Essential Climate Variables GTOS 68 - Fire

Essential Climate Variables GTOS 68

Fire disturbance

T13 Assessment of the status
of the development of the standards for the
Terrestrial Essential Climate Variables


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Rome, 2009

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Fire is an important ecosystem disturbance with varying return frequencies, resulting in land cover alteration and change, and atmospheric emissions on multiple time scales. Fire is also an important land management practice and is an important natural abiotic agent in fire dependent ecosystems. Fires not only affect above-ground biomass but also surface and below-ground organic matter such as peat. Information on fire activity is used for global change research, estimating atmospheric emissions and developing periodic global and regional assessments. It is also used for fire and ecosystem management planning and operational purposes (fire use, preparedness and wildfire suppression) and development of informed policies.

The Fire Disturbance Essential Climate Variable includes Burned Area as the primary variable and two supplementary variables: Active Fire and Fire Radiated Power (or Fire Radiative Power - FRP). Burned Area is defined as the area affected by human-made or natural fire and is expressed in units of area such as hectare (ha) or square kilometre (km2). Active Fire is the location of burning at the time of the observation and is expressed in spatial coordinates or by an indicator of presence of absence of fire in a spatially explicit digital raster map, such as a satellite image. FRP is the rate of emitted radiative energy by the fire at the time of the observation and is expressed in units of power, such as Watts (W).

Fire activity is a global phenomenon characterized by strong spatial and temporal variability. Documentation of fire activity by aerial means (including manned or unmanned aircraft), such as GPS plotting, post-fire photography or high resolution radiometers, is done traditionally in some countries, notably in Russia and other countries of the former Soviet Union. However, declining fire management budgets result in incomplete and inconsistent coverage. Other countries that have limited fire activity, e.g. Central European countries, are using aerial patrols for early fire detection. Groundbased observations from fire lookout towers or by automated observing systems are also in place but usually concentrated on limited areas of high-value forests or nature reserves. Data from satellite remote sensing are the most suitable and useful means for large and global scale monitoring. Observing systems have been developed using sensors on board both polar orbiting and geostationary satellites.

© FAO 2009