scholarly journals Highlighting Biome-Specific Sensitivity of Fire Size Distributions to Time-Gap Parameter Using a New Algorithm for Fire Event Individuation

2016 ◽  
Vol 8 (8) ◽  
pp. 663 ◽  
Author(s):  
Duarte Oom ◽  
Pedro Silva ◽  
Ioannis Bistinas ◽  
José Pereira
Keyword(s):  
Size Distributions ◽  
Fire Size ◽  
Fire Event ◽  
Specific Sensitivity ◽  
Time Gap ◽  
Gap Parameter

scholarly journals Analyzing Wildfires and their Socio-economic Factors in Sardinia

2021 ◽  
Author(s):  
Laura Serra ◽  
Claudio Detotto ◽  
Marco Vannini
Keyword(s):  
Public Lands ◽  
Local Communities ◽  
Time Span ◽  
Burned Area ◽  
Economic Factors ◽  
Size Distributions ◽  
Fire Size ◽  
Spatio Temporal ◽  
Socio Economic Factors

Abstract In the last decades, wildfire hazards have increased to dangerous levels, becoming the focus of debate among policymakers both at the local and national levels. This paper proposes a Spatio-temporal approach to study the determinants of fire size distributions taking Sardinia as a case study in the time span 1998-2009. Special attention is devoted to socioeconomic factors of local communities where wildfires occurred. The main finding of this study is that the proportion of public lands in a given municipality tends to mitigate the extent of the burned area. In addition, communities with a higher percentage of people employed in the primary sector are less likely to experience large burned extents.

Patch Sizes, Area, and Spatial Distribution of Nonforests Are Vital Ingredients to Fire-Adapted Western US Forests

2021 ◽  
Author(s):  
Paul Hessburg
Keyword(s):  
Potential Energy ◽  
Size Distributions ◽  
Bare Ground ◽  
Fire Event ◽  
Forested Area ◽  
Blue Mountains ◽  
Vegetation Height ◽  
Western Us ◽  
Driven System ◽  
Potential Map

<p><strong>Abstract:  </strong>In prior published work with reconstructions of early and late 20<sup>th</sup> century forest landscapes, we were surprised by the large amount of historical meadows, shrubfields, sparse woodlands, and bare ground (hereafter, nonforests) we observed on forest-capable biophysical settings. We also noted a trend of forest encroachment and densification in the late 20<sup>th</sup>-century. Here, using LANDFIRE remotely sensed, existing vegetation height and cover, and environmental site potential map layers for seven western provinces--rescaled to match the grain of photogrammetric data--we quantitatively compare the area and patch size distributions of early- (E20<sup>th</sup>), late 20<sup>th</sup>-century (L20<sup>th</sup>), and early 21<sup>st</sup>-century (E21<sup>st</sup>) nonforest conditions. Our results showed a trend of increasing nonforest area from the E20<sup>th</sup> to E21<sup>st</sup>-century and declining forested area in most provinces, with increases occurring primarily in the larger patch sizes. Our results coupled with other reburn modeling research suggest that extensive nonforest patchworks are intimately linked to forest landscape resilience, which is changing in uncharacteristic ways in some provinces. For example, in the Northern and Southern Cascade, and Blue Mountains provinces, we see an uncharacteristic coarsening of the grain by recent fires, while in the Upper Klamath province, we see a return to a large fire event-driven system. In a physical science sense, our results suggest that fire-prone forests -- in the largest context -- function as stored potential energy, and there is an ongoing tug-of-war waged over space and time between factors growing and removing forests. Nonforests on forest capable sites represent areas where stored potential energy has been reduced. Modern changes we observe in forested area foreshadow changes we can expect with climate warming.</p>

scholarly journals Wilderness shapes contemporary fire size distributions across landscapes of the western United States

Ecosphere ◽  
2013 ◽  
Vol 4 (1) ◽  
pp. art15 ◽  
Author(s):  
Sandra L. Haire ◽  
Kevin McGarigal ◽  
Carol Miller
Keyword(s):  
United States ◽  
Western United States ◽  
Size Distributions ◽  
Fire Size

scholarly journals Spatiotemporal prediction of wildfire extremes with Bayesian finite sample maxima

2018 ◽  
Author(s):  
Maxwell B. Joseph ◽  
Matthew W. Rossi ◽  
Nathan P. Mietkiewicz ◽  
Adam L. Mahood ◽  
Megan E. Cattau ◽  
...  
Keyword(s):  
United States ◽  
Negative Binomial ◽  
Nonlinear Effects ◽  
Predictive Distribution ◽  
Fire Frequency ◽  
Size Distributions ◽  
Finite Sample ◽  
Fire Size ◽  
Posterior Predictive Distribution ◽  
Data Set

AbstractWildfires are becoming more frequent in parts of the globe, but predicting where and when wildfires occur remains difficult. To predict wildfire extremes across the contiguous United States, we integrate a 30 year wildfire record with meteorological and housing data in spatiotemporal Bayesian statistical models with spatially varying nonlinear effects. We compared different distributions for the number and sizes of large fires to generate a posterior predictive distribution based on finite sample maxima for extreme events (the largest fires over bounded spatiotemporal domains). A zero-inflated negative binomial model for fire counts and a lognormal model for burned areas provided the best performance. This model attains 99% interval coverage for the number of fires and 93% coverage for fire sizes over a six year withheld data set. Dryness and air temperature strongly predict extreme wildfire probabilities. Housing density has a hump-shaped relationship with fire occurrence, with more fires occurring at intermediate housing densities. Statistically, these drivers affect the chance of an extreme wildfire in two ways: by altering fire size distributions, and by altering fire frequency, which influences sampling from the tails of fire size distributions. We conclude that recent extremes should not be surprising, and that the contiguous United States may be on the verge of even larger wildfire extremes.

254. A Comparison of the Particle Size Distributions for Aerosols Generated During Wet Grinding and Dry Deburring of Beryllium

1999 ◽  
Author(s):  
K.K. Ellis ◽  
R. Buchan ◽  
M. Hoover ◽  
J. Martyny ◽  
B. Bucher-Bartleson ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Wet Grinding
Sign in / Sign up

Export Citation Format

Share Document