Intensified burn severity in California’s northern coastal mountains by drier climatic condition DOI Creative Commons
Yuhan Huang, Yufang Jin, Mark W. Schwartz

et al.

Environmental Research Letters, Journal Year: 2020, Volume and Issue: 15(10), P. 104033 - 104033

Published: July 16, 2020

Abstract The severity of wildfire burns in interior lands western US ecosystems has been increasing. However, less is known about its coastal mountain ecosystems, especially under extreme weather conditions, raising concerns the vulnerability these populated areas to catastrophic fires. Here we examine fine-scale association between burn and a suite environmental drivers including explicit fuel information, weather, climate, topography, for diverse California’s northern mountains. Burn was quantified using Relative difference Normalized Ratio from Landsat multispectral imagery during 1984–2017. We found significant increasing trend burned severity. During low-precipitation years, that had much lower moisture higher climatic water deficit than wetter percentage high-severity doubled, most recent 2012–2016 drought. random forest (RF) machine learning model achieved overall accuracy 79% classifying categories Aspect, slope, type availability, temperature were important drivers, based on both classification regression RF models. further examined importance four conditions: dry vs. wet two extended drought periods (the warmer 1987–1992 drought). warm spatial variability mixed effect long-term minimum temperature, amount, moisture. In contrast, short-term became dominant factors fires years. These results suggest relative broader domain mountains varied with scenarios, when exacerbated by Our findings highlight targeting high risk fire adaptation mitigation strategies changing climate intensifying extremes.

Language: Английский

Wildfires and global change DOI
Juli G. Pausas, Jon E. Keeley

Frontiers in Ecology and the Environment, Journal Year: 2021, Volume and Issue: 19(7), P. 387 - 395

Published: June 3, 2021

No single factor produces wildfires; rather, they occur when fire thresholds (ignitions, fuels, and drought) are crossed. Anomalous weather events may lower these thereby enhance the likelihood spread of wildfires. Climate change increases frequency with which some crossed, extending duration season increasing dry years. However, climate‐related factors do not explain all complexity global fire‐regime changes, as altered ignition patterns (eg human behavior) fuel structures land‐use suppression, drought‐induced dieback, fragmentation) extremely important. When size a will largely depend on extent available area continuous fuels in landscape.

Language: Английский

Citations

342
Large California wildfires: 2020 fires in historical context DOI Creative Commons
Jon E. Keeley, Alexandra D. Syphard

Fire Ecology, Journal Year: 2021, Volume and Issue: 17(1)

Published: Aug. 25, 2021

Abstract Background California in the year 2020 experienced a record breaking number of large fires. Here, we place this and other recent years historical context by examining records fire events state back to 1860. Since drought is commonly associated with events, investigated relationship droughts over 160 period. Results This study shows that extreme such as seen are not unknown historically, what stands out distinctly new increased fires (defined here > 10,000 ha) last couple years, most prominently 2020. Nevertheless, there have been periods even greater numbers fires, e.g., 1929 had second greatest In fact, 1920’s decade one many Conclusions decade, several exceptionally Earlier show similar size nineteenth early twentieth century. Lengthy droughts, measured Palmer Drought Severity Index (PDSI), were peaks both 1920s twenty-first

Language: Английский

Citations

157
Factors Associated with Structure Loss in the 2013–2018 California Wildfires DOI Creative Commons
Alexandra D. Syphard, Jon E. Keeley

Fire, Journal Year: 2019, Volume and Issue: 2(3), P. 49 - 49

Published: Sept. 2, 2019

Tens of thousands structures and hundreds human lives have been lost in recent fire events throughout California. Given the potential for these types wildfires to continue, need understand why how are being destroyed has taken on a new level urgency. We compiled analyzed an extensive dataset building inspectors’ reports documenting homeowner mitigation practices more than 40,000 wildfire-exposed from 2013–2018. Comparing homes that survived fires were destroyed, we investigated role defensible space distance, defensive actions, structural characteristics, statewide parsed into three broad regions. Overall, characteristics explained difference between distance. The most consistently important characteristics—having enclosed eaves, vent screens, multi-pane windows—were those potentially prevented wind-born ember penetration structures, although windows also known protect against radiant heat. In North-Interior part state, active firefighting was reason structure survival. deviance any given variable relatively low, suggesting other factors be accounted full spectrum loss contributors. Furthermore, while preferentially included study, many “fire-safe” having > 30 m or fire-resistant materials, destroyed. Thus, may play survival, additional strategies should considered reduce future loss.

Language: Английский

Citations

84
Mortgage Markets with Climate-Change Risk: Evidence from Wildfires in California DOI

Paulo Issler,

Richard Stanton, Carles Vergara‐Alert

et al.

SSRN Electronic Journal, Journal Year: 2019, Volume and Issue: unknown

Published: Jan. 1, 2019

This paper studies wildfires in California from 2000 to 2018 using comprehensive merged dataon fires, mortgage and property characteristics, weather. We find a significant increase delinquency foreclosure after fire, but these effects decrease the size of fire,which we argue results coordination externalities afforded by large fires. Recent losses,combined with regulatory distortions, cast doubt on continued ability insurance companiesto absorb fire-related losses. provides central banks regulators witha framework for evaluating proposed banking insurance-company models, similar bankstress-testing.

Language: Английский

Citations

77
Anthropogenic Influence on Recent Severe Autumn Fire Weather in the West Coast of the United States DOI
Linnia Hawkins, John T. Abatzoglou, Sihan Li

et al.

Geophysical Research Letters, Journal Year: 2022, Volume and Issue: 49(4)

Published: Feb. 5, 2022

Abstract Extreme wind‐driven autumn wildfires are hazardous to life and property, due their rapid rate of spread. Recent catastrophic in the western United States co‐occurred with record‐ or near‐record fire weather indices that a byproduct extreme fuel dryness strong offshore dry winds. Here, we use formal, probabilistic, event attribution analysis investigate anthropogenic influence on 2017 2018. We show while present‐day climate change has slightly decreased prevalence downslope winds, it increased likelihood by 40% areas where recent fires have occurred northern California Oregon. The increase was primarily through aridity warmer temperatures during wind events. These findings illustrate is exacerbating extremes contribute high‐impact populated regions US.

Language: Английский

Citations

61
Downslope Wind‐Driven Fires in the Western United States DOI Creative Commons
John T. Abatzoglou, Crystal A. Kolden, Park Williams

et al.

Earth s Future, Journal Year: 2023, Volume and Issue: 11(5)

Published: May 1, 2023

Abstract Downslope wind‐driven fires have resulted in many of the wildfire disasters western United States and represent a unique hazard to infrastructure human life. We analyze co‐occurrence wildfires downslope winds across (US) during 1992–2020. accounted for 13.4% 11.9% burned area US yet majority local portions southern California, central Washington, front range Rockies. These were predominantly ignited by humans, occurred closer population centers, outsized impacts on lives infrastructure. Since 1999, 60.1% structures 52.4% lost US. under anomalously dry fuels exhibited seasonality distinct from other fires—occurring primarily spring fall. Over 1992–2020, we document 25% increase annual number 140% their respective area, which partially reflects trends toward drier fuels. results advance our understanding importance driving disastrous that threaten populated regions adjacent mountain ranges The characteristics require increased fire prevention adaptation strategies minimize losses incorporation changing human‐ignitions, fuel availability dryness, wind occurrence elucidate future risk.

Language: Английский

Citations

26
Toward a Better Understanding of Wildfire Behavior in the Wildland‐Urban Interface: A Case Study of the 2021 Marshall Fire DOI Creative Commons
Timothy W. Juliano, Neil P. Lareau, Maria Frediani

et al.

Geophysical Research Letters, Journal Year: 2023, Volume and Issue: 50(10)

Published: May 16, 2023

Abstract On 30 December 2021, the Marshall Fire devastated Boulder, Colorado region. The fire initiated in fine fuels open space just southeast of Boulder and spread rapidly due to strong, downslope winds that penetrated into Foothills. Despite increasing occurrence wildland‐urban interface (WUI) disasters, many questions remain about how fires progress through vegetation built environment. To help answer these for Fire, we use a coupled fire‐atmosphere model Doppler on Wheels (DOW) observations study fire's progression as well examine physical drivers its spread. Evaluation using DOW suggests is able capture general characteristics flow field; however, it does not produce robust hydraulic jump one observed. Our results highlight limitations should be addressed successful WUI simulations.

Language: Английский

Citations

25
Dry Live Fuels Increase the Likelihood of Lightning‐Caused Fires DOI Creative Commons
K. H. Rao, Park Williams, Noah S. Diffenbaugh

et al.

Geophysical Research Letters, Journal Year: 2023, Volume and Issue: 50(15)

Published: Aug. 2, 2023

Abstract Live fuel moisture content (LFMC) is a key determinant of landscape ignition potential, but quantitative estimates its effects on wildfire are lacking. We present causal inference framework to isolate the effect LFMC from other drivers like type, amount, and meteorology. show that in California when below critical flammability threshold, likelihood fires 1.8 times as high statewide (2.25% vs. 1.27%) 2.5 shrubs, compared greater than threshold. This risk ratio >2 10% less Between 2016 2021, was highest 2020 (2.3 times), potentially contributing record‐breaking activity 2020. Our can inform several prediction management applications, including suppression, prescribed burn planning, public safety power shutoff implementation.

Language: Английский

Citations

24
California Case Study of Wildfires and Prescribed Burns: PM2.5 Emissions, Concentrations, and Implications for Human Health DOI Creative Commons
Laura Kiely, Soroush E. Neyestani,

Samiha Binte-Shahid

et al.

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(12), P. 5210 - 5219

Published: March 14, 2024

Wildfires are a significant threat to human health, in part through degraded air quality. Prescribed burning can reduce wildfire severity but also lead an increase pollution. The complexities of fires and atmospheric processes uncertainties when predicting the quality impacts fire make it difficult fully assess costs benefits expansion prescribed fire. By modeling differences emissions, surface conditions, meteorology between burns, we present novel comparison these types under specific scenarios. One two burn scenarios were considered, with one scenario optimized for potential smoke exposure. We found that PM2.5 emissions reduced by 52%, from 0.27 0.14 Tg, burned considerably reducing concentrations. Excess short-term mortality exposure was 40 deaths conditions 39 15 default scenarios, respectively. Our findings suggest particularly planned during minimize exposure, could be net benefit wildfires on health.

Language: Английский

Citations

11
Evaluating the performance of WRF in simulating winds and surface meteorology during a Southern California wildfire event DOI Creative Commons
Mukesh Kumar, Branko Kosović, Hara Prasad Nayak

et al.

Frontiers in Earth Science, Journal Year: 2024, Volume and Issue: 11

Published: Jan. 19, 2024

The intensity and frequency of wildfires in California (CA) have increased recent years, causing significant damage to human health property. In October 2007, a number small fire events, collectively referred as the Witch Creek Fire or started Southern CA intensified under strong Santa Ana winds. As test current mesoscale modeling capabilities, we use Weather Research Forecasting (WRF) model simulate 2007 wildfire event terms meteorological conditions. main objectives present study are investigate impact horizontal grid resolution planetary boundary layer (PBL) scheme on simulation conditions associated with Mega fire. We evaluate predictive capability WRF key fire-weather forecast parameters such wind, moisture, temperature. Results this suggest that more accurate predictions temperature wind speed relevant for better prediction spread can be achieved by downscaling regional numerical weather products 1 km resolution. Furthermore, near-surface depends choice parameterization. MYNN parameterization yields compared YSU simulations at result than relative humidity during Fire. summary, PBL finer improves event.

Language: Английский

Citations

10