scholarly journals Where there's smoke, there's fuel: predicting Great Basin rangeland wildfire

2021 ◽  
Author(s):  
Joseph T Smith ◽  
Brady W Allred ◽  
Chad S Boyd ◽  
Kirk W Davies ◽  
Matthew O. Jones ◽  
...  
Keyword(s):  
Great Basin ◽  
Spatial Data ◽  
Ground Cover ◽  
Fire Regimes ◽  
Machine Learning Algorithms ◽  
Fire Season ◽  
Drought Indices ◽  
Area Burned ◽  
Fire Activity ◽  
Fine Fuels

Wildfires are a growing management concern in western US rangelands, where invasive annual grasses have altered fire regimes and contributed to an increased incidence of catastrophic large wildfires. Fire activity in arid, non-forested regions is thought to be largely controlled by interannual variation in fuel amount, which in turn is controlled by antecedent weather. Thus, long-range forecasting of fire activity in rangelands should be feasible given annual estimates of fuel quantity. Using a 32 yr time series of spatial data, we employ machine learning algorithms to predict the relative probability of large (>400 ha) wildfire in the Great Basin based on fine-scale annual and 16-day estimates of cover and production of vegetation functional groups, weather, and multitemporal scale drought indices. We evaluate the predictive utility of these models with a leave-one-year-out cross-validation, building spatial forecasts of fire probability for each year that we compare against actual maps of large wildfires. Herbaceous vegetation aboveground biomass production, bare ground cover, and long-term drought indices were the most important predictors of fire probability. Across 32 fire seasons, >80% of the area burned in large wildfires coincided with predicted fire probabilities ≥0.5. At the scale of the Great Basin, several metrics of fire season severity were moderately to strongly correlated with average fire probability, including total area burned in large wildfires, number of large wildfires, and average and maximum fire size. Our findings show that recent years of exceptional fire activity in the Great Basin were predictable based on antecedent weather and biomass of fine fuels, and reveal a significant increasing trend in fire probability over the last three decades driven by widespread changes in fine fuel characteristics.

Relationships between climate and macroscale area burned in the western United States

2013 ◽  
Vol 22 (7) ◽  
pp. 1003 ◽  
Author(s):  
John T. Abatzoglou ◽  
Crystal A. Kolden
Keyword(s):  
United States ◽  
Snow Water Equivalent ◽  
Climatic Factors ◽  
Fire Danger ◽  
Western United States ◽  
Fire Season ◽  
Drought Indices ◽  
Climate Variables ◽  
Area Burned ◽  
Fire Activity

Increased wildfire activity (e.g. number of starts, area burned, fire behaviour) across the western United States in recent decades has heightened interest in resolving climate–fire relationships. Macroscale climate–fire relationships were examined in forested and non-forested lands for eight Geographic Area Coordination Centers in the western United States, using area burned derived from the Monitoring Trends in Burn Severity dataset (1984–2010). Fire-specific biophysical variables including fire danger and water balance metrics were considered in addition to standard climate variables of monthly temperature, precipitation and drought indices to explicitly determine their optimal capacity to explain interannual variability in area burned. Biophysical variables tied to the depletion of fuel and soil moisture and prolonged periods of elevated fire-danger had stronger correlations to area burned than standard variables antecedent to or during the fire season, particularly in forested systems. Antecedent climate–fire relationships exhibited inter-region commonality with area burned in forested lands correlated with winter snow water equivalent and emergent drought in late spring. Area burned in non-forested lands correlated with moisture availability in the growing season preceding the fire year. Despite differences in the role of antecedent climate in preconditioning fuels, synchronous regional fire activity in forested and non-forested lands suggests that atmospheric conditions during the fire season unify fire activity and can compound or supersede antecedent climatic stressors. Collectively, climate–fire relationships viewed through the lens of biophysical variables provide a more direct link to fuel flammability and wildfire activity than standard climate variables, thereby narrowing the gap in incorporating top-down climatic factors between empirical and process-based fire models.

Inter- and intra-annual profiles of fire regimes in the managed forests of Canada and implications for resource sharing

2012 ◽  
Vol 21 (4) ◽  
pp. 328 ◽  
Author(s):  
Steen Magnussen ◽  
Stephen W. Taylor
Keyword(s):  
Resource Sharing ◽  
Joint Distribution ◽  
Fire Management ◽  
Fire Regime ◽  
Fire Regimes ◽  
Fire Season ◽  
Burned Area ◽  
Fire Activity ◽  
In Fire ◽  
Regional Synchrony

Year-to-year variation in fire activity in Canada constitutes a key challenge for fire management agencies. Interagency sharing of fire management resources has been ongoing on regional, national and international scales in Canada for several decades to better cope with peaks in resource demand. Inherent stressors on these schemes determined by the fire regimes in constituent jurisdictions are not well known, nor described by averages. We developed a statistical framework to examine the likelihood of regional synchrony of peaks in fire activity at a timescale of 1 week. Year-to-year variations in important fire regime variables and 48 regions in Canada are quantified by a joint distribution and profiled at the Provincial or Territorial level. The fire regime variables capture the timing of the fire season, the average number of fires, area burned, and the timing and extent of annual maxima. The onset of the fire season was strongly correlated with latitude and longitude. Regional synchrony in the timing of the maximum burned area within fire seasons delineates opportunities for and limitations to sharing of fire suppression resources during periods of stress that were quantified in Monte Carlo simulations from the joint distribution.

Interactions between antecedent climate and wildfire variability across south-eastern Arizona

2004 ◽  
Vol 13 (4) ◽  
pp. 455 ◽  
Author(s):  
Michael A. Crimmins ◽  
Andrew C. Comrie
Keyword(s):  
High Elevation ◽  
Fire Season ◽  
Climate Conditions ◽  
Area Burned ◽  
South Eastern ◽  
Antecedent Conditions ◽  
Positive Correlations ◽  
Fine Fuels ◽  
Long Timescales ◽  
High Elevation Forests

Long-term antecedent climate conditions are often overlooked as important drivers of wildfire variability. Fuel moisture levels and fine-fuel productivity are controlled by variability in precipitation and temperature at long timescales (months to years) before wildfire events. This study examines relationships between wildfire statistics (total area burned and total number of fires) aggregated for south-eastern Arizona and antecedent climate conditions relative to 29 fire seasons (April–May–June) between 1973 and 2001. High and low elevation fires were examined separately to determine the influence of climate variability on dominant fuel types (low elevation grasslands with fine fuels v. high elevation forests with heavy fuels). Positive correlations between lagged precipitation and total area burned highlight the importance of climate in regulating fine fuel production for both high and low elevation fires. Surprisingly, no significant negative correlations between precipitation and seasonal wildfire statistics were found at any seasonal lag. Drought conditions were not associated with higher area burned or a greater number of fires. Larger low elevation fires were actually associated with wet antecedent conditions until just before the fire season. Larger high elevation fires were associated with wet conditions during seasons up to 3 years before the fire season.

Different fire–climate relationships on forested and non-forested landscapes in the Sierra Nevada ecoregion

2015 ◽  
Vol 24 (1) ◽  
pp. 27 ◽  
Author(s):  
Jon E. Keeley ◽  
Alexandra D. Syphard
Keyword(s):  
Sierra Nevada ◽  
Strong Relationship ◽  
Fire Regimes ◽  
Fuel Load ◽  
Fire Season ◽  
Global Changes ◽  
Land Use Patterns ◽  
Climatic Effects ◽  
Lower Elevation ◽  
Fire Activity

In the California Sierra Nevada region, increased fire activity over the last 50 years has only occurred in the higher-elevation forests on US Forest Service (USFS) lands, and is not characteristic of the lower-elevation grasslands, woodlands and shrublands on state responsibility lands (Cal Fire). Increased fire activity on USFS lands was correlated with warmer and drier springs. Although this is consistent with recent global warming, we found an equally strong relationship between fire activity and climate in the first half of the 20th century. At lower elevations, warmer and drier conditions were not strongly tied to fire activity over the last 90 years, although prior-year precipitation was significant. It is hypothesised that the fire–climate relationship in forests is determined by climatic effects on spring and summer fuel moisture, with hotter and drier springs leading to a longer fire season and more extensive burning. In contrast, future fire activity in the foothills may be more dependent on rainfall patterns and their effect on the herbaceous fuel load. We predict spring and summer warming will have a significant impact on future fire regimes, primarily in higher-elevation forests. Lower elevation ecosystems are likely to be affected as much by global changes that directly involve land-use patterns as by climate change.

scholarly journals Precipitation dominates fire occurrence in Greece (1900–2010): its dual role in fuel build-up and dryness

2014 ◽  
Vol 14 (1) ◽  
pp. 21-32 ◽  
Author(s):  
F. Xystrakis ◽  
A. S. Kallimanis ◽  
P. Dimopoulos ◽  
J. M. Halley ◽  
N. Koutsias
Keyword(s):  
Climate Change ◽  
Fire Regimes ◽  
Extreme Weather ◽  
Dual Role ◽  
Fire Season ◽  
Dominant Factor ◽  
Negative Events ◽  
Fire Occurrence ◽  
Area Burned

Abstract. Historical fire records and meteorological observations spanning over one century (1894–2010) were assembled in a database to collect long-term fire and weather data in Greece. Positive/negative events of fire occurrence on an annual basis were considered as the years where the annual values of the examined parameters were above (positive values) or below (negative values) the 95% confidence limits around the trend line of the corresponding parameter. To analyse the association of positive/negative events of fire occurrence with meteorological extremes, we proceeded with a cross-tabulation analysis based on a Monte Carlo randomization. Positive/negative values of total annual precipitation were randomly associated with the corresponding values of burned areas, and significant associations were observed for seasonal precipitation totals (spring and fire season). Fire season precipitation is the dominant factor coinciding with negative values of area burned, while years with high spring precipitation coincide with years with large areas burned. These results demonstrate the dual role of precipitation in controlling a fire's extent through fuel build-up and dryness. Additionally, there is a clear outperformance of precipitation-related variables compared with temperature-related weather revealing that, at least in Greece, total area burned at the national scale is controlled by precipitation totals rather than air temperature. This analysis improves our understanding of the underlying mechanisms of fire regimes and provides valuable information concerning the development of models relating fire activity to weather parameters, which are essential when facing a changing climate that may be associated with shifts in various aspects of the typical fire regimes of ecosystems. Our results may allow fire managers to more easily incorporate the effect of extreme weather conditions into long-term planning strategies. They contribute to the exploration of fire–climate relationships and may become more important if climate change scenarios are used to predict the occurrence of future extreme weather taking into consideration that climate change is discussed on the basis of changes of extremes rather than changes in means.

Fire-regime changes in Canada over the last half century

2019 ◽  
Vol 49 (3) ◽  
pp. 256-269 ◽  
Author(s):  
Chelene C. Hanes ◽  
Xianli Wang ◽  
Piyush Jain ◽  
Marc-André Parisien ◽  
John M. Little ◽  
...  
Keyword(s):  
Fire Regime ◽  
Fire Regimes ◽  
Fire Season ◽  
Western Canada ◽  
Half Century ◽  
Regime Changes ◽  
Area Burned ◽  
Active Fire ◽  
Large Fires ◽  
In Fire

Contemporary fire regimes of Canadian forests have been well documented based on forest fire records between the late 1950s to 1990s. Due to known limitations of fire datasets, an analysis of changes in fire-regime characteristics could not be easily undertaken. This paper presents fire-regime trends nationally and within two zonation systems, the homogeneous fire-regime zones and ecozones, for two time periods, 1959–2015 and 1980–2015. Nationally, trends in both area burned and number of large fires (≥200 ha) have increased significantly since 1959, which might be due to increases in lightning-caused fires. Human-caused fires, in contrast, have shown a decline. Results suggest that large fires have been getting larger over the last 57 years and that the fire season has been starting approximately one week earlier and ending one week later. At the regional level, trends in fire regimes are variable across the country, with fewer significant trends. Area burned, number of large fires, and lightning-caused fires are increasing in most of western Canada, whereas human-caused fires are either stable or declining throughout the country. Overall, Canadian forests appear to have been engaged in a trajectory towards more active fire regimes over the last half century.

scholarly journals Preceding Fall Drought Conditions and Overwinter Precipitation Effects on Spring Wildland Fire Activity in Canada

Fire ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 24
Author(s):  
Chelene Hanes ◽  
Mike Wotton ◽  
Douglas G. Woolford ◽  
David L. Martell ◽  
Mike Flannigan
Keyword(s):  
Boreal Forests ◽  
Wildland Fire ◽  
Fire Suppression ◽  
Fire Season ◽  
Fire Weather Index ◽  
Area Burned ◽  
Fire Activity ◽  
Drought Conditions ◽  
Carry Over ◽  
The Impact

Spring fire activity has increased in parts of Canada, particularly in the west, prompting fire managers to seek indicators of potential activity before the fire season starts. The overwintering adjustment of the Canadian Fire Weather Index System’s Drought Code (DC) is a method to adjust and carry-over the previous season’s drought conditions into the spring and potentially point to what lies ahead. The occurrence of spring fires is most strongly influenced by moisture in fine fuels. We used a zero-inflated Poisson regression model to examine the impact of the previous end of season Drought Code (DCf) and overwinter precipitation (Pow) while accounting for the day-to-day variation in fine fuel moisture that drives ignition potential. Impacts of DCf and Pow on area burned and fire suppression effectiveness were also explored using linear and logistic regression frameworks. Eight fire management regions across the boreal forests were analyzed using data from 1979 to 2018. For the majority of regions, drier fall conditions resulted in more human-caused spring fires, but not in greater area burned or reduced suppression effectiveness. The influence of Pow was much more variable pointing to the conclusion that Pow alone is not a good indicator of spring drought conditions.

A chronological overview of the 1989 fire season in Manitoba

1991 ◽  
Vol 67 (4) ◽  
pp. 358-365 ◽  
Author(s):  
Kelvin G. Hirsch
Keyword(s):  
New Record ◽  
Fire Behavior ◽  
Fire Season ◽  
General Description ◽  
Area Burned ◽  
Fire Activity ◽  
Major Outbreak ◽  
Fire Ignitions ◽  
Second Peak ◽  
Extreme Fire

In 1989 a new record was established for the number of fires (1147) and area burned (3.28 million ha) in Manitoba. These fires resulted in the unprecedented evacuation of 24,500 people from 32 different communities and cost over $68 million (CDN) to suppress. The first major outbreak of fires occurred in central Manitoba in mid-May and was followed by a second peak of fire activity in northern Manitoba between July 16 and August 2. Both periods were characterized by multiple fire ignitions, severe fire weather and fire danger conditions, and extreme fire behavior. A general description of the events that took place during this historic fire season are presented in this paper.

scholarly journals Decreasing fire season precipitation increased recent western US forest wildfire activity

2018 ◽  
Vol 115 (36) ◽  
pp. E8349-E8357 ◽  
Author(s):  
Zachary A. Holden ◽  
Alan Swanson ◽  
Charles H. Luce ◽  
W. Matt Jolly ◽  
Marco Maneta ◽  
...  
Keyword(s):  
United States ◽  
Surface Air Temperature ◽  
Summer Precipitation ◽  
Western United States ◽  
Fire Season ◽  
Burned Area ◽  
Evaporative Demand ◽  
Near Surface ◽  
Area Burned ◽  
Fire Activity

Western United States wildfire increases have been generally attributed to warming temperatures, either through effects on winter snowpack or summer evaporation. However, near-surface air temperature and evaporative demand are strongly influenced by moisture availability and these interactions and their role in regulating fire activity have never been fully explored. Here we show that previously unnoted declines in summer precipitation from 1979 to 2016 across 31–45% of the forested areas in the western United States are strongly associated with burned area variations. The number of wetting rain days (WRD; days with precipitation ≥2.54 mm) during the fire season partially regulated the temperature and subsequent vapor pressure deficit (VPD) previously implicated as a primary driver of annual wildfire area burned. We use path analysis to decompose the relative influence of declining snowpack, rising temperatures, and declining precipitation on observed fire activity increases. After accounting for interactions, the net effect of WRD anomalies on wildfire area burned was more than 2.5 times greater than the net effect of VPD, and both the WRD and VPD effects were substantially greater than the influence of winter snowpack. These results suggest that precipitation during the fire season exerts the strongest control on burned area either directly through its wetting effects or indirectly through feedbacks to VPD. If these trends persist, decreases in summer precipitation and the associated summertime aridity increases would lead to more burned area across the western United States with far-reaching ecological and socioeconomic impacts.

scholarly journals Twenty-first century droughts have not increasingly exacerbated fire season severity in the Brazilian Amazon

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Libonati ◽  
J. M. C. Pereira ◽  
C. C. Da Camara ◽  
L. F. Peres ◽  
D. Oom ◽  
...  
Keyword(s):  
Forest Fires ◽  
Brazilian Amazon ◽  
First Century ◽  
Fire Season ◽  
Fire Intensity ◽  
Amazon Forest ◽  
Active Fire ◽  
Fire Activity ◽  
Twenty First Century ◽  
In Fire

AbstractBiomass burning in the Brazilian Amazon is modulated by climate factors, such as droughts, and by human factors, such as deforestation, and land management activities. The increase in forest fires during drought years has led to the hypothesis that fire activity decoupled from deforestation during the twenty-first century. However, assessment of the hypothesis relied on an incorrect active fire dataset, which led to an underestimation of the decreasing trend in fire activity and to an inflated rank for year 2015 in terms of active fire counts. The recent correction of that database warrants a reassessment of the relationships between deforestation and fire. Contrasting with earlier findings, we show that the exacerbating effect of drought on fire season severity did not increase from 2003 to 2015 and that the record-breaking dry conditions of 2015 had the least impact on fire season of all twenty-first century severe droughts. Overall, our results for the same period used in the study that originated the fire-deforestation decoupling hypothesis (2003–2015) show that decoupling was clearly weaker than initially proposed. Extension of the study period up to 2019, and novel analysis of trends in fire types and fire intensity strengthened this conclusion. Therefore, the role of deforestation as a driver of fire activity in the region should not be underestimated and must be taken into account when implementing measures to protect the Amazon forest.

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