Canadian Forest Service Publications
Generating annual estimates of forest fire disturbance in Canada: the National Burned Area Composite. 2020. Hall, R.J.; Skakun, R.S.; Metsaranta, J.M.; Landry, R.; Fraser, R.H.; Raymond, D.; Gartrell, M.; Decker, V.; Little, J. International Journal of Wildland Fire 2020(29):878-891.
Issued by: Northern Forestry Centre
Catalog ID: 40176
Availability: PDF (download)
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Determining burned area in Canada across fire management agencies is challenging because of different mapping scales and methods. The inconsistent removal of unburned islands and water features from within burned polygon perimeters further complicates the problem. To improve the determination of burned area, the Canada Centre for Mapping and Earth Observation and the Canadian Forest Service developed the National Burned Area Composite (NBAC). The primary data sources for this tool are an automated system to derive fire polygons from 30-m Landsat imagery (Multi-Acquisition Fire Mapping System) and high-quality agency polygons delineated from imagery with spatial resolution ≤30 m. For fires not mapped by these sources, the Hotspot and Normalized Difference Vegetation Index Differencing Synergy method was used with 250–1000-m satellite data. From 2004 to 2016, the National Burned Area Composite reported an average of 2.26 Mha burned annually, with considerable interannual variability. Independent assessment of Multi-Acquisition Fire Mapping System polygons achieved an average accuracy of 96% relative to burned-area data with high spatial resolution. Confidence intervals for national area burned statistics averaged ±4.3%, suggesting that NBAC contributes relatively little uncertainty to current estimates of the carbon balance of Canada’s forests.
Plain Language Summary
To understand how forest fires are affecting Canada’s forests we need information about the area, location, and shape of burned areas. The National Burned Area Composite was developed in 2004 to provide an annual compilation of the area burned by forest fires in Canada, using a variety of data sources. This information is used to estimate carbon emissions to meet national reporting requirements on Canada’s forests. In this paper we describe the components of the National Burned Area Composite, the process involved in generating it each year, and the annual burned area over a twelve-year time series from 2004 to 2016. An automated system was developed for mapping burned areas from satellite imagery, and the maps produced contain information not only on the spatial extent of fires but also on their start date and their cause (people or lightning). The area burned in Canada varied considerably, with an average annual burned area of 2.26 million hectares. We conclude the paper by calculating the precision of the annual statistics derived from the National Burned Area Composite.