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Survival analysis and classification methods for forest fire size

Author(s): Piers-Olivier Tremblay, Thierry Duchesne, Steve G. Cumming
Year Published: 2018

Factors affecting wildland-fire size distribution include weather, fuels, and fire suppression activities. We present a novel application of survival analysis to quantify the effects of these factors on a sample of sizes of lightning-caused fires from Alberta, Canada. Two events were observed for each fire: the size at initial assessment (by the first fire fighters to arrive at the scene) and the size at “being held” (a state when no further increase in size is expected). We developed a statistical classifier to try to predict cases where there will be a growth in fire size (i.e., the size at “being held” exceeds the size at initial assessment). Logistic regression was preferred over two alternative classifiers, with covariates consistent with similar past analyses. We conducted survival analysis on the group of fires exhibiting a size increase. A screening process selected three covariates: an index of fire weather at the day the fire started, the fuel type burning at initial assessment, and a factor for the type and capabilities of the method of initial attack. The Cox proportional hazards model performed better than three accelerated failure time alternatives. Both fire weather and fuel type were highly significant, with effects consistent with known fire behaviour. The effects of initial attack method were not statistically significant, but did suggest a reverse causality that could arise if fire management agencies were to dispatch resources based on a-priori assessment of fire growth potentials. We discuss how a more sophisticated analysis of larger data sets could produce unbiased estimates of fire suppression effect under such circumstances.

Citation: Tremblay, Pier-Olivier; Duchesne, Thierry; Cumming, Steven B. 2018. Survival analysis and classification methods for forest fire size. PLoS ONE 13(1):e0189860. https://doi.org/10.1371/journal.pone.0189860
Topic(s): Fire Regime, Fire and Landscape Mosaics, Patch Size
Ecosystem(s): None
Document Type: Book or Chapter or Journal Article
NRFSN number: 17328
FRAMES RCS number: 25626
Record updated: Jul 26, 2018