Research Database
Displaying 61 - 80 of 141
Human ignitions on private lands drive USFS cross‑boundary wildfire transmission and community impacts in the western US
Year: 2022
Wildfires in the western United States (US) are increasingly expensive, destructive, and deadly. Reducing wildfire losses is particularly challenging when fires frequently start on one land tenure and damage natural or developed assets on other ownerships. Managing wildfire risk in multijurisdictional landscapes has recently become a centerpiece of wildfire strategic planning, legislation, and risk research. However, important empirical knowledge gaps remain regarding cross-boundary fire activity in the western US. Here, we use lands administered by the US Forest Service as a study system to…
Publication Type: Journal Article
Changes in fire behavior caused by fire exclusion and fuel build-up vary with topography in California montane forests, USA
Year: 2022
Wildfire sizes and proportions burned with high severity effects are increasing in seasonally dry forests, especially in the western USA. A critical need in efforts to restore or maintain these forest ecosystems is to determine where fuel build-up caused by fire exclusion reaches thresholds that compromise resilience to fire. Empirical studies identifying drivers of fire severity patterns in actual wildfires can be confounded by co-variation of vegetation and topography and the stochastic effects of weather and rarely consider long-term changes in fuel caused by fire exclusion. To overcome…
Publication Type: Journal Article
Plant-water sensitivity regulates wildfire vulnerability
Year: 2022
Extreme wildfires extensively impact human health and the environment. Increasing vapour pressure deficit (VPD) has led to a chronic increase in wildfire area in the western United States, yet some regions have been more affected than others. Here we show that for the same increase in VPD, burned area increases more in regions where vegetation moisture shows greater sensitivity to water limitation (plant-water sensitivity; R2 = 0.71). This has led to rapid increases in human exposure to wildfire risk, both because the population living in areas with high plant-water sensitivity grew 50%…
Publication Type: Journal Article
Extreme fire spread events and area burned under recent and future climate in the western USA
Year: 2022
Aim: Wildfire activity in recent years is notable not only for an expansion of total area burned but also for large, single-day fire spread events that pose challenges to ecological systems and human communities. Our objectives were to gain new insight into the relationships between extreme single-day fire spread events, annual area burned, and fire season climate and to predict changes under future warming. Location: Fire-prone regions of the western USA. Time period: 2002–2020; a future +2°C scenario. Methods: We used a satellite-derived dataset of daily fire spread events and gridded…
Publication Type: Journal Article
Evaluating rural Pacific Northwest towns for wildfire evacuation vulnerability
Year: 2021
Wildfire is an annual threat for many rural communities in the Pacific Northwest region of the United States. In some severe events, evacuation is one potential course of action to gain safety from an advancing wildfire. Since most evacuations occur in a personal vehicle along the surrounding road network, the quality of this network is a critical component of a community's vulnerability to wildfire. In this paper, we leverage a high-resolution spatial dataset of wildfire burn probability and mean fireline intensity to conduct a regional-scale screening of wildfire evacuation vulnerability…
Publication Type: Journal Article
Stop going around in circles: towards a reconceptualisation of disaster risk management phases
Year: 2021
Purpose The way that disasters are managed, or indeed mis-managed, is often represented diagrammatically as a “disaster cycle”. The cyclical aspects of the disaster (risk) management concept, comprised of numerous operational phases, have, in recent years, been criticised for conceptualising and representing disasters in an overly simplistic way that typically starts with a disaster “event” – and subsequently leads onto yet another disaster. Such cyclical thinking has been proven to not be very useful for the complexities associated with understanding disasters and their risks. This paper…
Publication Type: Journal Article
Tribes & Climate Change
Year: 2020
Native Americans rely on tribally important ecosystem services such as traditional foods, hunting, timber production, non-timber forest resources (recreation, water), and cultural resources. Unfortunately, many of these resources may be highly vulnerable to the impacts of climate change. A research team sought to answer the question: Where and which tribally-important ecosystem services will be affected by climate change in the Pacific Northwest? They used projections from climate and vegetation models and stakeholder input to demonstrate a generalizable approach for assessing possible…
Publication Type: Web project page
The hot-dry-windy index: A new tool for forecasting fire weather
Year: 2020
Accurate predictions of how weather may affect a wildfire’s behavior are needed to protect crews on the line and efficiently allocate firefighting resources. Since 1988, fire meteorologists have used a tool called the Haines Index to predict days when the weather will exacerbate a wildfire. Although the Haines Index is widely believed to have value, it never received rigorous testing on the line. Even Don Haines, the U.S. Forest Service meteorologist who developed the index, has said the Haines Index needs further refinement. Recognizing that a new fire weather prediction tool was needed, a…
Publication Type: Report
Repeated fire altered succession and increased fire behavior in basin big sagebrush–native perennial grasslands
Year: 2020
The structure and composition of sagebrush-dominated ecosystems have been altered by changes in fire regimes, land use, invasive species, and climate change. This often decreases resilience to disturbance and degrades critical habitat for species of conservation concern. Basin big sagebrush (Artemisia tridentata ssp. tridentata) ecosystems, in particular, are greatly reduced in distribution as land has been converted to agriculture and other land uses. The fire regime, relative proportions of shrub and grassland patches, and the effects of repeated burns in this ecosystem are poorly understood…
Publication Type: Journal Article
Social Vulnerability and Wildfire in the Wildland-Urban Interface - Annotated Bibliography
Year: 2019
Publication Type: Report
Social Vulnerability and Wildfire in the Wildland-Urban Interface: Literature synthesis
Year: 2019
The overall objective of this paper is to clarify areas of debate, clearly define and contrast disparate approaches, and synthesize findings that may help address vulnerability to wildfires and other natural hazards. While land managers and fire personnel might find it pertinent to approach biophysical and social issues separately, addressing both aspects of wildfire hazard can be productive for minimizing risk and empowering communities, neighborhoods, and households to prepare and recover from wildfire events. We aim to provide a practical grasp of social vulnerability research as it…
Publication Type: Report
Evaluating Model Predictions of Fire Induced Tree Mortality Using Wildfire-Affected Forest Inventory Measurements
Year: 2019
Forest land managers rely on predictions of tree mortality generated from fire behavior models to identify stands for post-fire salvage and to design fuel reduction treatments that reduce mortality. A key challenge in improving the accuracy of these predictions is selecting appropriate wind and fuel moisture inputs. Our objective was to evaluate postfire mortality predictions using the Forest Vegetation Simulator Fire and Fuels Extension (FVS-FFE) to determine if using representative fire-weather data would improve prediction accuracy over two default weather scenarios. We used pre- and post-…
Publication Type: Journal Article
A Classification of US Wildland Firefighter Entrapments Based on Coincident Fuels, Weather, and Topography
Year: 2019
Previous attempts to identify the environmental factors associated with firefighter entrapments in the United States have suggested that there are several common denominators. Despite the widespread acceptance of the assumed commonalities, few studies have quantified how often entrapments actually meet these criteria. An analysis of the environmental conditions at the times and locations of 166 firefighter entrapments involving 1202 people and 117 fatalities that occurred between 1981 and 2017 in the conterminous United States revealed some surprising results. Contrary to general assumptions…
Publication Type: Journal Article
Social Vulnerability and Wildfire in the Wildland-Urban Interface
Year: 2019
People living in the Pacific Northwest confrontrisks associated with environmentalhazards such as wildfire. Vulnerability towildfire hazard is commonly recognized as beingspatially distributed according to geographic conditionsthat collectively determine the probabilityof exposure. For example, exposure to wildfirehazard is higher for people living in rural, forestedsettings than in a strictly urban neighborhood becauserural housing is built in close proximity tothe threat source, e.g., flammable landscapes suchas forests and chaparral. Yet, even if levels of exposureare held constant, not…
Publication Type: Report
Fire behaviour and smoke modelling: model improvement and measurement needs for next-generation smoke research and forecasting systems
Year: 2019
There is an urgent need for next-generation smoke research and forecasting (SRF) systems to meet the challenges of the growing air quality, health and safety concerns associated with wildland fire emissions. This review paper presents simulations and experiments of hypothetical prescribed burns with a suite of selected fire behaviour and smoke models and identifies major issues for model improvement and the most critical observational needs. The results are used to understand the new and improved capability required for the next-generation SRF systems and to support the design of the Fire and…
Publication Type: Journal Article
Evidence for scale‐dependent topographic controls on wildfire spread
Year: 2018
Wildfire ecosystems are thought to be self‐regulated through pattern–process interactions between ignition frequency and location, and patterns of burned and recovering vegetation. Yet, recent increases in the frequency of large wildfires call into question the application of self‐organization theory to landscape resilience. Topography represents a stable bottom‐up template upon which fire interacts as both a physical and an ecological process. However, it is unclear how topographic control changes geographically and across spatial scales. We analyzed fire perimeter and topography data from…
Publication Type: Journal Article
Advancing the Science of Wildland Fire Dynamics Using Process-Based Models
Year: 2018
As scientists and managers seek to understand fire behavior in conditions that extend beyond the limits of our current empirical models and prior experiences, they will need new tools that foster a more mechanistic understanding of the processes driving fire dynamics and effects. Here we suggest that process-based models are powerful research tools that are useful for investigating a large number of emerging questions in wildland fire sciences. These models can play a particularly important role in advancing our understanding, in part, because they allow their users to evaluate the potential…
Publication Type: Journal Article
Fuel Treatments: Are we doing enough?
Year: 2018
Although a natural ecological process, wildfire in unhealthy forests can be uncharacteristically destructive. Fuel treatments—such as thinning, mowing, prescribed fire, or managed wildfire—can help reduce or redistribute the flammable fuels that threaten to carry and intensify fire. Using both field-tested data and computer simulations, Pacific Northwest Research Station scientists are addressing critical questions such as Are we treating enoughof the landscape to restore fire-adapted forests? Are fuel treatments effective at changing fire behavior? Together with land managers, fuel planners…
Publication Type: Report
Embracing Complexity to Advance the Science of Wildland Fire Behavior
Year: 2018
Wildland fire behavior research has largely focused on the steady-state interactions between fuels and heat fluxes. Contemporary research is revealing new questions outside the bounds of this simplified approach. Here, we explore the complex interactions taking place beyond steady-state assumptions through acknowledging the manufactured separation of research disciplines in fire science and the dynamic interactions that unfold when these separations are removed. Through a series of examples spanning at least four research disciplines and three ranges of spatial scale, we illustrate that by…
Publication Type: Journal Article
Defining extreme wildfire events: Difficulties, challenges, and impacts
Year: 2018
Every year worldwide some extraordinary wildfires occur, overwhelming suppression capabilities, causing substantial damages, and often resulting in fatalities. Given their increasing frequency, there is a debate about how to address these wildfires with significant social impacts, but there is no agreement upon terminology to describe them. The concept of extreme wildfire event (EWE) has emerged to bring some coherence on this kind of events. It is increasingly used, often as a synonym of other terms related to wildfires of high intensity and size, but its definition remains elusive. The goal…
Publication Type: Journal Article