Quantifying wildland fire resources deployed during the compound threat of COVID-19

Abstract

Fire agencies across the United States must make complex resource allocation decisions to manage wildfires using a national network of shared firefighting resources. Firefighters play a critical role in suppressing fires and protecting vulnerable communities. However, they are exposed to health and safety risks associated with fire, smoke inhalation, and infectious disease transmission. The COVID-19 pandemic further complicated these risks, prompting fire agencies to propose resource management adaptations to minimize COVID-19 exposure and transmission. It is unclear if and how the pandemic may have operationally influenced wildland firefighting personnel resource use given compounding wildfire and COVID-19 risks. Therefore, we developed generalized linear mixed models that were fit using multiple integrated datasets to detect changes in personnel resource use for years prior to and during the COVID-19 pandemic, while controlling for historical fire and landscape conditions, societal risks, and management objectives. Analyses of observed and predicted firefighting resource use revealed reductions in the mean personnel resources used per wildfire per day during the pandemic for models developed across the western U.S. and for various western U.S. fire regions. Notably, the Northern California and the Great Basin Coordination Centers showed statistically significant reductions in ground personnel use during the COVID-19 pandemic. Learning from wildland fire management strategies and resource use trends that occurred during the COVID-19 pandemic, fire agencies can better anticipate resource constraints that may arise during the compounding threats of severe wildland fire activity and infectious disease outbreaks to proactively prepare and adapt suppression management strategies.

Figure 1

Conceptual framework illustrating model covariates and the predicted model outputs—ground personnel used per incident per day. The fixed effects covariates were included to control for fire characteristics, weather conditions, Preparedness Levels, strategic objectives, and societal risks on ground personnel resource use. Random effects included parameters for multiple fire day observations within a fire incident and a temporal autocorrelation within year.

Figure 2

A timeseries trend of U.S. total monthly fire acres burned (orange shaded area) and mean ground personnel used per fire day (black lines with shaded standard deviations). Monthly fire acres burned were derived from monthly fire incident counts published by the National Centers for Environmental Information Fire History Data (NCEI, 2024) from January 2017 through December 2021.

Figure 3

(a,b) Predicted and observed ground personnel used per fire day by (a) year and across the (b) pre-COVID (2017–2019) and during-COVID (2020–2021) time periods across the western U.S. The black boxplots show the predicted mean ground personnel per fire day and the approximate 95% confidence intervals around the mean for each year. The blue diamonds represent the observed mean, the red triangles represent the observed median ground personnel per fire day, and the gray bars show the observed interquartile range. For the pre- and during-COVID group comparison, the estimated mean ground personnel from the GLMMs was averaged over the respective years.

Figure 4

(a–g) Predicted ground personnel per fire day for each year according to GLMMs developed for each western fire region. The black boxplots show the predicted mean ground personnel per fire day and the approximate 95% confidence intervals around the mean for each year. The blue diamonds represent the observed mean, the red triangles represent the observed median ground personnel per fire day, and the gray bars show the observed interquartile range. The percentage change shown next to the name of each fire region reports the pre- to during-COVID change in the mean ground personnel used per fire day.