development, coastal land use and land cover etc.

    27/11/2019
  • PRISMA (Hyperspectral Precursor of the Application Mission), mission fully funded by Italian Space Agency (ASI), is an Earth Observation system with innovative, electro-optical instrumentation that combine a hyperspectral sensor with a medium-resolution panchromatic camera. The advantages of this combination are that in addition to the usual capability of observation based on recognising the geometric characteristics of the scene there are hyperspectral sensors which determine the chemical-physical composition of the objects present on the scene. This offers the scientific community and users many applications in the field of environmental monitoring, resource management, crop classification, pollution control and other things.

    22/03/2019
  • Constellation of multiple satellites

    03/12/2018

UN-SPIDER Regional Support Offices with hazard-specific expertise