Suppression Expenditures Research Articles

Human and climatic influences on wildfires ignited by recreational activities in national forests in Washington, Oregon, and California * *This project was funded through Joint Fire Science Program award #21–2–01–1.

In Washington, Oregon, and California, ignitions from recreational activities accounted for 12% of human-caused wildfires, and 8% of the area burned, from 1992–2020. Wildfires ignited by recreational activities not only increase fire suppression expenditures but have the potential to limit recreational activities traditionally associated with use of fire, such as camping. From 1992–2020, 50% of recreation-caused ignitions in these three states occurred on lands managed by the U.S. Forest Service. The mean annual number of recreation-caused ignitions on national forests in the three states during this period was relatively stable, about 500, whereas recreation-caused ignitions within other jurisdictions decreased by 40%. Improved understanding of the impact of human and climatic factors on recreation-caused ignitions could provide valuable insights for shaping policy and management decisions. We found that mean annual densities of recreation-caused ignitions on national forests were 7 times greater within 1 km of designated campgrounds than >1 km from campgrounds, although 80% of recreation-caused ignitions occured >1 km from designated campgrounds. Ignition density in campgrounds increased non-linearly with overnight visitor density; a doubling of visitor density was associated with a ∼40% increase in ignitions. Large (≥4 ha) recreation-caused wildfires, especially those ignited in designated campgrounds, tended to occur concurrent with drought and 1–2 years after anomalously wet conditions. These results suggest that accounting for drought in implementation of fire restrictions, and targeting wildfire-prevention awareness to recreational users outside designated campgrounds, might reduce the likelihood of recreation-caused ignitions.

Modeling Individual Extended Attack Wildfire Suppression Expenditures in British Columbia

AbstractWe developed models of suppression expenditures for individual extended attack fires in British Columbia using parametric and nonparametric machine-learning (ML) methods. Our models revealed that suppression expenditures were significantly affected by a fire’s size, proximity to the wildland–urban interface (WUI) and populated places, a weather based fire severity index, and the amount of coniferous forest cover. We also found that inflation-adjusted individual fire suppression expenditures have increased over the 1981 to 2014 study period. The ML and parametric models had similar predictive performance: the ML models had somewhat lower root mean squared errors but not on mean average errors. Better specification of fire priority as well as resource constraints might improve future model performance.

Historical and future global burned area with changing climate and human demography

Summary Wildfires influence terrestrial carbon cycling and represent a safety risk, and yet a process-based understanding of their frequency and spatial distributions remains elusive. We combine satellite-based observations with an enhanced dynamic global vegetation model to make regionally resolved global assessments of burned area (BA) responses to changing climate, derived from 34 Earth system models and human demographics for 1860–2100. Limited by climate and socioeconomics, recent BA has decreased, especially in central South America and mesic African savannas. However, future simulations predict increasing BA due to changing climate, rapid population density growth, and urbanization. BA increases are especially notable at high latitudes, due to accelerated warming, and over the tropics and subtropics, due to drying and human ignitions. Conversely, rapid urbanization also limits BA via enhanced fire suppression in the immediate vicinity of settlements, offsetting the potential for dramatic future increases, depending on warming extent. Our analysis provides further insight into regional and global BA trends, highlighting the importance of including human demographic change in models for wildfire under changing climate.

Resource Allocation under Fire

Rising suppression cost and severity of wildfires in the United States have prompted debate over federal wildfire management policy. We estimate an econometric model of suppression resource allocation using a dynamic panel dataset on over 500 wildfires in the western United States. We find that more hand crews and engines are dispatched to fires that threaten homes, while more aircraft are dispatched to fires that start near higher-value homes. We combine our results with projected housing growth estimates in California to show that suppression expenditures may rise by nearly $24 million per year.

The Role of Previous Fires in the Management and Expenditures of Subsequent Large Wildfires

Previously burned areas can influence the occurrence, extent, and severity of subsequent wildfires, which may influence expenditures on large fires. We develop a conceptual model of how interactions of fires with previously burned areas may influence fire management, fire behavior, expenditures, and test hypotheses using regression models of wildfire size and suppression expenditures. Using a sample of 722 large fires from the western United States, we observe whether a fire interacted with a previous fire, the percent area of fires burned by previous fires, and the percent perimeter overlap with previous fires. Fires that interact with previous fires are likely to be larger and have lower total expenditures on average. Conditional on a fire encountering a previous fire, a greater extent of interaction with previous fires is associated with reduced fire size but higher expenditures, although the expenditure effect is small and imprecisely estimated. Subsequent analysis suggests that fires that interact with previous fires may be systematically different from other fires along several dimensions. We do not find evidence that interactions with previous fires reduce suppression expenditures for subsequent fires. Results suggest that previous fires may allow suppression opportunities that otherwise might not exist, possibly reducing fire size but increasing total expenditures.

Modeling Fuel Treatment Leverage: Encounter Rates, Risk Reduction, and Suppression Cost Impacts

The primary theme of this study is the cost-effectiveness of fuel treatments at multiple scales of investment. We focused on the nexus of fuel management and suppression response planning, designing spatial fuel treatment strategies to incorporate landscape features that provide control opportunities that are relevant to fire operations. Our analysis explored the frequency and magnitude of fire-treatment encounters, which are critical determinants of treatment efficacy. Additionally, we examined avoided area burned, avoided suppression costs, and avoided damages, and combined all three under the umbrella of leverage to explore multiple dimensions with which to characterize return on investment. We chose the Sierra National Forest, California, USA, as our study site, due to previous work providing relevant data and analytical products, and because it has the potential for large, long-duration fires and corresponding potential for high suppression expenditures. Modeling results generally confirmed that fire-treatment encounters are rare, such that median suppression cost savings are zero, but in extreme years, savings can more than offset upfront investments. Further, reductions in risk can expand areas where moderated suppression response would be appropriate, and these areas can be mapped in relation to fire control opportunities.

The Effect of Higher Temperatures on Wildfire Size: Evidence from Wildfires on U.S. Forest Service Lands in the Northern Rockies

This paper investigates the effect that rising temperatures will have on wildfire size in the United States. Using data for 586 wildfires that occurred on US Forest Service land in the Northern Rockies between 1995 and 2012, I find that a 1% increase in the maximum temperature observed during the month a wildfire occurs is associated with a 2.34% increase in wildfire size, holding all other factors constant. Given that current climate models predict temperatures to rise by 32% in this region by the end of the century, this estimate suggests that average wildfire size could increase by 75%. I estimate that perfectly offsetting this increase in wildfire size would require the US Forest Service to increase per-fire suppression expenditures by 202%. This would translate into a $5 million increase in suppression expenditures for the average wildfire in my dataset.

Prior wildfires influence burn severity of subsequent large fires

With longer and more severe fire seasons predicted, the incidence and extent of fires are expected to increase in western North America. As more area is burned, past wildfires may influence the spread and burn severity of subsequent fires, with implications for ecosystem resilience and fire management. We examined how previous burn severity, topography, vegetation, and weather influenced burn severity on four wildfires, two in Idaho, one in Washington, and one in British Columbia. These were large fire events, together burning 330 000 ha and cost $165 million USD in fire suppression expenditures. Collectively, these four study fires reburned over 50 000 ha previously burned between 1984 and 2006. We used sequential autoregression to analyze how past fires, topography, vegetation, and weather influenced burn severity. We found that areas burned in the last three decades, at any severity, had significantly lower severity in the subsequent fire. Final models included maximum temperature, vegetation cover typ...

The Impact of Residential Development Pattern on Wildland Fire Suppression Expenditures

Despite a growing body of literature on the economics of wildland fire suppression, the effect of development pattern in the wildland-urban interface (WUI) has received only cursory treatment. We model the relationship between fire suppression expenditures and the spatial pattern of residential development using data from 281 fires in the northern Rocky Mountains. We find that the effect of WUI development on suppression expenditures is dependent on the spatial pattern of development. Our results suggest that policies to control the spatial pattern of WUI development can be nearly as effective as policies that completely restrict WUI development.

Scofield, Anna. “The Impacts of Residential Development Pattern on Wildland Fire Suppression Expenditures.” MS Thesis, University of Wyoming. Outstanding Master's Thesis

Scofield, Anna. “The Impacts of Residential Development Pattern on Wildland Fire Suppression Expenditures.” MS Thesis, University of Wyoming. Outstanding Master's Thesis

Examining heterogeneity and wildfire management expenditures using spatially and temporally descriptive data

Increasing costs of wildfire management have highlighted the need to better understand suppression expenditures and potential tradeoffs of land management activities that may affect fire risks. Spatially and temporally descriptive data is used to develop a model of wildfire suppression expenditures, providing new insights into the role of spatial and temporal heterogeneity in determining expenditures. Incorporating heterogeneity improves model fit and predictive ability over a model with data based on the point and time of fire ignition. The model is potentially useful for providing expenditure information for simulated fire applications and post-season evaluation of suppression activities.

The net benefits of human-ignited wildfire forecasting: the case of Tribal land units in the United States.

Research shows that some categories of human-ignited wildfires might be forecastable, due to their temporal clustering, with the possibility that resources could be pre-deployed to help reduce the incidence of such wildfires. We estimated several kinds of incendiary and other human-ignited wildfire forecast models at the weekly time step for tribal land units in the United States, evaluating their forecast skill out of sample. Analyses show that an Autoregressive Conditional Poisson (ACP) model of both incendiary and non-incendiary human-ignited wildfires is more accurate out of sample compared to alternatives, and the simplest of the ACP models performed the best. Additionally, an ensemble of these and simpler, less analytically intensive approaches performed even better. Wildfire hotspot forecast models using all model types were evaluated in a simulation mode to assess the net benefits of forecasts in the context of law enforcement resource reallocations. Our analyses show that such hotspot tools could yield large positive net benefits for the tribes in terms of suppression expenditures averted for incendiary wildfires but that the hotspot tools were less likely to be beneficial for addressing outbreaks of non-incendiary human-ignited wildfires.

Effect of fire prevention programs on accidental and incendiary wildfires on tribal lands in the United States

Humans cause more than 55% of wildfires on lands managed by the USDA Forest Service and US Department of the Interior, contributing to both suppression expenditures and damages. One means to reduce the expenditures and damages associated with these wildfires is through fire prevention activities, which can include burn permits, public service programs or announcements, outreach efforts to schools, youth groups and equipment operators, and law enforcement. Using data from 17 US Bureau of Indian Affairs tribal units, we modelled the effect of prevention programs and law enforcement on the number of human-caused ignitions. We also included weather and lagged burned area in our estimation of fixed-effects count models. The results show that prevention activities led to significant reductions in wildfires caused by escaped campfires, juveniles, fire-use (e.g. escaped debris burns) and equipment. Increased law enforcement resulted in fewer incendiary- and equipment-caused wildfires. Using average suppression expenditures by wildfire and our estimate of avoided wildfires per additional year of prevention, we estimate partial benefit–cost ratios of greater than 4.5 for all Bureau of Indian Affairs regions for the continuation of the prevention program.

Climate change presents increased potential for very large fires in the contiguous United States

Very large fires (VLFs) have important implications for communities, ecosystems, air quality and fire suppression expenditures. VLFs over the contiguous US have been strongly linked with meteorological and climatological variability. Building on prior modelling of VLFs (>5000 ha), an ensemble of 17 global climate models were statistically downscaled over the US for climate experiments covering the historic and mid-21st-century periods to estimate potential changes in VLF occurrence arising from anthropogenic climate change. Increased VLF potential was projected across most historically fire-prone regions, with the largest absolute increase in the intermountain West and Northern California. Complementary to modelled increases in VLF potential were changes in the seasonality of atmospheric conditions conducive to VLFs, including an earlier onset across the southern US and more symmetric seasonal extension in the northern regions. These projections provide insights into regional and seasonal distribution of VLF potential under a changing climate, and serve as a basis for future strategic and tactical fire management options.

Dormant season grazing may decrease wildfire probability by increasing fuel moisture and reducing fuel amount and continuity

Mega-fires and unprecedented expenditures on fire suppression over the past decade have resulted in a renewed focus on presuppression management. Dormant season grazing may be a treatment to reduce fuels in rangeland, but its effects have not been evaluated. In the present study, we evaluated the effect of dormant season grazing (winter grazing in this ecosystem) by cattle on fuel characteristics in sagebrush (Artemisia L.) communities at five sites in south-eastern Oregon. Winter grazing reduced herbaceous fuel cover, continuity, height and biomass without increasing exotic annual grass biomass or reducing bunchgrass basal area or production. Fuel moisture in winter-grazed areas was high enough that burning was unlikely until late August; in contrast, fuels in ungrazed areas were dry enough to burn in late June. Fuel biomass on perennial bunchgrasses was decreased by 60% with winter grazing, which may reduce the potential for fire-induced mortality. The cumulative effect of winter grazing from altering multiple fuel characteristics may reduce the likelihood of fire and the potential severity in sagebrush communities with an understorey dominated by herbaceous perennials. Dormant season grazing has the potential to reduce wildfire suppression expenditures in many rangelands where herbaceous fuels are an issue; however, increasing woody vegetation and extreme fire weather may limit its influence.

Modeling Wildfire Incident Complexity Dynamics

Wildfire management in the United States and elsewhere is challenged by substantial uncertainty regarding the location and timing of fire events, the socioeconomic and ecological consequences of these events, and the costs of suppression. Escalating U.S. Forest Service suppression expenditures is of particular concern at a time of fiscal austerity as swelling fire management budgets lead to decreases for non-fire programs, and as the likelihood of disruptive within-season borrowing potentially increases. Thus there is a strong interest in better understanding factors influencing suppression decisions and in turn their influence on suppression costs. As a step in that direction, this paper presents a probabilistic analysis of geographic and temporal variation in incident management team response to wildfires. The specific focus is incident complexity dynamics through time for fires managed by the U.S. Forest Service. The modeling framework is based on the recognition that large wildfire management entails recurrent decisions across time in response to changing conditions, which can be represented as a stochastic dynamic system. Daily incident complexity dynamics are modeled according to a first-order Markov chain, with containment represented as an absorbing state. A statistically significant difference in complexity dynamics between Forest Service Regions is demonstrated. Incident complexity probability transition matrices and expected times until containment are presented at national and regional levels. Results of this analysis can help improve understanding of geographic variation in incident management and associated cost structures, and can be incorporated into future analyses examining the economic efficiency of wildfire management.

A Risk-Based Approach to Wildland Fire Budgetary Planning

The financial impact of wildfire management within the USDA Forest Service challenges the ability of the agency to meet societal demands and maintain forest health. The extent of this financial crisis has been attributed to historical and continuing fire management practices, changing climatic conditions, and increasing human development in fire-prone areas, as well as the lack of financial accountability of fire managers and misaligned incentive structures. In this article, we focus on incentives related to cost containment. We review the literature on the incentive structure facing wildfire managers and describe how the incentive structure does not sufficiently reward cost containment. We then cover a range of possible approaches to promote cost containment, culminating in a novel solution premised on the application of actuarial principles to wildfire budgetary planning that we believe most closely aligns with the Forest Service's transition to risk-based management paradigms and that most comprehensively incentivizes containment across the spectrum of wildfire management activities. We illustrate through a proof of concept case study how risk-based performance measures would be calculated and compare our results with historic suppression expenditures. Preliminary results suggest that our simulation model performs well in a relative sense to identify high- and low-cost forests, and we detail modeling improvements to refine estimates. We then illustrate potential extension to an actuarial system, which would further incentivize appropriate risk management and cost containment across the fire management continuum. We address the strengths and weaknesses of the proposed approaches, including potential roadblocks to implementation, and conclude by summarizing our major findings and offer recommen- dations for future agency direction. FOR .S CI. 59(1):63-77.

Quantifying the Potential Impacts of Fuel Treatments on Wildfire Suppression Costs

Modeling the impacts and effects of hazardous fuel reduction treatments is a pressing issue within the wildfire management community. Prospective evaluation of fuel treatment effectiveness allows for comparison of alternative treatment strategies in terms of socioeconomic and ecological impacts and facilitates analysis of tradeoffs across land-management objectives. Studies have yet to rigorously examine potential impacts to fire suppression expenditures associated with prior hazardous fuel reduction treatments. Such information would be helpful for federal land-management agencies struggling to contain escalating wildfire management costs. In this article we establish a methodology for estimating potential reductions in wildfire suppression costs. Our approach pairs wildfire simulation outputs with a regression cost model and quantifies the influence of fuel treatments on distributions of wildfire sizes and suppression costs. Our case study focuses on a landscape within the Deschutes National Forest in central Oregon that was selected to receive funding under the auspices of the Collaborative Forest Landscape Restoration Program. Results suggest substantial reductions in distributions of wildfire size and suppression cost on a per fire basis. Furthermore, because fewer ignitions become large fires on the treated landscape, distributions of annual area burned and annual suppression costs also shift downward because of fuel treatments. Results are contingent on four key factors: large-scale implementation of fuel treatments across the landscape, assumed treatment effectiveness over the duration of the analysis period, accuracy of wildfire and cost models, and accuracy of projected changes to fire behavior fuel models resulting from fuel treatments. We discuss strengths and limitations of the modeling approach and offer suggestions for future improvements and applications.

Corrigendum to: Factors influencing large wildland fire suppression expenditures

There is an urgent and immediate need to address the excessive cost of large fires. Here, we studied large wildland fire suppression expenditures by the US Department of Agriculture Forest Service. Among 16 potential non-managerial factors, which represented fire size and shape, private properties, public land attributes, forest and fuel conditions, and geographic settings, we found only fire size and private land had a strong effect on suppression expenditures. When both were accounted for, all the other variables had no significant effect. A parsimonious model to predict suppression expenditures was suggested, in which fire size and private land explained 58% of variation in expenditures. Other things being equal, suppression expenditures monotonically increased with fire size. For the average fire size, expenditures first increased with the percentage of private land within burned area, but as the percentage exceeded 20%, expenditures slowly declined until they stabilised when private land reached 50% of burned area. The results suggested that efforts to contain federal suppression expenditures need to focus on the highly complex, politically sensitive topic of wildfires on private land.

The association between Northern Hemisphere climate patterns and interannual variability in Canadian wildfire activity

Wildfire impacts on ecological and socioeconomic systems are regulated, in part, by climate. Association between hemispheric-scale climate patterns and annual wildfire activity can be obscured by local factors that also control the initiation and spread of fires. Vegetation, topography, and fire suppression can be expected to influence conventional measures of annual wildfire activity such as area burned, effectively concealing evidence of broad-scale climate influences. This study investigates alternatives to area-burned statistics for quantifying annual wildfire activity in Canada in relation to Northern Hemisphere climate variability represented by the Atlantic Multidecadal Oscillation (AMO). We depart from conventional approaches by including socioeconomic measures of wildfire activity and by assessing spatially referenced wildfire data over units of observation chosen explicitly to diminish variability caused by factors unrelated to broad-scale climate. Our data-centred approach, combined with linear regression modelling, revealed that the AMO was positively correlated with national time series of very large fires (≥10 000 ha), wildfire-related evacuations, and fire suppression expenditures over the period 1975–2007. The AMO and wildfire activity were most closely coupled during a period of predominantly positive-phase Arctic Oscillation (AO) and Pacific Decadal Oscillation (PDO) between 1989 and 2001. Positive correlation between maximum evacuation wind speed and the AMO suggests that wind may be a causal factor in the AMO–wildfire relationship.