Predicting fire behavior in U.S. Mediterranean ecosystems

Treesearch

Frank A. Albini; Earl B. Anderson

1982-01-01

Quantification and methods of prediction of wildland fire behavior are discussed briefly and factors of particular relevance to the prediction of fire behavior in Mediterranean ecosystems are reviewed. A computer-based system which uses relevant fuel information and current weather data to predict fire behavior is in operation in southern California. Some of the...

BehavePlus fire modeling system: Past, present, and future

Treesearch

Patricia L. Andrews

2007-01-01

Use of mathematical fire models to predict fire behavior and fire effects plays an important supporting role in wildland fire management. When used in conjunction with personal fire experience and a basic understanding of the fire models, predictions can be successfully applied to a range of fire management activities including wildfire behavior prediction, prescribed...

Impact of a community based fire prevention intervention on fire safety knowledge and behavior in elementary school children

PubMed Central

Hwang, V; Duchossois, G P; Garcia‐Espana, J F; Durbin, D R

2006-01-01

The objective of this study was to determine the impact of a community based fire prevention intervention directed only to parents on the fire safety knowledge and behavior in elementary school children. This was a prospective, quasi‐randomized controlled study in which third and fourth grade students from two elementary schools in an urban, poor, minority community completed knowledge/behavior surveys at baseline and following completion of the intervention. The intervention group received an in‐home visit from fire department personnel who installed free lithium smoke detectors and provided a fire escape plan. After accounting for a small difference in baseline summary scores of knowledge and behavior between the control and intervention groups, this study found a modest improvement in fire safety behavior among children whose families received a fire prevention intervention reflecting a change in household fire safety practices. However, there was no significant change in fire safety knowledge. PMID:17018679

Synthesis of knowledge of extreme fire behavior: volume I for fire managers

Treesearch

Paul A. Werth; Brian E. Potter; Craig B. Clements; Mark A. Finney; Scott L. Goodrick; Martin E. Alexander; Miguel G. Cruz; Jason A. Forthofer; Sara S. McAllister

2011-01-01

The National Wildfire Coordinating Group definition of extreme fire behavior (EFB) indicates a level of fire behavior characteristics that ordinarily precludes methods of direct control action. One or more of the following is usually involved: high rate of spread, prolific crowning/spotting, presence of fire whirls, and strong convection column. Predictability is...

Charts for interpreting wildland fire behavior characteristics

Treesearch

Patricia L. Andrews; Richard C. Rothermel

1982-01-01

The fire characteristics chart is proposed as a graphical method ofpresenting two primary characteristics of fire behavior – spread rate and intensity. Its primary use is communicating and interpreting either site-specific predictions of fire behavior or National Fire-Danger Rating System (NFDRS) indexes and components. Rate of spread, heat per unit area, flame length...

In-situ characterization of wildland fire behavior

Treesearch

Bret Butler; D. Jimenez; J. Forthofer; Paul Sopko; K. Shannon; Jim Reardon

2010-01-01

A system consisting of two enclosures has been developed to characterize wildand fire behavior: The first enclosure is a sensor/data logger combination that measures and records convective/radiant energy released by the fire. The second is a digital video camera housed in a fire proof enclosure that records visual images of fire behavior. Together this system provides...

75 FR 58347 - Information Collection; Overcoming Barriers to Wildland Fire Defensible Space Behaviors

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-24

... Information Collection; Overcoming Barriers to Wildland Fire Defensible Space Behaviors AGENCY: Forest Service... new information collection, Overcoming Barriers to Wildland Fire Defensible Space Behaviors. DATES... time, Monday through Friday. SUPPLEMENTARY INFORMATION: Title: Overcoming Barriers to Wildland Fire...

Stochastic representation of fire behavior in a wildland fire protection planning model for California.

Treesearch

J. Keith Gilless; Jeremy S. Fried

1998-01-01

A fire behavior module was developed for the California Fire Economics Simulator version 2 (CFES2), a stochastic simulation model of initial attack on wildland fire used by the California Department of Forestry and Fire Protection. Fire rate of spread (ROS) and fire dispatch level (FDL) for simulated fires "occurring" on the same day are determined by making...

Modeling the spatial distribution of forest crown biomass and effects on fire behavior with FUEL3D and WFDS

Treesearch

Russell A. Parsons; William Mell; Peter McCauley

2010-01-01

Crown fire poses challenges to fire managers and can endanger fire fighters. Understanding of how fire interacts with tree crowns is essential to informed decisions about crown fire. Current operational crown fire predictions in the United States assume homogeneous crown fuels. While a new class of research fire models, which model fire behavior with computational...

Fire weather and fire behavior in the 1966 loop fire

Treesearch

C.M. Countryman; M.A. Fosberg; R.C. Rothermel; M.J. Schroeder

1968-01-01

Southern California regularly experiences a wind condition known as the Santa Ana winds. This paper describes the phenomenon and the effects it had on fire behavior during the 1966 Loop Fire in the Angeles National Forest, which claimed the lives of 12 fire fighters.

Fire behavior, fuel treatments, and fire suppression on the Hayman Fire - Part 4: Relation of roads to burn severity

Treesearch

Charles W. McHugh; Mark A. Finney

2003-01-01

Effects of roads on fire behavior intensity and severity can be studied directly or indirectly. A direct study of road effects would include uses by fire suppression, burnout operations, and delay of fire progress at the roadside. Interpretations after the fire burns are easily confounded by the unknown nature of suppression activities and fire arrival time, and fire...

Fire characteristics charts for fire behavior and U.S. fire danger rating

Treesearch

Faith Ann Heinsch; Pat Andrews

2010-01-01

The fire characteristics chart is a graphical method of presenting U.S. National Fire Danger Rating indices or primary surface or crown fire behavior characteristics. A desktop computer application has been developed to produce fire characteristics charts in a format suitable for inclusion in reports and presentations. Many options include change of scales, colors,...

Bald Mountain Fire, Eagle Cap Wilderness Area, Wallowa-Whitman National Forest, FARSITE analysis

Treesearch

LaWen Hollingsworth

2012-01-01

While the Near Term Fire Behavior analysis option in WFDSS is similar to FARSITE, the advantage of using FARSITE lies in the ability to use gridded winds which produces more reliable fire behavior results in complex terrain. A couple of FARSITE simulations were completed to evaluate fire growth and fire behavior in relation to the values, notably Red's Horse Ranch...

Fuel type characterization and potential fire behavior estimation in Sardinia and Corsica islands

NASA Astrophysics Data System (ADS)

Bacciu, V.; Pellizzaro, G.; Santoni, P.; Arca, B.; Ventura, A.; Salis, M.; Barboni, T.; Leroy, V.; Cancellieri, D.; Leoni, E.; Ferrat, L.; Perez, Y.; Duce, P.; Spano, D.

2012-04-01

Wildland fires represent a serious threat to forests and wooded areas of the Mediterranean Basin. As recorded by the European Commission (2009), during the last decade Southern Countries have experienced an annual average of about 50,000 forest fires and about 470,000 burned hectares. The factor that can be directly manipulated in order to minimize fire intensity and reduce other fire impacts, such as three mortality, smoke emission, and soil erosion, is wildland fuel. Fuel characteristics, such as vegetation cover, type, humidity status, and biomass and necromass loading are critical variables in affecting wildland fire occurrence, contributing to the spread, intensity, and severity of fires. Therefore, the availability of accurate fuel data at different spatial and temporal scales is needed for fire management applications, including fire behavior and danger prediction, fire fighting, fire effects simulation, and ecosystem simulation modeling. In this context, the main aims of our work are to describe the vegetation parameters involved in combustion processes and develop fire behavior fuel maps. The overall work plan is based firstly on the identification and description of the different fuel types mainly affected by fire occurrence in Sardinia (Italy) and Corsica (France) Islands, and secondly on the clusterization of the selected fuel types in relation to their potential fire behavior. In the first part of the work, the available time series of fire event perimeters and the land use map data were analyzed with the purpose of identifying the main land use types affected by fires. Thus, field sampling sites were randomly identified on the selected vegetation types and several fuel variables were collected (live and dead fuel load partitioned following Deeming et al., (1977), depth of fuel layer, plant cover, surface area-to-volume ratio, heat content). In the second part of the work, the potential fire behavior for every experimental site was simulated using BEHAVE fire behavior prediction system (Andrews, 1989) and experimental fuel data. Fire behavior was simulated by setting different weather scenarios representing the most frequent summer meteorological conditions. The simulation outputs (fireline intensity, rate of spread, flame length) were then analyzed for clustering the different fuel types in relation to their potential fire behavior. The results of this analysis can be used to produce fire behavior fuel maps that are important tools in evaluating fire hazard and risk for land management planning, locating and rating fuel treatments, and aiding in environmental assessments and fire danger programs modeling. This work is supported by FUME Project FP7-ENV-2009-1, Grant Agreement Number 243888 and Proterina-C Project, EU Italia-Francia Marittimo 2007-2013 Programme.

Fire Technology Abstracts, volume 4, issue 1, August, 1981

NASA Astrophysics Data System (ADS)

Holtschlag, L. J.; Kuvshinoff, B. W.; Jernigan, J. B.

This bibliography contains over 400 citations with abstracts addressing various aspects of fire technology. Subjects cover the dynamics of fire, behavior and properties of materials, fire modeling and test burns, fire protection, fire safety, fire service organization, apparatus and equipment, fire prevention, suppression, planning, human behavior, medical problems, codes and standards, hazard identification, safe handling of materials, insurance, economics of loss and prevention, and more.

How to generate and interpret fire characteristics charts for the U.S. fire danger rating system

Treesearch

Faith Ann Heinsch; Patricia L. Andrews; Deb Tirmenstein

2017-01-01

The fire characteristics chart is a graphical method of presenting U.S. National Fire Danger Rating System (NFDRS) indexes and components as well as primary surface or crown fire behavior characteristics. Computer software has been developed to produce fire characteristics charts for both fire danger and fire behavior in a format suitable for inclusion in reports and...

Relative impact of weather vs. fuels on fire regimes in coastal California

Treesearch

Jon E. Keeley

2008-01-01

Extreme fire weather is of over riding importance in determining fire behavior in coastal chaparral and on these landscapes fire suppression policy has not resulted in fire exclusion. There is regional variation in foehn winds, which are most important in southern California. Under these severe fire weather conditions fuel age does not constrain fire behavior. As a...

Linking 3D spatial models of fuels and fire: Effects of spatial heterogeneity on fire behavior

Treesearch

Russell A. Parsons; William E. Mell; Peter McCauley

2011-01-01

Crownfire endangers fire fighters and can have severe ecological consequences. Prediction of fire behavior in tree crowns is essential to informed decisions in fire management. Current methods used in fire management do not address variability in crown fuels. New mechanistic physics-based fire models address convective heat transfer with computational fluid dynamics (...

Assessing crown fire potential by linking models of surface and crown fire behavior

Treesearch

Joe H. Scott; Elizabeth D. Reinhardt

2001-01-01

Fire managers are increasingly concerned about the threat of crown fires, yet only now are quantitative methods for assessing crown fire hazard being developed. Links among existing mathematical models of fire behavior are used to develop two indices of crown fire hazard-the Torching Index and Crowning Index. These indices can be used to ordinate different forest...

Performance of fire behavior fuel models developed for the Rothermel Surface Fire Spread Model

Treesearch

Robert Ziel; W. Matt Jolly

2009-01-01

In 2005, 40 new fire behavior fuel models were published for use with the Rothermel Surface Fire Spread Model. These new models are intended to augment the original 13 developed in 1972 and 1976. As a compiled set of quantitative fuel descriptions that serve as input to the Rothermel model, the selected fire behavior fuel model has always been critical to the resulting...

Standard fire behavior fuel models: a comprehensive set for use with Rothermel's surface fire spread model

Treesearch

Joe H. Scott; Robert E. Burgan

2005-01-01

This report describes a new set of standard fire behavior fuel models for use with Rothermel's surface fire spread model and the relationship of the new set to the original set of 13 fire behavior fuel models. To assist with transition to using the new fuel models, a fuel model selection guide, fuel model crosswalk, and set of fuel model photos are provided.

Estimating fire behavior with FIRECAST: user's manual

Treesearch

Jack D. Cohen

1986-01-01

FIRECAST is a computer program that estimates fire behavior in terms of six fire parameters. Required inputs vary depending on the outputs desired by the fire manager. Fuel model options available to users are these: Northern Forest Fire Laboratory (NFFL), National Fire Danger Rating System (NFDRS), and southern California brushland (SCAL). The program has been...

Modeling the effects of vegetation heterogeneity on wildland fire behavior

NASA Astrophysics Data System (ADS)

Atchley, A. L.; Linn, R.; Sieg, C.; Middleton, R. S.

2017-12-01

Vegetation structure and densities are known to drive fire-spread rate and burn severity. Many fire-spread models incorporate an average, homogenous fuel density in the model domain to drive fire behavior. However, vegetation communities are rarely homogenous and instead present significant heterogeneous structure and fuel densities in the fires path. This results in observed patches of varied burn severities and mosaics of disturbed conditions that affect ecological recovery and hydrologic response. Consequently, to understand the interactions of fire and ecosystem functions, representations of spatially heterogeneous conditions need to be incorporated into fire models. Mechanistic models of fire disturbance offer insight into how fuel load characterization and distribution result in varied fire behavior. Here we use a physically-based 3D combustion model—FIRETEC—that solves conservation of mass, momentum, energy, and chemical species to compare fire behavior on homogenous representations to a heterogeneous vegetation distribution. Results demonstrate the impact vegetation heterogeneity has on the spread rate, intensity, and extent of simulated wildfires thus providing valuable insight in predicted wildland fire evolution and enhanced ability to estimate wildland fire inputs into regional and global climate models.

High-fire-risk behavior in critical fire areas

Treesearch

William S. Folkman

1977-01-01

Observations of fire-related behavior of wildland visitors were made in three types of areas-wilderness, established campground, and built-up commercial and residential areas-within the San Bernardino National Forest, California. Interviews were conducted with all persons so observed. Types of fire-related behavior differed markedly from one area to another, as did the...

Fire danger index efficiency as a function of fuel moisture and fire behavior.

PubMed

Torres, Fillipe Tamiozzo Pereira; Romeiro, Joyce Machado Nunes; Santos, Ana Carolina de Albuquerque; de Oliveira Neto, Ricardo Rodrigues; Lima, Gumercindo Souza; Zanuncio, José Cola

2018-08-01

Assessment of the performance of forest fire hazard indices is important for prevention and management strategies, such as planning prescribed burnings, public notifications and firefighting resource allocation. The objective of this study was to evaluate the performance of fire hazard indices considering fire behavior variables and susceptibility expressed by the moisture of combustible material. Controlled burns were carried out at different times and information related to meteorological conditions, characteristics of combustible material and fire behavior variables were recorded. All variables analyzed (fire behavior and fuel moisture content) can be explained by the prediction indices. The Brazilian EVAP/P showed the best performance, both at predicting moisture content of the fuel material and fire behavior variables, and the Canadian system showed the best performance to predicting the rate of spread. The coherence of the correlations between the indices and the variables analyzed makes the methodology, which can be applied anywhere, important for decision-making in regions with no records or with only unreliable forest fire data. Copyright © 2018 Elsevier B.V. All rights reserved.

WRF-Fire: coupled weather-wildland fire modeling with the weather research and forecasting model

Treesearch

Janice L. Coen; Marques Cameron; John Michalakes; Edward G. Patton; Philip J. Riggan; Kara M. Yedinak

2012-01-01

A wildland fire behavior module (WRF-Fire) was integrated into the Weather Research and Forecasting (WRF) public domain numerical weather prediction model. The fire module is a surface fire behavior model that is two-way coupled with the atmospheric model. Near-surface winds from the atmospheric model are interpolated to a finer fire grid and used, with fuel properties...

Temporal scaling behavior of forest and urban fires

NASA Astrophysics Data System (ADS)

Wang, J.; Song, W.; Zheng, H.; Telesca, L.

2009-04-01

It has been found that many natural systems are characterized by scaling behavior. In such systems natural factors dominate the event dynamics. Forest fires in different countries have been found to exhibit frequency-size power law over many orders of magnitude and with similar value of parameters. But in countries with high population density such as China and Japan, more than 95% of the forest fire disasters are caused by human activities. Furthermore, with the development of society, the wildland-urban interface (WUI) area is becoming more and more populated, and the forest fire is much connected with urban fire. Therefore exploring the scaling behavior of fires dominated by human-related factors is very challenging. The present paper explores the temporal scaling behavior of forest fires and urban fires in Japan with mathematical methods. Two factors, Allan factor (AF) and Fano factor (FF) are used to investigate time-scaling of fire systems. It is found that the FF for both forest fires and urban fires increases linearly in log-log scales, and this indicates that it behaves as a power-law for all the investigated timescales. From the AF plot a 7 days cycle is found, which indicates a weekly cycle. This may be caused by human activities which has a weekly periodicity because on weekends people usually have more outdoor activities, which may cause more hidden trouble of fire disasters. Our findings point out that although the human factors are the main cause, both the forest fires and urban fires exhibit time-scaling behavior. At the same time, the scaling exponents for urban fires are larger than forest fires, signifying a more intense clustering. The reason may be that fires are affected not only by weather condition, but also by human activities, which play a more important role for urban fires than forest fires and have a power law distribution and scaling behavior. Then some work is done to the relative humidity. Similar distribution law characterizes the relative humidity. The AF plot and FF plot of relative humidity validate the existence of a strong link between weather and fires, and it is very likely that the daily humidity cycle determines the daily fire periodicity.

Ecological forestry in the Southeast: Understanding the ecology of fuels

Treesearch

R.J. Mitchell; J.K. Hiers; J. O’Brien; G. Starr

2009-01-01

Fire is a dominant disturbance within many forested ecosystems worldwide. Understanding the complex feedbacks among vegetation as a fuel for fire, the effects of fuels on fire behavior, and the impact of fire behavior on future vegetation are critical for sustaining biodiversity in fire-dependent forests. Nonetheless, understanding in fire ecology has been limited in...

An Overview of FlamMap Fire Modeling Capabilities

Treesearch

Mark A. Finney

2006-01-01

Computerized and manual systems for modeling wildland fire behavior have long been available (Rothermel 1983, Andrews 1986). These systems focus on one-dimensional behaviors and assume the fire geometry is a spreading line-fire (in contrast with point or area-source fires). Models included in these systems were developed to calculate fire spread rate (Rothermel 1972,...

Fire effects on basal area, tiller production, and mortality of the C4 Bunchgrass, Purple Threeawn

USDA-ARS?s Scientific Manuscript database

Fire behavior associated with wild and prescribed fires is variable, but plays a vital role in how a plant responds to fire. The relationship of fire behavior to rangeland plant community response has not been investigated, with a few exceptions, until recently. Fire is an important ecological pro...

Sensitivity of fire behavior simulations to fuel model variations

Treesearch

Lucy A. Salazar

1985-01-01

Stylized fuel models, or numerical descriptions of fuel arrays, are used as inputs to fire behavior simulation models. These fuel models are often chosen on the basis of generalized fuel descriptions, which are related to field observations. Site-specific observations of fuels or fire behavior in the field are not readily available or necessary for most fire management...

Solution Focused Empathy Training Groups for Students with Fire-Setting Behaviors

ERIC Educational Resources Information Center

Froeschle, Janet G.

2006-01-01

Fire-setting students are those who intentionally or unintentionally set one or more fires due to curiosity, stress, a need for attention, or due to criminal delinquency. This article describes the nature of fire-setting behaviors, discusses the profile and risk factors associated with the behavior, and outlines a group program using empathy…

Uncertainty and risk in wildland fire management: A review

Treesearch

Matthew P. Thompson; Dave E. Calkin

2011-01-01

Wildland fire management is subject to manifold sources of uncertainty. Beyond the unpredictability of wildfire behavior, uncertainty stems from inaccurate/missing data, limited resource value measures to guide prioritization across fires and resources at risk, and an incomplete scientific understanding of ecological response to fire, of fire behavior response to...

How did prefire treatments affect the Biscuit Fire?

Treesearch

Crystal Raymond; David L. Peterson

2005-01-01

Most scientific literature supports forest thinning to reduce the severity of wildland fires, but the effectiveness of thinning in modifying fire behavior has not been well documented. The Biscuit Fire of 2002 offered a great opportunity to study the effects of mechanical thinning on fire behavior during a megafire.

FARSITE: Fire Area Simulator-model development and evaluation

Treesearch

Mark A. Finney

1998-01-01

A computer simulation model, FARSITE, includes existing fire behavior models for surface, crown, spotting, point-source fire acceleration, and fuel moisture. The model's components and assumptions are documented. Simulations were run for simple conditions that illustrate the effect of individual fire behavior models on two-dimensional fire growth.

Monthly fire behavior patterns

Treesearch

Mark J. Schroeder; Craig C. Chandler

1966-01-01

From tabulated frequency distributions of fire danger indexes for a nationwide network of 89 stations, the probabilities of four types of fire behavior ranging from 'fire out' to 'critical' were calculated for each month and are shown in map form.

Fire behavior, fuel treatments, and fire suppression on the Hayman Fire - Part 1: Fire weather, meteorology, and climate

Treesearch

Larry Bradshaw; Roberta Bartlette; John McGinely; Karl Zeller

2003-01-01

The Hayman Fire in June 2002 was heavily influenced by antecedent regional weather conditions, culminating in a series of daily weather events that aligned to produce widely varying fire behavior. This review of weather conditions associated with the Hayman Fire consists of two parts: 1) A brief overview of prior conditions as described by a regional climate review and...

Fire technology abstracts, volume 4. Cumulative indexes

NASA Astrophysics Data System (ADS)

1982-03-01

Cumulative subject, author, publisher, and report number indexes referencing articles, books, reports, and patents are provided. The dynamics of fire, behavior and properties of materials, fire modeling and test burns, fire protection, fire safety, fire service organization, apparatus and equipment, fire prevention suppression, planning, human behavior, medical problems, codes and standards, hazard identification, safe handling of materials, and insurance economics of loss and prevention are among the subjects covered.

Field procedures for verification and adjustment of fire behavior predictions

Treesearch

Richard C. Rothermel; George C. Rinehart

1983-01-01

The problem of verifying predictions of fire behavior, primarily rate of spread, is discussed in terms of the fire situation for which predictions are made, and the type of fire where data are to be collected. Procedures for collecting data and performing analysis are presented for both readily accessible fires where data should be complete, and for inaccessible fires...

BehavePlus fire modeling system, version 5.0: Design and Features

Treesearch

Faith Ann Heinsch; Patricia L. Andrews

2010-01-01

The BehavePlus fire modeling system is a computer program that is based on mathematical models that describe wildland fire behavior and effects and the fire environment. It is a flexible system that produces tables, graphs, and simple diagrams. It can be used for a host of fire management applications, including projecting the behavior of an ongoing fire, planning...

Simulation of quaking aspen potential fire behavior in Northern Utah, USA

Treesearch

R. Justin DeRose; A. Joshua Leffler

2014-01-01

Current understanding of aspen fire ecology in western North America includes the paradoxical characterization that aspen-dominated stands, although often regenerated following fire, are “fire-proof”. We tested this idea by predicting potential fire behavior across a gradient of aspen dominance in northern Utah using the Forest Vegetation Simulator and the Fire and...

An evaluation of The Great Escape: can an interactive computer game improve young children's fire safety knowledge and behaviors?

PubMed

Morrongiello, Barbara A; Schwebel, David C; Bell, Melissa; Stewart, Julia; Davis, Aaron L

2012-07-01

Fire is a leading cause of unintentional injury and, although young children are at particularly increased risk, there are very few evidence-based resources available to teach them fire safety knowledge and behaviors. Using a pre-post randomized design, the current study evaluated the effectiveness of a computer game (The Great Escape) for teaching fire safety information to young children (3.5-6 years). Using behavioral enactment procedures, children's knowledge and behaviors related to fire safety were compared to a control group of children before and after receiving the intervention. The results indicated significant improvements in knowledge and fire safety behaviors in the intervention group but not the control. Using computer games can be an effective way to promote young children's understanding of safety and how to react in different hazardous situations.

A mixed integer program to model spatial wildfire behavior and suppression placement decisions

Treesearch

Erin J. Belval; Yu Wei; Michael Bevers

2015-01-01

Wildfire suppression combines multiple objectives and dynamic fire behavior to form a complex problem for decision makers. This paper presents a mixed integer program designed to explore integrating spatial fire behavior and suppression placement decisions into a mathematical programming framework. Fire behavior and suppression placement decisions are modeled using...

Crown fuel spatial variability and predictability of fire spread

Treesearch

Russell A. Parsons; Jeremy Sauer; Rodman R. Linn

2010-01-01

Fire behavior predictions, as well as measures of uncertainty in those predictions, are essential in operational and strategic fire management decisions. While it is becoming common practice to assess uncertainty in fire behavior predictions arising from variability in weather inputs, uncertainty arising from the fire models themselves is difficult to assess. This is...

Fire weather and behavior of the Little Sioux fire.

Treesearch

Rodney W. Sando; Donald A. Haines

1972-01-01

In mid-May 1971, a northern Minnesota fire burned almost 15,000 acres of forest land. The extreme fire behavior it exhibited was the product of a number of described features. This paper documents the attendant fuel and weather conditions.

Evaluating potential fire behavior in lodgepole pine-dominated forests after a mountain pine beetle epidemic in north-central Colorado

Treesearch

Jennifer G. Klutsch; Mike A. Battaglia; Daniel R. West; Sheryl L. Costello; Jose F. Negron

2011-01-01

A mountain pine beetle outbreak in Colorado lodgepole pine forests has altered stand and fuel characteristics that affect potential fire behavior. Using the Fire and Fuels Extension to the Forest Vegetation Simulator, potential fire behavior was modeled for uninfested and mountain pine beetle-affected plots 7 years after outbreak initiation and 10 and 80% projected...

Fire behavior simulation in Mediterranean forests using the minimum travel time algorithm

Treesearch

Kostas Kalabokidis; Palaiologos Palaiologou; Mark A. Finney

2014-01-01

Recent large wildfires in Greece exemplify the need for pre-fire burn probability assessment and possible landscape fire flow estimation to enhance fire planning and resource allocation. The Minimum Travel Time (MTT) algorithm, incorporated as FlamMap's version five module, provide valuable fire behavior functions, while enabling multi-core utilization for the...

Appraising fuels and flammability in western aspen: a prescribed fire guide

Treesearch

James K. Brown; Dennis G. Simmerman

1986-01-01

Describes a method for appraising fuels and fire behavior potential in aspen forests to guide the use of prescribed fire and the preparation of fire prescriptions. Includes an illustrated classification of aspen fuels; appraisals of fireline intensity, rate of spread, adjective ratings for fire behavior and probability of burn success; and evaluations of seasonal...

Davis Fire: Fire behavior and fire effects analysis

Treesearch

LaWen T. Hollingsworth

2010-01-01

The Davis Fire presents an interesting example of fire behavior in subalpine fir, partially dead lodgepole pine with multiple age classes, and moist site Douglas-fir vegetation types. This has been summer of moderate temperatures and intermittent moisture that has kept live herbaceous and live woody moistures fairly high and dead fuel moistures at a moderate level....

The effectiveness and limitations of fuel modeling using the fire and fuels extension to the Forest Vegetation Simulator

Treesearch

Erin K. Noonan-Wright; Nicole M. Vaillant; Alicia L. Reiner

2014-01-01

Fuel treatment effectiveness is often evaluated with fire behavior modeling systems that use fuel models to generate fire behavior outputs. How surface fuels are assigned, either using one of the 53 stylized fuel models or developing custom fuel models, can affect predicted fire behavior. We collected surface and canopy fuels data before and 1, 2, 5, and 8 years after...

BEHAVE: fire behavior prediction and fuel modeling system-BURN Subsystem, part 1

Treesearch

Patricia L. Andrews

1986-01-01

Describes BURN Subsystem, Part 1, the operational fire behavior prediction subsystem of the BEHAVE fire behavior prediction and fuel modeling system. The manual covers operation of the computer program, assumptions of the mathematical models used in the calculations, and application of the predictions.

Uncertainty in Wildfire Behavior

NASA Astrophysics Data System (ADS)

Finney, M.; Cohen, J. D.

2013-12-01

The challenge of predicting or modeling fire behavior is well recognized by scientists and managers who attempt predictions of fire spread rate or growth. At the scale of the spreading fire, the uncertainty in winds, moisture, fuel structure, and fire location make accurate predictions difficult, and the non-linear response of fire spread to these conditions means that average behavior is poorly represented by average environmental parameters. Even more difficult are estimations of threshold behaviors (e.g. spread/no-spread, crown fire initiation, ember generation and spotting) because the fire responds as a step-function to small changes in one or more environmental variables, translating to dynamical feedbacks and unpredictability. Recent research shows that ignition of fuel particles, itself a threshold phenomenon, depends on flame contact which is absolutely not steady or uniform. Recent studies of flame structure in both spreading and stationary fires reveals that much of the non-steadiness of the flames as they contact fuel particles results from buoyant instabilities that produce quasi-periodic flame structures. With fuel particle ignition produced by time-varying heating and short-range flame contact, future improvements in fire behavior modeling will likely require statistical approaches to deal with the uncertainty at all scales, including the level of heat transfer, the fuel arrangement, and weather.

Toward improving our application and understanding of crown fire behavior

Treesearch

Martin E. Alexander; Miguel G. Cruz; Nicole M. Vaillant

2014-01-01

The suggestion has been made that most wildland fire operations personnel base their expectations of how a fire will behave largely on experience and, to a lesser extent, on guides to predicting fire behavior (Burrows 1984). Experienced judgment is certainly needed in any assessment of wildland fire potential but it does have its limitations. The same can be said for...

Assessment of the FARSITE model for predicting fire behavior in the Southern Appalachian Mountains

Treesearch

Ross J. Phillips; Thomas A. Waldrop; Dean M. Simon

2006-01-01

Fuel reduction treatments are necessary in fire-adapted ecosystems where fire has been excluded for decades and the potential for severe wildfire is high. Using the Fire Area Simulator, FARSITE, we examined the spatial and temporal effects of these treatments on fire behavior in the Southern Appalachian Mountains. With measurements from temperature sensors during...

An uncommon case of random fire-setting behavior associated with Todd paralysis: a case report.

PubMed

Kanehisa, Masayuki; Morinaga, Katsuhiko; Kohno, Hisae; Maruyama, Yoshihiro; Ninomiya, Taiga; Ishitobi, Yoshinobu; Tanaka, Yoshihiro; Tsuru, Jusen; Hanada, Hiroaki; Yoshikawa, Tomoya; Akiyoshi, Jotaro

2012-08-31

The association between fire-setting behavior and psychiatric or medical disorders remains poorly understood. Although a link between fire-setting behavior and various organic brain disorders has been established, associations between fire setting and focal brain lesions have not yet been reported. Here, we describe the case of a 24-year-old first time arsonist who suffered Todd's paralysis prior to the onset of a bizarre and random fire-setting behavior. A case of a 24-year-old man with a sudden onset of a bizarre and random fire-setting behavior is reported. The man, who had been arrested on felony arson charges, complained of difficulties concentrating and of recent memory disturbances with leg weakness. A video-EEG recording demonstrated a close relationship between the focal motor impairment and a clear-cut epileptic ictal discharge involving the bilateral motor cortical areas. The SPECT result was statistically analyzed by comparing with standard SPECT images obtained from our institute (easy Z-score imaging system; eZIS). eZIS revealed hypoperfusion in cingulate cortex, basal ganglia and hyperperfusion in frontal cortex,. A neuropsychological test battery revealed lower than normal scores for executive function, attention, and memory, consistent with frontal lobe dysfunction. The fire-setting behavior and Todd's paralysis, together with an unremarkable performance on tests measuring executive function fifteen months prior, suggested a causal relationship between this organic brain lesion and the fire-setting behavior. The case describes a rare and as yet unreported association between random, impulse-driven fire-setting behavior and damage to the brain and suggests a disconnection of frontal lobe structures as a possible pathogenic mechanism.

Prevalence and correlates of fire-setting in the United States: results from the National Epidemiological Survey on Alcohol and Related Conditions.

PubMed

Vaughn, Michael G; Fu, Qiang; Delisi, Matt; Wright, John Paul; Beaver, Kevin M; Perron, Brian E; Howard, Matthew O

2010-01-01

Fire-setting is a serious and costly form of antisocial behavior. Our objective in this study was to examine the prevalence and correlates of intentional fire-setting behavior in the United States. Data were derived from a nationally representative sample of US residents 18 years and older. Structured psychiatric interviews (N = 43,093) were completed by trained lay interviewers between 2001 and 2002. Fire-setting as well as mood, anxiety, substance use, and personality disorders of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition were assessed with the Alcohol Use Disorder and Associated Disabilities Interview Schedule (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) version. The prevalence of lifetime fire-setting in the US population was 1.0%. Respondents who were men, white, 18 to 35 years old, born in the United States, and living in the western region of the United States had significantly higher rates of fire-setting than their counterparts. Fire-setting was significantly associated with a wide range of antisocial behaviors. Multivariate logistic regression analyses identified strong associations between lifetime alcohol and marijuana use disorders, conduct disorder, antisocial and obsessive-compulsive personality disorders, and family history of antisocial behavior. Intentional illicit fire-setting behavior is associated with a broad array of antisocial behaviors and psychiatric comorbidities. Given the substantial personal and social costs related to arson, prevention and treatment interventions targeting fire-setters potentially could save lives and property. 2010 Elsevier Inc. All rights reserved.

Validation of BEHAVE fire behavior predictions in oak savannas using five fuel models

Treesearch

Keith Grabner; John Dwyer; Bruce Cutter

1997-01-01

Prescribed fire is a valuable tool in the restoration and management of oak savannas. BEHAVE, a fire behavior prediction system developed by the United States Forest Service, can be a useful tool when managing oak savannas with prescribed fire. BEHAVE predictions of fire rate-of-spread and flame length were validated using four standardized fuel models: Fuel Model 1 (...

Fire behavior sensor package remote trigger design

Treesearch

Dan Jimenez; Jason Forthofer; James Reardon; Bret Butler

2007-01-01

Fire behavior characteristics (such as temperature, radiant and total heat flux, 2- and 3-dimensional velocities, and air flow) are extremely difficult to measure insitu. Although insitu sensor packages are capable of such measurements in realtime, it is also essential to acquire video documentation as a means of better understanding the fire behavior data recorded by...

The simulation of surface fire spread based on Rothermel model in windthrow area of Changbai Mountain (Jilin, China)

NASA Astrophysics Data System (ADS)

Yin, Hang; Jin, Hui; Zhao, Ying; Fan, Yuguang; Qin, Liwu; Chen, Qinghong; Huang, Liya; Jia, Xiang; Liu, Lijie; Dai, Yuhong; Xiao, Ying

2018-03-01

The forest-fire not only brings great loss to natural resources, but also destructs the ecosystem and reduces the soil fertility, causing some natural disasters as soil erosion and debris flow. However, due to the lack of the prognosis for forest fire spreading trend in forest fire fighting, it is difficult to formulate rational and effective fire-fighting scheme. In the event of forest fire, achieving accurate judgment to the fire behavior would greatly improve the fire-fighting efficiency, and reduce heavy losses caused by fire. Researches on forest fire spread simulation can effectively reduce the loss of disasters. The present study focused on the simulation of "29 May 2012" wildfire in windthrow area of Changbai Mountain. Basic data were retrieved from the "29 May 2012" wildfire and field survey. A self-development forest fire behavior simulated program based on Rothermel Model was used in the simulation. Kappa coefficient and Sørensen index were employed to evaluate the simulation accuracy. The results showed that: The perimeter of simulated burned area was 4.66 km, the area was 56.47 hm2 and the overlapped burned area was 33.68 hm2, and the estimated rate of fire spread was 0.259 m/s. Between the simulated fire and actual fire, the Kappa coefficient was 0.7398 and the Sørensen co-efficient was 0.7419. This proved the application of Rothermel model to conduct fire behavior simulation in windthrow meadow was feasible. It can achieve the goal of forecasting for the spread behavior in windthrow area of Changbai Mountain. Thus, our self-development program based on the Rothermel model can provide a effective forecast of fire spread, which will facilitate the fire suppression work.

Report of the Army Scientific Advisory Panel Ad Hoc Group on Fire Suppression

DTIC Science & Technology

1975-07-01

initially should be provided a nucleus of a seven- person technical staff composed of one 0-6 combat arme officer as Director, two senior behavioral ...If the suppressee perceives the fire as being reactive to his own behavior then the personal danger factor will be reinforced,1 Fire...that is not periodic hut also not reactive to his behavior may be like periodic fire in its personal threat except more difficult to

Firing patterns transition and desynchronization induced by time delay in neural networks

NASA Astrophysics Data System (ADS)

Huang, Shoufang; Zhang, Jiqian; Wang, Maosheng; Hu, Chin-Kun

2018-06-01

We used the Hindmarsh-Rose (HR) model (Hindmarsh and Rose, 1984) to study the effect of time delay on the transition of firing behaviors and desynchronization in neural networks. As time delay is increased, neural networks exhibit diversity of firing behaviors, including regular spiking or bursting and firing patterns transitions (FPTs). Meanwhile, the desynchronization of firing and unstable bursting with decreasing amplitude in neural system, are also increasingly enhanced with the increase of time delay. Furthermore, we also studied the effect of coupling strength and network randomness on these phenomena. Our results imply that time delays can induce transition and desynchronization of firing behaviors in neural networks. These findings provide new insight into the role of time delay in the firing activities of neural networks, and can help to better understand the firing phenomena in complex systems of neural networks. A possible mechanism in brain that can cause the increase of time delay is discussed.

Fire-danger rating and observed wildfire behavior in the Northeastern United States.

Treesearch

Donald A. Haines; William A. Main; Albert J. Simard

1986-01-01

Compares the 1978 National Fire-Danger Rating System and its 20 fuel models, along with other danger rating systems, with observed fire behavior and rates the strengths and weaknesses of models and systems.

Synchronization transition of a coupled system composed of neurons with coexisting behaviors near a Hopf bifurcation

NASA Astrophysics Data System (ADS)

Jia, Bing

2014-05-01

The coexistence of a resting condition and period-1 firing near a subcritical Hopf bifurcation point, lying between the monostable resting condition and period-1 firing, is often observed in neurons of the central nervous systems. Near such a bifurcation point in the Morris—Lecar (ML) model, the attraction domain of the resting condition decreases while that of the coexisting period-1 firing increases as the bifurcation parameter value increases. With the increase of the coupling strength, and parameter and initial value dependent synchronization transition processes from non-synchronization to compete synchronization are simulated in two coupled ML neurons with coexisting behaviors: one neuron chosen as the resting condition and the other the coexisting period-1 firing. The complete synchronization is either a resting condition or period-1 firing dependent on the initial values of period-1 firing when the bifurcation parameter value is small or middle and is period-1 firing when the parameter value is large. As the bifurcation parameter value increases, the probability of the initial values of a period-1 firing neuron that lead to complete synchronization of period-1 firing increases, while that leading to complete synchronization of the resting condition decreases. It shows that the attraction domain of a coexisting behavior is larger, the probability of initial values leading to complete synchronization of this behavior is higher. The bifurcations of the coupled system are investigated and discussed. The results reveal the complex dynamics of synchronization behaviors of the coupled system composed of neurons with the coexisting resting condition and period-1 firing, and are helpful to further identify the dynamics of the spatiotemporal behaviors of the central nervous system.

Wildland Fire Forecasting: Predicting Wildfire Behavior, Growth, and Feedbacks on Weather

NASA Astrophysics Data System (ADS)

Coen, J. L.

2005-12-01

Recent developments in wildland fire research models have represented more complex of fire behavior. The cost has been to increase the computational requirements. When operational constraints are included, such as the need to produce such forecasts faster than real time, the challenge becomes a balance of how much complexity (with corresponding gains in realism) and accuracy can be achieved in producing the quantities of interest while meeting the specified operational constraints. Current field tools are calculator or Palm-Pilot based algorithms such as BEHAVE and BEHAVE Plus that produce timely estimates of instantaneous fire spread rates, flame length, and fire intensity at a point using readily estimated inputs of fuel model, terrain slope, and atmospheric wind speed at a point. At the cost of requiring a PC and slower calculation, FARSITE represents two-dimensional fire spread and adds capabilities including a parameterized representation of crown fire ignition, This work describes how a coupled atmosphere-fire model previously used as a research tool has been adapted for production of real-time forecasts of fire growth and its interactions with weather over a domain focusing on Colorado during summer 2004. The coupled atmosphere-wildland fire-environment (CAWFE) model composed of a 3-dimensional atmospheric prediction model that has been two-way coupled with an empirical fire spread model. The models are connected in that atmospheric conditions (and fuel conditions influenced by the atmosphere) affect the rate and direction of fire propagation, which releases sensible and latent heat (i.e. thermal and water vapor fluxes) to the atmosphere that in turn alter the winds and atmospheric structure around the fire. Thus, it can represent time and spatially-varying weather and the fire feedbacks on the atmospheric which are at the heart of sudden changes in fire behavior and examples of extreme fire behavior such as blow ups, which are now not predictable with current tools. Thus, although this work shows that is it possible to perform more detailed simulations in real time, fire behavior forecasting remains a challenging problem. This is due to challenges in weather prediction, particularly at fine spatial and temporal scales considered "nowcasting" (0-6 hrs), uncertainties in fire behavior even with known meteorological conditions, limitations in quantitative datasets on fuel properties such as fuel loading, and verification. This work describes efforts to advance these capabilities with input from remote sensing data on fuel characteristics and dynamic steering and object-based verification with remotely sensed fire perimeters.

Caudate neuronal recording in freely behaving animals following acute and chronic dose response methylphenidate exposure

PubMed Central

Claussen, Catherine M; Dafny, Nachum

2016-01-01

The misuse and abuse of the psychostimulant, methylphenidate (MPD) the drug of choice in the treatment of attention deficit hyperactivity disorder (ADHD) has seen a sharp uprising in recent years among both youth and adults for its cognitive enhancing effects and for recreational purposes. This uprise in illicit use has lead to many questions concerning the long term consequences of MPD exposure. The objective of this study was to record animal behavior concomitantly with the caudate nucleus (CN) neuronal activity following acute and repetitive (chronic) dose response exposure to methylphenidate (MPD). A saline control and three MPD dose (0.6, 2.5, and 10.0 mg/kg) groups were used. Behaviorally, the same MPD dose in some animals following chronic MPD exposure elicited behavioral sensitization and other animals elicited behavioral tolerance. Based on this finding, the CN neuronal population recorded from animals expressing behavioral sensitization were also evaluated separately from CN neurons recorded from animals expressing behavioral tolerance to chronic MPD exposure, respectively. Significant differences in CN neuronal population responses between the behaviorally sensitized and the behaviorally tolerant animals was observed for the 2.5 and 10.0 mg/kg MPD exposed groups. For 2.5 mg/kg MPD, behaviorally sensitized animals responded by decreasing their firing rates while behaviorally tolerant animals showed mainly an increase in their firing rates. The CN neuronal responses recorded from the behaviorally sensitized animals following 10.0 mg/kg MPD responded by increasing their firing rates whereas the CN neuronal recordings from the behaviorally tolerant animals showed that approximately half decreased their firing rates in response to 10.0 mg/kg MPD exposure. The comparison of percentage change in neuronal firing rates showed that the behaviorally tolerant animals trended to exhibit increases in their neuronal firing rates at ED1 following initial MPD exposure and oppositely at ED10 MPD rechallenge. While the behaviorally sensitized animals in general increased in their percentage change of firing rats were observed following acute 10.0 mg/kg MPD and the behaviorally sensitized 10.0 mg/kg MPD animals and a robust increase in neuronal firing rates at ED1 and ED10 rechallenge. These results suggest the need to first individually analyze animal behavioral activity, and than to evaluate the neuronal responses to the drug based on the animals behavioral response to chronic MPD exposure. PMID:26101057

Fire behavior in northern Rocky Mountain forests

Treesearch

J. S. Barrows

1951-01-01

Knowledge of fire behavior is an essential requirement for firefighters. Successful fire control operations depend, first of all, upon the ability of the protection forces to judge where and when fires will start and how they will behave once ignition takes place. Every member of the firefighting team from ranger to smokechaser must be able to make reliable estimates...

BEHAVE: fire behavior prediction and fuel modeling system - BURN subsystem, Part 2

Treesearch

Patricia L. Andrews; Carolyn H. Chase

1989-01-01

This is the third publication describing the BEHAVE system of computer programs for predicting behavior of wildland fires. This publication adds the following predictive capabilities: distance firebrands are lofted ahead of a wind-driven surface fire, probabilities of firebrands igniting spot fires, scorch height of trees, and percentage of tree mortality. The system...

Putting out fire with gasoline: pitfalls in the silvicultural treatment of canopy fuels

Treesearch

Christopher R. Keyes; J. Morgan Varner

2007-01-01

There is little question that forest stand structure is directly related to fire behavior, and that canopy fuel structure may be altered using silvicultural methods to successfully modify forest fire behavior and reduce susceptibility to crown fire initiation and spread. Silvicultural treatments can remediate hazardous stand structures that have developed as a result...

Modeling fuels and fire effects in 3D: Model description and applications

Treesearch

Francois Pimont; Russell Parsons; Eric Rigolot; Francois de Coligny; Jean-Luc Dupuy; Philippe Dreyfus; Rodman R. Linn

2016-01-01

Scientists and managers critically need ways to assess how fuel treatments alter fire behavior, yet few tools currently exist for this purpose.We present a spatially-explicit-fuel-modeling system, FuelManager, which models fuels, vegetation growth, fire behavior (using a physics-based model, FIRETEC), and fire effects. FuelManager's flexible approach facilitates...

Chapter 2: Fire and Fuels Extension: Model description

Treesearch

Sarah J. Beukema; Elizabeth D. Reinhardt; Julee A. Greenough; Donald C. E. Robinson; Werner A. Kurz

2003-01-01

The Fire and Fuels Extension to the Forest Vegetation Simulator is a model that simulates fuel dynamics and potential fire behavior over time, in the context of stand development and management. Existing models are used to represent forest stand development (the Forest Vegetation Simulator, Wykoff and others 1982), fire behavior (Rothermel 1972, Van Wagner 1977, and...

Research efforts on fuels, fuel models, and fire behavior in eastern hardwood forests

Treesearch

Thomas A. Waldrop; Lucy Brudnak; Ross J. Phillips; Patrick H. Brose

2006-01-01

Although fire was historically important to most eastern hardwood systems, its reintroduction by prescribed burning programs has been slow. As a result, less information is available on these systems to fire managers. Recent research and nationwide programs are beginning to produce usable products to predict fuel accumulation and fire behavior. We introduce some of...

Fire fighting aboard ships. Volume 1: Hazard analysis and behavior of combustible materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stavitskiy, M.G.; Kortunov, M.F.; Sidoryuk, V.M.

1983-01-01

The volume zeros in on fire hazards on ships afloat or under construction/repair. It examines fire hazards peculiar to ships carrying particular cargoes, such as dry-cargo ships, tankers, and factory and fishing vessels. This volume examines specific features of fire-fighting equipment, along with the thermal behavior of materials used in shipbuilding.

Potential fire behavior in pine flatwood forests following three different fuel reduction techniques

Treesearch

Patrick Brose; Dale Wade

2002-01-01

A computer modeling study to determine the potential fire behavior in pine flatwood forests following three fuel hazard reduction treatments: herbicide, prescribed fire and thinning was conducted in Florida following the 1998 wildfire season. Prescribed fire provided immediate protection but this protection quickly disappeared as the rough recovered. Thinning had a...

Measuring fire behavior with photography

Treesearch

Hubert B. Clements; Darold E. Ward; Carl W. Adkins

1983-01-01

Photography is practical for recording and measuring some aspects of forest fire behavior if the scale and perspective can be determined. This paper describes a photogrammetric method for measuring flame height and rate of spread for fires on flat terrain. The flames are photographed at known times with a camera in front of the advancing fire. Scale and perspective of...

Spatially explicit measurements of forest structure and fire behavior following restoration treatments in dry forests

Treesearch

Justin Paul Ziegler; Chad Hoffman; Michael Battaglia; William Mell

2017-01-01

Restoration treatments in dry forests of the western US often attempt silvicultural practices to restore the historical characteristics of forest structure and fire behavior. However, it is suggested that a reliance on non-spatial metrics of forest stand structure, along with the use of wildland fire behavior models that lack the ability to handle complex structures,...

Modeling fire behavior on tropical islands with high-resolution weather data

Treesearch

John W. Benoit; Francis M. Fujioka; David R. Weise

2009-01-01

In this study, we consider fire behavior simulation in tropical island scenarios such as Hawaii and Puerto Rico. The development of a system to provide real-time fire behavior prediction in Hawaii is discussed. This involves obtaining fuels and topography information at a fine scale, as well as supplying daily high-resolution weather forecast data for the area of...

Resistance is not futile: The response of hardwoods to fire-caused wounding

Treesearch

Elaine Kennedy Sutherland; Kevin Smith

2000-01-01

Fires wound trees; but not all of them, and not always. Specific fire behavior and differences among tree species and individual trees produce variable patterns of wounding and wound response. Our work focuses on the relationships between fire behavior and tree biology to better understand how hardwood trees resist injury to the lower stem and either survive or succumb...

Exposure to fire setting behavior on YouTube.

PubMed

Thomas, Meara; Mackay, Sherri; Salsbury, Debbie

2012-07-01

This study is a preliminary examination of fire setting behaviors on YouTube. Data are based on a 1 day search of YouTube. Results indicate YouTube is replete with inappropriate models of fire setting. The findings have potential implications for intervention with fire setting youth. Copyright © 2012 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Building Fire Behavior Analyst (FBAN) capability and capacity: Lessons learned From Victoria, Australia's Bushfire Behavior Predictive Services Strategy

Treesearch

K. E. Gibos; A. Slijepcevic; T. Wells; L. Fogarty

2015-01-01

Wildland fire managers must frequently make meaning from chaos in order to protect communities and infrastructure from the negative impacts of fire. Fire management personnel are increasingly turning to science to support their experience-based decision-making processes and to provide clear, confident leadership for communities frequently exposed to risk from wildfire...

Predicting behavior and size of crown fires in the northern Rocky Mountains

Treesearch

Richard C. Rothermel

1991-01-01

Describes methods for approximating behavior and size of a wind-driven crown fire in mountainous terrain. Covers estimation of average rate of spread, energy release from tree crowns and surface fuel, fireline intensity, flame length, and unit area power of the fire and ambient wind. Plume-dominated fires, which may produce unexpectedly fast spread rates even with low...

Mastication and prescribed fire influences on tree mortality and predicted fire behavior in ponderosa pine

Treesearch

Alicia L. Reiner; Nicole M. Vaillant; Scott N. Dailey

2012-01-01

The purpose of this study was to provide land managers with information on potential wildfire behavior and tree mortality associated with mastication and masticated/fire treatments in a plantation. Additionally, the effect of pulling fuels away from tree boles before applying fire treatment was studied in relation to tree mortality. Fuel characteristics and tree...

Utilization of remote sensing techniques for the quantification of fire behavior in two pine stands

Treesearch

Eric V. Mueller; Nicholas Skowronski; Kenneth Clark; Michael Gallagher; Robert Kremens; Jan C. Thomas; Mohamad El Houssami; Alexander Filkov; Rory M. Hadden; William Mell; Albert Simeoni

2017-01-01

Quantification of field-scale fire behavior is necessary to improve the current scientific understanding of wildland fires and to develop and test relevant, physics-based models. In particular, detailed descriptions of individual fires are required, for which the available literature is limited. In this work, two such field-scale experiments, carried out in pine stands...

A tale of two fires: The relative effectiveness of past wildfires in mitigating wildfire behavior and effects

Treesearch

Robert W. Gray; Susan J. Prichard

2015-01-01

The incidence of large, costly landscape-scale fires in western North America is increasing. To combat these fires, researchers and managers have expressed increased interest in investigating the effectiveness of past, stand-replacing wildfires as bottom-up controls on fire spread and severity. Specifically, how effective are past wildfires in mitigating the behavior...

Effects of Mountain Pine Beetle on Fuels and Expected Fire Behavior in Lodgepole Pine Forests, Colorado, USA

PubMed Central

Schoennagel, Tania; Veblen, Thomas T.; Negron, José F.; Smith, Jeremy M.

2012-01-01

In Colorado and southern Wyoming, mountain pine beetle (MPB) has affected over 1.6 million ha of predominantly lodgepole pine forests, raising concerns about effects of MPB-caused mortality on subsequent wildfire risk and behavior. Using empirical data we modeled potential fire behavior across a gradient of wind speeds and moisture scenarios in Green stands compared three stages since MPB attack (Red [1–3 yrs], Grey [4–10 yrs], and Old-MPB [∼30 yrs]). MPB killed 50% of the trees and 70% of the basal area in Red and Grey stages. Across moisture scenarios, canopy fuel moisture was one-third lower in Red and Grey stages compared to the Green stage, making active crown fire possible at lower wind speeds and less extreme moisture conditions. More-open canopies and high loads of large surface fuels due to treefall in Grey and Old-MPB stages significantly increased surface fireline intensities, facilitating active crown fire at lower wind speeds (>30–55 km/hr) across all moisture scenarios. Not accounting for low foliar moistures in Red and Grey stages, and large surface fuels in Grey and Old-MPB stages, underestimates the occurrence of active crown fire. Under extreme burning conditions, minimum wind speeds for active crown fire were 25–35 km/hr lower for Red, Grey and Old-MPB stands compared to Green. However, if transition to crown fire occurs (outside the stand, or within the stand via ladder fuels or wind gusts >65 km/hr), active crown fire would be sustained at similar wind speeds, suggesting observed fire behavior may not be qualitatively different among MPB stages under extreme burning conditions. Overall, the risk (probability) of active crown fire appears elevated in MPB-affected stands, but the predominant fire hazard (crown fire) is similar across MPB stages and is characteristic of lodgepole pine forests where extremely dry, gusty weather conditions are key factors in determining fire behavior. PMID:22272268

Using behavioral science to improve fire escape behaviors in response to a smoke alarm.

PubMed

Thompson, N J; Waterman, M B; Sleet, D A

2004-01-01

Although the likelihood of fire-related death in homes with smoke alarms is about one-half that in homes without alarms, alarm effectiveness is limited by behavior. Only 16% of residents of homes with alarms have developed and practiced plans for escape when the alarm sounds. We reviewed literature to identify behavioral constructs that influence smoke alarm use. We then convened experts in the behavioral aspects of smoke alarms who reviewed the constructs and determined that the appropriate areas for behavioral focus were formulating, practicing, and implementing escape plans should an alarm sound. They subsequently identified important behaviors to be addressed by burn-prevention programs and incorporated the constructs into a behavioral model for use in such programs. Finally, we organized the available literature to support this model and make programmatic recommendations. Many gaps remain in behavioral research to improve fire escape planning and practice. Future research must select the target behavior, apply behavioral theories, and distinguish between initiation and maintenance of behaviors associated with planning, practicing, and implementing home fire escape plans.

A system to evaluate fire impacts from simulated fire behavior in Mediterranean areas of Central Chile.

PubMed

Castillo, Miguel E; Molina, Juan R; Rodríguez Y Silva, Francisco; García-Chevesich, Pablo; Garfias, Roberto

2017-02-01

Wildfires constitute the greatest economic disruption to Mediterranean ecosystems, from a socio-economic and ecological perspective (Molina et al., 2014). This study proposes to classify fire intensity levels based on potential fire behavior in different types of Mediterranean vegetation types, using two geographical scales. The study considered >4 thousand wildfires over a period of 25years, identifying fire behavior on each event, based on simulations using "KITRAL", a model developed in Chile in 1993 and currently used in the entire country. Fire intensity values allowed results to be classified into six fire effects categories (levels), each of them with field indicators linking energy values with damage related to burned vegetation and wildland urban interface zone. These indicators also facilitated a preliminary assessment of wildfire impact on different Mediterranean land uses and, are therefore, a useful tool to prioritize future interventions. Copyright © 2016 Elsevier B.V. All rights reserved.

Winds, Mountains, and Wildland Fire: Improved Understanding of Coupled Atmosphere-Topography-Fire Interactions Through Large-Eddy Simulation

NASA Astrophysics Data System (ADS)

Munoz-Esparza, D.; Sauer, J.; Linn, R.

2015-12-01

Anomalous and unexpected fire behavior in complex terrain continues to result in substantial loss of property and extremely dangerous conditions for firefighting field personnel. We briefly discuss proposed hypotheses of fire interactions with atmospheric flows over complex terrain that can lead to poorly-understood and potentially catastrophic scenarios. Then, our recent results of numerical investigations via large-eddy simulation of coupled atmosphere-topography-fire phenomenology with the Los Alamos National Laboratory, HiGrad-Firetec model are presented as an example of the potential for increased understanding of these complex processes. This investigation focuses on the influence of downslope surface wind enhancement through stably stratified flow over an isolated hill, and the resulting dramatic changes in fire behavior including spread rate, and intensity. Implications with respect to counter-intuitive fire behavior and extreme fire events are discussed. This work demonstrates a tremendous opportunity to immediately create safer and more effective policy for field personnel through improved predictability of atmospheric conditions over complex terrain

The use of fuel breaks in landscape fire management

USGS Publications Warehouse

Agee, James K.; Bahro, Berni; Finney, Mark A.; Omi, Philip N.; Sapsis, David B.; Skinner, Carl N.; Van Wagtendonk, Jan W.; Weatherspoon, C. Phillip

2000-01-01

Shaded fuelbreaks and larger landscape fuel treatments, such as prescribed fire, are receiving renewed interest as forest protection strategies in the western United States. The effectiveness of fuelbreaks remains a subject of debate because of differing fuelbreak objectives, prescriptions for creation and maintenance, and their placement in landscapes with differing fire regimes. A well-designed fuelbreak will alter the behavior of wildland fire entering the fuel-altered zone. Both surface and crown fire behavior may be reduced. Shaded fuelbreaks must be created in the context of the landscape within which they are placed. No absolute standards for fuelbreak width or fuel reduction are possible, although recent proposals for forested fuelbreaks suggest 400 m wide bands where surface fuels are reduced and crown fuels are thinned. Landscape-level treatments such as prescribed fire can use shaded fuelbreaks as anchor points, and extend the zone of altered fire behavior to larger proportions of the landscape. Coupling fuelbreaks with area-wide fuel treatments can reduce the size, intensity, and effects of wildland fires.

Fuel loads and simulated fire behavior in "old-stage" beetle-infested ponderosa pine of the Colorado Plateau

Treesearch

E. Matthew Hansen; Morris C. Johnson; Barbara J. Bentz; James C. Vandygriff; A. Steven Munson

2015-01-01

Recent bark beetle outbreaks in western North America have led to concerns regarding changes in fuel profiles and associated changes in fire behavior. Data are lacking for a range of infestation severities and time since outbreak, especially for relatively arid cover types. We surveyed fuel loads and simulated fire behavior for ponderosa pine stands of the...

Probability model for analyzing fire management alternatives: theory and structure

Treesearch

Frederick W. Bratten

1982-01-01

A theoretical probability model has been developed for analyzing program alternatives in fire management. It includes submodels or modules for predicting probabilities of fire behavior, fire occurrence, fire suppression, effects of fire on land resources, and financial effects of fire. Generalized "fire management situations" are used to represent actual fire...

Forest-fire models

Treesearch

Haiganoush Preisler; Alan Ager

2013-01-01

For applied mathematicians forest fire models refer mainly to a non-linear dynamic system often used to simulate spread of fire. For forest managers forest fire models may pertain to any of the three phases of fire management: prefire planning (fire risk models), fire suppression (fire behavior models), and postfire evaluation (fire effects and economic models). In...

Integrating fire behavior models and geospatial analysis for wildland fire risk assessment and fuel management planning

Treesearch

Alan A. Ager; Nicole M. Vaillant; Mark A. Finney

2011-01-01

Wildland fire risk assessment and fuel management planning on federal lands in the US are complex problems that require state-of-the-art fire behavior modeling and intensive geospatial analyses. Fuel management is a particularly complicated process where the benefits and potential impacts of fuel treatments must be demonstrated in the context of land management goals...

Fire behavior in masticated fuels: a review

Treesearch

Jesse K. Kreye; Nolan W. Brewer; Penelope Morgan; J. Morgan Varner; Alistair M.S. Smith; Chad M. Hoffman; Roger D. Ottmar

2014-01-01

Mastication is an increasingly common fuels treatment that redistributes ‘‘ladder’’ fuels to the forest floor to reduce vertical fuel continuity, crown fire potential, and fireline intensity, but fuel models do not exist for predicting fire behavior in these fuel types. Recent fires burning in masticated fuels have behaved in unexpected and contradictory ways, likely...

Fuels and predicted fire behavior in the southern Appalachian Mountains and fire and fire surrogate treatments

Treesearch

Thomas Waldrop; Ross J. Phillips; Dean A. Simon

2010-01-01

This study tested the success of fuel reduction treatments for mitigating wildfire behavior in an area that has had little previous research on fire, the southern Appalachian Mountains. A secondary objective of treatments was to restore the community to an open woodland condition. Three blocks of four treatments were installed in a mature hardwood forest in western...

Surface fire intensity influences simulated crown fire behavior in lodgepole pine forests with recent mountain pine beetle-caused tree mortality

Treesearch

Chad M. Hoffman; Penelope Morgan; William Mell; Russell Parsons; Eva Strand; Steve Cook

2013-01-01

Recent bark beetle outbreaks have had a significant impact on forests throughout western North America and have generated concerns about interactions and feedbacks between beetle attacks and fire. However, research has been hindered by a lack of experimental studies and the use of fire behavior models incapable of accounting for the heterogeneous fuel complexes. We...

Fuel and fire behavior in high-elevation five-needle pines affected by mountain pine beetle

Treesearch

Michael J. Jenkins

2011-01-01

Bark beetle-caused tree mortality in conifer forests affects the quantity and quality of forest fuels and has long been assumed to increase fire hazard and potential fire behavior. In reality, bark beetles and their effects on fuel accumulation and subsequent fire hazard have only recently been described. We have extensively sampled fuels in three conifer forest types...

Numerical Field Model Simulation of Full Scale Fire Tests in a Closed Spherical/Cylindrical Vessel.

DTIC Science & Technology

1987-12-01

the behavior of an actual fire on board a ship. The computer model will be verified by the experimental data obtained in Fire-l. It is important to... behavior in simulations where convection is important. The upwind differencing scheme takes into account the unsymmetrical phenomenon of convection by using...TANK CELL ON THE NORTH SIDE) FOR A * * PARTICULAR FIRE CELL * * COSUMS (I,J) = THE ARRAY TO STORE THE SIMILIAR VALUE FOR THE FIRE * * CELL TO THE SOUTH

The compensatory interaction between motor unit firing behavior and muscle force during fatigue

PubMed Central

De Luca, Carlo J.; Kline, Joshua C.

2016-01-01

Throughout the literature, different observations of motor unit firing behavior during muscle fatigue have been reported and explained with varieties of conjectures. The disagreement amongst previous studies has resulted, in part, from the limited number of available motor units and from the misleading practice of grouping motor unit data across different subjects, contractions, and force levels. To establish a more clear understanding of motor unit control during fatigue, we investigated the firing behavior of motor units from the vastus lateralis muscle of individual subjects during a fatigue protocol of repeated voluntary constant force isometric contractions. Surface electromyographic decomposition technology provided the firings of 1,890 motor unit firing trains. These data revealed that to sustain the contraction force as the muscle fatigued, the following occurred: 1) motor unit firing rates increased; 2) new motor units were recruited; and 3) motor unit recruitment thresholds decreased. Although the degree of these adaptations was subject specific, the behavior was consistent in all subjects. When we compared our empirical observations with those obtained from simulation, we found that the fatigue-induced changes in motor unit firing behavior can be explained by increasing excitation to the motoneuron pool that compensates for the fatigue-induced decrease in muscle force twitch reported in empirical studies. Yet, the fundamental motor unit control scheme remains invariant throughout the development of fatigue. These findings indicate that the central nervous system regulates motor unit firing behavior by adjusting the operating point of the excitation to the motoneuron pool to sustain the contraction force as the muscle fatigues. PMID:27385798

The compensatory interaction between motor unit firing behavior and muscle force during fatigue.

PubMed

Contessa, Paola; De Luca, Carlo J; Kline, Joshua C

2016-10-01

Throughout the literature, different observations of motor unit firing behavior during muscle fatigue have been reported and explained with varieties of conjectures. The disagreement amongst previous studies has resulted, in part, from the limited number of available motor units and from the misleading practice of grouping motor unit data across different subjects, contractions, and force levels. To establish a more clear understanding of motor unit control during fatigue, we investigated the firing behavior of motor units from the vastus lateralis muscle of individual subjects during a fatigue protocol of repeated voluntary constant force isometric contractions. Surface electromyographic decomposition technology provided the firings of 1,890 motor unit firing trains. These data revealed that to sustain the contraction force as the muscle fatigued, the following occurred: 1) motor unit firing rates increased; 2) new motor units were recruited; and 3) motor unit recruitment thresholds decreased. Although the degree of these adaptations was subject specific, the behavior was consistent in all subjects. When we compared our empirical observations with those obtained from simulation, we found that the fatigue-induced changes in motor unit firing behavior can be explained by increasing excitation to the motoneuron pool that compensates for the fatigue-induced decrease in muscle force twitch reported in empirical studies. Yet, the fundamental motor unit control scheme remains invariant throughout the development of fatigue. These findings indicate that the central nervous system regulates motor unit firing behavior by adjusting the operating point of the excitation to the motoneuron pool to sustain the contraction force as the muscle fatigues. Copyright © 2016 the American Physiological Society.

Developing custom fire behavior fuel models from ecologically complex fuel structures for upper Atlantic Coastal Plain forests.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parresol, Bernard, R.; Scott, Joe, H.; Andreu, Anne

2012-01-01

Currently geospatial fire behavior analyses are performed with an array of fire behavior modeling systems such as FARSITE, FlamMap, and the Large Fire Simulation System. These systems currently require standard or customized surface fire behavior fuel models as inputs that are often assigned through remote sensing information. The ability to handle hundreds or thousands of measured surface fuelbeds representing the fine scale variation in fire behavior on the landscape is constrained in terms of creating compatible custom fire behavior fuel models. In this study, we demonstrate an objective method for taking ecologically complex fuelbeds from inventory observations and converting thosemore » into a set of custom fuel models that can be mapped to the original landscape. We use an original set of 629 fuel inventory plots measured on an 80,000 ha contiguous landscape in the upper Atlantic Coastal Plain of the southeastern United States. From models linking stand conditions to component fuel loads, we impute fuelbeds for over 6000 stands. These imputed fuelbeds were then converted to fire behavior parameters under extreme fuel moisture and wind conditions (97th percentile) using the fuel characteristic classification system (FCCS) to estimate surface fire rate of spread, surface fire flame length, shrub layer reaction intensity (heat load), non-woody layer reaction intensity, woody layer reaction intensity, and litter-lichen-moss layer reaction intensity. We performed hierarchical cluster analysis of the stands based on the values of the fire behavior parameters. The resulting 7 clusters were the basis for the development of 7 custom fire behavior fuel models from the cluster centroids that were calibrated against the FCCS point data for wind and fuel moisture. The latter process resulted in calibration against flame length as it was difficult to obtain a simultaneous calibration against both rate of spread and flame length. The clusters based on FCCS fire behavior parameters represent reasonably identifiable stand conditions, being: (1) pine dominated stands with more litter and down woody debriscomponents than other stands, (2) hardwood and pine stands with no shrubs, (3) hardwood dominated stands with low shrub and high non-woody biomass and high down woody debris, (4) stands with high grass and forb (i.e., non-woody) biomass as well as substantial shrub biomass, (5) stands with both high shrub and litter biomass, (6) pine-mixed hardwood stands with moderate litter biomass and low shrub biomass, and (7) baldcypress-tupelo stands. Models representing these stand clusters generated flame lengths from 0.6 to 2.3 musing a 30 km h{sub 1} wind speed and fireline intensities of 100-1500 kW m{sub 1} that are typical within the range of experience on this landscape. The fuel models ranked 1 < 2 < 7 < 5 < 4 < 3 < 6 in terms of both flame length and fireline intensity. The method allows for ecologically complex data to be utilized in order to create a landscape representative of measured fuel conditions and to create models that interface with geospatial fire models.« less

Chapter 13 - Conventional fire behavior modeling systems are inadequate for predicting fire behavior in bark beetle-impacted forests (Project INT-EM-F-11-03)

Treesearch

Sharon M. Hood; Robert E. Keane; Helen Y. Smith; Joel Egan; Lisa Holsinger

2018-01-01

Understanding the impacts of mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins) on fire behavior is important from both an ecological and land management viewpoint. However, numerous uncertainties exist in the linkages of MPB-caused treemortality to changes in canopy and surface fuels (e.g., fuel loading, arrangement, and availability) and the...

Burning Down the Silos: Integrating new perspectives from the social sciences into human behavior in fire research.

PubMed

Kuligowski, Erica

2017-01-01

The traditional social science disciplines can provide many benefits to the field of human behavior in fire (HBiF). First, the social sciences delve further into insights only marginally examined by HBiF researchers, in turn, expanding the depth of HBiF research. In this paper, I present examples of studies from the fields of social psychology and sociology that would expand HBiF research into non-engineering or "unobservable" aspects of behavior during a fire event. Second, the social sciences can provide insight into new areas of research; in turn, expanding the scope of HBiF research. In this section, I introduce pre- and post-fire studies and explore potential research questions that fall outside of the response period of a fire, the phase upon which most focus is currently placed. Third, the social sciences elucidate the value of research methods available to study human behavior. Qualitative research methods are specifically highlighted. These three benefits will allow HBiF researchers to collect a wider range of data, further develop and expand current behavioral knowledge, and increase the impact of this research for both social and engineering applications. Finally, I end with a discussion on possible ways to better integrate the social sciences within human behavior in fire.

Differential Activation of Fast-Spiking and Regular-Firing Neuron Populations During Movement and Reward in the Dorsal Medial Frontal Cortex

PubMed Central

Insel, Nathan; Barnes, Carol A.

2015-01-01

The medial prefrontal cortex is thought to be important for guiding behavior according to an animal's expectations. Efforts to decode the region have focused not only on the question of what information it computes, but also how distinct circuit components become engaged during behavior. We find that the activity of regular-firing, putative projection neurons contains rich information about behavioral context and firing fields cluster around reward sites, while activity among putative inhibitory and fast-spiking neurons is most associated with movement and accompanying sensory stimulation. These dissociations were observed even between adjacent neurons with apparently reciprocal, inhibitory–excitatory connections. A smaller population of projection neurons with burst-firing patterns did not show clustered firing fields around rewards; these neurons, although heterogeneous, were generally less selective for behavioral context than regular-firing cells. The data suggest a network that tracks an animal's behavioral situation while, at the same time, regulating excitation levels to emphasize high valued positions. In this scenario, the function of fast-spiking inhibitory neurons is to constrain network output relative to incoming sensory flow. This scheme could serve as a bridge between abstract sensorimotor information and single-dimensional codes for value, providing a neural framework to generate expectations from behavioral state. PMID:24700585

Firefighter attitudes, norms, beliefs, barriers, and behaviors toward post-fire decontamination processes in an era of increased cancer risk.

PubMed

Harrison, Tyler R; Muhamad, Jessica Wendorf; Yang, Fan; Morgan, Susan E; Talavera, Ed; Caban-Martinez, Alberto; Kobetz, Erin

2018-04-01

Firefighters are exposed to carcinogens such as volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) during fires and from their personal protective equipment (PPE). Recent research has shown that decontamination processes can reduce contamination on both gear and skin. While firefighter cultures that honor dirty gear are changing, little is known about current attitudes and behaviors toward decontamination in the fire service. Four hundred eighty-five firefighters from four departments completed surveys about their attitudes, beliefs, perceived norms, barriers, and behaviors toward post-fire decontamination processes. Overall, firefighters reported positive attitudes, beliefs, and perceived norms about decontamination, but showering after a fire was the only decontamination process that occurred regularly, with field decontamination, use of cleansing wipes, routine gear cleaning, and other behaviors all occurring less frequently. Firefighters reported time and concerns over wet gear as barriers to decontamination.

Convection and downbursts

Treesearch

Joseph J. Charney; Brian E. Potter

2017-01-01

Convection and downbursts are connected meteorological phenomena with the potential to affect fire behavior and thereby alter the evolution of a wildland fire. Meteorological phenomena related to convection and downbursts are often discussed in the context of fire behavior and smoke. The physical mechanisms that contribute to these phenomena are interrelated, but the...

Effectiveness of mechanical thinning and prescribed burning on fire behavior in Pinus nigra forests in NE Spain.

PubMed

Piqué, Míriam; Domènech, Rut

2018-03-15

Fuel treatments can mitigate present and future impacts of climate change by reducing fire intensity and severity. In recent years, Pinus nigra forests in the Mediterranean basin have been dramatically affected by the new risk of highly intense and extreme fires and its distribution area has been reduced. New tools are necessary for assessing the management of these forests so they can adapt to the challenges to come. Our main goal was to evaluate the effects of different fuel treatments on Mediterranean Pinus nigra forests. We assessed the forest response, in terms of forest structure and fire behavior, to different intensities of low thinning treatments followed by different slash prescriptions (resulting in: light thinning and lop and scatter; light thinning and burn; heavy thinning and lop and scatter; heavy thinning and burn; and, untreated control). Treatments that used fire to decrease the resulting slash were the most effective for reducing active crown fires decreasing the rate of spread and flame length more than 89%. Low thinning had an effect on torching potential, but there was no difference between intensities of thinning. Only an outcoming crown fire could spread actively if it was sustained by a high-enough constant wind speed and enough surface fuel load. Overall, treatments reduce fire intensity and treated areas have a more homogenous fire behavior response than untreated areas. This provides opportunities to extinguish the fire and reduce the probability of trees dying from the fire. It would be helpful to include ecological principles and fire behavior criteria in silvicultural treatment guidelines in order to perform more efficient management techniques in the future. Copyright © 2017 Elsevier B.V. All rights reserved.

Forecasting wildland fire behavior using high-resolution large-eddy simulations

NASA Astrophysics Data System (ADS)

Munoz-Esparza, D.; Kosovic, B.; Jimenez, P. A.; Anderson, A.; DeCastro, A.; Brown, B.

2016-12-01

Wildland fires are responsible for large socio-economic impacts. Fires affect the environment, damage structures, threaten lives, cause health issues, and involve large suppression costs. These impacts can be mitigated via accurate fire spread forecast to inform the incident management team. To this end, the state of Colorado is funding the development of the Colorado Fire Prediction System (CO-FPS). The system is based on the Weather Research and Forecasting (WRF) model enhanced with a fire behavior module (WRF-Fire). Realistic representation of wildland fire behavior requires explicit representation of small scale weather phenomena to properly account for coupled atmosphere-wildfire interactions. Moreover, transport and dispersion of biomass burning emissions from wildfires is controlled by turbulent processes in the atmospheric boundary layer, which are difficult to parameterize and typically lead to large errors when simplified source estimation and injection height methods are used. Therefore, we utilize turbulence-resolving large-eddy simulations at a resolution of 111 m to forecast fire spread and smoke distribution using a coupled atmosphere-wildfire model. This presentation will describe our improvements to the level-set based fire-spread algorithm in WRF-Fire and an evaluation of the operational system using 12 wildfire events that occurred in Colorado in 2016, as well as other historical fires. In addition, the benefits of explicit representation of turbulence for smoke transport and dispersion will be demonstrated.

Forecasting wildland fire behavior using high-resolution large-eddy simulations

NASA Astrophysics Data System (ADS)

Munoz-Esparza, D.; Kosovic, B.; Jimenez, P. A.; Anderson, A.; DeCastro, A.; Brown, B.

2017-12-01

Wildland fires are responsible for large socio-economic impacts. Fires affect the environment, damage structures, threaten lives, cause health issues, and involve large suppression costs. These impacts can be mitigated via accurate fire spread forecast to inform the incident management team. To this end, the state of Colorado is funding the development of the Colorado Fire Prediction System (CO-FPS). The system is based on the Weather Research and Forecasting (WRF) model enhanced with a fire behavior module (WRF-Fire). Realistic representation of wildland fire behavior requires explicit representation of small scale weather phenomena to properly account for coupled atmosphere-wildfire interactions. Moreover, transport and dispersion of biomass burning emissions from wildfires is controlled by turbulent processes in the atmospheric boundary layer, which are difficult to parameterize and typically lead to large errors when simplified source estimation and injection height methods are used. Therefore, we utilize turbulence-resolving large-eddy simulations at a resolution of 111 m to forecast fire spread and smoke distribution using a coupled atmosphere-wildfire model. This presentation will describe our improvements to the level-set based fire-spread algorithm in WRF-Fire and an evaluation of the operational system using 12 wildfire events that occurred in Colorado in 2016, as well as other historical fires. In addition, the benefits of explicit representation of turbulence for smoke transport and dispersion will be demonstrated.

Simulating Fire Disturbance and Plant Mortality Using Antecedent Eco-hydrological Conditions to Inform a Physically Based Combustion Model

NASA Astrophysics Data System (ADS)

Atchley, A. L.; Linn, R.; Middleton, R. S.; Runde, I.; Coon, E.; Michaletz, S. T.

2016-12-01

Wildfire is a complex agent of change that both affects and depends on eco-hydrological systems, thereby constituting a tightly linked system of disturbances and eco-hydrological conditions. For example, structure, build-up, and moisture content of fuel are dependent on eco-hydrological regimes, which impacts fire spread and intensity. Fire behavior, on the other hand, determines the severity and extent of eco-hydrological disturbance, often resulting in a mosaic of untouched, stressed, damaged, or completely destroyed vegetation within the fire perimeter. This in turn drives new eco-hydrological system behavior. The cycles of disturbance and recovery present a complex evolving system with many unknowns especially in the face of climate change that has implications for fire risk, water supply, and forest composition. Physically-based numerical experiments that attempt to capture the complex linkages between eco-hydrological regimes that affect fire behavior and the echo-hydrological response from those fire disturbances help build the understanding required to project how fire disturbance and eco-hydrological conditions coevolve over time. Here we explore the use of FIRETEC—a physically-based 3D combustion model that solves conservation of mass, momentum, energy, and chemical species—to resolve fire spread over complex terrain and fuel structures. Uniquely, we couple a physically-based plant mortality model with FIRETEC and examine the resultant hydrologic impact. In this proof of concept demonstration we spatially distribute fuel structure and moisture content based on the eco-hydrological condition to use as input for FIRETEC. The fire behavior simulation then produces localized burn severity and heat injures which are used as input to a spatially-informed plant mortality model. Ultimately we demonstrate the applicability of physically-based models to explore integrated disturbance and eco-hydrologic response to wildfire behavior and specifically map how fire spread and intensity is affect by the antecedent eco-hydrological condition, which then affects the resulting tree mortality patterns.

Wildfires

MedlinePlus

... motels Expand sub-navigation Hotel fire safety tips Marijuana grow & extraction facilities Nightclubs and other assembly occupancies ... Fire behavior research Fire loss and injury research Benefits of home fire sprinklers Expand sub-navigation Environmental ...

Fire behavior and risk analysis in spacecraft

NASA Technical Reports Server (NTRS)

Friedman, Robert; Sacksteder, Kurt R.

1988-01-01

Practical risk management for present and future spacecraft, including space stations, involves the optimization of residual risks balanced by the spacecraft operational, technological, and economic limitations. Spacecraft fire safety is approached through three strategies, in order of risk: (1) control of fire-causing elements, through exclusion of flammable materials for example; (2) response to incipient fires through detection and alarm; and (3) recovery of normal conditions through extinguishment and cleanup. Present understanding of combustion in low gravity is that, compared to normal gravity behavior, fire hazards may be reduced by the absence of buoyant gas flows yet at the same time increased by ventilation flows and hot particle expulsion. This paper discusses the application of low-gravity combustion knowledge and appropriate aircraft analogies to fire detection, fire fighting, and fire-safety decisions for eventual fire-risk management and optimization in spacecraft.

Information-Seeking and Sharing Behaviors among Fire Service Field Staff Instructors: A Qualitative Study

ERIC Educational Resources Information Center

Ruan, Lian J.

2011-01-01

Fire service field staff instructors seek and share information and use information sources during their instructional work of teaching, training and curriculum development. This study is the first attempt to study their information-seeking and sharing behaviors, which have not previously been investigated empirically. Twenty-five fire service…

A multi-scale conceptual model of fire and disease interactions in North American forests

NASA Astrophysics Data System (ADS)

Varner, J. M.; Kreye, J. K.; Sherriff, R.; Metz, M.

2013-12-01

One aspect of global change with increasing attention is the interactions between irruptive pests and diseases and wildland fire behavior and effects. These pests and diseases affect fire behavior and effects in spatially and temporally complex ways. Models of fire and pathogen interactions have been constructed for individual pests or diseases, but to date, no synthesis of this complexity has been attempted. Here we synthesize North American fire-pathogen interactions into syndromes with similarities in spatial extent and temporal duration. We base our models on fire interactions with three examples: sudden oak death (caused by the pathogen Phytopthora ramorum) and the native tree tanoak (Notholithocarpus densiflorus); mountain pine beetle (Dendroctonus ponderosae) and western Pinus spp.; and hemlock woolly adelgid (Adelges tsugae) on Tsuga spp. We evaluate each across spatial (severity of attack from branch to landscape scale) and temporal scales (from attack to decades after) and link each change to its coincident effects on fuels and potential fire behavior. These syndromes differ in their spatial and temporal severity, differentially affecting windows of increased or decreased community flammability. We evaluate these models with two examples: the recently emergent ambrosia beetle-vectored laurel wilt (caused by the pathogen Raffaelea lauricola) in native members of the Lauraceae and the early 20th century chestnut blight (caused by the pathogen Cryphonectria parasitica) that led to the decline of American chestnut (Castanea dentata). Some changes (e.g., reduced foliar moisture content) have short-term consequences for potential fire behavior while others (functional extirpation) have more complex indirect effects on community flammability. As non-native emergent diseases and pests continue, synthetic models that aid in prediction of fire behavior and effects will enable the research and management community to prioritize mitigation efforts to realized effects.

Brief communication: Reaction to fire by savanna chimpanzees (Pan troglodytes verus) at Fongoli, Senegal: Conceptualization of "fire behavior" and the case for a chimpanzee model.

PubMed

Pruetz, Jill D; LaDuke, Thomas C

2010-04-01

The use and control of fire are uniquely human traits thought to have come about fairly late in the evolution of our lineage, and they are hypothesized to correlate with an increase in intellectual complexity. Given the relatively sophisticated cognitive abilities yet small brain size of living apes compared to humans and even early hominins, observations of wild chimpanzees' reactions to naturally occurring fire can help inform hypotheses about the likely responses of early hominins to fire. We use data on the behavior of savanna chimpanzees (Pan troglodytes verus) at Fongoli, Senegal during two encounters with wildfires to illuminate the similarities between great apes and humans regarding their reaction to fire. Chimpanzees' close relatedness to our lineage makes them phylogenetically relevant to the study of hominid evolution, and the open, hot and dry environment at Fongoli, similar to the savanna mosaic thought to characterize much of hominid evolution, makes these apes ecologically important as a living primate model as well. Chimpanzees at Fongoli calmly monitor wildfires and change their behavior in anticipation of the fire's movement. The ability to conceptualize the "behavior" of fire may be a synapomorphic trait characterizing the human-chimpanzee clade. If the cognitive underpinnings of fire conceptualization are a primitive hominid trait, hypotheses concerning the origins of the control and use of fire may need revision. We argue that our findings exemplify the importance of using living chimpanzees as models for better understanding human evolution despite recently published suggestions to the contrary. (c) 2009 Wiley-Liss, Inc.

Inaja Fire - 1956, Pine Hills Fire - 1967...similar, yet different

Treesearch

Mark J. Schroeder; Bernadine B. Taylor

1968-01-01

Two fires burned in the same area in southern California under nearly similar weather conditions, 11 years apart. Yet the Inaja fire of 1956 was much more disastrous than the Pine Hills fire of 1967. The earlier fire claimed 11 lives, and covered an area five times larger than the 1967 fire. Differences in fuels, topography, fire behavior, fire-control action, and...

An unusual case of random fire-setting behavior associated with lacunar stroke.

PubMed

Bosshart, Herbert; Capek, Sonia

2011-06-15

A case of a 47-year-old man with a sudden onset of a bizarre and random fire-setting behavior is reported. The man, who had been arrested on felony arson charges, complained of difficulties concentrating and of recent memory impairment. Axial T1-weighted magnetic resonance imaging showed a low intensity lacunar lesion in the genu and anterior limb of the left internal capsule. A neuropsychological test battery revealed lower than normal scores for executive functions, attention and memory, consistent with frontal lobe dysfunction. The recent onset of fire-setting behavior and the chronic nature of the lacunar lesion, together with an unremarkable performance on tests measuring executive functions two years prior, suggested a causal relationship between this organic brain lesion and the fire-setting behavior. The present case describes a rare and as yet unreported association between random impulse-driven fire-setting behavior and damage to the left internal capsule and suggests a disconnection of frontal lobe structures as a possible pathogenic mechanism. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

A review of fire interactions and mass fires

Treesearch

Mark A. Finney; Sara S. McAllister

2011-01-01

The character of a wildland fire can change dramatically in the presence of another nearby fire. Understanding and predicting the changes in behavior due to fire-fire interactions cannot only be life-saving to those on the ground, but also be used to better control a prescribed fire to meet objectives. In discontinuous fuel types, such interactions may elicit fire...

FireWorks educational program and its effectiveness

Treesearch

Jane Kapler Smith; Nancy E. McMurray

2004-01-01

FireWorks is an educational program that provides interactive, hands-on activities for studying fire behavior, fire ecology, and human influences on three fire-dependent forest types-ponderosa pine (Pinus ponderosa), interior lodgepolepine (P. contorta var.latifolia), and whitebark pine (P. albicaulis)....

Selection of fire spread model for Russian fire behavior prediction system

Treesearch

Alexandra V. Volokitina; Kevin C. Ryan; Tatiana M. Sofronova; Mark A. Sofronov

2010-01-01

Mathematical modeling of fire behavior prediction is only possible if the models are supplied with an information database that provides spatially explicit input parameters for modeled area. Mathematical models can be of three kinds: 1) physical; 2) empirical; and 3) quasi-empirical (Sullivan, 2009). Physical models (Grishin, 1992) are of academic interest only because...

Intrapsychic dynamics, behavioral manifestations, and related interventions with youthful fire setters.

PubMed

Williams, Dian L; Clements, Paul T

2007-01-01

Fire setting in youth has often been overlooked and misunderstood as a coping skill for expressing rage. The act of deliberate fire setting, if uninterrupted, may continue throughout an individual's lifetime. Forensic examiners, mental health care providers, and criminal justice professionals can help guide referral and treatment through better understanding of behaviors and intrapsychic dynamics.

Nomographs for estimating surface fire behavior characteristics

Treesearch

Joe H. Scott

2007-01-01

A complete set of nomographs for estimating surface fire rate of spread and flame length for the original 13 and new 40 fire behavior fuel models is presented. The nomographs allow calculation of spread rate and flame length for wind in any direction with respect to slope and allow for nonheading spread directions. Basic instructions for use are included.

Invasive grasses change landscape structure and fire behavior in Hawaii

Treesearch

Lisa M. Ellsworth; Creighton M. Litton; Alexander P. Dale; Tomoaki Miura

2014-01-01

How does potential fire behavior differ in grass-invaded non-native forests vs open grasslands? How has land cover changed from 1950–2011 along two grassland/forest ecotones in Hawaii with repeated fires? A study on non-native forest with invasive grass understory and invasive grassland (Megathyrsus maximus) ecosystems on Oahu, Hawaii, USA was...

Use of Video Modeling to Teach Extinguishing of Cooking Related Fires to Individuals with Moderate Intellectual Disabilities

ERIC Educational Resources Information Center

Mechling, Linda C.; Gast, David L.; Gustafson, Melissa R.

2009-01-01

This study evaluated the effectiveness of video modeling to teach fire extinguishing behaviors to three young adults with moderate intellectual disabilities. A multiple probe design across three fire extinguishing behaviors and replicated across three students was used to evaluate the effectiveness of the video-based program. Results indicate that…

Practical tools for assessing potential crown fire behavior and canopy fuel characteristics

Treesearch

Martin E. Alexander; Miguel G. Cruz

2015-01-01

This presentation recapitulates the main points made at a technology and information transfer workshop held in advance of the conference that provided overviews of two software applications, developed by the authors, for use in assessing crown fire behavior and canopy fuel characteristics. These are the Crown Fire Initiation and Spread (CFIS) software system and the...

Establishing Fire Safety Skills Using Behavioral Skills Training

ERIC Educational Resources Information Center

Houvouras, Andrew J., IV; Harvey, Mark T.

2014-01-01

The use of behavioral skills training (BST) to educate 3 adolescent boys on the risks of lighters and fire setting was evaluated using in situ assessment in a school setting. Two participants had a history of fire setting. After training, all participants adhered to established rules: (a) avoid a deactivated lighter, (b) leave the training area,…

Fuel treatment longevity in a Sierra Nevada mixed conifer forest

Treesearch

Scott. L. Stephens; Brandon M. Collins; Gary. Roller

2012-01-01

Understanding the longevity of fuel treatments in terms of their ability to maintain fire behavior and effects within a desired range is an important question. The objective of this study was to determine how fuels, forest structure, and predicted fire behavior changed 7-years after initial treatments. Three different treatments: mechanical only, mechanical plus fire,...

Early fire history near Papineau lake, Ontario

Treesearch

Daniel C. Dey; Richard P. Guyette

1996-01-01

Research that defines the role of fire in upland red oak-pine ecosystems in central Ontario is being conducted by the Great Lakes-St. Lawrence Silviculture program. Site-specific fire histories are being developed that document fire frequency, fire behavior, fire effects on forest regeneration and grwoth, and the influnce of human activites on fire disturbances. This...

Forecasting distribution of numbers of large fires

Treesearch

Haiganoush K. Preisler; Jeff Eidenshink; Stephen Howard; Robert E. Burgan

2015-01-01

Systems to estimate forest fire potential commonly utilize one or more indexes that relate to expected fire behavior; however they indicate neither the chance that a large fire will occur, nor the expected number of large fires. That is, they do not quantify the probabilistic nature of fire danger. In this work we use large fire occurrence information from the...

Electric ants: A cross-disciplinary approach to understanding insect behavior

DOE Office of Scientific and Technical Information (OSTI.GOV)

Slowik, T.J.; Thorvilson, H.G.; Green, B.L.

1996-12-31

The response and attraction of the red imported fire ant, Solenopsis invicta, to electrical equipment was examined using an interdisciplinary approach. Entomologists specializing in fire ant behavior combined expertise with electrical engineers to investigate the economically damaging interaction of fire ants with electrical circuitry. Knowledge from the realms of physics, engineering, and biology were integrated in experimentation to test for a fire ant response to electric fields and magnetic fields associated with electrical equipment. It was determined that fire ants react to electrified conductive material and the alternating-current magnetic fields associated with electricity.

Fire hazards at the urban-wildland interface: What the public expects

NASA Astrophysics Data System (ADS)

Cortner, Hanna J.; Gardner, Philip D.; Taylor, Jonathan G.

1990-01-01

Urban-wildland issues have become among the most contentious and problematic issues for forest managers. Using data drawn from surveys conducted by the authors and others, this article discusses how public knowledge and perceptions of fire policies and fire hazards change over time, the kinds of policy responses homeowners prefer as a way of preventing fire hazards at the urban-wildland interface, and how citizens view their own obligations as participants in interface issues. These data show that public attitudes toward fire have changed significantly over the past two decades and that educating the public about fire and the managers' use of fire can have positive effects on behavior. Yet, modifying the individual's behavior in regard to interface fire risks must also deal with important issues of individual incentives, the distribution of costs, and unanticipated policy impacts.

Fire hazards at the urban-wildland interface: what the public expects

USGS Publications Warehouse

Cortner, Hanna J.; Gardner, Philip D.; Taylor, Jonathan G.

1990-01-01

Urban-wildland issues have become among the most contentious and problematic issues for forest managers. Using data drawn from surveys conducted by the authors and others, this article discusses how public knowledge and perceptions of fire policies and fire hazards change over time, the kinds of policy responses homeowners prefer as a way of preventing fire hazards at the urban-wildland interface, and how citizens view their own obligations as participants in interface issues. These data show that public attitudes toward fire have changed significantly over the past two decades and that educating the public about fire and the managers' use of fire can have positive effects on behavior. Yet, modifying the individual's behavior in regard to interface fire risks must also deal with important issues of individual incentives, the distribution of costs, and unanticipated policy impacts.

Prevalence and correlates of fire-setting in the United States: results from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC).

PubMed

Blanco, Carlos; Alegría, Analucía A; Petry, Nancy M; Grant, Jon E; Simpson, H Blair; Liu, Shang-Min; Grant, Bridget F; Hasin, Deborah S

2010-09-01

To estimate the prevalence, sociodemographic correlates, comorbidity, and rates of mental health service utilization of fire-setters in the general population. A face-to-face survey of more than 43,000 adults aged 18 years and older residing in households was conducted during the 2001-2002 period. Diagnoses of mood, anxiety, substance use disorders, and personality disorders were based on the Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM-IV Version (AUDADIS-IV). The prevalence of lifetime fire-setting in the US population was 1.13 (95% CI, 1.0-1.3). Being male, never married, and US-born and having a yearly income over $70,000 were risk factors for lifetime fire-setting, while being Asian or Hispanic and older than 30 years were protective factors for lifetime fire-setting. The strongest associations with fire-setting were with disorders often associated with deficits in impulse control, such as antisocial personality disorder (ASPD) (odds ratio [OR] = 21.8; CI, 6.6-28.5), drug dependence (OR = 7.6; 95% CI, 5.2-10.9), bipolar disorder (OR = 5.6; 95% CI, 4.0-7.9), and pathological gambling (OR = 4.8; 95% CI, 2.4-9.5). Associations between fire-setting and all antisocial behaviors were positive and significant. A lifetime history of fire-setting, even in the absence of an ASPD diagnosis, was strongly associated with substantial rates of Axis I comorbidity, a history of antisocial behavior, a family history of other antisocial behaviors, decreased functioning, and higher treatment-seeking rates. Our findings suggest that fire-setting may be better understood as a behavioral manifestation of a broader impaired control syndrome and part of the externalizing spectrum. Fire-setting and other antisocial behaviors tend to be strongly associated with each other and increase the risk of lifetime and current psychiatric disorders, even in the absence of a DSM-IV diagnosis of ASPD. © Copyright 2010 Physicians Postgraduate Press, Inc.

A method for mapping fire hazard and risk across multiple scales and its application in fire management

Treesearch

Robert E. Keane; Stacy A. Drury; Eva C. Karau; Paul F. Hessburg; Keith M. Reynolds

2010-01-01

This paper presents modeling methods for mapping fire hazard and fire risk using a research model called FIREHARM (FIRE Hazard and Risk Model) that computes common measures of fire behavior, fire danger, and fire effects to spatially portray fire hazard over space. FIREHARM can compute a measure of risk associated with the distribution of these measures over time using...

The Cooney Ridge Fire Experiment: An early operation to relate pre-, active, and post-fire field and remotely sensed measurements

Treesearch

Andrew T. Hudak; Patrick H. Freeborn; Sarah A. Lewis; Sharon M. Hood; Helen Y. Smith; Colin C. Hardy; Robert J. Kremens; Bret W. Butler; Casey Teske; Robert G. Tissell; Lloyd P. Queen; Bryce L. Nordgren; Benjamin C. Bright; Penelope Morgan; Philip J. Riggan; Lee Macholz; Leigh B. Lentile; James P. Riddering; Edward E. Mathews

2018-01-01

The Cooney Ridge Fire Experiment conducted by fire scientists in 2003 was a burnout operation supported by a fire suppression crew on the active Cooney Ridge wildfire incident. The fire experiment included measurements of pre-fire fuels, active fire behavior, and immediate post-fire effects. Heat flux measurements collected at multiple scales with multiple ground and...

Fire behavior modeling-a decision tool

Treesearch

Jack Cohen; Bill Bradshaw

1986-01-01

The usefulness of an analytical model as a fire management decision tool is determined by the correspondence of its descriptive capability to the specific decision context. Fire managers must determine the usefulness of fire models as a decision tool when applied to varied situations. Because the wildland fire phenomenon is complex, analytical fire spread models will...

Domains of Risk in the Developmental Continuity of Fire Setting

ERIC Educational Resources Information Center

McCarty, Carolyn A.; McMahon, Robert J.

2005-01-01

Juvenile fire setting is a serious, dangerous, and costly behavior. The majority of research examining youth fire setting has been cross-sectional. We sought to examine early risk attributes that could differentiate fire setters from non-fire setters, in addition to examining their association with the developmental continuity of fire-setting…

Fire growth maps for the 1988 Greater Yellowstone Area Fires

Treesearch

Richard C. Rothermel; Roberta A Hartford; Carolyn H. Chase

1994-01-01

Daily fire growth maps display the growth of the 1988 fires in the Greater Yellowstone Area. Information and data sources included daily infrared photography flights, satellite imagery, ground and aerial reconnaissance, command center intelligence, and the personal recollections of fire behavior observers. Fire position was digitized from topographic maps using GRASS...

Little Bear Fire Summary Report

Treesearch

Sarah McCaffrey; Melanie Stidham; Hannah. Brenkert-Smith

2013-01-01

In June 2012, immediately after the Little Bear Fire burned outside Ruidoso, New Mexico, a team of researchers interviewed fire managers, local personnel, and residents to understand perceptions of the event itself, communication, evacuation, and pre-fire preparedness. The intensity of fire behavior and resulting loss of 242 homes made this a complex fire with a...

Fire interest and antisociality as risk factors in the severity and persistence of juvenile firesetting.

PubMed

MacKay, Sherri; Henderson, Joanna; Del Bove, Giannetta; Marton, Peter; Warling, Diane; Root, Carol

2006-09-01

In the DSM-IV-TR, firesetting is included as a criterion for the diagnoses of conduct disorder and pyromania. The link between firesetting and antisocial behavior is well established in the empirical literature. Although theoretical models of firesetting often include fire interest as a putative risk factor, there is little research on the role of fire interest in firesetting or on the construct of pyromania. The present study evaluated a sample of children and adolescents referred to an outpatient specialty program for juvenile firesetters with firesetting as the primary presenting problem. By assessing fire interest and antisocial behavior concurrently, the contribution of fire interest to firesetting after controlling for the role of conduct problems was evaluated. Results revealed that fire interest and antisocial behavior were significantly and positively correlated. Moreover, variations in fire interest added to the prediction of firesetting severity at assessment and firesetting recidivism at 18-month follow-up above and beyond what was predicted by antisociality alone. These findings have implications for an empirically derived taxonomy of pathological firesetting.

Laboratory fire behavior measurements of chaparral crown fire

Treesearch

C. Sanpakit; S. Omodan; D. Weise; M Princevac

2015-01-01

In 2013, there was an estimated 9,900 wildland fires that claimed more than 577,000 acres of land. That same year, about 542 prescribed fires were used to treat 48,554 acres by several agencies in California. Being able to understand fires using laboratory models can better prepare individuals to combat or use fires. Our research focused on chaparral crown fires....

Fire and Smoke Model Evaluation Experiment (FASMEE): Modeling gaps and data needs

Treesearch

Yongqiang Liu; Adam Kochanski; Kirk Baker; Ruddy Mell; Rodman Linn; Ronan Paugam; Jan Mandel; Aime Fournier; Mary Ann Jenkins; Scott Goodrick; Gary Achtemeier; Andrew Hudak; Matthew Dickson; Brian Potter; Craig Clements; Shawn Urbanski; Roger Ottmar; Narasimhan Larkin; Timothy Brown; Nancy French; Susan Prichard; Adam Watts; Derek McNamara

2017-01-01

Fire and smoke models are numerical tools for simulating fire behavior, smoke dynamics, and air quality impacts of wildland fires. Fire models are developed based on the fundamental chemistry and physics of combustion and fire spread or statistical analysis of experimental data (Sullivan 2009). They provide information on fire spread and fuel consumption for safe and...

Response of Bighead Carp and Silver Carp to repeated water gun operation in an enclosed shallow pond

USGS Publications Warehouse

Romine, Jason G.; Jensen, Nathan; Parsley, Michael J.; Gaugush, Robert F.; Severson, Todd J.; Hatton, Tyson W.; Adams, Ryan F.; Gaikowski, Mark P.

2015-01-01

The Bighead Carp Hypophthalmichthys nobilis and Silver Carp H. molitrix are nonnative species that pose a threat to Great Lakes ecosystems should they advance into those areas. Thus, technologies to impede Asian carp movement into the Great Lakes are needed; one potential technology is the seismic water gun. We evaluated the efficacy of a water gun array as a behavioral deterrent to the movement of acoustic-tagged Bighead Carp and Silver Carp in an experimental pond. Behavioral responses were evaluated by using four metrics: (1) fish distance from the water guns (D); (2) spatial area of the fish's utilization distribution (UD); (3) persistence velocity (Vp); and (4) number of times a fish transited the water gun array. For both species, average D increased by 10 m during the firing period relative to the pre-firing period. During the firing period, the spatial area of use within the pond decreased. Carp were located throughout the pond during the pre-firing period but were concentrated in the north end of the pond during the firing period, thus reducing their UDs by roughly 50%. Overall, Vp decreased during the firing period relative to the pre-firing period, as fish movement became more tortuous and confined, suggesting that the firing of the guns elicited a change in carp behavior. The water gun array was partially successful at impeding carp movement, but some fish did transit the array. Bighead Carp moved past the guns a total of 78 times during the pre-firing period and 15 times during the firing period; Silver Carp moved past the guns 96 times during the pre-firing period and 13 times during the firing period. Although the water guns did alter carp behavior, causing the fish to move away from the guns, this method was not 100% effective as a passage deterrent.

A tilting wind tunnel for fire behavior studies

Treesearch

David R. Weise

1994-01-01

The combined effects of wind velocity and slope on wildland fire behavior can be studied in the laboratory using a tilting wind tunnel. The tilting wind tunnel requires a commercially available fan to induce wind and can be positioned to simulate heading and backing fires spreading up and down slope. The tunnel is portable and can be disassembled for transport using a...

Photo guide for estimating fuel loading and fire behavior in mixed-oak forests of the Mid-Atlantic Region

Treesearch

Patrick H. Brose

2009-01-01

A field guide of 45 pairs of photographs depicting ericaceous shrub, leaf litter, and logging slash fuel types of eastern oak forests and observed fire behavior of these fuel types during prescribed burning. The guide contains instructions on how to use the photo guide to choose appropriate fuel models for prescribed fire planning.

A simplified test for adhesive behavior in wood sections exposed to fire

Treesearch

E. L. Schaffer

1968-01-01

A relatively simple test procedure was developed to evaluate the behavior of various adhesives near fire-exposed surfaces in laminated constructions. A number of sections cut from laminated blocks were exposed to fire on one surface. After this exposure, the sections were transversely cut, and the gluelines were examined for separation depth. In addition, the cool...

1st Fire Behavior and Fuels Conference: Fuels Management-How to Measure Success

Treesearch

Patricia L. Andrews

2006-01-01

The 1st Fire Behavior and Fuels Conference: Fuels Management -- How to Measure Success was held in Portland, Oregon, March 28-30, 2006. The International Association of Wildland Fire (IAWF) initiated a conference on this timely topic primarily in response to the needs of the U.S. National Interagency Fuels Coordinating Group (http://www.nifc.gov/).

Investigation of firebrand generation from an experimental fire: Development of a reliable data collection methodology

Treesearch

Jan C. Thomas; Eric V. Mueller; Simon Santamaria; Michael Gallagher; Mohamad El Houssami; Alexander Filkov; Kenneth Clark; Nicholas Skowronski; Rory M. Hadden; William Mell; Albert Simeoni

2017-01-01

An experimental approach has been developed to quantify the characteristics and flux of firebrands during a management-scale wildfire in a pine-dominated ecosystem. By characterizing the local fire behavior and measuring the temporal and spatial variation in firebrand collection, the flux of firebrands has been related to the fire behavior for the first time. This...

Photo Series for Estimating Post-Hurricane Residues and Fire Behavior in Southern Pine

Treesearch

Dale D. Wade; James K. Forbus; James M. Saveland

1993-01-01

Following Hurricane Hugo, fuels were sampled on nine 2-acre blocks which were then burned during the spring wildfire season. The study was superimposed on dormant-season fire-interval research plots established in 1958 on the Francis Marion National Forest near Charleston, SC. Photographs of preburn fuel loads, fire behavior, and postburn fuel loads were taken to...

Evaluating potential changes in fire risk from Eucalyptus plantings in the Southern United States

Treesearch

Scott L. Goodrick; John A. Stanturf

2012-01-01

Renewed interest in short-rotation woody crops for bioenergy and bioproducts has prompted a reevaluation of the Eucalyptus species for the southern United States. One question that arises about the potential effects of introducing a nonnative species is what effect will there be on fire behavior. Our approximate answer based on modeling fire behavior...

Smoke Alarms for People Who Are Deaf or Hard-of-Hearing

MedlinePlus

... motels Expand sub-navigation Hotel fire safety tips Marijuana grow & extraction facilities Nightclubs and other assembly occupancies ... Fire behavior research Fire loss and injury research Benefits of home fire sprinklers Expand sub-navigation Environmental ...

Comparison of crown fire modeling systems used in three fire management applications

Treesearch

Joe H. Scott

2006-01-01

The relative behavior of surface-crown fire spread rate modeling systems used in three fire management applications-CFIS (Crown Fire Initiation and Spread), FlamMap and NEXUS- is compared using fire environment characteristics derived from a dataset of destructively measured canopy fuel and associated stand characteristics. Although the surface-crown modeling systems...

Simulating spatial and temporally related fire weather

Treesearch

Isaac C. Grenfell; Mark Finney; Matt Jolly

2010-01-01

Use of fire behavior models has assumed an increasingly important role for managers of wildfire incidents to make strategic decisions. For fire risk assessments and danger rating at very large spatial scales, these models depend on fire weather variables or fire danger indices. Here, we describe a method to simulate fire weather at a national scale that captures the...

Decision making under uncertainty: Recommendations for the Wildland Fire Decision Support System (WFDSS)

Treesearch

Matthew P. Thompson

2015-01-01

The management of wildfire is a dynamic, complex, and fundamentally uncertain enterprise. Fire managers face uncertainties regarding fire weather and subsequent influence on fire behavior, the effects of fire on socioeconomic and ecological resources, and the efficacy of alternative suppression actions on fire outcomes. In these types of difficult decision environments...

Atmospheric turbulence observations in the vicinity of surface fires in forested environments

Treesearch

Warren E. Heilman; Xindi Bian; Kenneth L. Clark; Nicholas S. Skowronski; John L. Hom; Michael R. Gallagher

2017-01-01

Ambient and fire-induced atmospheric turbulence in the vicinity of wildland fires can affect the behavior of those fires and the dispersion of smoke. The presence of forest overstory vegetation can further complicate the evolution of local turbulence regimes and their interaction with spreading fires and smoke plumes. Previous observational studies of wildland fire...

Decision modeling for analyzing fire action outcomes

Treesearch

Donald MacGregor; Armando Gonzalez-Caban

2008-01-01

A methodology for incident decomposition and reconstruction is developed based on the concept of an "event-frame model." The event-frame model characterizes a fire incident in terms of (a) environmental events that pertain to the fire and the fire context (e.g., fire behavior, weather, fuels) and (b) management events that represent responses to the fire...

Shift in fire-ecosystems and weather changes

Treesearch

Bongani Finiza

2013-01-01

During recent decades too much focus fell on fire suppression and fire engineering methods. Little attention has been given to understanding the shift in the changing fire weather resulting from the global change in weather patterns. Weather change have gradually changed the way vegetation cover respond to fire occurrence and brought about changes in fire behavior and...

Fuels planning: science synthesis and integration; forest structure and fire hazard fact sheet 02: fire hazard

Treesearch

Rocky Mountain Research Station USDA Forest Service

2004-01-01

Fire hazard reflects the potential fire behavior and magnitude of effects as a function of fuel conditions. This fact sheet discusses crown fuels, surface fuels, and ground fuels and their contribution and involvement in wildland fire.Other publications in this series...

The fire environment--innovations, management, and policy; conference proceedings

Treesearch

Bret W. Butler; Wayne Cook

2007-01-01

The International Association of Wildland Fire sponsored the second Fire Behavior and Fuels conference in Destin, Florida. The conference theme was "Fire Environment--Innovations, Management, and Policy." Over 450 attendees participated in presentations on the latest innovations in wildland fire management, examples of successful and maybe not so successful...

Resource allocation for wildland fire suppression planning using a stochastic program

Treesearch

Alex Taylor Masarie

2011-01-01

Resource allocation for wildland fire suppression problems, referred to here as Fire-S problems, have been studied for over a century. Not only have the many variants of the base Fire-S problem made it such a durable one to study, but advances in suppression technology and our ever-expanding knowledge of and experience with wildland fire behavior have required almost...

Effectiveness of Fire and Fire Surrogate Treatments For Controlling Wildfire Behavior in Piedmont Forests: A Simulation Study

Treesearch

Helen H. Mohr; Thomas A. Waldrop; Sandra Rideout; Ross J. Phillips; Charles T. Flint

2004-01-01

The need for fuel reduction has increased in United States forests due to decades of fire exclusion. Excessive fuel buildup has led to uncharacteristically severe fires in areas with historically short-interval, low-to-moderate-intensity fire regimes. The National Fire and Fire Surrogate (NFFS) Study compared the impacts of three fuel-reduction treatments on numerous...

Fire and forest history at Mount Rushmore.

PubMed

Brown, Peter M; Wienk, Cody L; Symstad, Amy J

2008-12-01

Mount Rushmore National Memorial in the Black Hills of South Dakota is known worldwide for its massive sculpture of four of the United States' most respected presidents. The Memorial landscape also is covered by extensive ponderosa pine (Pinus ponderosa) forest that has not burned in over a century. We compiled dendroecological and forest structural data from 29 plots across the 517-ha Memorial and used fire behavior modeling to reconstruct the historical fire regime and forest structure and compare them to current conditions. The historical fire regime is best characterized as one of low-severity surface fires with occasional (> 100 years) patches (< 100 ha) of passive crown fire. We estimate that only approximately 3.3% of the landscape burned as crown fire during 22 landscape fire years (recorded at > or = 25% of plots) between 1529 and 1893. The last landscape fire was in 1893. Mean fire intervals before 1893 varied depending on spatial scale, from 34 years based on scar-to-scar intervals on individual trees to 16 years between landscape fire years. Modal fire intervals were 11-15 years and did not vary with scale. Fire rotation (the time to burn an area the size of the study area) was estimated to be 30 years for surface fire and 800+ years for crown fire. The current forest is denser and contains more small trees, fewer large trees, lower canopy base heights, and greater canopy bulk density than a reconstructed historical (1870) forest. Fire behavior modeling using the NEXUS program suggests that surface fires would have dominated fire behavior in the 1870 forest during both moderate and severe weather conditions, while crown fire would dominate in the current forest especially under severe weather. Changes in the fire regime and forest structure at Mount Rushmore parallel those seen in ponderosa pine forests from the southwestern United States. Shifts from historical to current forest structure and the increased likelihood of crown fire justify the need for forest restoration before a catastrophic wildfire occurs and adversely impacts the ecological and aesthetic setting of the Mount Rushmore sculpture.

Ecological effects of the Hayman Fire - Part 1: Historical (pre-1860) and current (1860-2002) fire regimes

Treesearch

William H. Romme; Thomas T. Veblen; Merrill R. Kaufmann; Rosemary Sherriff; Claudia M. Regan

2003-01-01

To address historical and current fire regimes in the Hayman landscape, we first present the concepts of “historical range of variability” and ”fire regime” to provide the necessary conceptual tools for evaluating fire occurrence, fire behavior, and fire effects. Next we summarize historical (pre-1860) fire frequency and fire effects for the major forest types of the...

The influence of an incomplete fuels treatment on fire behavior and effects in the 2007 Tin Cup Fire, Bitterroot National Forest, Montana

Treesearch

Michael Harrington; Erin Noonan-Wright

2010-01-01

Extensive forested areas have received fuels treatments in recent decades and significant funding is available for additional treatments in an attempt to mitigate undesirable high wildfire intensities and impacts. Fuel treatment successes and failures in moderating fire behavior and effects can be found in quantified and anecdotal reports. Questions remain about the...

Predicting the effect of climate change on wildfire behavior and initial attack success

Treesearch

Jeremy S. Fried; J. Keith Gilless; William J. Riley; Tadashi J. Moody; Clara Simon de Blas; Katharine Hayhoe; Max Mortiz; Scott Stephens; Margaret Torn

2008-01-01

This study focused on how climate change-induced effects on weather will translate into changes in wildland fire severity and outcomes in California, particularly on the effectiveness of initial attack at limiting the number of fires that escape initial attack. The results indicate that subtle shifts in fire behavior of the sort that might be induced by the climate...

Use of models to study forest fire behavior

Treesearch

Wallace L. Fons

1961-01-01

The U.S. Forest Service has started a laboratory study with the ultimate objective of determining model laws for fire behavior. The study includes an examination of the effect of such variables as species of wood, density of wood, moisture content, size of fuel particle, spacing, dimensions of fuel bed, wind, and slope on the rate of spread of fire and the partition of...

Wild Fire Computer Model Helps Firefighters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Canfield, Jesse

2012-09-04

A high-tech computer model called HIGRAD/FIRETEC, the cornerstone of a collaborative effort between U.S. Forest Service Rocky Mountain Research Station and Los Alamos National Laboratory, provides insights that are essential for front-line fire fighters. The science team is looking into levels of bark beetle-induced conditions that lead to drastic changes in fire behavior and how variable or erratic the behavior is likely to be.

Wild Fire Computer Model Helps Firefighters

ScienceCinema

Canfield, Jesse

2018-02-14

A high-tech computer model called HIGRAD/FIRETEC, the cornerstone of a collaborative effort between U.S. Forest Service Rocky Mountain Research Station and Los Alamos National Laboratory, provides insights that are essential for front-line fire fighters. The science team is looking into levels of bark beetle-induced conditions that lead to drastic changes in fire behavior and how variable or erratic the behavior is likely to be.

Strategic Placement of Treatments (SPOTS): Maximizing the Effectiveness of Fuel and Vegetation Treatments on Problem Fire Behavior and Effects

Treesearch

Diane M. Gercke; Susan A. Stewart

2006-01-01

In 2005, eight U.S. Forest Service and Bureau of Land Management interdisciplinary teams participated in a test of strategic placement of treatments (SPOTS) techniques to maximize the effectiveness of fuel treatments in reducing problem fire behavior, adverse fire effects, and suppression costs. This interagency approach to standardizing the assessment of risks and...

Predicting wildfire behavior in black spruce forests in Alaska.

Treesearch

Rodney A. Norum

1982-01-01

The current fire behavior system, when properly adjusted, accurately predicts forward rate of spread and flame length of wildfires in black spruce (Picea mariana (Mill.) B.S.P.) forests in Alaska. After fire behavior was observed and quantified, adjustment factors were calculated and assigned to the selected fuel models to correct the outputs to...

Landslides, forest fires, and earthquakes: examples of self-organized critical behavior

NASA Astrophysics Data System (ADS)

Turcotte, Donald L.; Malamud, Bruce D.

2004-09-01

Per Bak conceived self-organized criticality as an explanation for the behavior of the sandpile model. Subsequently, many cellular automata models were found to exhibit similar behavior. Two examples are the forest-fire and slider-block models. Each of these models can be associated with a serious natural hazard: the sandpile model with landslides, the forest-fire model with actual forest fires, and the slider-block model with earthquakes. We examine the noncumulative frequency-area statistics for each natural hazard, and show that each has a robust power-law (fractal) distribution. We propose an inverse-cascade model as a general explanation for the power-law frequency-area statistics of the three cellular-automata models and their ‘associated’ natural hazards.

Fire behavior of transformer dielectric insulating fluids

DOT National Transportation Integrated Search

1980-01-31

This report presents results for the fire behavior of pure and askarel-contaminated fluids which are candidates for use as railroad transformer dielectric insulating fluids. In the study a hydrocarbon and a dimethyl-siloxane fluid were examined. The ...

An Examination of Extreme Fire Behavior and its Impact on Smoke Injection Altitude using Remote Sensing and Meteorological Data

NASA Astrophysics Data System (ADS)

Peterson, D. A.; Hyer, E. J.; Campbell, J. R.; Fromm, M. D.; Hair, J. W.; Butler, C. F.; Fenn, M. A.

2014-12-01

A variety of regional smoke forecasting applications are currently available to identify air quality, visibility, and societal impacts during large fire events. However, these systems typically assume persistent fire activity, and therefore can have large errors before, during, and after short-term periods of extreme fire behavior. This study employs a wide variety of ground, airborne, and satellite observations, including data collected during a major NASA airborne and field campaign, to examine the conditions required for both extreme spread and pyrocumulonimbus (pyroCb) development. Results highlight the importance of upper-level and nocturnal meteorology, as well as the limitations of traditional fire weather indices. Increasing values of fire radiative power (FRP) at the pixel and sub-pixel level are shown to systematically correspond to higher altitude smoke plumes, and an increased probability of injection above the boundary layer. Lidar data collected during the 2013 Rim Fire, one of the most severe fire events in California's history, show that high FRP observed during extreme spread can facilitate long-distance smoke transport, but fails to loft smoke to the altitude of a large pyroCb. The most extreme fire spread was also observed on days without pyroCb activity or significant regional convection. By incorporating additional fire events across North America, conflicting hypotheses surrounding the primary source of moisture during pyroCb development are examined. The majority of large pyroCbs, and therefore the highest direct injection altitude of smoke particles, is shown to occur with conditions very similar to those that produce dry thunderstorms. The current suite of automated forecasting applications predict only general trends in fire behavior, and specifically do not predict (1) extreme fire spread events and (2) injection of smoke to high altitudes. While (1) and (2) are related, results show that they are not predicted by the same set of conditions and variables. The combination of meteorology from numerical forecast models and satellite observations exhibits great potential for improving regional forecasts of fire behavior and smoke production in automated systems, especially in remote areas where detailed observations are unavailable

Variability of fire behavior, fire effects, and emissions in Scotch pine forests of central Siberia

Treesearch

D. J. McRae; Susan Conard; G. A. Ivanova; A. I. Sukhinin; Steve Baker; Y. N. Samsonov; T. W. Blake; V. A. Ivanov; A. V. Ivanov; T. V. Churkina; WeiMin Hao; K. P. Koutzenogij; Nataly Kovaleva

2006-01-01

As part of the Russian FIRE BEAR (Fire Effects in the Boreal Eurasia Region) Project, replicated 4-ha experimental fires were conducted on a dry Scotch pine (Pinus sylvestris)/lichen (Cladonia sp.)/feathermoss (Pleurozeum schreberi) forest site in central Siberia. Observations from the initial seven surface fires (2000-2001) ignited under a range of burning...

Effectiveness of Prescribed Fire as a Fuel Treatment in Californian Coniferous Forests

Treesearch

Nicole M. Vaillant; JoAnn Fites-Kaufman; Scott L. Stephens

2006-01-01

Effective fire suppression for the past century has altered forest structure and increased fuel loads. Prescribed fire as a fuels treatment can reduce wildfire size and severity. This study investigates how prescribed fire affects fuel loads, forest structure, potential fire behavior, and modeled tree mortality at 80th, 90th, and 97.5th percentile fire weather...

Continental-scale simulation of burn probabilities, flame lengths, and fire size distribution for the United States

Treesearch

Mark A. Finney; Charles W. McHugh; Isaac Grenfell; Karin L. Riley

2010-01-01

Components of a quantitative risk assessment were produced by simulation of burn probabilities and fire behavior variation for 134 fire planning units (FPUs) across the continental U.S. The system uses fire growth simulation of ignitions modeled from relationships between large fire occurrence and the fire danger index Energy Release Component (ERC). Simulations of 10,...

Progression and Behavior of the Canoe Fire in Coast Redwood

Treesearch

Hugh Scanlon

2007-01-01

Lightning caused fires occur in coast redwood forests, but large fires have been rare since the 1930s. Coast redwood (Sequoia sempervirens) is considered fire resistant. In 2003, the Canoe Fire, a lightning fire started in an old-growth redwood stand in Humboldt Redwoods State Park, burned 5,554 hectares (13,774 acres) before it was contained. Fuel...

Wilderness fire science: A state of knowledge review

Treesearch

James K. Agee

2000-01-01

Wilderness fire science has progressed since the last major review of the topic, but it was significantly affected by the large fire events of 1988. Strides have been made in both fire behavior and fire effects, and in the issues of scaling, yet much of the progress has not been specifically tied to wilderness areas or funding. Although the management of fire in...

Space station internal environmental and safety concerns

NASA Technical Reports Server (NTRS)

Cole, Matthew B.

1987-01-01

Space station environmental and safety concerns, especially those involving fires, are discussed. Several types of space station modules and the particular hazards associated with each are briefly surveyed. A brief history of fire detection and suppression aboard spacecraft is given. Microgravity fire behavior, spacecraft fire detector systems, space station fire suppression equipment and procedures, and fire safety in hyperbaric chambers are discussed.

Value and challenges of conducting rapid response research on wildland fires

Treesearch

L. Lentile; P. Morgan; C. Hardy; A. Hudak; R. Means; R. Ottmar; P. Robichaud; E. Kennedy Sutherland; J. Szymoniak; F. Way; J. Fites-Kaufman; S. Lewis; E. Mathews; H. Shovik; K. Ryan

2007-01-01

Rapid Response Research is conducted during and immediately after wildland fires, in coordination with fire management teams, in order to collect information that can best be garnered in situ and in real-time. This information often includes fire behavior and fire effects data, which can be used to generate practical tools such as predictive fire models for managers....

BehavePlus fire modeling system, version 4.0: User's Guide

Treesearch

Patricia L. Andrews; Collin D. Bevins; Robert C. Seli

2005-01-01

The BehavePlus fire modeling system is a program for personal computers that is a collection of mathematical models that describe fire and the fire environment. It is a flexible system that produces tables, graphs, and simple diagrams. It can be used for a multitude of fire management applications including projecting the behavior of an ongoing fire, planning...

Thermocouple Probe Orientation Affects Prescribed Fire Behavior Estimation.

PubMed

Coates, T Adam; Chow, Alex T; Hagan, Donald L; Waldrop, Thomas A; Wang, G Geoff; Bridges, William C; Rogers, Mary-Frances; Dozier, James H

2018-01-01

Understanding the relationship between fire intensity and fuel mass is essential information for scientists and forest managers seeking to manage forests using prescribed fires. Peak burning temperature, duration of heating, and area under the temperature profile are fire behavior metrics obtained from thermocouple-datalogger assemblies used to characterize prescribed burns. Despite their recurrent usage in prescribed burn studies, there is no simple protocol established to guide the orientation of thermocouple installation. Our results from dormant and growing season burns in coastal longleaf pine ( Mill.) forests in South Carolina suggest that thermocouples located horizontally at the litter-soil interface record significantly higher estimates of peak burning temperature, duration of heating, and area under the temperature profile than thermocouples extending 28 cm vertically above the litter-soil interface ( < 0.01). Surprisingly, vertical and horizontal estimates of these measures did not show strong correlation with one another ( ≤ 0.14). The horizontal duration of heating values were greater in growing season burns than in dormant season burns ( < 0.01), but the vertical values did not indicate this difference ( = 0.52). Field measures of fuel mass and depth before and after fire showed promise as significant predictive variables ( ≤ 0.05) for the fire behavior metrics. However, all correlation coefficients were less than or equal to = 0.41. Given these findings, we encourage scientists, researchers, and managers to carefully consider thermocouple orientation when investigating fire behavior metrics, as orientation may affect estimates of fire intensity and the distinction of fire treatment effects, particularly in forests with litter-dominated surface fuels. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Previous fires moderate burn severity of subsequent wildland fires in two large western US wilderness areas

Treesearch

Sean A. Parks; Carol Miller; Cara R. Nelson; Zachary A. Holden

2014-01-01

Wildland fire is an important natural process in many ecosystems. However, fire exclusion has reduced frequency of fire and area burned in many dry forest types, which may affect vegetation structure and composition, and potential fire behavior. In forests of the western U.S., these effects pose a challenge for fire and land managers who seek to restore the ecological...

Short- and long-term effects on fuels, forest structure, and wildfire potential from prescribed fire and resource benefit fire in southwestern forests, USA

Treesearch

Molly E. Hunter; Jose M. Iniguez; Leigh B. Lentile

2011-01-01

Prescribed and resource benefit fires are used to manage fuels in fire-prone landscapes in the Southwest. These practices, however, typically occur under different conditions, potentially leading to differences in fire behavior and effects. The objectives of this study were to investigate the effects of recent prescribed fires, resource benefit fires, and repeated...

Interactions among livestock grazing, vegetation type, and fire behavior in the Murphy Wildland Fire Complex in Idaho and Nevada, July 2007

USGS Publications Warehouse

Launchbaugh, Karen; Brammer, Bob; Brooks, Matthew L.; Bunting, Stephen C.; Clark, Patrick; Davison, Jay; Fleming, Mark; Kay, Ron; Pellant, Mike; Pyke, David A.

2008-01-01

A series of wildland fires were ignited by lightning in sagebrush and grassland communities near the Idaho-Nevada border southwest of Twin Falls, Idaho in July 2007. The fires burned for over two weeks and encompassed more than 650,000 acres. A team of scientists, habitat specialists, and land managers was called together by Tom Dyer, Idaho BLM State Director, to examine initial information from the Murphy Wildland Fire Complex in relation to plant communities and patterns of livestock grazing. Three approaches were used to examine this topic: (1) identify potential for livestock grazing to modify fuel loads and affect fire behavior using fire models applied to various vegetation types, fuel loads, and fire conditions; (2) compare levels of fuel consumed within and among major vegetation types; and (3) examine several observed lines of difference and discontinuity in fuel consumed to determine what factors created these contrasts. The team found that much of the Murphy Wildland Fire Complex burned under extreme fuel and weather conditions that likely overshadowed livestock grazing as a factor influencing fire extent and fuel consumption in many areas where these fires burned. Differences and abrupt contrast lines in the level of fuels consumed were affected mostly by the plant communities that existed on a site before fire. A few abrupt contrasts in burn severity coincided with apparent differences in grazing patterns of livestock, observed as fence-line contrasts. Fire modeling revealed that grazing in grassland vegetation can reduce surface rate of spread and fire-line intensity to a greater extent than in shrubland types. Under extreme fire conditions (low fuel moisture, high temperatures, and gusty winds), grazing applied at moderate utilization levels has limited or negligible effects on fire behavior. However, when weather and fuel-moisture conditions are less extreme, grazing may reduce the rate of spread and intensity of fires allowing for patchy burns with low levels of fuel consumption. The team suggested that targeted grazing to accomplish fuel objectives holds promise but requires detailed planning that includes clearly defined goals for fuel modification and appropriate monitoring to assess effectiveness. It was recommended that a pilot plan be devised to strategically place grazed blocks across a landscape to create fuel-reduction bands capable of influencing fire behavior. Also suggested was the development of a general technical report that highlights information and examples of how livestock grazing influences fire extent, severity, and intensity. Finally, the team encouraged continued research and monitoring of the effects of the Murphy Wildland Fire Complex. Much more can be learned from the effects of this extensive fire complex that may offer insight for future management decisions.

Post-fire vegetation and fuel development influences fire severity patterns in reburns.

PubMed

Coppoletta, Michelle; Merriam, Kyle E; Collins, Brandon M

2016-04-01

In areas where fire regimes and forest structure have been dramatically altered, there is increasing concern that contemporary fires have the potential to set forests on a positive feedback trajectory with successive reburns, one in which extensive stand-replacing fire could promote more stand-replacing fire. Our study utilized an extensive set of field plots established following four fires that occurred between 2000 and 2010 in the northern Sierra Nevada, California, USA that were subsequently reburned in 2012. The information obtained from these field plots allowed for a unique set of analyses investigating the effect of vegetation, fuels, topography, fire weather, and forest management on reburn severity. We also examined the influence of initial fire severity and time since initial fire on influential predictors of reburn severity. Our results suggest that high- to moderate-severity fire in the initial fires led to an increase in standing snags and shrub vegetation, which in combination with severe fire weather promoted high-severity fire effects in the subsequent reburn. Although fire behavior is largely driven by weather, our study demonstrates that post-fire vegetation composition and structure are also important drivers of reburn severity. In the face of changing climatic regimes and increases in extreme fire weather, these results may provide managers with options to create more fire-resilient ecosystems. In areas where frequent high-severity fire is undesirable, management activities such as thinning, prescribed fire, or managed wildland fire can be used to moderate fire behavior not only prior to initial fires, but also before subsequent reburns.

Fire safety

Treesearch

Robert H. White; Mark A. Dietenberger

1999-01-01

Fire safety is an important concern in all types of construction. The high level of national concern for fire safety is reflected in limitations and design requirements in building codes. These code requirements are discussed in the context of fire safety design and evaluation in the initial section of this chapter. Since basic data on fire behavior of wood products...

Linking complex forest fuel structure and fire behavior at fine scales

Treesearch

EL Loudermilk; Joseph O' Brien; RJ Mitchell; JK Hiers; WP Cropper; S Grunwald; J Grego; J Fernandez

2012-01-01

Improved fire management of savannas and open woodlands requires better understanding of the fundamental connection between fuel heterogeneity, variation in fire behaviour and the influence of fire variation on vegetation feedbacks. In this study, we introduce a novel approach to predicting fire behaviour at the submetre scale, including measurements of forest...

Benefits of hindsight: reestablishing fire on the landscape.

Treesearch

Sally Duncan

2001-01-01

Well-intentioned fire suppression efforts during the last 80 to 100 years have altered the structure of low-elevation forests in the interior Northwest. Historically, nondestructive, frequent, low-intensity fires have given way to larger, infrequent, severe, high-intensity fires. Because of altered fire behavior, forests now have increased fuel, and consequently, are...

Fire in southern forest landscapes

Treesearch

John A. Stanturf; Dale D. Wade; Thomas A. Waldrop; Deborah K. Kennard; Gary L. Achtemeier

2002-01-01

Other than land clearing for urban development (Wear and others 1998), no disturbance is more common in southern forests than fire. The pervasive role of fire predates human activity in the South (Komarek 1964, 1974), and humans magnified that role. Repeating patterns of fire behavior lead to recognizable fire regimes, with temporal and spatial dimensions....

Fire behavior modeling to assess net benefits of forest treatments on fire hazard mitigation and bioenergy production in Northeastern California

Treesearch

David J. Ganz; David S. Saah; Klaus Barber; Mark Nechodom

2007-01-01

The fire behavior modeling described here, conducted as part of the Biomass to Energy (B2E) life cycle assessment, is funded by the California Energy Commission to evaluate the potential net benefits associated with treating and utilizing forest biomass. The B2E project facilitates economic, environmental, energy, and effectiveness assessments of the potential public...

Using Earth Observations to Assess the Socioeconomic Impact of Human Decision Making during the Suppression of a Wildland Fire

NASA Astrophysics Data System (ADS)

Miller, V. V.; Kochanski, A.; Mandel, J.; Herr, V.; Schranz, S.

2016-12-01

This presentation will discuss the fire simulation system based on WRF-SFIRE and assimilation of satellite Active Fires detection to estimate the socio-economic impact of Earth observations and fire behavior modeling for the 2011 Las Conchas fire in New Mexico. Multiple scenarios will be developed with the WRF-SFIRE simulation based on value of information (VOI) provided by retired incident commanders, whose decision inputs will steer scenario development and simulation. The scenarios will differ according to the Earth observations available through NASA and then deemed useful to incident commanders. Each scenario will be evaluated in terms of its socio-economic impact as specified by NASA (2012) for its wildland fire program. This presentation is a proposed supplement to NASA grant NNX13AH59G Wildland Fire Behavior and Risk Forecasting, Sher Schranz, PI.

Catching fire? Social interactions, beliefs, and wildfire risk mitigation behaviors

Treesearch

Katherine Dickinson; Hannah Brenkert-Smith; Patricia Champ; Nicholas Flores

2015-01-01

Social interactions are widely recognized as a potential influence on risk-related behaviors. We present a mediation model in which social interactions (classified as formal/informal and generic-fire-specific) are associated with beliefs about wildfire risk and mitigation options, which in turn shape wildfire mitigation behaviors. We test this model using survey data...

Fossils and fire: a study on the effects of fire on paleontological resources at Badlands National Park

Treesearch

Rachel Benton; James Reardon

2006-01-01

National Park Service policies stipulate that each park with vegetation capable of burning will prepare a fire management plan. Badlands National Park completed its fire management plan in 2004. Fossils are a principle resource of the park and the fire sensitivity of fossils is the focus of this study. The surface temperatures of fossil specimens and fire behavior...

Challenges and a checklist for biodiversity conservation in fire-prone forests: perspecitves from the Pacific Northwest of USA and Southeastern Australia

Treesearch

Thomas A. Spies; David B. Lindenmayer; A. Malcolm Gill; Scott L. Stephens; James K. Agee

2012-01-01

Conserving biodiversity in fire-prone forest ecosystems is challenging for several reasons including differing and incomplete conceptual models of fire-related ecological processes, major gaps in ecological and management knowledge, high variability in fire behavior and ecological responses to fires, altered fire regimes as a result of land-use history and climate...

Simulation and thermal imaging of the 2006 Esperanza Wildfire in southern California: application of a coupled weather-wildland fire model

Treesearch

Janice L. Coen; Philip J Riggan

2014-01-01

The 2006 Esperanza Fire in Riverside County, California, was simulated with the Coupled Atmosphere-Wildland Fire Environment (CAWFE) model to examine how dynamic interactions of the atmosphere with large-scale fire spread and energy release may affect observed patterns of fire behavior as mapped using the FireMapper thermal imaging radiometer. CAWFE simulated the...

Fire behavior, fuel treatments, and fire suppression on the Hayman Fire - Part 5: Fire suppression activities

Treesearch

Charles W. McHugh; Paul Gleason

2003-01-01

The purpose of this report is to document the suppression actions taken during the Hayman Fire. The long duration of suppression activities (June 8 through July 18), and multiple incident management teams assigned to the fire, makes this a challenging task. Original records and reports produced independently by the various teams assigned to different portions of the...

Post-fire logging reduces surface woody fuels up to four decades following wildfire

Treesearch

David W. Peterson; Erich Kyle Dodson; Richy J. Harrod

2015-01-01

Severe wildfires create pulses of dead trees that influence future fuel loads, fire behavior, and fire effects as they decay and deposit surface woody fuels. Harvesting fire-killed trees may reduce future surface woody fuels and related fire hazards, but the magnitude and timing of post-fire logging effects on woody fuels have not been fully assessed. To address this...

Inhibitory neurons promote robust critical firing dynamics in networks of integrate-and-fire neurons.

PubMed

Lu, Zhixin; Squires, Shane; Ott, Edward; Girvan, Michelle

2016-12-01

We study the firing dynamics of a discrete-state and discrete-time version of an integrate-and-fire neuronal network model with both excitatory and inhibitory neurons. When the integer-valued state of a neuron exceeds a threshold value, the neuron fires, sends out state-changing signals to its connected neurons, and returns to the resting state. In this model, a continuous phase transition from non-ceaseless firing to ceaseless firing is observed. At criticality, power-law distributions of avalanche size and duration with the previously derived exponents, -3/2 and -2, respectively, are observed. Using a mean-field approach, we show analytically how the critical point depends on model parameters. Our main result is that the combined presence of both inhibitory neurons and integrate-and-fire dynamics greatly enhances the robustness of critical power-law behavior (i.e., there is an increased range of parameters, including both sub- and supercritical values, for which several decades of power-law behavior occurs).

Fire control method and analytical model for large liquid hydrocarbon pool fires

NASA Technical Reports Server (NTRS)

Fenton, D. L.

1986-01-01

The dominate parameter governing the behavior of a liquid hydrocarbon (JP-5) pool fire is wind speed. The most effective method of controlling wind speed in the vicinity of a large circular (10 m dia.) pool fire is a set of concentric screens located outside the perimeter. Because detailed behavior of the pool fire structure within one pool fire diameter is unknown, an analytical model supported by careful experiments is under development. As a first step toward this development, a regional pool fire model was constructed for the no-wind condition consisting of three zones -- liquid fuel, combustion, and plume -- where the predicted variables are mass burning rate and characteristic temperatures of the combustion and plume zones. This zone pool fire model can be modified to incorporate plume bending by wind, radiation absorption by soot particles, and a different ambient air flow entrainment rate. Results from the zone model are given for a pool diameter of 1.3 m and are found to reproduce values in the literature.

BEHAVE: fire behavior prediction and fuel modeling system--FUEL subsystem

Treesearch

Robert E. Burgan; Richard C. Rothermel

1984-01-01

This manual documents the fuel modeling procedures of BEHAVE--a state-of-the-art wildland fire behavior prediction system. Described are procedures for collecting fuel data, using the data with the program, and testing and adjusting the fuel model.

Review of vortices in wildland fire

Treesearch

Jason M. Forthofer; Scott L. Goodrick

2011-01-01

Vortices are almost always present in the wildland fire environment and can sometimes interact with the fire in unpredictable ways, causing extreme fire behavior and safety concerns. In this paper, the current state of knowledge of the interaction of wildland fire and vortices is examined and reviewed. A basic introduction to vorticity is given, and the two common...

Use of prescribed fire to reduce wildfire potential

Treesearch

Robert E. Martin; J. Boone Kauffman

1989-01-01

Fires were a part of our wildlands prehistorically. Prescribed burning reduces fire hazard and potential fire behavior primarily by reducing fuel quantity and continuity. Fuel continuity should be considered on the micro scale within stands, the mid-scale among, and the macro-scale among watersheds or entire forests. Prescribed fire is only one of the tools which can...

A simulation of wildfire behavior in piedmont forests

Treesearch

Helen H. Mohr; Thomas A. Waldrop

2006-01-01

Decades of fire exclusion have increased the need for fuel reduction in U.S. forests. The buildup of excessive fuels has led to uncharacteristically severe fires in areas with historically short-interval, low to moderate intensity fire regimes. The National Fire and Fire Surrogate Study compares the impacts of three fuel reduction treatments on numerous response...

Fire on the mountain: birds and burns in the Rocky Mountains

Treesearch

Natasha B. Kotliar; Victoria A. Saab; Richard L. Hutto

2005-01-01

The diversity of climate and topography across the Rocky Mountains has resulted in a broad spectrum of fire regimes ranging from frequent, low-severity fires to infrequent stand-replacement events. Such variation in fire history contributes to landscape structure and dynamics, and in turn can influence subsequent fire behavior (Allen et al. 2002). In essence,...

Invasive plant species and the Joint Fire Science Program.

Treesearch

Heather E. Erickson; Rachel White

2007-01-01

Invasive nonnative plants may be responsible for serious, long-term ecological impacts, including altering fire behavior and fire regimes. Therefore, knowing how to successfully manage invasive plants and their impacts on natural resources is crucial. We present a summary of research on invasive plants and fire that has been generated through the Joint Fire Science...

Fire Prevention in California's Riverside County Headstart Project: An Evaluation.

ERIC Educational Resources Information Center

Folkman, William S.; Taylor, Jean

Results of evaluation are reported for a safety program devised by Head Start teachers and California Division of Forestry personnel to teach fire prevention education to Head Start children. Chapters describe the place of fire prevention in Head Start and causes of fire starting behavior in children. The Head Start Fire Prevention Kit is also…

Measuring the rate of spread of chaparral prescribed fires in northern California

Treesearch

S. L. Stephens; D. R. Weise; D. L. Fry; R. J. Keiffer; J. Dawson; E. Koo; J. Potts; P. J. Pagni

2008-01-01

Prescribed fire is a common method used to produce desired ecological effects in chaparral by mimicking the natural role of fire. Since prescribed fires are usually conducted in moderate fuel and weather conditions, models that accurately predict fire behavior and effects under these scenarios are important for management. In this study, explosive audio devices and...

FireWorks curriculum featuring ponderosa, lodgepole, and whitebark pine forests

Treesearch

Jane Kapler Smith; Nancy E. McMurray

2000-01-01

FireWorks is an educational program for students in grades 1-10. The program consists of the curriculum in this report and a trunk of laboratory materials, specimens, and reference materials. It provides interactive, hands-on activities for studying fire ecology, fire behavior, and the influences of people on three fire-dependent forest types - Pinus ponderosa...

Massachusetts Public Fire and Safety Education Curriculum Planning Guidebook. Second Version.

ERIC Educational Resources Information Center

Massachusetts Department of Fire Services, Stow.

This updated curriculum planning guidebook is a resource for fire educators throughout the state of Massachusetts. It is designed to be a tool in efforts to: identify fire problems in the community; select appropriate behaviors and lessons to correct the fire problems; design fire education programs; and implement and evaluate the programs. The…

Modeling impacts of fire severity on successional trajectories and future fire behavior in Alaskan boreal forests

Treesearch

Jill F. Johnstone; T. Scott Rupp; Mark Olson; David. Verbyla

2011-01-01

Much of the boreal forest in western North America and Alaska experiences frequent, stand-replacing wildfires. Secondary succession after fire initiates most forest stands and variations in fire characteristics can have strong effects on pathways of succession. Variations in surface fire severity that influence whether regenerating forests are dominated by coniferous...

Economic efficiency and risk character of fire management programs, Northern Rocky Mountains

Treesearch

Thomas J. Mills; Frederick W. Bratten

1988-01-01

Economic efficiency and risk have long been considered during the selection of fire management programs and the design of fire management polices. The risk considerations was largely subjective, however, and efficiency has only recently been calculated for selected portions of the fire management program. The highly stochastic behavior of the fire system and the high...

Enhanced Risk of Wildfire Resulting from the Interactions between Pyro-Cumulus and Mountain Waves: Implications for Fire Research and Management

NASA Astrophysics Data System (ADS)

Kim, Y. J.; Linn, R.; Sauer, J.; Canfield, J.; Costigan, K. R.; Munoz-Esparza, D.

2014-12-01

The Los Alamos National Laboratory is conducting a research project to understand the physical mechanisms behind the Las Conchas Fire that occurred in Santa Fe National Forest near Los Alamos, New Mexico on June 26, 2011. Between 8 pm on June 26 and 3 am on June 27, the fire grew from 8,000 to 43,000 acres, spreading downhill in sparse fuels and lighter winds than were present during the first several hours of the fire. Fire behavior experts and fire management officers expected the fire to reach 9,000 to 12,000 acres by sunrise due to the anticipated burning conditions, but it actually increased 440% in size before 3 am, surprising everyone. One viable hypothesis was suggested for this baffling fire behavior: a partial collapse of the soot-laden pyrocumulus column (pyro-cu) that towered above the fire, causing a sustained density current carrying fire at high speed. Moreover, another mechanism has been suggested recently that could have significantly affected the fire characteristics around mountainous regions, such as Jemez Mountains near Los Alamos: the drastic changes in the speed, direction, and gustiness of the winds due to the development of mountain waves. The present research tests these hypotheses and attempts to decipher the combination of environmental conditions, due to pyro-cu and mountain wave interactions, and fire behavior dynamics associated with this anomalous wildfire event. Preliminary results from WRF (Weather Research and Forecasting model) and HIGRAD (High-GRADient model developed at LANL) simulations suggest that these two mechanisms may need to be taken into account in order to fully understand and prepare for atypical wildfire behavior in regions with complex topography. It is possible that the Las Conchas Fire could have directly affected the nearby Los Alamos National Laboratory if the fire broke out concurrently with both pyro-cu and strong mountain waves along the upstream of the Laboratory. This research also addresses its implications for the management as well as the research of wildfire in that, in order to prepare for potential wildfire, the topography of the surrounding region as well as the region of importance itself should be taken into account.

Prefrontal Cortex HCN1 Channels Enable Intrinsic Persistent Neural Firing and Executive Memory Function

PubMed Central

Thuault, Sébastien J.; Malleret, Gaël; Constantinople, Christine M.; Nicholls, Russell; Chen, Irene; Zhu, Judy; Panteleyev, Andrey; Vronskaya, Svetlana; Nolan, Matthew F.; Bruno, Randy

2013-01-01

In many cortical neurons, HCN1 channels are the major contributors to Ih, the hyperpolarization-activated current, which regulates the intrinsic properties of neurons and shapes their integration of synaptic inputs, paces rhythmic activity, and regulates synaptic plasticity. Here, we examine the physiological role of Ih in deep layer pyramidal neurons in mouse prefrontal cortex (PFC), focusing on persistent activity, a form of sustained firing thought to be important for the behavioral function of the PFC during working memory tasks. We find that HCN1 contributes to the intrinsic persistent firing that is induced by a brief depolarizing current stimulus in the presence of muscarinic agonists. Deletion of HCN1 or acute pharmacological blockade of Ih decreases the fraction of neurons capable of generating persistent firing. The reduction in persistent firing is caused by the membrane hyperpolarization that results from the deletion of HCN1 or Ih blockade, rather than a specific role of the hyperpolarization-activated current in generating persistent activity. In vivo recordings show that deletion of HCN1 has no effect on up states, periods of enhanced synaptic network activity. Parallel behavioral studies demonstrate that HCN1 contributes to the PFC-dependent resolution of proactive interference during working memory. These results thus provide genetic evidence demonstrating the importance of HCN1 to intrinsic persistent firing and the behavioral output of the PFC. The causal role of intrinsic persistent firing in PFC-mediated behavior remains an open question. PMID:23966682

Mann Gulch fire: A race that couldn't be won

Treesearch

Richard C. Rothermel

1993-01-01

Describes the final 20 minutes of a smokejumper fire-fighting crew and the fire that overran 16 men as they were attempting to escape. The foreman and two firefighters escaped. Comparison with the behavior of a crew trapped by a fire in 1985 is described.

Simulating wildfire spread behavior between two NASA Active Fire data timeframes

NASA Astrophysics Data System (ADS)

Adhikari, B.; Hodza, P.; Xu, C.; Minckley, T. A.

2017-12-01

Although NASA's Active Fire dataset is considered valuable in mapping the spatial distribution and extent of wildfires across the world, the data is only available at approximately 12-hour time intervals, creating uncertainties and risks associated with fire spread and behavior between the two Visible Infrared Imaging Radiometer Satellite (VIIRS) data collection timeframes. Our study seeks to close the information gap for the United States by using the latest Active Fire data collected for instance around 0130 hours as an ignition source and critical inputs to a wildfire model by uniquely incorporating forecasted and real-time weather conditions for predicting fire perimeter at the next 12 hour reporting time (i.e. around 1330 hours). The model ingests highly dynamic variables such as fuel moisture, temperature, relative humidity, wind among others, and prompts a Monte Carlo simulation exercise that uses a varying range of possible values for evaluating all possible wildfire behaviors. The Monte Carlo simulation implemented in this model provides a measure of the relative wildfire risk levels at various locations based on the number of times those sites are intersected by simulated fire perimeters. Model calibration is achieved using data at next reporting time (i.e. after 12 hours) to enhance the predictive quality at further time steps. While initial results indicate that the calibrated model can predict the overall geometry and direction of wildland fire spread, the model seems to over-predict the sizes of most fire perimeters possibly due to unaccounted fire suppression activities. Nonetheless, the results of this study show great promise in aiding wildland fire tracking, fighting and risk management.

Development and demonstration of smoke plume, fire emissions, and pre- and postprescribed fire fuel models on North Carolina Coastal Plain forest ecosystems

Treesearch

Robert A. Mickler; Miriam Rorig; Christopher D. Geron; Gary L. Achtemier; Andrew D. Bailey; Candice Krull; David Brownlie

2007-01-01

Wildland fuels have been accumulating in the United States during at least the past half-century due to wildland fire management practices and policies. The additional fuels contribute to intense fire behavior, increase the costs of wildland fire control, and contribute to the degradation of local and regional air quality. The management of prescribed and wildland fire...

Fire Safety in Extraterrestrial Environments

NASA Technical Reports Server (NTRS)

Friedman, Robert

1998-01-01

Despite rigorous fire-safety policies and practices, fire incidents are possible during lunar and Martian missions. Fire behavior and hence preventive and responsive safety actions in the missions are strongly influenced by the low-gravity environments in flight and on the planetary surfaces. This paper reviews the understanding and key issues of fire safety in the missions, stressing flame spread, fire detection, suppression, and combustion performance of propellants produced from Martian resources.

Self-extinguishing behavior of kerosene spray fire in a completely enclosed compartment

NASA Astrophysics Data System (ADS)

Wang, Changjian; Guo, Jin; Yan, Weigang; Lu, Shouxiang

2013-10-01

The self-extinguishing behavior of kerosene spray fire was investigated in a completely enclosed compartment with the size of 3 m × 3 m × 3.4 m. The spray was generated by locating one BETE nozzle at the center of the bottom wall. A series of spray fire videos were obtained by changing BETE nozzle type and injecting pressure. The results show that spray fire undergoes four stages: the growth stage, the quasi-steady stage, the stretch stage and the self-extinguishing stage. Consumption of large quantities of oxygen causes spray fire to first be stretched and then quench. In this process, fire base migrates away from spray region and leads to the emergence of ghosting fire. Ghosting fire promotes the instability of spray fire and large fluctuation of its height, which provides help to its self-extinguishing. With increasing the injecting pressure or the nozzle diameter, the self-extinguishing time decreases. It is found that the self-extinguishing time is approximately in inverse relation with injecting flow rate. Additionally, we also observed the occurrence of two-phase deflagration just after ignition, and it accelerates the spray fire growth and induces a larger fire height than the following quasi-steady spray fire. The deflagration turns stronger with increasing the injecting pressure.

Fuel loads, fire regimes, and post-fire fuel dynamics in Florida Keys pine forests

USGS Publications Warehouse

Sah, J.P.; Ross, M.S.; Snyder, J.R.; Koptur, S.; Cooley, H.C.

2006-01-01

In forests, the effects of different life forms on fire behavior may vary depending on their contributions to total fuel loads. We examined the distribution of fuel components before fire, their effects on fire behavior, and the effects of fire on subsequent fuel recovery in pine forests within the National Key Deer Refuge in the Florida Keys. We conducted a burning experiment in six blocks, within each of which we assigned 1-ha plots to three treatments: control, summer, and winter burn. Owing to logistical constraints, we burned only 11 plots, three in winter and eight in summer, over a 4-year period from 1998 to 2001. We used path analysis to model the effects of fuel type and char height, an indicator of fire intensity, on fuel consumption. Fire intensity increased with surface fuel loads, but was negatively related to the quantity of hardwood shrub fuels, probably because these fuels are associated with a moist microenvironment within hardwood patches, and therefore tend to resist fire. Winter fires were milder than summer fires, and were less effective at inhibiting shrub encroachment. A mixed seasonal approach is suggested for fire management, with burns applied opportunistically under a range of winter and summer conditions, but more frequently than that prevalent in the recent past. ?? IAWF 2006.

Identification of Soldier Behaviors Associated with Search and Target Acquisition (STA)

DTIC Science & Technology

2010-05-01

specifically concentrated on representing Soldier and small unit behavior engaging "non-acquired" targets and "non-standard" entities, such as: muzzle ...Forces Are Targeting (e.g., weapon orientation, bullet impacts) Area Where Fire Coming From (e.g., muzzle Flash) Target Handoff...Surveys Cue Average Sum* Participants Muzzle Flash 7.51 34 Hostile Behaviors 7.35 40 Outgoing Fire 7.22 18 Suspicious Behaviors/Activities 6.91

Prevalence of behaviors related to cigarette‐caused fires: a survey of Ontario smokers

PubMed Central

O'Connor, R J; Bauer, J E; Giovino, G A; Hammond, D; Hyland, A; Fong, G T; Cummings, K M

2007-01-01

Objective To identify the prevalence and correlates of behaviors related to the risk of cigarette‐caused fires. Design and setting Random‐digit‐dialed telephone survey in Ontario, Canada, July–September, 2005. Subjects 596 current cigarette smokers. Outcome measures Prevalence of fire‐risk events and behaviors such as burning clothing or objects in the home, leaving lit cigarettes unattended, dozing while smoking, and smoking in bed and correlates of these behaviors. Respondents were also asked if they ever worry about cigarette‐caused fires. Results One in four smokers admitted to leaving lit cigarettes unattended in the last 30 days, while 15% admitted to smoking while in bed. Leaving lit cigarettes unattended was independent of demographic, socioeconomic or nicotine dependence indicators, but was related to worry about burning other persons with a cigarette (OR 1.72, 95% CI 1.04 to 2.85) and smoking inside the home (OR 2.98, 95% CI 1.66 to 5.35). Persons who were not white (OR 3.97, 95% CI 1.80 to 8.80), aged 18–24 years (OR 3.75, 95% CI 1.41 to 9.96), who had high nicotine dependence (OR 9.13, 95% CI 2.22 to 37.52) and worried about burning objects in their home (OR 2.43, 95% CI 1.31 to 4.52) were more likely to smoke in bed. 10 (1.7%) smokers reported having ever had a fire in their home started by a cigarette. Conclusions Smokers engage in behaviors such as smoking in bed and leaving lit cigarettes unattended that may place them at an increased risk of cigarette‐caused fires. As governments move to regulate cigarette ignition propensity, it is important to establish surveillance for behaviors related to fire risk. PMID:17686933

An examination of fuel particle heating during fire spread

Treesearch

Jack D. Cohen; Mark A. Finney

2010-01-01

Recent high intensity wildfires and our demonstrated inability to control extreme fire behavior suggest a need for alternative approaches for preventing wildfire disasters. Current fire spread models are not sufficiently based on a basic understanding of fire spread processes to provide more effective management alternatives. An experimental and theoretical approach...

Design of structures against fire. Civil engineering/buildings, architecture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anchor, R.D.; Malhotra, H.L.; Purkiss, J.A.

1986-01-01

The book covers structural design criteria, along with background theory on fire protection methods for structures from a variety of materials, including timber, steel, and concrete. Research on the behavior of structural materials in the presence of fire is highlighted, and the need for fire-resistant materials is addressed.

Keeping Haines Real - Or Really Changing Haines?

Treesearch

Brian E. Potter; Dan Borsum; Don Haines

2002-01-01

Most incident command teams can handle low- to moderate-intensity fires with few unanticipated problems. However, high-intensity situations, especially the plume-dominated fires that often develop when winds are low and erratic behavior is unexpected, can create dangerous situations even for well-trained, experienced fire crews (Rothermel 1991). Plume-dominated fires...

Public perspectives on the "wildfire problem."

Treesearch

Antony S. Cheng; Dennis R. Becker

2005-01-01

Just as wildland fire managers must have a working knowledge of fire behavior, they must also understand the social dimensions of wildland fire in order to effectively engage the public.Social scientists are therefore gathering information about public attitudes toward wildland fire and wildfire mitigation. How do people see the "wildfire problem"? What...

Weather, fuels, fire behavior, plumes, and smoke - the nexus of fire meteorology

Treesearch

Scott L. Goodrick; Timothy J. Brown; W. Matt Jolly

2017-01-01

In a pair of review papers, Potter (2012a, 2012b) summarized the significant fire weather research findings over about the past hundred years. Our scientific understanding of wildland fire-atmosphere interactions has evolved: from simple correlations supporting the notion that hot, dry, and windy conditions lead to more intense fires, we have moved towards more...

Fuel moisture influences on fire-altered carbon in masticated fuels: An experimental study

Treesearch

Nolan W. Brewer; Alistair M.S. Smith; Jeffery A. Hatten; Philip E. Higuera; Andrew T. Hudak; Roger D. Ottmar; Wade T. Tinkham

2013-01-01

Biomass burning is a significant contributor to atmospheric carbon emissions but may also provide an avenue in which fire-affected ecosystems can accumulate carbon over time, through the generation of highly resistant fire-altered carbon. Identifying how fuel moisture, and subsequent changes in the fire behavior, relates to the production of fire-altered carbon is...

The Fire and Fuels Extension to the Forest Vegetation Simulator

Treesearch

Elizabeth Reinhardt; Nicholas L. Crookston

2003-01-01

The Fire and Fuels Extension (FFE) to the Forest Vegetation Simulator (FVS) simulates fuel dynamics and potential fire behaviour over time, in the context of stand development and management. Existing models of fire behavior and fire effects were added to FVS to form this extension. New submodels representing snag and fuel dynamics were created to complete the linkages...

Historical and cultural fires, tribal management and research issue in Northern California: Trails, fires and tribulations

Treesearch

Frank K. Lake

2013-01-01

Indigenous people’s detailed traditional knowledge about fire, although superficially referenced in various writings, has not for the most part been analyzed in detail or simulated by resource managers, wildlife biologists, and ecologists. . . . Instead, scientists have developed the principles and theories of fire ecology, fire behavior and effects models, and...

High-severity fire: Evaluating its key drivers and mapping its probability across western US forests

Treesearch

Sean A. Parks; Lisa M. Holsinger; Matthew H. Panunto; W. Matt Jolly; Solomon Z. Dobrowski; Gregory K. Dillon

2018-01-01

Wildland fire is a critical process in forests of the western United States (US). Variation in fire behavior, which is heavily influenced by fuel loading, terrain, weather, and vegetation type, leads to heterogeneity in fire severity across landscapes. The relative influence of these factors in driving fire severity, however, is poorly understood. Here, we explore the...

An assessment of climate and fire danger rating in the Northern Rockies during the 1910 fire season

Treesearch

Charles W. McHugh; Mark A. Finney; Larry S. Bradshaw

2010-01-01

The 1910 fires of western Montana and northern Idaho have received much publicity in the popular media but little scientific attention regarding the factors that contribute to fire behavior and fire danger. Here we present information surrounding the weather, and reconstructed measures of Palmer Drought Severity Index (PDSI), Keetch-Byram Drought Index (KBDI), Energy...

Predicted fire behavior and societal benefits in three eastern Sierra Nevada vegetation types

Treesearch

C.A. Dicus; K. Delfino; D.R. Weise

2009-01-01

We investigated potential fire behavior and various societal benefits (air pollution removal, carbon sequestration, and carbon storage) provided by woodlands of pinyon pine (Pinus monophylla) and juniper (Juniperus californica), shrublands of Great Basin sagebrush (Artemisia tridentata) and rabbitbrush (Ericameria nauseosa...

Pyrokinin β-neuropeptide affects necrophoretic behavior in fire ants (S. invicta), and expression of β-NP in a mycoinsecticide increases its virulence.

PubMed

Fan, Yanhua; Pereira, Roberto M; Kilic, Engin; Casella, George; Keyhani, Nemat O

2012-01-01

Fire ants are one of the world's most damaging invasive pests, with few means for their effective control. Although ecologically friendly alternatives to chemical pesticides such as the insecticidal fungus Beauveria bassiana have been suggested for the control of fire ant populations, their use has been limited due to the low virulence of the fungus and the length of time it takes to kill its target. We present a means of increasing the virulence of the fungal agent by expressing a fire ant neuropeptide. Expression of the fire ant (Solenopsis invicta) pyrokinin β-neuropeptide (β-NP) by B. bassiana increased fungal virulence six-fold towards fire ants, decreased the LT(50), but did not affect virulence towards the lepidopteran, Galleria mellonella. Intriguingly, ants killed by the β-NP expressing fungus were disrupted in the removal of dead colony members, i.e. necrophoretic behavior. Furthermore, synthetic C-terminal amidated β-NP but not the non-amidated peptide had a dramatic effect on necrophoretic behavior. These data link chemical sensing of a specific peptide to a complex social behavior. Our results also confirm a new approach to insect control in which expression of host molecules in an insect pathogen can by exploited for target specific augmentation of virulence. The minimization of the development of potential insect resistance by our approach is discussed.

Pyrokinin β-Neuropeptide Affects Necrophoretic Behavior in Fire Ants (S. invicta), and Expression of β-NP in a Mycoinsecticide Increases Its Virulence

PubMed Central

Fan, Yanhua; Pereira, Roberto M.; Kilic, Engin; Casella, George; Keyhani, Nemat O.

2012-01-01

Fire ants are one of the world's most damaging invasive pests, with few means for their effective control. Although ecologically friendly alternatives to chemical pesticides such as the insecticidal fungus Beauveria bassiana have been suggested for the control of fire ant populations, their use has been limited due to the low virulence of the fungus and the length of time it takes to kill its target. We present a means of increasing the virulence of the fungal agent by expressing a fire ant neuropeptide. Expression of the fire ant (Solenopsis invicta) pyrokinin β -neuropeptide (β-NP) by B. bassiana increased fungal virulence six-fold towards fire ants, decreased the LT50, but did not affect virulence towards the lepidopteran, Galleria mellonella. Intriguingly, ants killed by the β-NP expressing fungus were disrupted in the removal of dead colony members, i.e. necrophoretic behavior. Furthermore, synthetic C-terminal amidated β-NP but not the non-amidated peptide had a dramatic effect on necrophoretic behavior. These data link chemical sensing of a specific peptide to a complex social behavior. Our results also confirm a new approach to insect control in which expression of host molecules in an insect pathogen can by exploited for target specific augmentation of virulence. The minimization of the development of potential insect resistance by our approach is discussed. PMID:22238569

Fuel buildup and potential fire behavior after stand-replacing fires, logging fire-killed trees and herbicide shrub removal in Sierra Nevada forests

USGS Publications Warehouse

McGinnis, Thomas W.; Keeley, Jon E.; Stephens, Scott L.; Roller, Gary B.

2010-01-01

Typically, after large stand-replacing fires in mid-elevation Sierra Nevada forests, dense shrub fields occupy sites formerly occupied by mature conifers, until eventually conifers overtop and shade out shrubs. Attempting to reduce fuel loads and expedite forest regeneration in these areas, the USDA Forest Service often disrupts this cycle by the logging of fire-killed trees, replanting of conifers and killing of shrubs. We measured the effects of these treatments on live and dead fuel loads and alien species and modeled potential fire behavior and fire effects on regenerating forests. Sampling occurred in untreated, logged and herbicide-treated stands throughout the Sierra Nevada in four large fire areas 4–21 years after stand-replacing fires. Logging fire-killed trees significantly increased total available dead fuel loads in the short term but did not affect shrub cover, grass and forb cover, alien species cover or alien species richness. Despite the greater available dead fuel loads, fire behavior was not modeled to be different between logged and untreated stands, due to abundant shrub fuels in both logged and untreated stands. In contrast, the herbicide treatment directed at shrubs resulted in extremely low shrub cover, significantly greater alien species richness and significantly greater alien grass and forb cover. Grass and forb cover was strongly correlated with solar radiation on the ground, which may be the primary reason that grass and forb cover was higher in herbicide treated stands with low shrub and tree cover. Repeat burning exacerbated the alien grass problem in some stands. Although modeled surface fire flame lengths and rates of spread were found to be greater in stands dominated by shrubs, compared to low shrub cover conifer plantations, surface fire would still be intense enough to kill most trees, given their small size and low crown heights in the first two decades after planting.

Effects of mountain pine beetle on fuels and expected fire behavior in lodgepole pine forests, Colorado, USA

Treesearch

Tania Schoennagel; Thomas T. Veblen; Jose F. Negron; Jeremy M. Smith

2012-01-01

In Colorado and southern Wyoming, mountain pine beetle (MPB) has affected over 1.6 million ha of predominantly lodgepole pine forests, raising concerns about effects of MPB-caused mortality on subsequent wildfire risk and behavior. Using empirical data we modeled potential fire behavior across a gradient of wind speeds and moisture scenarios in Green stands compared...

Long-term trends in fire behavior and changes in population at risk

EPA Science Inventory

Long-term trends in fire behavior and changes in population at risk Rappold AG, Peterson GC, US EPA Matt Jolly, USFS Air pollution regulations and technological advances have successfully reduced emissions of air pollutants from many anthropogenic sources in recent decades. Duri...

Self-organization, the cascade model, and natural hazards.

PubMed

Turcotte, Donald L; Malamud, Bruce D; Guzzetti, Fausto; Reichenbach, Paola

2002-02-19

We consider the frequency-size statistics of two natural hazards, forest fires and landslides. Both appear to satisfy power-law (fractal) distributions to a good approximation under a wide variety of conditions. Two simple cellular-automata models have been proposed as analogs for this observed behavior, the forest fire model for forest fires and the sand pile model for landslides. The behavior of these models can be understood in terms of a self-similar inverse cascade. For the forest fire model the cascade consists of the coalescence of clusters of trees; for the sand pile model the cascade consists of the coalescence of metastable regions.

Self-organization, the cascade model, and natural hazards

PubMed Central

Turcotte, Donald L.; Malamud, Bruce D.; Guzzetti, Fausto; Reichenbach, Paola

2002-01-01

We consider the frequency-size statistics of two natural hazards, forest fires and landslides. Both appear to satisfy power-law (fractal) distributions to a good approximation under a wide variety of conditions. Two simple cellular-automata models have been proposed as analogs for this observed behavior, the forest fire model for forest fires and the sand pile model for landslides. The behavior of these models can be understood in terms of a self-similar inverse cascade. For the forest fire model the cascade consists of the coalescence of clusters of trees; for the sand pile model the cascade consists of the coalescence of metastable regions. PMID:11875206

A generalized linear integrate-and-fire neural model produces diverse spiking behaviors.

PubMed

Mihalaş, Stefan; Niebur, Ernst

2009-03-01

For simulations of neural networks, there is a trade-off between the size of the network that can be simulated and the complexity of the model used for individual neurons. In this study, we describe a generalization of the leaky integrate-and-fire model that produces a wide variety of spiking behaviors while still being analytically solvable between firings. For different parameter values, the model produces spiking or bursting, tonic, phasic or adapting responses, depolarizing or hyperpolarizing after potentials and so forth. The model consists of a diagonalizable set of linear differential equations describing the time evolution of membrane potential, a variable threshold, and an arbitrary number of firing-induced currents. Each of these variables is modified by an update rule when the potential reaches threshold. The variables used are intuitive and have biological significance. The model's rich behavior does not come from the differential equations, which are linear, but rather from complex update rules. This single-neuron model can be implemented using algorithms similar to the standard integrate-and-fire model. It is a natural match with event-driven algorithms for which the firing times are obtained as a solution of a polynomial equation.

A Generalized Linear Integrate-and-Fire Neural Model Produces Diverse Spiking Behaviors

PubMed Central

Mihalaş, Ştefan; Niebur, Ernst

2010-01-01

For simulations of neural networks, there is a trade-off between the size of the network that can be simulated and the complexity of the model used for individual neurons. In this study, we describe a generalization of the leaky integrate-and-fire model that produces a wide variety of spiking behaviors while still being analytically solvable between firings. For different parameter values, the model produces spiking or bursting, tonic, phasic or adapting responses, depolarizing or hyperpolarizing after potentials and so forth. The model consists of a diagonalizable set of linear differential equations describing the time evolution of membrane potential, a variable threshold, and an arbitrary number of firing-induced currents. Each of these variables is modified by an update rule when the potential reaches threshold. The variables used are intuitive and have biological significance. The model’s rich behavior does not come from the differential equations, which are linear, but rather from complex update rules. This single-neuron model can be implemented using algorithms similar to the standard integrate-and-fire model. It is a natural match with event-driven algorithms for which the firing times are obtained as a solution of a polynomial equation. PMID:18928368

Historical, observed, and modeled wildfire severity in montane forests of the Colorado Front Range.

PubMed

Sherriff, Rosemary L; Platt, Rutherford V; Veblen, Thomas T; Schoennagel, Tania L; Gartner, Meredith H

2014-01-01

Large recent fires in the western U.S. have contributed to a perception that fire exclusion has caused an unprecedented occurrence of uncharacteristically severe fires, particularly in lower elevation dry pine forests. In the absence of long-term fire severity records, it is unknown how short-term trends compare to fire severity prior to 20th century fire exclusion. This study compares historical (i.e. pre-1920) fire severity with observed modern fire severity and modeled potential fire behavior across 564,413 ha of montane forests of the Colorado Front Range. We used forest structure and tree-ring fire history to characterize fire severity at 232 sites and then modeled historical fire-severity across the entire study area using biophysical variables. Eighteen (7.8%) sites were characterized by low-severity fires and 214 (92.2%) by mixed-severity fires (i.e. including moderate- or high-severity fires). Difference in area of historical versus observed low-severity fire within nine recent (post-1999) large fire perimeters was greatest in lower montane forests. Only 16% of the study area recorded a shift from historical low severity to a higher potential for crown fire today. An historical fire regime of more frequent and low-severity fires at low elevations (<2260 m) supports a convergence of management goals of ecological restoration and fire hazard mitigation in those habitats. In contrast, at higher elevations mixed-severity fires were predominant historically and continue to be so today. Thinning treatments at higher elevations of the montane zone will not return the fire regime to an historic low-severity regime, and are of questionable effectiveness in preventing severe wildfires. Based on present-day fuels, predicted fire behavior under extreme fire weather continues to indicate a mixed-severity fire regime throughout most of the montane forest zone. Recent large wildfires in the Front Range are not fundamentally different from similar events that occurred historically under extreme weather conditions.

Historical, Observed, and Modeled Wildfire Severity in Montane Forests of the Colorado Front Range

PubMed Central

Sherriff, Rosemary L.; Platt, Rutherford V.; Veblen, Thomas T.; Schoennagel, Tania L.; Gartner, Meredith H.

2014-01-01

Large recent fires in the western U.S. have contributed to a perception that fire exclusion has caused an unprecedented occurrence of uncharacteristically severe fires, particularly in lower elevation dry pine forests. In the absence of long-term fire severity records, it is unknown how short-term trends compare to fire severity prior to 20th century fire exclusion. This study compares historical (i.e. pre-1920) fire severity with observed modern fire severity and modeled potential fire behavior across 564,413 ha of montane forests of the Colorado Front Range. We used forest structure and tree-ring fire history to characterize fire severity at 232 sites and then modeled historical fire-severity across the entire study area using biophysical variables. Eighteen (7.8%) sites were characterized by low-severity fires and 214 (92.2%) by mixed-severity fires (i.e. including moderate- or high-severity fires). Difference in area of historical versus observed low-severity fire within nine recent (post-1999) large fire perimeters was greatest in lower montane forests. Only 16% of the study area recorded a shift from historical low severity to a higher potential for crown fire today. An historical fire regime of more frequent and low-severity fires at low elevations (<2260 m) supports a convergence of management goals of ecological restoration and fire hazard mitigation in those habitats. In contrast, at higher elevations mixed-severity fires were predominant historically and continue to be so today. Thinning treatments at higher elevations of the montane zone will not return the fire regime to an historic low-severity regime, and are of questionable effectiveness in preventing severe wildfires. Based on present-day fuels, predicted fire behavior under extreme fire weather continues to indicate a mixed-severity fire regime throughout most of the montane forest zone. Recent large wildfires in the Front Range are not fundamentally different from similar events that occurred historically under extreme weather conditions. PMID:25251103

Co-firing switchgrass in a 50 MW pulverized coal boiler

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ragland, K.W.; Aerts, D.J.; Weiss, C.

1996-12-31

Switchgrass is being co-fired with pulverized coal in a 50 MW wall-fired, radiant boiler at MG&E`s Blount Street generating station. Shredded switchgrass is fed to a hammermill onto a live bottom storage bunker. Twin screw augers move the switchgrass onto a belt conveyor which leads to a rotary air lock valve and through a pressurized pipe to the boiler where it is injected into the furnace at two points between first and second level coal burners. The main objective of the project is to evaluate the boiler performance, slagging behavior, and emissions of the co-fired switchgrass at replacement of ratesmore » of up to 20% by mass (13% by heat input). Initial co-firing tests to examine fuel handling and feeding, combustion behavior, boiler response and emissions are favorable. In November a 100 hour co-fire test is planned.« less

A GIS-based framework for evaluating investments in fire management: Spatial allocation of recreation values

Treesearch

Kenneth A. Baerenklau; Armando González-Cabán; Catrina I. Páez; Edgard Chávez

2009-01-01

The U.S. Forest Service is responsible for developing tools to facilitate effective and efficient fire management on wildlands and urban-wildland interfaces. Existing GIS-based fire modeling software only permits estimation of the costs of fire prevention and mitigation efforts as well as the effects of those efforts on fire behavior. This research demonstrates how the...

Estimating fuel consumption during prescribed fires in Arkansas

Treesearch

Virginia L. McDaniel; James M. Guldin; Roger W. Perry

2012-01-01

While prescribed fire is essential to maintaining numerous plant communities, fine particles produced in smoke can impair human health and reduce visibility in scenic areas. The Arkansas Smoke Management Program was established to mitigate the impacts of smoke from prescribed fires. This program uses fuel loading and consumption estimates from standard fire-behavior...

Behavioral and cognitive evaluation of FireWorks education trunk

Treesearch

Linda R. Thomas; James A. Walsh; Jane Kapler Smith

2000-01-01

This study assessed the effectiveness of FireWorks, an educational trunk about wildland fire, in increasing student understanding, enabling students to apply classroom learning in a field setting, and improving the learning environment. Students who were in classrooms using the FireWorks educational trunk demonstrated more knowledge in both classroom and field-based...

How to predict the spread and intensity of forest and range fires

Treesearch

Richard C. Rothermel

1983-01-01

This manual documents procedures for estimating the rate of forward spread, intensity, flame length, and size of fires burning in forests and rangelands. Contains instructions for obtaining fuel and weather data, calculating fire behavior, and interpreting the results for application to actual fire problems. This is a companion publication to "

Understanding the long-term fire risks in forests affected by sudden oak death

Treesearch

Yana Valachovic; Chris Lee; Radoslaw Glebocki; Hugh Scanlon; J. Morgan Varner; David Rizzo

2010-01-01

It is assumed that large numbers of dead and down tanoak in forests infested by Phytophthora ramorum contribute to increased fire hazard risk and fuel loading. We studied the impact of P. ramorum infestation on surface fuel loading, potential fire hazard, and potential fire behavior in Douglas-fir- (Pseudotsuga...

Retrospective fire modeling: Quantifying the impacts of fire suppression

Treesearch

Brett H. Davis; Carol Miller; Sean A. Parks

2010-01-01

Land management agencies need to understand and monitor the consequences of their fire suppression decisions. We developed a framework for retrospective fire behavior modeling and impact assessment to determine where ignitions would have spread had they not been suppressed and to assess the cumulative effects that would have resulted. This document is a general...

Developing the U.S. Wildland Fire Decision Support System

Treesearch

Erin Noonan-Wright; Tonja S. Opperman; Mark A. Finney; Tom Zimmerman; Robert C. Seli; Lisa M. Elenz; David E. Calkin; John R. Fiedler

2011-01-01

A new decision support tool, the Wildland Fire Decision Support System (WFDSS) has been developed to support risk-informed decision-making for individual fires in the United States. WFDSS accesses national weather data and forecasts, fire behavior prediction, economic assessment, smoke management assessment, and landscape databases to efficiently formulate and apply...

Frequency and season of prescribed fire affect understory plant communities in longleaf pine stands

Treesearch

James D. Haywood

2012-01-01

Prescribed fire research on the Kisatchie National Forest in Louisiana spanned the last 7 decades and led to a greater understanding of fire behavior and the importance of fire in longleaf pine (Pinus palustris Mill.) stands. Early research focused on management of the bluestem (Andropogon spp. and Schizachyrium...

Reformulation of Rothermel's wildland fire behaviour model for heterogeneous fuelbeds.

Treesearch

David V. Sandberg; Cynthia L. Riccardi; Mark D. Schaaf

2007-01-01

Abstract: The Fuel Characteristic Classification System (FCCS) includes equations that calculate energy release and one-dimensional spread rate in quasi-steady-state fires in heterogeneous but spatially uniform wildland fuelbeds, using a reformulation of the widely used Rothermel fire spread model. This reformulation provides an automated means to predict fire behavior...

Vorticity and turbulence observations during a wildland fire on sloped terrain

NASA Astrophysics Data System (ADS)

Contezac, J.; Clements, C. B.; Hall, D.; Seto, D.; Davis, B.

2013-12-01

Fire-atmosphere interactions represent an atmospheric boundary-layer regime typically associated with complex circulations that interact with the fire front. In mountainous terrain, these interactions are compounded by terrain-driven circulations that often lead to extreme fire behavior. To better understand the role of complex terrain on fire behavior, a set of field experiments was conducted in June 2012 in the Coast Range of central California. The experiments were conducted on steep valley sidewalls to allow fires to spread upslope. Instrumentation used to measure fire-atmosphere interactions included three micrometeorological towers arranged along the slope and equipped with sonic anemometers, heat flux radiometers, and fine-wire thermocouples. In addition, a scanning Doppler lidar was used to measured winds within and above the valley, and airborne video imagery was collected to monitor fire behavior characteristics. The experimental site was located on the leeside of a ridge where terrain-induced flow and opposing mesoscale winds aloft interacted to create a zone of high wind shear. During the burn, the interaction between the fire and atmosphere caused the generation of several fire whirls that develop as a result of several environmental conditions including shear-generated vorticity and fire front geometry. Airborne video imagery indicated that upon ignition, the plume tilted in the opposite direction from the fire movement suggesting that higher horizontal momentum from aloft was brought to the surface, resulting in much slower fire spread rates due to opposing winds. However, after the fire front had passed the lowest tower located at the base of the slope, a shift in wind speed and direction caused a fire whirl to develop near an L-shaped kink in the fire front. Preliminary results indicate that at this time, winds at the bottom of the slope began to rotate with horizontal vorticity values of -0.2 s^-1. Increased heat flux values at this time indicated that winds were continuing to transport heat towards the slope. As the winds shifted with the fire whirl, heat flux values returned to ambient indicating the passage of the fire plume. A 0.15 hPa decrease in pressure was also observed at the first tower during this period. Further analyses to be presented include vorticity estimates from the Doppler lidar and turbulence kinetic energy measurements from the in situ towers.

Characterization of potential fire regimes: applying landscape ecology to fire management in Mexico

NASA Astrophysics Data System (ADS)

Jardel, E.; Alvarado, E.; Perez-Salicrup, D.; Morfín-Rios, J.

2013-05-01

Knowledge and understanding of fire regimes is fundamental to design sound fire management practices. The high ecosystem diversity of Mexico offers a great challenge to characterize the fire regime variation at the landscape level. A conceptual model was developed considering the main factors controlling fire regimes: climate and vegetation cover. We classified landscape units combining bioclimatic zones from the Holdridge life-zone system and actual vegetation cover. Since bioclimatic conditions control primary productivity and biomass accumulation (potential fuel), each landscape unit was considered as a fuel bed with a particular fire intensity and behavior potential. Climate is also a determinant factor of post-fire recovery rates of fuel beds, and climate seasonality (length of the dry and wet seasons) influences fire probability (available fuel and ignition efficiency). These two factors influence potential fire frequency. Potential fire severity can be inferred from fire frequency, fire intensity and behavior, and vegetation composition and structure. Based in the conceptual model, an exhaustive literature review and expert opinion, we developed rules to assign a potential fire regime (PFR) defined by frequency, intensity and severity (i.e. fire regime) to each bioclimatic-vegetation landscape unit. Three groups and eight types of potential fire regimes were identified. In Group A are fire-prone ecosystems with frequent low severity surface fires in grasslands (PFR type I) or forests with long dry season (II) and infrequent high-severity fires in chaparral (III), wet temperate forests (IV, fire restricted by humidity), and dry temperate forests (V, fire restricted by fuel recovery rate). Group B includes fire-reluctant ecosystems with very infrequent or occasional mixed severity surface fires limited by moisture in tropical rain forests (VI) or fuel availability in seasonally dry tropical forests (VII). Group C and PFR VIII include fire-free environments that correspond to deserts. Application of PFR model to fire management is discussed.

77 FR 33158 - Plumas National Forest, California, Sugarloaf Hazardous Fuels Reduction Project

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-05

... to the economic stability of rural communities through: fuels treatments; group selections (GS); area... (DFPZs), modify fire behavior, promote forest and watershed health, while contributing to the economic stability of rural communities in Plumas County, CA. Fire behavior needs to be modified in selected forest...

AEGIS: a wildfire prevention and management information system

NASA Astrophysics Data System (ADS)

Kalabokidis, Kostas; Ager, Alan; Finney, Mark; Athanasis, Nikos; Palaiologou, Palaiologos; Vasilakos, Christos

2016-03-01

We describe a Web-GIS wildfire prevention and management platform (AEGIS) developed as an integrated and easy-to-use decision support tool to manage wildland fire hazards in Greece (http://aegis.aegean.gr). The AEGIS platform assists with early fire warning, fire planning, fire control and coordination of firefighting forces by providing online access to information that is essential for wildfire management. The system uses a number of spatial and non-spatial data sources to support key system functionalities. Land use/land cover maps were produced by combining field inventory data with high-resolution multispectral satellite images (RapidEye). These data support wildfire simulation tools that allow the users to examine potential fire behavior and hazard with the Minimum Travel Time fire spread algorithm. End-users provide a minimum number of inputs such as fire duration, ignition point and weather information to conduct a fire simulation. AEGIS offers three types of simulations, i.e., single-fire propagation, point-scale calculation of potential fire behavior, and burn probability analysis, similar to the FlamMap fire behavior modeling software. Artificial neural networks (ANNs) were utilized for wildfire ignition risk assessment based on various parameters, training methods, activation functions, pre-processing methods and network structures. The combination of ANNs and expected burned area maps are used to generate integrated output map of fire hazard prediction. The system also incorporates weather information obtained from remote automatic weather stations and weather forecast maps. The system and associated computation algorithms leverage parallel processing techniques (i.e., High Performance Computing and Cloud Computing) that ensure computational power required for real-time application. All AEGIS functionalities are accessible to authorized end-users through a web-based graphical user interface. An innovative smartphone application, AEGIS App, also provides mobile access to the web-based version of the system.

Changes in contaminant loading and hydro-chemical storm behavior after the Station Fire

NASA Astrophysics Data System (ADS)

Burke, M. P.; Hogue, T. S.; Barco, J.; Wessel, C. J.

2010-12-01

The 2009 Station Fire, currently noted as the largest fire in Los Angeles County history, consumed over 650 square kilometers of National Forest land in the San Gabriel Mountain Range. These mountains, located on the east side (leeward) of the Los Angeles basin, are known to have some of the highest deposition rates of atmospheric pollutants in the nation. Even pre-fire, urban-fringe basins in this mountain range serve as an upstream source of contaminants to downstream urban streams. Burned watersheds undergo significant physical and chemical changes that dramatically alter hydrologic flowpaths, erosion potential, surface soil chemistry, and pollutant delivery. Much of the degradation in water quality is attributed to the extensive soil erosion during post-fire runoff events which carry large sediment loads, mobilizing and transporting contaminants to and within downstream waters. High resolution storm samples collected from a small front range watershed provide a unique opportunity to investigate the impacts of wildfire contaminant loading in a watershed that is significantly impacted by high atmospheric deposition of urban contaminates. Data includes four events from WY 2009 (pre-fire) and WY 2010 (post-fire), along with inter-storm grab samples from each storm season. Samples were analyzed for basic anions, nutrients, trace metals, and total suspended solids. Following the fire, storms with similar precipitation patterns yielded loads up to three orders of magnitude greater than pre-fire for some toxic metals, including lead and cadmium. Dramatic increases were also observed in trace metal concentrations typically associated with particulates, while weathering solute concentrations decreased. Post fire intra-storm dynamics exhibited a shift back toward pre-fire behavior by the end of the first rainy season for most of the measured constituents. Additionally, some unexpected behaviors were observed; specifically mercury loads continued to increase throughout the first post-fire rainy season regardless of storm size.

Contribution from motor unit firing adaptations and muscle co-activation during fatigue.

PubMed

Contessa, Paola; Letizi, John; De Luca, Gianluca; Kline, Joshua C

2018-03-14

The control of motor unit firing behavior during fatigue is still debated in the literature. Most studies agree that the central nervous system increases the excitation to the motoneuron pool to compensate for decreased force contributions of individual motor units and sustain muscle force output during fatigue. However, some studies claim that motor units may decrease their firing rates despite increased excitation, contradicting the direct relationship between firing rates and excitation that governs the voluntary control of motor units. To investigate whether the control of motor units in fact changes with fatigue, we measured motor unit firing behavior during repeated contractions of the first dorsal interosseous (FDI) muscle while concurrently monitoring the activation of surrounding muscles - including the flexor carpi radialis, extensor carpi radialis, and pronator teres. Across all subjects, we observed an overall increase in FDI activation and motor unit firing rates by the end of the fatigue task. However, in some subjects we observed increases in FDI activation and motor unit firing rates only during the initial phase of the fatigue task, followed by subsequent decreases during the late phase of the fatigue task while the co-activation of surrounding muscles increased. These findings indicate that the strategy for sustaining force output may occasionally change leading to increases in the relative activation of surrounding muscles while the excitation to the fatiguing muscle decreases. Importantly, irrespective of changes in the strategy for sustaining force output, the control properties regulating motor unit firing behavior remain unchanged during fatigue.

Irresistible ants: exposure to novel toxic prey increases consumption over multiple temporal scales.

PubMed

Herr, Mark W; Robbins, Travis R; Centi, Alan; Thawley, Christopher J; Langkilde, Tracy

2016-07-01

As species become increasingly exposed to novel challenges, it is critical to understand how evolutionary (i.e., generational) and plastic (i.e., within lifetime) responses work together to determine a species' fate or predict its distribution. The introduction of non-native species imposes novel pressures on the native species that they encounter. Understanding how native species exposed to toxic or distasteful invaders change their feeding behavior can provide insight into their ability to cope with these novel threats as well as broader questions about the evolution of this behavior. We demonstrated that native eastern fence lizards do not avoid consuming invasive fire ants following repeated exposure to this toxic prey. Rather fence lizards increased their consumption of these ants following exposure on three different temporal scales. Lizards ate more fire ants when they were exposed to this toxic prey over successive days. Lizards consumed more fire ants if they had been exposed to fire ants as juveniles 6 months earlier. Finally, lizards from populations exposed to fire ants over multiple generations consumed more fire ants than those from fire ant-free areas. These results suggest that the potentially lethal consumption of fire ants may carry benefits resulting in selection for this behavior, and learning that persists long after initial exposure. Future research on the response of native predators to venomous prey over multiple temporal scales will be valuable in determining the long-term effects of invasion by these novel threats.

Numerical modeling of the effects of fire-induced convection and fire-atmosphere interactions on wildfire spread and fire plume dynamics

NASA Astrophysics Data System (ADS)

Sun, Ruiyu

It is possible due to present day computing power to produce a fluid dynamical physically-based numerical solution to wildfire behavior, at least in the research mode. This type of wildfire modeling affords a flexibility and produces details that are not available in either current operational wildfire behavior models or field experiments. However before using these models to study wildfire, validation is necessary, and model results need to be systematically and objectively analyzed and compared to real fires. Plume theory and data from the Meteotron experiment, which was specially designed to provide results from measurements for the theoretical study of a convective plume produced by a high heat source at the ground, are used here to evaluate the fire plume properties simulated by two numerical wildfire models, the Fire Dynamics Simulator or FDS, and the Clark coupled atmosphere-fire model. The study indicates that the FDS produces good agreement with the plume theory and the Meteotron results. The study also suggests that the coupled atmosphere-fire model, a less explicit and ideally less computationally demanding model than the FDS; can produce good agreement, but that the agreement is sensitive to the method of putting the energy released from the fire into the atmosphere. The WFDS (Wildfire and wildland-urban interface FDS), an extension of the FDS to the vegetative fuel, and the Australian grass fire experiments are used to evaluate and improve the UULES-wildfire coupled model. Despite the simple fire parameterization in the UULES-wildfire coupled model, the fireline is fairly well predicted in terms of both shape and location in the simulation of Australian grass fire experiment F19. Finally, the UULES-wildfire coupled model is used to examine how the turbulent flow in the atmospheric boundary layer (ABL) affects the growth of the grass fires. The model fires showed significant randomness in fire growth: Fire spread is not deterministic in the ABL, and a probabilistic prediction method is warranted. Of the two contributors to the variability in fire growth in the grass fire simulations in the ABL, fire-induced convection, as opposed to the turbulent ABL wind, appears to be the more important one. One mechanism associated with enhanced fire-induced flow is the downdraft behind the frontal fireline. The downdraft is the direct result of the random interaction between the fire plume and the large eddies in the ABL. This study indicates a connection between fire variability in rate of spread and area burnt and so-called convective velocity scale, and it may be possible to use this boundary-layer scale parameter to account for the effects of ABL turbulence on fire spread and fire behavior in today's operational fire prediction systems.

Pre-fire treatment effects and post-fire forest dynamics on the Rodeo-Chediski burn area, Arizona

Treesearch

Barbara A. Strom

2005-01-01

The 2002 Rodeo-Chediski fire was the largest wildfire in Arizona history at 189,000 ha (468,000 acres), and exhibited some of the most extreme fire behavior ever seen in the Southwest. Pre-fire fuel reduction treatments of thinning, timber harvesting, and prescribed burning on the White Mountain Apache Tribal lands (WMAT) and thinning on the Apache-Sitgreaves National...

Fire behavior, weather, and burn severity of the 2007 Anaktuvuk River tundra fire, North Slope, Alaska

Treesearch

Benjamin M. Jones; Crystal A. Kolden; Randi Jandt; John T. Abatzoglu; Frank Urban; Christopher D. Arp

2009-01-01

In 2007, the Anaktuvuk River Fire (ARF) became the largest recorded tundra fire on the North Slope of Alaska. The ARF burned for nearly three months, consuming more than 100,000 ha. At its peak in early September, the ARF burned at a rate of 7000 ha d-1. The conditions potentially responsible for this large tundra fire include modeled record high...

Characterizing fire behavior from laboratory burns of multi-aged, mixed-conifer masticated fuels in the western United States

Treesearch

Faith Ann Heinsch; Pamela G. Sikkink; Helen Y. Smith; Molly L. Retzlaff

2018-01-01

Mastication is the process of chipping or shredding components of the tree canopy or above-ground vegetation to reduce the canopy, alter fire spread rates, and reduce crown fire potential. Mastication as a fuel treatment, either alone or in combination with prescribed fire, has been the subject of much research. This research has shown that modeling expected fire...

[Fire behavior of Mongolian oak leaves fuel-bed under no-wind and zero-slope conditions. I. Factors affecting fire spread rate and modeling].

PubMed

Jin, Sen; Liu, Bo-Fei; Di, Xue-Ying; Chu, Teng-Fei; Zhang, Ji-Li

2012-01-01

Aimed to understand the fire behavior of Mongolian oak leaves fuel-bed under field condition, the leaves of a secondary Mongolian oak forest in Northeast Forestry University experimental forest farm were collected and brought into laboratory to construct fuel-beds with varied loading, height, and moisture content, and a total of 100 experimental fires were burned under no-wind and zero-slope conditions. It was observed that the fire spread rate of the fuel-beds was less than 0.5 m x min(-1). Fuel-bed loading, height, and moisture contents all had significant effects on the fire spread rate. The effect of fuel-bed moisture content on the fire spread had no significant correlations with fuel-bed loading and height, but the effect of fuel-bed height was related to the fuel-bed loading. The packing ratio of fuel-beds had less effect on the fire spread rate. Taking the fuel-bed loading, height, and moisture content as predictive variables, a prediction model for the fire spread rate of Mongolian oak leaves fuel-bed was established, which could explain 83% of the variance of the fire spread rate, with a mean absolute error 0.04 m x min(-1) and a mean relative error less than 17%.

The Impact of Reduced Ignition Propensity Cigarette Regulation on Smoking Behavior in a Cohort of Ontario Smokers

PubMed Central

O’Connor, Richard J.; Fix, Brian V.; Hammond, David; Giovino, Gary A.; Hyland, Andrew; Fong, Geoffrey T.; Cummings, K. Michael

2016-01-01

Introduction This study examined the degree to which legislation intended to reduce the incidence of cigarette-caused fires influenced the behaviors of a cohort of smokers in Ontario, Canada. Evaluating the effectiveness of existing cigarette fire-safety has the potential to inform the development of similar standards in other jurisdictions. Methods A random digit dialed telephone survey of adult smokers residing in the Province of Ontario was conducted between July and September of 2005, ending one month prior to the RIP regulation’s implementation date. A follow-up survey was conducted between August and November of 2006 to examine changes in engaging in fire risk behaviors, perceptions of changes to cigarettes, and behavioral changes in response to smoking reduced ignition propensity cigarettes. Of the baseline participants, 73.0% (n=435) completed the follow-up survey. Results The frequency of fire risk behaviors was similar across both surveys. At baseline, only 3.7% (95% CI: 2.20–5.76) of smokers interviewed reported that their cigarettes went out on their own ‘often’ while smoking. Following the implementation of the reduced ignition propensity legislation, this increased significantly to 14.7% (95% CI: 11.41–18.42). Discussion The results observed in this study suggest that the proportion of Ontario smokers who reported engaging in behavior such as leaving a cigarette burning unattended and smoking in bed actually declined, although these declines were not statistically significant across all measures of fire risk. As other nations look to implement RIP regulations, the Canadian experience thus far has revealed no risk compensatory behaviors that would offset the potential public health benefit of the regulations. PMID:20643872

A conceptual framework for ranking crown fire potential in wildland fuelbeds.

Treesearch

Mark D. Schaaf; David V. Sandberg; Maarten D. Schreuder; Cynthia L. Riccardi

2007-01-01

This paper presents a conceptual framework for ranking the crown fire potential of wildland fuelbeds with forest canopies. This approach extends the work by Van Wagner and Rothermel, and introduces several new physical concepts to the modeling of crown fire behavior derived from the reformulated Rothemel surface fire modeling concepts proposed by Sandberg et al. This...

Chapter 2: Effects of fire on nonnative invasive plants and invasibility of wildland ecosystems

Treesearch

Kristin Zouhar; Jane Kapler Smith; Steve Sutherland

2008-01-01

Considerable experimental and theoretical work has been done on general concepts regarding nonnative species and disturbance, but experimental research on the effects of fire on nonnative invasive species is sparse. We begin this chapter by connecting fundamental concepts from the literature of invasion ecology to fire. Then we examine fire behavior characteristics,...

Equipping tomorrow's fire manager

Treesearch

Christopher A. Dicus

2008-01-01

Fire managers are challenged with an ever-increasing array of both responsibilities and critics. As in the past, fire managers must master the elements of fire behavior and ecology using the latest technologies. In addition, today’s managers must be equipped with the skills necessary to understand and liaise with a burgeoning group of vocal stakeholders while also...

A study of the flow field surrounding interacting line fires

Treesearch

Trevor Maynard; Marko Princevac; David R. Weise

2016-01-01

The interaction of converging fires often leads to significant changes in fire behavior, including increased flame length, angle, and intensity. In this paper, the fluid mechanics of two adjacent line fires are studied both theoretically and experimentally. A simple potential flow model is used to explain the tilting of interacting flames towards each other, which...

Quantifying the effect of fuel reduction treatments on fire behavior in boreal forests

Treesearch

B.W. Butler; R.D. Ottmar; T.S. Rupp; R. Jandt; E. Miller; K. Howard; R. Schmoll; S. Theisen; R.E. Vihnanek; D. Jimenez

2013-01-01

Mechanical (e.g., shearblading) and manual (e.g., thinning) fuel treatments have become the preferred strategy of many fire managers and agencies for reducing fire hazard in boreal forests. This study attempts to characterize the effectiveness of four fuel treatments through direct measurement of fire intensity and forest floor consumption during a single prescribed...

Evaluating potential trade-offs among fuel treatment strategies in mixed-conifer forests of the Sierra Nevada

Treesearch

Jens T. Stevens; Brandon M. Collins; Jonathan W. Long; Malcolm P. North; Susan J. Prichard; Leland W. Tarnay; Angela M. White

2016-01-01

Fuel treatments in fire-suppressed mixed-conifer forests are designed to moderate potential wildfire behavior and effects. However, the objectives for modifying potential fire effects can vary widely, from improving fire suppression efforts and protecting infrastructure, to reintroducing low-severity fire, to restoring and maintaining variable forest structure and...

The Role of Social Influence on How Residence Hall Inhabitants Respond to Fire Alarms

ERIC Educational Resources Information Center

Leytem, Michael; Stark, Emily

2016-01-01

College resident halls pose a threat for a catastrophic event in the case of fire, but little research has examined potential influences on students' responses to fire alarms, particularly the role of social influence in affecting their behaviors. In the current study, residence hall inhabitants reported their knowledge about fire safety, their…

BehavePlus fire modeling system, version 5.0: Variables

Treesearch

Patricia L. Andrews

2009-01-01

This publication has been revised to reflect updates to version 4.0 of the BehavePlus software. It was originally published as the BehavePlus fire modeling system, version 4.0: Variables in July, 2008.The BehavePlus fire modeling system is a computer program based on mathematical models that describe wildland fire behavior and effects and the...

Cigarette Fires Involving Upholstered Furniture in Residences: The Role that Smokers, Smoker Behavior, and Fire Standard Compliant Cigarettes Play.

PubMed

Butry, David T; Thomas, Douglas S

2017-05-01

Residential structure fires pose a significant risk to life and property. A major source of these fires is the ignition of upholstered furniture by cigarettes. It has long been established that cigarettes and other lighted tobacco products could ignite upholstered furniture and were a leading cause of fire deaths in residences. In recent years, states have adopted fire standard compliant cigarettes ('FSC cigarettes') that are made with a wrapping paper that contains regularly spaced bands, which increases the likelihood of self-extinguishment. This paper measures the effectiveness of FSC cigarettes on the number of residential fires involving upholstered furniture, and the resulting fatalities, injuries, and extent of flame spread, while accounting for the under-reporting of fire incidents. In total, four models were estimated using fire department data from 2002 to 2011. The results provide evidence that FSC cigarettes, on average, reduced the number of residential fires by 45 %, reduced fatalities by 23 %, and extent of flame spread by 27 % in 2011. No effect on injuries was found. Within each state, effectiveness is moderated by the number of smokers and their consumption patterns. In general, FSC cigarettes are more effective in places with a large smoking population who engage in heavier smoking. There is a very limited effect on the lightest of smokers, suggesting behavioral differences between heavy and light smokers that influence fire risk.

Cigarette Fires Involving Upholstered Furniture in Residences: The Role that Smokers, Smoker Behavior, and Fire Standard Compliant Cigarettes Play

PubMed Central

Butry, David T.; Thomas, Douglas S.

2017-01-01

Residential structure fires pose a significant risk to life and property. A major source of these fires is the ignition of upholstered furniture by cigarettes. It has long been established that cigarettes and other lighted tobacco products could ignite upholstered furniture and were a leading cause of fire deaths in residences. In recent years, states have adopted fire standard compliant cigarettes (‘FSC cigarettes’) that are made with a wrapping paper that contains regularly spaced bands, which increases the likelihood of self-extinguishment. This paper measures the effectiveness of FSC cigarettes on the number of residential fires involving upholstered furniture, and the resulting fatalities, injuries, and extent of flame spread, while accounting for the under-reporting of fire incidents. In total, four models were estimated using fire department data from 2002 to 2011. The results provide evidence that FSC cigarettes, on average, reduced the number of residential fires by 45 %, reduced fatalities by 23 %, and extent of flame spread by 27 % in 2011. No effect on injuries was found. Within each state, effectiveness is moderated by the number of smokers and their consumption patterns. In general, FSC cigarettes are more effective in places with a large smoking population who engage in heavier smoking. There is a very limited effect on the lightest of smokers, suggesting behavioral differences between heavy and light smokers that influence fire risk. PMID:28751788

Postfire logging in riparian areas.

Treesearch

Gordon H. Reeves; Peter A. Bisson; Bruce E. Rieman; Lee E. Benda

2006-01-01

We reviewed the behavior of wildfire in riparian zones, primarily in the western United States, and the potential ecological consequences of postfire logging. Fire behavior in riparian zones is complex, but many aquatic and riparian organisms exhibit a suite of adaptations that allow relatively rapid recovery after fire. Unless constrained by other factors, fish tend...

Moisture dynamics in masticated fuelbeds: A preliminary analysis

Treesearch

Jesse Kreye; J. Morgan Varner

2007-01-01

Mastication has become a popular fuels treatment in the Western United States, but predicting subsequent fire behavior and effects has proven difficult. Fire behavior and effects in masticated fuelbeds have been more intense and erratic in comparison with model predictions. While various particle or fuelbed characteristics in these fuels may contribute to the...

Intrinsic modulation of pulse-coupled integrate-and-fire neurons

NASA Astrophysics Data System (ADS)

Coombes, S.; Lord, G. J.

1997-11-01

Intrinsic neuromodulation is observed in sensory and neuromuscular circuits and in biological central pattern generators. We model a simple neuronal circuit with a system of two pulse-coupled integrate-and-fire neurons and explore the parameter regimes for periodic firing behavior. The inclusion of biologically realistic features shows that the speed and onset of neuronal response plays a crucial role in determining the firing phase for periodic rhythms. We explore the neurophysiological function of distributed delays arising from both the synaptic transmission process and dendritic structure as well as discrete delays associated with axonal communication delays. Bifurcation and stability diagrams are constructed with a mixture of simple analysis, numerical continuation and the Kuramoto phase-reduction technique. Moreover, we show that, for asynchronous behavior, the strength of electrical synapses can control the firing rate of the system.

Community partnership to promote home fire safety in children with special needs.

PubMed

Lehna, Carlee; Janes, Erika G; Rengers, Sharon; Graviss, Jackie; Scrivener, Drane; Knabel, Tom; Carver, Elizabeth; Myers, John

2014-09-01

Parents of children with special needs are vigilant as their child may have difficulty independently escaping a burning home. The purpose of this study was to evaluate if providing home fire safety information via a digital video disc (DVD) increases families' knowledge, behavior and ability regarding home fire safety. A school based classroom intervention (using a home fire safety DVD) was provided to parents (n=40) of children with and without special needs to improve home fire safety knowledge, behavior and ability. In addition, parents seen at the Kentucky Commission for Children with Special Health Care Needs clinics (n=47) received the same intervention in cohorts of 1-2 children. For both groups, knowledge, and behavior were measured before and after intervention. Repeated measures ANOVA were used to test for differences between groups and over time. Significance was set at p<0.05. No difference in scores between pre- and post-test scores existed between groups (with special needs vs. without special needs, or classroom vs. individualized instruction). However, some differences were noted for some individual survey questions during post-hoc comparisons. Having a smoke alarm in the home (90% vs. 95%, p=0.029) and having a smoke alarm outside of where everyone sleeps (75% vs. 95%, p=0.005) increased over time and was retained. Having a fire escape plan increased at post intervention (58% vs. 79%, p=0.033), but returned to pre levels at follow-up (58%). Perceived knowledge (7.7 vs. 9.3, p<0.001) and ability (8.7 vs. 9.1, p=0.069) increased over time. Parents of children with special needs had a significant increase in knowledge and behavior over those parents of children without special needs. They also perceived having a high fire safety ability. Many of the post-test questions/behaviors (e.g., capable of exiting home during a fire, etc.) were reported at 100%. The intervention was well received, but may not necessarily be needed. Focus for home fire safety may need to look at younger children and smaller families. Parents of special needs children may have had frequent interaction with health care professionals. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

Leaching and geochemical behavior of fired bricks containing coal wastes.

PubMed

Taha, Yassine; Benzaazoua, Mostafa; Edahbi, Mohamed; Mansori, Mohammed; Hakkou, Rachid

2018-03-01

High amounts of mine wastes are continuously produced by the mining industry all over the world. Recycling possibility of some wastes in fired brick making has been investigated and showed promising results. However, little attention is given to the leaching behavior of mine wastes based fired bricks. The objective of this paper is to evaluate the geochemical behavior of fired bricks containing different types of coal wastes. The leachates were analyzed for their concentration of As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Zn and sulfates using different leaching tests; namely Tank Leaching tests (NEN 7375), Toxicity Characteristic Leaching Procedure (TCLP) and pH dependence test (EPA, 1313). The results showed that the release of constituents of potential interest was highly reduced after thermal treatment and were immobilized within the glassy matrix of the fired bricks. Moreover, it was also highlighted that the final pH of all fired samples changed and stabilized around 8-8.5 when the initial pH of leaching solution was in the range 2.5-11.5. The release of heavy metals and metalloids (As) tended to decrease with the increase of pH from acidic to alkaline solutions while Mo displayed a different trend. Copyright © 2017 Elsevier Ltd. All rights reserved.

Deconstructing the King Megafire.

PubMed

Coen, Janice L; Stavros, E Natasha; Fites-Kaufman, Josephine A

2018-05-24

Hypotheses that megafires - very large, high impact fires - are caused by either climate effects such as drought or fuel accumulation due to fire exclusion with accompanying changes to forest structure have long been alleged and guided policy but their physical basis remains untested. Here, unique airborne observations and microscale simulations using a coupled weather - wildland fire behavior model allowed a recent megafire, the King Fire, to be deconstructed and the relative impacts of forest structure, fuel load, weather, and drought on fire size, behavior, and duration to be separated. Simulations reproduced observed details including the arrival at an inclined canyon, a 25-km run, and later slower growth and features. Analysis revealed that fire-induced winds that equaled or exceeded ambient winds and fine-scale airflow undetected by surface weather networks were primarily responsible for the fire's rapid growth and size. Sensitivity tests varied fuel moisture and amount across wide ranges and showed that both drought and fuel accumulation effects were secondary, limited to sloped terrain where they compounded each other, and, in this case, unable to significantly impact the final extent. Compared to standard data, fuel models derived solely from remote sensing of vegetation type and forest structure improved simulated fire progression, notably in disturbed areas, and the distribution of burn severity. These results point to self-reinforcing internal dynamics rather than external forces as a means of generating this and possibly other outlier fire events. Hence, extreme fires need not arise from extreme fire environment conditions. Kinematic models used in operations do not capture fire-induced winds and dynamic feedbacks so can underestimate megafire events. The outcomes provided a nuanced view of weather, forest structure, fuel accumulation, and drought impacts on landscape-scale fire behavior - roles that can be misconstrued using correlational analyses between area burned and macroscale climate data or other exogenous factors. A practical outcome is that fuel treatments should be focused on sloped terrain, where factors multiply, for highest impact. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Fuel model selection for BEHAVE in midwestern oak savannas

USGS Publications Warehouse

Grabner, K.W.; Dwyer, J.P.; Cutter, B.E.

2001-01-01

BEHAVE, a fire behavior prediction system, can be a useful tool for managing areas with prescribed fire. However, the proper choice of fuel models can be critical in developing management scenarios. BEHAVE predictions were evaluated using four standardized fuel models that partially described oak savanna fuel conditions: Fuel Model 1 (Short Grass), 2 (Timber and Grass), 3 (Tall Grass), and 9 (Hardwood Litter). Although all four models yielded regressions with R2 in excess of 0.8, Fuel Model 2 produced the most reliable fire behavior predictions.

Linking surface-fire behavior, stem heating, and tissue necrosis

Treesearch

A.S. Bova; M.B. Dickinson; M.B. Dickinson

2005-01-01

Data from 69 experimental, small-plot fires are used to describe relationships among fire intensity, barksurface heat flux, and depth of necrosis in stem tissue for red maple (Acer rubrum L.) and chestnut oak (Quercus prinus L.j. A tetrazolium staining technique was used to determine the depth of necrosis in tree boles subjected to fires with intensities of 20 to 2000...

Interactions among livestock grazing, vegetation type, and fire behavior in the Murphy wildland fire complex in Idaho and Nevada, July 2007

USDA-ARS?s Scientific Manuscript database

A series of wildland fires were ignited by lightning in sagebrush and grassland communities near the Idaho-Nevada border southwest of Twin Falls, Idaho in July 2007. The fires burned for over two weeks and encompassed more than 650,000 acres. A team of scientists, habitat specialists, and land manag...

Users Guide for Fire Image Analysis System - Version 5.0: A Tool for Measuring Fire Behavior Characteristics

Treesearch

Carl W. Adkins

1995-01-01

The Fire Image Analysis System is a tool for quantifying flame geometry and relative position at selected points along a spreading line fire. At present, the system requires uniform terrain (constant slope). The system has been used in field and laboratory studies for determining flame length, depth, cross sectional area, and rate of spread.

Modeling tree-level fuel connectivity to evaluate the effectiveness of thinning treatments for reducing crown fire potential

Treesearch

Marco A. Contreras; Russell A. Parsons; Woodam Chung

2012-01-01

Land managers have been using fire behavior and simulation models to assist in several fire management tasks. These widely-used models use average attributes to make stand-level predictions without considering spatial variability of fuels within a stand. Consequently, as the existing models have limitations in adequately modeling crown fire initiation and propagation,...

The ability of winter grazing to reduce wildfire size, intensity, and fire-induced plant mortality was not demonstrated: A comment on Davies et al. (2015)

EPA Science Inventory

A recent study by Davies et al. sought to test whether winter grazing could reduce wildfire size, fire behavior metrics, and fire-induced plant mortality in shrub-grasslands. The authors concluded that ungrazed rangelands may experience more fire-induced mortality of native peren...

The ability of winter grazing to reduce wildfire size, intensity, and fire-induced plant mortality was not demonstrated: a comment on Davies et al. (2015)

USDA-ARS?s Scientific Manuscript database

A recent study by Davies et al. sought to test whether winter grazing could reduce wildfire size, fire behavior and intensity metrics, and fire-induced plant mortality in shrub-grasslands. The authors concluded that ungrazed rangelands may experience fire-induced mortality of native perennial bunchg...

A study of flame spread in engineered cardboard fuelbeds: Part II: Scaling law approach

Treesearch

Brittany A. Adam; Nelson K. Akafuah; Mark Finney; Jason Forthofer; Kozo Saito

2013-01-01

In this second part of a two part exploration of dynamic behavior observed in wildland fires, time scales differentiating convective and radiative heat transfer is further explored. Scaling laws for the two different types of heat transfer considered: Radiation-driven fire spread, and convection-driven fire spread, which can both occur during wildland fires. A new...

Fire behavior associated with the 1994 South Canyon fire on Storm King Mountain, Colorado

Treesearch

Bret W. Butler; Roberta A. Bartlette; Larry S. Bradshaw; Jack D. Cohen; Patricia L. Andrews; Ted Putnam; Richard J. Mangan

1998-01-01

In the aftermath of the deaths of 14 firefighters during the South Canyon Fire in July 1994, fire scientists assessed what occurred and suggested guidelines that may help firefighters avert such a tragedy in the future. This report describes the fuel, weather, and topographical factors that caused the transition from a relatively slow-spreading, low-intensity surface...

Ignition patterns & prescribed fire behavior in southern pine stands

Treesearch

Ragnar W. Johansen

1987-01-01

As an aid to forest managers who use or contemplate using aerial ignition techniques in their prescribed burning programs, a study was designed to evaluate the magnitude of the differences that could occur depending on whether lines of fire were used (ignited by a helitorch) or a spot-fire technique was used (ignited by aerial ignition devices). Six experimental fires...

Wallace L. Fons: fire research pioneer

Treesearch

David R. Weise; Ted R. Fons

2014-01-01

During his 30-year career with the U.S. Forest Service, Wally Fons laid the foundation for much of the understanding we have today of forest fire's many properties by applying his mechanical engineering background. He left a legacy of research that formed the basis for the fire behavior and danger systems still used in the United States. In addition to fire...

Fire weather and large fire potential in the northern Sierra Nevada

Treesearch

Brandon M. Collins

2014-01-01

Fuels, weather, and topography all contribute to observed fire behavior. Of these, weather is not only the most dynamic factor, it is the most likely to be directly influenced by climate change. In this study 40 years of daily fire weather observations from five weather stations across the northern Sierra Nevada were analyzed to investigate potential changes or trends...

Climatic variability of a fire-weather index based on turbulent kinetic energy and the Haines Index

Treesearch

Warren E. Heilman; Xindi Bian

2010-01-01

Combining the Haines Index (HI) with near-surface turbulent kinetic energy (TKEs) through a product of the two values (HITKEs) has shown promise as an indicator of the atmospheric potential for extreme and erratic fire behavior in the U.S. Numerical simulations of fire-weather evolution during past wildland fire episodes in...

Predicted fuel consumption in the Burnup model: sensitivity to four user inputs

Treesearch

D. C. Lutes

2013-01-01

Fuelbeds consist of a number of combustible components that are consumed during a fire, including duff, litter, vegetation (herbs, shrub, foliage, and branches) and down dead woody material (DWM). Combustion of DWM during a fire has a well-documented role in determining fire effects and fire behavior impacts such as emissions (Sandberg and others 2002), vegetative...

VISUAL-SEVEIF, a tool for integrating fire behavior simulation and economic evaluation of the impact of Wildfires

Treesearch

Francisco Rodríguez y Silva; Juan Ramón Molina Martínez; Miguel Ángel Herrera Machuca; Jesús Mª Rodríguez Leal

2013-01-01

Progress made in recent years in fire science, particularly as applied to forest fire protection, coupled with the increased power offered by mathematical processors integrated into computers, has led to important developments in the field of dynamic and static simulation of forest fires. Furthermore, and similarly, econometric models applied to economic...

Control effects of stimulus paradigms on characteristic firings of parkinsonism

NASA Astrophysics Data System (ADS)

Zhang, Honghui; Wang, Qingyun; Chen, Guanrong

2014-09-01

Experimental studies have shown that neuron population located in the basal ganglia of parkinsonian primates can exhibit characteristic firings with certain firing rates differing from normal brain activities. Motivated by recent experimental findings, we investigate the effects of various stimulation paradigms on the firing rates of parkinsonism based on the proposed dynamical models. Our results show that the closed-loop deep brain stimulation is superior in ameliorating the firing behaviors of the parkinsonism, and other control strategies have similar effects according to the observation of electrophysiological experiments. In addition, in conformity to physiological experiments, we found that there exists optimal delay of input in the closed-loop GPtrain|M1 paradigm, where more normal behaviors can be obtained. More interestingly, we observed that W-shaped curves of the firing rates always appear as stimulus delay varies. We furthermore verify the robustness of the obtained results by studying three pallidal discharge rates of the parkinsonism based on the conductance-based model, as well as the integrate-and-fire-or-burst model. Finally, we show that short-term plasticity can improve the firing rates and optimize the control effects on parkinsonism. Our conclusions may give more theoretical insight into Parkinson's disease studies.

The Pictorial Fire Stroop: a measure of processing bias for fire-related stimuli.

PubMed

Gallagher-Duffy, Joanne; MacKay, Sherri; Duffy, Jim; Sullivan-Thomas, Meara; Peterson-Badali, Michele

2009-11-01

Fire interest is a risk factor for firesetting. This study tested whether a fire-specific emotional Stroop task can effectively measure an information-processing bias for fire-related stimuli. Clinic-referred and nonreferred adolescents (aged 13-16 years) completed a pictorial "Fire Stroop," as well as a self-report fire interest questionnaire and several control tasks. Results showed (a) comparatively greater fire-specific attentional bias among referred adolescent firesetters, (b) a negative relationship between Fire Stroop attentional bias and self-reported fire interest, and (c) positive correspondence between Fire Stroop attentional bias and self-reported firesetting frequency. These findings suggest that instruments that measure an automatic bias for fire-specific stimuli may usefully supplement self-report measures in the assessment and understanding of firesetting behavior.

Burning behavior within a seat armrest cavity

DOT National Transportation Integrated Search

2002-09-01

The purpose of this technical note is to document the results of fire tests conducted to examine the characteristics of fire that may occur in the cavity of an aircraft seat armrest and the fire-containment capacity of the cavity. In all the tests th...

Fire and Children: Learning Survival Skills.

ERIC Educational Resources Information Center

Block, Jeanne H.; And Others

This paper describes a study designed to investigate: (1) children's interest in, anxieties about, attitudes toward, and reactions to fire; (2) the relationship of particular personality characteristics to attitudes about and behavior with potentially hazardous fire material; (3) socialization techniques and teaching strategies of mothers in…

Multistability, local pattern formation, and global collective firing in a small-world network of nonleaky integrate-and-fire neurons.

PubMed

Rothkegel, Alexander; Lehnertz, Klaus

2009-03-01

We investigate numerically the collective dynamical behavior of pulse-coupled nonleaky integrate-and-fire neurons that are arranged on a two-dimensional small-world network. To ensure ongoing activity, we impose a probability for spontaneous firing for each neuron. We study network dynamics evolving from different sets of initial conditions in dependence on coupling strength and rewiring probability. Besides a homogeneous equilibrium state for low coupling strength, we observe different local patterns including cyclic waves, spiral waves, and turbulentlike patterns, which-depending on network parameters-interfere with the global collective firing of the neurons. We attribute the various network dynamics to distinct regimes in the parameter space. For the same network parameters different network dynamics can be observed depending on the set of initial conditions only. Such a multistable behavior and the interplay between local pattern formation and global collective firing may be attributable to the spatiotemporal dynamics of biological networks.

Validation of behave fire behavior predictions in oak savannas

USGS Publications Warehouse

Grabner, Keith W.; Dwyer, John; Cutter, Bruce E.

1997-01-01

Prescribed fire is a valuable tool in the restoration and management of oak savannas. BEHAVE, a fire behavior prediction system developed by the United States Forest Service, can be a useful tool when managing oak savannas with prescribed fire. BEHAVE predictions of fire rate-of-spread and flame length were validated using four standardized fuel models: Fuel Model 1 (short grass), Fuel Model 2 (timber and grass), Fuel Model 3 (tall grass), and Fuel Model 9 (hardwood litter). Also, a customized oak savanna fuel model (COSFM) was created and validated. Results indicate that standardized fuel model 2 and the COSFM reliably estimate mean rate-of-spread (MROS). The COSFM did not appreciably reduce MROS variation when compared to fuel model 2. Fuel models 1, 3, and 9 did not reliably predict MROS. Neither the standardized fuel models nor the COSFM adequately predicted flame lengths. We concluded that standardized fuel model 2 should be used with BEHAVE when predicting fire rates-of-spread in established oak savannas.

Using simulated 3D surface fuelbeds and terrestrial laser scan data to develop inputs to fire behavior models

Treesearch

Eric Rowell; E. Louise Loudermilk; Carl Seielstad; Joseph O' Brien

2016-01-01

Understanding fine-scale variability in understory fuels is increasingly important as physics-based fire behavior modelsdrive needs for higher-resolution data. Describing fuelbeds 3Dly is critical in determining vertical and horizontal distributions offuel elements and the mass, especially in frequently burned pine ecosystems where fine-scale...

A Social Work Perspective of Childhood Trauma after a Residential Fire.

ERIC Educational Resources Information Center

Greenberg, Helaine S.; Keane, Anne

1997-01-01

Describes the posttraumatic stress, impact of the event, and behavioral responses of 56 schoolchildren, ages 6 to 17, following a fire in their homes. The children were tested two separate times: posttraumatic stress scores, impact of event scores, and problem behaviors decreased significantly from the first time to the second. Other results are…

Effects of a landscape disturbance on the habitat use and behavior of the black racer

Treesearch

Christopher A. F. Howey; Matthew B. Dickinson; Willem M. Roosenburg

2016-01-01

The effects of disturbance, including prescribed fire, vary among species and their ability to adjust to the altered environment. Our objective was to link fire-caused habitat changes with shifts in habitat use and behavioral changes in the Southern Black Racer (Coluber constrictor priapus). We compared habitat availability between burned (...

Fire Setting Behavior in a Child Welfare System: Prevalence, Characteristics and Co-Occurring Needs

ERIC Educational Resources Information Center

Lyons, John S.; McClelland, Gary; Jordan, Neil

2010-01-01

Fire setting is one of the most challenging behaviors for the child welfare system. However, existing knowledge about its prevalence and correlates has been limited to research on single programs. The Illinois Department of Children and Family Services initiated a uniform assessment process at entry into state custody using a trauma-informed…

Remote Sensing of Chaparral Fire Potential: Case Study in Topanga Canyon, California.

DTIC Science & Technology

Remote sensing techniques, especially the use of color infrared aerial photography, provide a useful tool for fire hazard analysis, including interpetive information about fuel volumes, physiognomic plant groupings, the relationships of buildings to both natural and planted vegetation, and fire vulnerability of roofing materials. In addition, the behavior of the September, 1970 Wright Fire in the Topanga study area suggested the validity of the fire potential analysis which had been made prior to that conflagration.

Smoke and fire characteristics for cerrado and deforestation burns in Brazil: BASE-B experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, D.E.; Susott, R.A.; Babbitt, R.E.

1992-09-20

Fires of the tropical forests and savannas are a major source of particulate matter and trace gases affecting the atmosphere globally. A paucity of quantitative information exists for these ecosystems with respect to fuel biomass, smoke emissions, and fire behavior conditions affecting the release of emissions. Five test fires were performed during August and September 1990 in the cerrado (savannalike region) in central Brazil (three fires) and tropical moist forest (two fires) in the eastern Amazon. This paper details the gases released, the ratios of the gases to each other and to particulate matter, fuel loads and the fraction consumedmore » (combustion factors), and the fire behavior associated with biomass consumption. Models are presented for evaluating emission factors for CH{sub 4}, CO{sub 2}, CO, H{sub 2}, and particles less than 2.5 {mu}m diameter (PM2.5) as a function of combustion efficiency. The ratio of carbon released as CO{sub 2} (combustion efficiency) for the cerrado fires averaged 0.94 and for the deforestation fires it decreased from 0.88 for the flaming phase to <0.80 during the smoldering phase of combustion. For tropical ecosystems, emissions of most products of incomplete combustion are projected to be lower than previous estimates for savanna ecosystems and somewhat higher for fires used for deforestation purposes. 59 refs., 9 figs., 10 tabs.« less

Uncertainty and risk in wildland fire management: a review.

PubMed

Thompson, Matthew P; Calkin, Dave E

2011-08-01

Wildland fire management is subject to manifold sources of uncertainty. Beyond the unpredictability of wildfire behavior, uncertainty stems from inaccurate/missing data, limited resource value measures to guide prioritization across fires and resources at risk, and an incomplete scientific understanding of ecological response to fire, of fire behavior response to treatments, and of spatiotemporal dynamics involving disturbance regimes and climate change. This work attempts to systematically align sources of uncertainty with the most appropriate decision support methodologies, in order to facilitate cost-effective, risk-based wildfire planning efforts. We review the state of wildfire risk assessment and management, with a specific focus on uncertainties challenging implementation of integrated risk assessments that consider a suite of human and ecological values. Recent advances in wildfire simulation and geospatial mapping of highly valued resources have enabled robust risk-based analyses to inform planning across a variety of scales, although improvements are needed in fire behavior and ignition occurrence models. A key remaining challenge is a better characterization of non-market resources at risk, both in terms of their response to fire and how society values those resources. Our findings echo earlier literature identifying wildfire effects analysis and value uncertainty as the primary challenges to integrated wildfire risk assessment and wildfire management. We stress the importance of identifying and characterizing uncertainties in order to better quantify and manage them. Leveraging the most appropriate decision support tools can facilitate wildfire risk assessment and ideally improve decision-making. Published by Elsevier Ltd.

Presynaptic learning and memory with a persistent firing neuron and a habituating synapse: a model of short term persistent habituation.

PubMed

Ramanathan, Kiruthika; Ning, Ning; Dhanasekar, Dhiviya; Li, Guoqi; Shi, Luping; Vadakkepat, Prahlad

2012-08-01

Our paper explores the interaction of persistent firing axonal and presynaptic processes in the generation of short term memory for habituation. We first propose a model of a sensory neuron whose axon is able to switch between passive conduction and persistent firing states, thereby triggering short term retention to the stimulus. Then we propose a model of a habituating synapse and explore all nine of the behavioral characteristics of short term habituation in a two neuron circuit. We couple the persistent firing neuron to the habituation synapse and investigate the behavior of short term retention of habituating response. Simulations show that, depending on the amount of synaptic resources, persistent firing either results in continued habituation or maintains the response, both leading to longer recovery times. The effectiveness of the model as an element in a bio-inspired memory system is discussed.

Documenting PyroCb Development on High-Intensity Boreal Fires: Implications for the Arctic Atmosphere

NASA Astrophysics Data System (ADS)

Stocks, B. J.; Fromm, M. D.; Servranckx, R.; Lindsey, D.

2007-12-01

The recent confirmation that smoke from high-intensity boreal forest fires can reach the Upper Troposphere/Lower Stratosphere (UTLS) through pyroconvection and be transported long distances has raised concern over the wider-scale environmental impact of boreal fire smoke. This concern is further elevated as climate change projections indicate a significant increase in the frequency and severity of boreal forest fires over the next century. Smoke in the UTLS is frequently transported to the Arctic and may have important implications for the radiative energy budget in the polar region. Soot deposition from fires may lead to enhanced melting of sea ice and glaciers, and the chemical impact of fire emissions at high altitudes is largely unknown. This knowledge gap will be addressed during the International Polar Year (IPY), as boreal fire emissions will be tracked and documented in detail through aerial, satellite and ground-based measurements, as a key component of the POLARCAT (Polar Study using Aircraft, Remote Sensing, Surface Measurements and Models, of Climate, Chemistry, Aerosols, and Transport) and ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) projects to be conducted in 2008. A large fire in the Canadian Northwest Territories burned throughout the month of June 2007, in a remote region where forest fires are not actively suppressed, eventually reaching 90,000 hectares in size. This fire was monitored for blowup one week in advance; it erupted into pyroconvection on June 25, 2007. We present an analysis of this event combining satellite data with ground-based measurements to document the development and impact of this classic pyroCb event. Under extreme fire danger conditions, the fire burned close to 20,000 hectares on that day. Fire behavior was consistent with predictions using the Canadian Fire Behavior Prediction System, with the fire spreading at 2.7 km/hr, consuming 33,000 kg of fuel hourly, generating an energy release rate of ~45,000 kW/m. This constitutes a typical high-intensity boreal crown fire, common across northern Canada every summer, and often capable of producing independent pyroconvection. The June 25 blowup was monitored using OMI AI, CALIPSO, Aqua MODIS, AVHRR and GOES satellite imagery, and these measurements validated the predicted fire behavior, including the development of a convection column that rose 10-11 km and injected smoke within the UTLS. Over subsequent days this smoke spread to Arctic latitudes (70-80 degrees N).

Using an agent-based model to examine forest management outcomes in a fire-prone landscape in Oregon, USA

Treesearch

Thomas A. Spies; Eric White; Alan Ager; Jeffrey D. Kline; John P. Bolte; Emily K. Platt; Keith A. Olsen; Robert J. Pabst; Ana M. G. Barros; John D. Bailey; Susan Charnley; Anita T. Morzillo; Jennifer Koch; Michelle M. Steen-Adams; Peter H. Singleton; James Sulzman; Cynthia Schwartz; Blair Csuti

2017-01-01

Fire-prone landscapes present many challenges for both managers and policy makers in developing adaptive behaviors and institutions. We used a coupled human and natural systems framework and an agent-based landscape model to examine how alternative management scenarios affect fire and ecosystem services metrics in a fire-prone multiownership landscape in the eastern...

Stand structure, fuelloads, and fire behavior in riparian and upland forests, Sierra Nevada Mountains, USA; a comparison of current and reconstructed conditions

Treesearch

Kip Van de Water; Malcolm North

2011-01-01

Fire plays an important role in shaping many Sierran coniferous forests, but longer fire return intervals and reductions in area burned have altered forest conditions. Productive, mesic riparian forests can accumulate high stem densities and fuel loads, making them susceptible to high-severity fire. Fuels treatments applied to upland forests, however, are...

Fire behavior, fuel treatments, and fire suppression on the Hayman Fire

Treesearch

Mark A. Finney; Roberta Bartlette; Larry Bradshaw; Kelly Close; Brandon M. Collins; Paul Gleason; Wei Min Hao; Paul Langowski; John McGinely; Charles W. McHugh; Erik Martinson; Phillip N. Omi; Wayne Shepperd; Karl Zeller

2003-01-01

The Hayman Fire started on June 8, 2002, about 1.5 miles southwest of Tappan Mountain on the south side of County Highway 77, in Park County, Colorado (fig. 1). It was first reported at about 1 acre in size at approximately 1655 hours (appendix C). An aggressive initial attack response consisted of air tankers, helicopters, engines, and ground crews, but they were...

Using BEHAVEPlus for predicting fire behavior in southern Appalachian hardwood stands subjected to fuel reduction treatments

Treesearch

Helen H. Mohr; Thomas A. Waldrop; Dean M. Simon

2010-01-01

There is a crucial need for fuel reduction in United States forests due to decades of fuel accumulation resulting from fire exclusion. The National Fire and Fire Surrogate Study (FFS) addresses this issue by examining the effects of three fuel reduction treatments on numerous response variables. At an FFS site in the southern Appalachian Mountains, fuels were altered...

Fuel treatments alter the effects of wildfire in a mixed-evergreen forest, Oregon, USA.

Treesearch

Crystal L. Raymond; David L. Peterson

2005-01-01

We had the rare opportunity to quantify the relationship between fuels and fire severity using prefire surface and canopy fuel data and fire severity data after a wildfire. The study area is a mixed-evergreen forest of southwestern Oregon with a mixed-severity fire regime. Modeled fire behavior showed that thinning reduced canopy fuels, thereby decreasing the potential...

The wildland fuel cell concept: an approach to characterize fine-scale variation in fuels and fire in frequently burned longleaf pine forests

Treesearch

J. Kevin Hiers; Joseph J. O’Brien; R. J. Mitchell; John M. Grego; E. Louise Loudermilk

2009-01-01

In ecosystems with frequent surface fire regimes, fire and fuel heterogeneity has been largely overlookedowing to the lack of unburned patches and the difficulty in measuring fire behavior at fine scales (0.1–10 m). The diversevegetation in these ecosystems varies at these fine scales. This diversity could be...

Fuels and fire in land-management planning: Part 3. Costs and losses for management options.

Treesearch

Wayne G. Maxwell; David V. Sandberg; Franklin R. Ward

1983-01-01

An approach is illustrated for computing expected costs of fire protection; fuel treatment; fire suppression; damage values; and percent of area lost to wildfire for a management or rotation cycle. Input is derived from Part 1, a method for collecting and classifying the total fuel complex, and Part 2, a method for appraising and rating probable fire behavior. This...

How fuel treatment types, locations, and amounts impact landscape-scale fire behavior and carbon dynamics

Treesearch

Christopher A. Dicus; Kevin J. Osborne

2015-01-01

When managing for fire across a large landscape, the types of fuel treatments, the locations of treatments, and the percentage of the landscape being treated should all interact to impact not only potential fire size, but also carbon dynamics across that landscape. To investigate these interactions, we utilized a forest growth model (FVS-FFE) and fire simulation...

Estimated smoldering probability: a new tool for predicting ground fire in the organic soils on the North Carolina Coastal Plain

Treesearch

James Reardon; Gary Curcio

2011-01-01

In the Southeastern United States, fires in pocosin wetlands and other similar vegetation communities with deep organic soils are a serious concern to fire managers. Highly flammable shrubs, such as gallberry and fetterbush, and small evergreen trees, such as red and loblolly bay, create the potential for extreme surface fire behavior. Moreover, deep organic soils...

Database of in-situ field measurements for estimates of fuel consumption and fire emissions in Siberia

NASA Astrophysics Data System (ADS)

Kukavskaya, Elena; Conard, Susan; Buryak, Ludmila; Ivanova, Galina; Soja, Amber; Kalenskaya, Olga; Zhila, Sergey; Zarubin, Denis; Groisman, Pavel

2016-04-01

Wildfires show great variability in the amount of fuel consumed and carbon emitted to the atmosphere. Various types of models are used to calculate global or large scale regional fire emissions. However, in the databases used to estimate fuel consumptions, data for Russia are typically under-represented. Meanwhile, the differences in vegetation and fire regimes in the boreal forests in North America and Eurasia argue strongly for the need of regional ecosystem-specific data. For about 15 years we have been collecting field data on fuel loads and consumption in different ecosystem types of Siberia. We conducted a series of experimental burnings of varying fireline intensity in Scots pine and larch forests of central Siberia to obtain quantitative and qualitative data on fire behavior and carbon emissions. In addition, we examined wildfire behavior and effects in different vegetation types including Scots pine, Siberian pine, fir, birch, poplar, and larch-dominated forests; evergreen coniferous shrubs; grasslands, and peats. We investigated various ecosystem zones of Siberia (central and southern taiga, forest-steppe, steppe, mountains) in the different subjects of the Russian Federation (Krasnoyarsk Kray, Republic of Khakassia, Republic of Buryatia, Tuva Republic, Zabaikalsky Kray). To evaluate the impact of forest practices on fire emissions, burned and unburned logged sites and forest plantations were examined. We found large variations of fuel consumption and fire emission rates among different vegetation types depending on growing conditions, fire behavior characteristics and anthropogenic factors. Changes in the climate system result in an increase in fire frequency, area burned, the number of extreme fires, fire season length, fire season severity, and the number of ignitions from lightning. This leads to an increase of fire-related emissions of carbon to the atmosphere. The field measurement database we compiled is required for improving accuracy of existing biomass burning models and for use by air quality agencies in developing regional strategies to mitigate negative smoke impacts on human health and environment. The research was supported by the Grant of the President of the Russian Federation MK-4646.2015.5, RFBR grant # 15-04-06567, and the NASA LCLUC Program.

Short-Range Temporal Interactions in Sleep; Hippocampal Spike Avalanches Support a Large Milieu of Sequential Activity Including Replay

PubMed Central

Mahoney, J. Matthew; Titiz, Ali S.; Hernan, Amanda E.; Scott, Rod C.

2016-01-01

Hippocampal neural systems consolidate multiple complex behaviors into memory. However, the temporal structure of neural firing supporting complex memory consolidation is unknown. Replay of hippocampal place cells during sleep supports the view that a simple repetitive behavior modifies sleep firing dynamics, but does not explain how multiple episodes could be integrated into associative networks for recollection during future cognition. Here we decode sequential firing structure within spike avalanches of all pyramidal cells recorded in sleeping rats after running in a circular track. We find that short sequences that combine into multiple long sequences capture the majority of the sequential structure during sleep, including replay of hippocampal place cells. The ensemble, however, is not optimized for maximally producing the behavior-enriched episode. Thus behavioral programming of sequential correlations occurs at the level of short-range interactions, not whole behavioral sequences and these short sequences are assembled into a large and complex milieu that could support complex memory consolidation. PMID:26866597

BK channels are required for multisensory plasticity in the oculomotor system

PubMed Central

Nelson, Alexandra; Faulstich, Michael; Moghadam, Setareh; Onori, Kimberly; Meredith, Andrea; du Lac, Sascha

2017-01-01

SUMMARY Neural circuits are endowed with several forms of intrinsic and synaptic plasticity that could contribute to adaptive changes in behavior, but circuit complexities have hindered linking specific cellular mechanisms with their behavioral consequences. Eye movements generated by simple brainstem circuits provide a means for relating cellular plasticity to behavioral gain control. Here we show that firing rate potentiation, a form of intrinsic plasticity mediated by reductions in BK-type calcium activated potassium currents in spontaneously firing neurons, is engaged during optokinetic reflex compensation for inner ear dysfunction. Vestibular loss triggers transient increases in postsynaptic excitability, occlusion of firing rate potentiation, and reductions in BK currents in vestibular nucleus neurons. Concurrently, adaptive increases in visually-evoked eye movements rapidly restore oculomotor function in wildtype mice but are profoundly impaired in BK channel null mice. Activity-dependent regulation of intrinsic excitability may be a general mechanism for adaptive control of behavioral output in multisensory circuits. PMID:27989457

Unmanned Vehicle Material Flammability Test

NASA Technical Reports Server (NTRS)

Urban, David; Ruff, Gary A.; Fernandez-Pello, A. Carlos; T’ien, James S.; Torero, Jose L.; Cowlard, Adam; Rouvreau, Sebastian; Minster, Olivier; Toth, Balazs; Legros, Guillaume;

On The Usage Of Fire Smoke Emissions In An Air Quality Forecasting System To Reduce Particular Matter Forecasting Error

NASA Astrophysics Data System (ADS)

Huang, H. C.; Pan, L.; McQueen, J.; Lee, P.; ONeill, S. M.; Ruminski, M.; Shafran, P.; DiMego, G.; Huang, J.; Stajner, I.; Upadhayay, S.; Larkin, N. K.

2016-12-01

Wildfires contribute to air quality problems not only towards primary emissions of particular matters (PM) but also emitted ozone precursor gases that can lead to elevated ozone concentration. Wildfires are unpredictable and can be ignited by natural causes such as lightning or accidently by human negligent behavior such as live cigarette. Although wildfire impacts on the air quality can be studied by collecting fire information after events, it is extremely difficult to predict future occurrence and behavior of wildfires for real-time air quality forecasts. Because of the time constraints of operational air quality forecasting, assumption of future day's fire behavior often have to be made based on observed fire information in the past. The United States (U.S.) NOAA/NWS built the National Air Quality Forecast Capability (NAQFC) based on the U.S. EPA CMAQ to provide air quality forecast guidance (prediction) publicly. State and local forecasters use the forecast guidance to issue air quality alerts in their area. The NAQFC fine particulates (PM2.5) prediction includes emissions from anthropogenic and biogenic sources, as well as natural sources such as dust storms and fires. The fire emission input to the NAQFC is derived from the NOAA NESDIS HMS fire and smoke detection product and the emission module of the US Forest Service BlueSky Smoke Modeling Framework. This study focuses on the error estimation of NAQFC PM2.5 predictions resulting from fire emissions. The comparisons between the NAQFC modeled PM2.5 and the EPA AirNow surface observation show that present operational NAQFC fire emissions assumption can lead to a huge error in PM2.5 prediction as fire emissions are sometimes placed at wrong location and time. This PM2.5 prediction error can be propagated from the fire source in the Northwest U.S. to downstream areas as far as the Southeast U.S. From this study, a new procedure has been identified to minimize the aforementioned error. An additional 24 hours reanalysis-run of NAQFC using same-day observed fire emission are being tested. Preliminary results have shown that this procedure greatly improves the PM2.5 predictions at both nearby and downstream areas from fire sources. The 24 hours reanalysis-run is critical and necessary especially during extreme fire events to provide better PM2.5 predictions.

Effects of fire on chaparral soils in Arizona and California and postfire management implications

Treesearch

Leonard F. DeBano

1989-01-01

Wildfires and prescribed burns are common throughout Arizona and California chaparral. Predicting fire effects requires understanding fire behavior, estimating soil heating, and predicting changes in soil properties. Substantial quantities of some nutrients, particularly nitrogen and phosphorus, are lost directly during combustion. Highly available nutrients released...

Wildland fire and the wilderness visitor experience

Treesearch

Sierra L. Schroeder; Ingrid E. Schneider

2010-01-01

The purpose of this study was to understand wilderness visitors' perceptions of wildland fire and describe visitors' wilderness recreational experience following wildland fire in the Boundary Waters Canoe Area Wilderness (BWCAW). Qualitative interviews revealed visitors' perceptions of burned areas as well as if and how activities and behaviors were...

Using a Simple Parcel Model to Investigate the Haines Index

Treesearch

Mary Ann Jenkins; Steven K. Krueger; Ruiyu Sun

2003-01-01

The Haines Index (Haines 1988) ia fire-weather index based on stability and moisture conditions of the lower atmosphere that rates the potential for large fire growth or extreme fire behavior. The Hained Index is calculated by adding a temperature term a to a moisture term b.

A plausible neural circuit for decision making and its formation based on reinforcement learning.

PubMed

Wei, Hui; Dai, Dawei; Bu, Yijie

2017-06-01

A human's, or lower insects', behavior is dominated by its nervous system. Each stable behavior has its own inner steps and control rules, and is regulated by a neural circuit. Understanding how the brain influences perception, thought, and behavior is a central mandate of neuroscience. The phototactic flight of insects is a widely observed deterministic behavior. Since its movement is not stochastic, the behavior should be dominated by a neural circuit. Based on the basic firing characteristics of biological neurons and the neural circuit's constitution, we designed a plausible neural circuit for this phototactic behavior from logic perspective. The circuit's output layer, which generates a stable spike firing rate to encode flight commands, controls the insect's angular velocity when flying. The firing pattern and connection type of excitatory and inhibitory neurons are considered in this computational model. We simulated the circuit's information processing using a distributed PC array, and used the real-time average firing rate of output neuron clusters to drive a flying behavior simulation. In this paper, we also explored how a correct neural decision circuit is generated from network flow view through a bee's behavior experiment based on the reward and punishment feedback mechanism. The significance of this study: firstly, we designed a neural circuit to achieve the behavioral logic rules by strictly following the electrophysiological characteristics of biological neurons and anatomical facts. Secondly, our circuit's generality permits the design and implementation of behavioral logic rules based on the most general information processing and activity mode of biological neurons. Thirdly, through computer simulation, we achieved new understanding about the cooperative condition upon which multi-neurons achieve some behavioral control. Fourthly, this study aims in understanding the information encoding mechanism and how neural circuits achieve behavior control. Finally, this study also helps establish a transitional bridge between the microscopic activity of the nervous system and macroscopic animal behavior.

Commanding Officer Firings for Personal Misconduct: Considerations for the Navy’s Long-term Ethical Leadership Strategy

DTIC Science & Technology

2013-04-11

commanding officers due to unethical personal behavior and offers suggestions for positive actions to be included as part of an overall strategy...concerning constructive ways to build a comprehensive strategy to stem the tide of unethical behavior at the command level in order to reinforce and...with unethical behavior of COs in the Navy today. The trend observed in 2010 continued in 2011 and 2012. The number of COs fired for personal

Progress in Fire Detection and Suppression Technology for Future Space Missions

NASA Technical Reports Server (NTRS)

Friedman, Robert; Urban, David L.

2000-01-01

Fire intervention technology (detection and suppression) is a critical part of the strategy of spacecraft fire safety. This paper reviews the status, trends, and issues in fire intervention, particularly the technology applied to the protection of the International Space Station and future missions beyond Earth orbit. An important contribution to improvements in spacecraft fire safety is the understanding of the behavior of fires in the non-convective (microgravity) environment of Earth-orbiting and planetary-transit spacecraft. A key finding is the strong influence of ventilation flow on flame characteristics, flammability limits and flame suppression in microgravity. Knowledge of these flow effects will aid the development of effective processes for fire response and technology for fire suppression.

Residents' responses to wildland fire programs: a review of cognitive and behavioral studies

Treesearch

James D. Absher; Jerry J. Vaske; Lori B. Shelby

2009-01-01

A compilation and summary of four research studies is presented. They were aimed at developing a theoretical and practical understanding of homeowners’ attitudes and behaviors in the wildland-urban interface (WUI) in relation to the threat from wildland fires. Individual studies focused on models and methods that measured (1) value orientations (patterns of basic...

Sudden oak death-caused changes to surface fuel loading and potential fire behavior in Douglas-fir-tanoak forests

Treesearch

Y.S. Valachovic; C.A. Lee; H. Scanlon; J.M. Varner; R. Glebocki; B.D. Graham; D.M. Rizzo

2011-01-01

We compared stand structure and fuel loading in northwestern California forests invaded by Phytophthora ramorum, the cause of sudden oak death, to assess whether the continued presence of this pathogen alters surface fuel loading and potential fire behavior in ways that may encumber future firefighting response. To attempt to account for these...

Chapter 11 - Post-hurricane fuel dynamics and implications for fire behavior (Project SO-EM-F-12-01)

Treesearch

Shanyue Guan; G. Geoff. Wang

2018-01-01

Hurricanes have long been a powerful and recurring disturbance in many coastal forest ecosystems. Intense hurricanes often produce a large amount of dead fuels in their affected forests. How the post-hurricane fuel complex changes with time, due todecomposition and management such as salvage, and its implications for fire behavior remain largely unknown....

Potential fire behavior is reduced following forest restoration treatments

Treesearch

Peter Z. Fule; Charles McHugh; Thomas A. Heinlein; W. Wallace Covington

2001-01-01

Potential fire behavior was compared under dry, windy weather conditions in 12 ponderosa pine stands treated with alternative thinning prescriptions in the wildland/urban interface of Flagstaff, Arizona. Prior to thinning, stands averaged 474 trees/ acre, 158 ft2/acre basal area, crown bulk density 0.0045 lb/ft3, and crown base height 19.2 ft. Three thinning treatments...

An improved canopy wind model for predicting wind adjustment factors and wildland fire behavior

Treesearch

W. J. Massman; J. M. Forthofer; M. A. Finney

2017-01-01

The ability to rapidly estimate wind speed beneath a forest canopy or near the ground surface in any vegetation is critical to practical wildland fire behavior models. The common metric of this wind speed is the "mid-flame" wind speed, UMF. However, the existing approach for estimating UMF has some significant shortcomings. These include the assumptions that...

Developing Custom Fire Behavior Fuel Models for Mediterranean Wildland-Urban Interfaces in Southern Italy

NASA Astrophysics Data System (ADS)

Elia, Mario; Lafortezza, Raffaele; Lovreglio, Raffaella; Sanesi, Giovanni

2015-09-01

The dramatic increase of fire hazard in wildland-urban interfaces (WUIs) has required more detailed fuel management programs to preserve ecosystem functions and human settlements. Designing effective fuel treatment strategies allows to achieve goals such as resilient landscapes, fire-adapted communities, and ecosystem response. Therefore, obtaining background information on forest fuel parameters and fuel accumulation patterns has become an important first step in planning fuel management interventions. Site-specific fuel inventory data enhance the accuracy of fuel management planning and help forest managers in fuel management decision-making. We have customized four fuel models for WUIs in southern Italy, starting from forest classes of land-cover use and adopting a hierarchical clustering approach. Furthermore, we provide a prediction of the potential fire behavior of our customized fuel models using FlamMap 5 under different weather conditions. The results suggest that fuel model IIIP (Mediterranean maquis) has the most severe fire potential for the 95th percentile weather conditions and the least severe potential fire behavior for the 85th percentile weather conditions. This study shows that it is possible to create customized fuel models directly from fuel inventory data. This achievement has broad implications for land managers, particularly forest managers of the Mediterranean landscape, an ecosystem that is susceptible not only to wildfires but also to the increasing human population and man-made infrastructures.

Developing Custom Fire Behavior Fuel Models for Mediterranean Wildland-Urban Interfaces in Southern Italy.

PubMed

Elia, Mario; Lafortezza, Raffaele; Lovreglio, Raffaella; Sanesi, Giovanni

2015-09-01

The dramatic increase of fire hazard in wildland-urban interfaces (WUIs) has required more detailed fuel management programs to preserve ecosystem functions and human settlements. Designing effective fuel treatment strategies allows to achieve goals such as resilient landscapes, fire-adapted communities, and ecosystem response. Therefore, obtaining background information on forest fuel parameters and fuel accumulation patterns has become an important first step in planning fuel management interventions. Site-specific fuel inventory data enhance the accuracy of fuel management planning and help forest managers in fuel management decision-making. We have customized four fuel models for WUIs in southern Italy, starting from forest classes of land-cover use and adopting a hierarchical clustering approach. Furthermore, we provide a prediction of the potential fire behavior of our customized fuel models using FlamMap 5 under different weather conditions. The results suggest that fuel model IIIP (Mediterranean maquis) has the most severe fire potential for the 95th percentile weather conditions and the least severe potential fire behavior for the 85th percentile weather conditions. This study shows that it is possible to create customized fuel models directly from fuel inventory data. This achievement has broad implications for land managers, particularly forest managers of the Mediterranean landscape, an ecosystem that is susceptible not only to wildfires but also to the increasing human population and man-made infrastructures.

Post-Fire Recovery of Eco-Hydrologic Behavior Given Historic and Projected Climate Variability in California Mediterranean Type Environments

NASA Astrophysics Data System (ADS)

Seaby, L. P.; Tague, C. L.; Hope, A. S.

2006-12-01

The Mediterranean type environments (MTEs) of California are characterized by a distinct wet and dry season and high variability in inter-annual climate. Water limitation in MTEs makes eco-hydrological processes highly sensitive to both climate variability and frequent fire disturbance. This research modeled post-fire eco- hydrologic behavior under historical and moderate and extreme scenarios of future climate in a semi-arid chaparral dominated southern California MTE. We used a physically-based, spatially-distributed, eco- hydrological model (RHESSys - Regional Hydro-Ecologic Simulation System), to capture linkages between water and vegetation response to the combined effects of fire and historic and future climate variability. We found post-fire eco-hydrologic behavior to be strongly influenced by the episodic nature of MTE climate, which intensifies under projected climate change. Higher rates of post-fire net primary productivity were found under moderate climate change, while more extreme climate change produced water stressed conditions which were less favorable for vegetation productivity. Precipitation variability in the historic record follows the El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO), and these inter-annual climate characteristics intensify under climate change. Inter-annual variation in streamflow follows these precipitation patterns. Post-fire streamflow and carbon cycling trajectories are strongly dependent on climate characteristics during the first 5 years following fire, and historic intra-climate variability during this period tends to overwhelm longer term trends and variation that might be attributable to climate change. Results have implications for water resource availability, vegetation type conversion from shrubs to grassland, and changes in ecosystem structure and function.

Evaluation of post-fire strength of concrete flexural members reinforced with glass fiber reinforced polymer (GFRP) bars

NASA Astrophysics Data System (ADS)

Ellis, Devon S.

Owing to their corrosion resistance and superior strength to weight ratio, there has been, over the past two decades, increased interest in the use of fiber-reinforced polymer (FRP) reinforcing bars in reinforced concrete structural members. The mechanical behavior of FRP reinforcement differs from that of steel reinforcement. For example, FRP reinforcement exhibit a linear stress-strain behavior until the bar ruptures and the strength, stiffness and bond properties of FRP reinforcement are affected more adversely by elevated temperatures. All structures are subject to the risk of damage by fire and fires continue to be a significant cause of damage to structures. Many structures do not collapse after being exposed to fire. The safety of the structure for any future use is dependent on the ability to accurately estimate the post-fire load capacity of the structure. Assuming that the changes, due to fire exposure, in the mechanical behavior of the GFRP reinforcing bar and concrete, and the bond between the reinforcing bar and the concrete are understood, an analytical procedure for estimating the post-fire strength of GFRP reinforced concrete flexural elements can be developed. This thesis investigates the changes in: a) tensile properties and bond of GFRP bars; and b) the flexural behavior of GFRP reinforced concrete beams flexural after being exposed to elevated temperatures up to 400°C and cooled to ambient temperature. To this end, twelve tensile tests, twelve pullout bond tests and ten four-point beam tests were performed. The data from the tests were used to formulate analytical procedures for evaluating the post-fire strength of GFRP reinforced concrete beams. The procedure produced conservative results when compared with the experimental data. In general, the residual tensile strength and modulus of elasticity of GFRP bars decrease as the exposure temperature increases. The loss in properties is however, smaller than that observed by other researchers when similar bars were tested while hot. The residual bond strength was also found to decrease with increase in exposure temperature. Residual bond mechanism and flexural behavior were found to be influenced, in complex ways, by the exposure to elevated temperatures. Additionally, an apparent "yielding plateau" and an apparent increase in bar ductility was observed in the post-heat behavior of some of the tensile specimens. This points to a potential for heat treatment of FRP bars to achieve higher ductility.

Fuels planning: science synthesis and integration; environmental consequences fact sheet 09: Fire and Fuels Extension to the Forest Vegetation Simulator (FFE-FVS)

Treesearch

Elizabeth Reinhardt

2005-01-01

FFE-FVS is a model linking stand development, fuel dynamics, fire behavior and fire effects. It allows comparison of mid- to long-term effects of management alternatives including harvest, mechanical fuel treatment, prescribed fire, salvage, and no action. This fact sheet identifies the intended users and uses, required inputs, what the model does, and tells the user...

Effects of dormant and growing season burning on surface fuels and potential fire behavior in northern Florida longleaf pine (Pinus palustris) flatwoods

Treesearch

James B. Cronan; Clinton S. Wright; Maria Petrova

2015-01-01

Prescribed fire is widely used to manage fuels in high-frequency, low-severity fire regimes including pine flatwoods of the southeastern USA where prescribed burning during the growing season (the frost-free period during the calendar year) has become more common in recent decades. Growing season prescribed fires address ecological management objectives that focus on...

Behavior of Insulated Carbon-FRP-Strengthened RC Beams Exposed to Fire

NASA Astrophysics Data System (ADS)

Sayin, B.

2014-09-01

There are two main approaches to improving the fire resistance of fiber-reinforced polymer (FRP) systems. While the most common method is to protect or insulate the FRP system, an other way is to use fibers and resins with a better fire performance. This paper presents a numerical investigation into the five protection behavior of insulated carbon-fiber-reinforced-polymer (CFRP)-strengthened reinforced concrete (RC) beams. The effects of external loading and thermal expansion of materials at elevated temperatures are taken into consideration in a finite-element model. The validity of the numerical model is demonstrated with results from an existing experimental study on insulated CFRP-strengthened RC beams. Conclusions of this investigation are employed to predict the structural behavior of CFRP-strengthened concrete structures.

[Vertical distribution of fuels in Pinus yunnanensis forest and related affecting factors].

PubMed

Wang, San; Niu, Shu-Kui; Li, De; Wang, Jing-Hua; Chen, Feng; Sun, Wu

2013-02-01

In order to understand the effects of fuel loadings spatial distribution on forest fire kinds and behaviors, the canopy fuels and floor fuels of Pinus yunnanensis forests with different canopy density, diameter at breast height (DBH), tree height, and stand age and at different altitude, slope grade, position, and aspect in Southwest China were taken as test objects, with the fuel loadings and their spatial distribution characteristics at different vertical layers compared and the fire behaviors in different stands analyzed. The relationships between the fuel loadings and the environmental factors were also analyzed by canonical correspondence analysis (CCA). In different stands, there existed significant differences in the vertical distribution of fuels. Pinus yunnanensis-Qak-Syzygium aromaticum, Pinus yunnanensis-oak, and Pinus yunnanensis forests were likely to occur floor fire but not crown fire, while Pinus yunnanensis-Platycladus orientalis, Pinus yunnanensis-Keteleeria fortune, and Keteleeria fortune-Pinus yunnanensis were not only inclined to occur floor fire, but also, the floor fire could be easily transformed into crown fire. The crown fuels were mainly affected by the stand age, altitude, DBH, and tree height, while the floor fuels were mainly by the canopy density, slope grade, altitude, and stand age.

[Fire behavior of ground surface fuels in Pinus koraiensis and Quercus mongolica mixed forest under no wind and zero slope condition: a prediction with extended Rothermel model].

PubMed

Zhang, Ji-Li; Liu, Bo-Fei; Chu, Teng-Fei; Di, Xue-Ying; Jin, Sen

2012-06-01

A laboratory burning experiment was conducted to measure the fire spread speed, residual time, reaction intensity, fireline intensity, and flame length of the ground surface fuels collected from a Korean pine (Pinus koraiensis) and Mongolian oak (Quercus mongolica) mixed stand in Maoer Mountains of Northeast China under the conditions of no wind, zero slope, and different moisture content, load, and mixture ratio of the fuels. The results measured were compared with those predicted by the extended Rothermel model to test the performance of the model, especially for the effects of two different weighting methods on the fire behavior modeling of the mixed fuels. With the prediction of the model, the mean absolute errors of the fire spread speed and reaction intensity of the fuels were 0.04 m X min(-1) and 77 kW X m(-2), their mean relative errors were 16% and 22%, while the mean absolute errors of residual time, fireline intensity and flame length were 15.5 s, 17.3 kW X m(-1), and 9.7 cm, and their mean relative errors were 55.5%, 48.7%, and 24%, respectively, indicating that the predicted values of residual time, fireline intensity, and flame length were lower than the observed ones. These errors could be regarded as the lower limits for the application of the extended Rothermel model in predicting the fire behavior of similar fuel types, and provide valuable information for using the model to predict the fire behavior under the similar field conditions. As a whole, the two different weighting methods did not show significant difference in predicting the fire behavior of the mixed fuels by extended Rothermel model. When the proportion of Korean pine fuels was lower, the predicted values of spread speed and reaction intensity obtained by surface area weighting method and those of fireline intensity and flame length obtained by load weighting method were higher; when the proportion of Korean pine needles was higher, the contrary results were obtained.

The ability of winter grazing to reduce wildfire size, intensity ...

EPA Pesticide Factsheets

A recent study by Davies et al. sought to test whether winter grazing could reduce wildfire size, fire behavior metrics, and fire-induced plant mortality in shrub-grasslands. The authors concluded that ungrazed rangelands may experience more fire-induced mortality of native perennial bunchgrasses. The authors also presented several statements regarding the benefits of winter grazing on post-fire plant community responses. However, this commentary will show that the study by Davies et al. has underlying methodological flaws, lacks data necessary to support their conclusions, and does not provide an accurate discussion on the effect of grazing on rangeland ecosystems. Importantly, Davies et al. presented no data on the post-fire mortality of the perennial bunchgrasses or on the changes in plant community composition following their experimental fires. Rather, Davies et al. inferred these conclusions based off their observed fire behavior metrics of maximum temperature and a term described as the “heat load”. However, neither metric is appropriate for elucidating the heat flux impacts on plants. This lack of post-fire data, several methodological flaws, and the use of inadequate metrics describing heat cast doubts on the authors’ ability to support their stated conclusions. This article is a commentary highlights the scientific shortcomings in a forthcoming paper by Davies et al. in the International Journal of Wildland Fire. The study has methodological flaw

Fire and riparian ecosystems in landscapes of the western USA

Treesearch

Kathleen A. Dwire; J. Boone Kauffman

2003-01-01

Despite the numerous values of riparian areas and the recognition of fire as a critical natural disturbance, few studies have investigated the behavior, properties, and influence of natural fire in riparian areas of the western USA. Riparian areas frequently differ from adjacent uplands in vegetative composition and structure, geomorphology, hydrology, microclimate,...

False Fire Alarms: A Deviant Pattern of Seeking Help.

ERIC Educational Resources Information Center

Camblin, Louise; Weinland, Laura

1987-01-01

Discusses the phenomenon of false fire alarms, the deliberate, intentional false reporting of fires, by mentally troubled persons as a primitive kind of help-seeking behavior. Several common themes found by reviewing false alarm cases are presented. Suggests that identifying the intrapsychic dynamics of false alarm reporters could be useful in…

Characterizing crown fuel distribution for conifers in the interior western United States

Treesearch

Seth Ex; Frederick W. Smith; Tara Keyser

2015-01-01

Canopy fire hazard evaluation is essential for prioritizing fuel treatments and for assessing potential risk to firefighters during suppression activities. Fire hazard is usually expressed as predicted potential fire behavior, which is sensitive to the methodology used to quantitatively describe fuel profiles: methodologies that assume that fuel is distributed...

A portable system for characterizing wildland fire behavior

Treesearch

Bret Butler; D. Jimenez; J. Forthofer; K. Shannon; Paul Sopko

2010-01-01

A field deployable system for quantifying energy and mass transport in wildland fires is described. The system consists of two enclosures: The first is a sensor/data logger combination package that allows characterization of convective/radiant energy transport in fires. This package contains batteries, a programmable data logger, sensors, and other electronics. The...

What kind of cutting and thinning can prevent crown fires?

Treesearch

Mick Harrington

2008-01-01

Many land managers are attempting to lessen the probability of severe wildfire behavior and impacts, especially near communities, by manipulating canopy and surface fuel characteristics. Various interest groups have questioned the value of fuels treatments. In reality, apart from fire exposure when a real fire went through a treated stand, effectiveness of fuel...

Impacts of climate on shrubland fuels and fire behavior in the Owyhee Basin, Idaho

NASA Astrophysics Data System (ADS)

Vogelmann, J. E.; Shi, H.; Hawbaker, T.; Li, Z.

2013-12-01

There is evidence that wildland fire is increasing as a function of global change. However, fire activity is spatially, temporally and ecologically variable across the globe, and our understanding of fire risk and behavior in many ecosystems is limited. After a series of severe fire seasons that occurred during the late 1990's in the western United States, the LANDFIRE program was developed with the goals of providing the fire community with objective spatial fuel data for assessing wildland fire risk. Even with access to the data provided by LANDFIRE, assessing fire behavior in shrublands in sagebrush-dominated ecosystems of the western United States has proven especially problematic, in part due to the complex nature of the vegetation, the variable influence of understory vegetation including invasive species (e.g. cheatgrass), and prior fire history events. Climate is undoubtedly playing a major role, affecting the intra- and inter-annual variability in vegetation conditions, which in turn impacts fire behavior. In order to further our understanding of climate-vegetation-fire interactions in shrublands, we initiated a study in the Owyhee Basin, which is located in southwestern Idaho and adjacent Nevada. Our goals include: (1) assessing the relationship between climate and vegetation condition, (2) quantifying the range of temporal variability in grassland and shrubland fuel loads, (3) identifying methods to operationally map the variability in fuel loads, and (4) assessing how the variability in fuel loads affect fire spread simulations. To address these goals, we are using a wide variety of geospatial data, including remotely sensed time-series data sets derived from MODIS and Landsat, and climate data from DAYMET and PRISM. Remotely-sensed information is used to characterize climate-induced temporal variability in primary productivity in the Basin, where fire spread can be extensive after senescence when dry vegetation is added to dead fuel loads. Gridded climate data indicate that this area has become warmer and dryer over the previous three decades. We have also observed that fires are especially prevalent in areas that have high Normalized Difference Vegetation Index (NDVI) values in the spring, followed by low NDVI in the summer. At present we are concentrating on the temporally rich MODIS data to map spatial and temporal variability in live fuel loads. To translate NDVI to biomass, we are scaling the range of biomass values using data from the literature. We assume that departure from maximum NDVI, typically occurring during spring, to NDVI values later in the season are related to the proportion of live biomass transferred to dead biomass, which burns more readily than green biomass. Using the FARSITE fire spread model, our initial simulations show that the conversion from live herbaceous fuel to dead fuel increases the burn area by 30% compared with using default static fuel parameters. This indicates that current fuel models underestimate fire spread and areas that could potentially burn. Our study also indicates that a combined remote sensing product with good temporal resolution (MODIS) and spatial resolution (Landsat) is necessary to provide accurate information on the fuel dynamics in shrublands.

Fire behavior of halogen-free flame retardant electrical cables with the cone calorimeter.

PubMed

Meinier, Romain; Sonnier, Rodolphe; Zavaleta, Pascal; Suard, Sylvain; Ferry, Laurent

2018-01-15

Fires involving electrical cables are one of the main hazards in Nuclear Power Plants (NPPs). Cables are complex assemblies including several polymeric parts (insulation, bedding, sheath) constituting fuel sources. This study provides an in-depth characterization of the fire behavior of two halogen-free flame retardant cables used in NPPs using the cone calorimeter. The influence of two key parameters, namely the external heat flux and the spacing between cables, on the cable fire characteristics is especially investigated. The prominent role of the outer sheath material on the ignition and the burning at early times was highlighted. A parameter of utmost importance called transition heat flux, was identified and depends on the composition and the structure of the cable. Below this heat flux, the decomposition is limited and concerns only the sheath. Above it, fire hazard is greatly enhanced because most often non-flame retarded insulation part contributes to heat release. The influence of spacing appears complex, and depends on the considered fire property. Copyright © 2017 Elsevier B.V. All rights reserved.

Behavior of Steel-Sheathed Shear Walls Subjected to Seismic and Fire Loads.

PubMed

Hoehler, Matthew S; Smith, Christopher M; Hutchinson, Tara C; Wang, Xiang; Meacham, Brian J; Kamath, Praveen

2017-07-01

A series of tests was conducted on six 2.7 m × 3.7 m shear wall specimens consisting of cold-formed steel framing sheathed on one side with sheet steel adhered to gypsum board and on the opposite side with plain gypsum board. The specimens were subjected to various sequences of simulated seismic shear deformation and fire exposure to study the influence of multi-hazard interactions on the lateral load resistance of the walls. The test program was designed to complement a parallel effort at the University of California, San Diego to investigate a six-story building subjected to earthquakes and fires. The test results reported here indicate that the fire exposure caused a shift in the failure mode of the walls from local buckling of the sheet steel in cases without fire exposure, to global buckling of the sheet steel with an accompanying 35 % reduction in lateral load capacity after the wall had been exposed to fire. This behavior appears to be predictable, which is encouraging from the standpoint of residual lateral load capacity under these severe multi-hazard actions.

Capabilities of current wildfire models when simulating topographical flow

NASA Astrophysics Data System (ADS)

Kochanski, A.; Jenkins, M.; Krueger, S. K.; McDermott, R.; Mell, W.

2009-12-01

Accurate predictions of the growth, spread and suppression of wild fires rely heavily on the correct prediction of the local wind conditions and the interactions between the fire and the local ambient airflow. Resolving local flows, often strongly affected by topographical features like hills, canyons and ridges, is a prerequisite for accurate simulation and prediction of fire behaviors. In this study, we present the results of high-resolution numerical simulations of the flow over a smooth hill, performed using (1) the NIST WFDS (WUI or Wildland-Urban-Interface version of the FDS or Fire Dynamic Simulator), and (2) the LES version of the NCAR Weather Research and Forecasting (WRF-LES) model. The WFDS model is in the initial stages of development for application to wind flow and fire spread over complex terrain. The focus of the talk is to assess how well simple topographical flow is represented by WRF-LES and the current version of WFDS. If sufficient progress has been made prior to the meeting then the importance of the discrepancies between the predicted and measured winds, in terms of simulated fire behavior, will be examined.

Changes in canopy fuels and fire behavior after ponderosa pine restoration treatments: A landscape perspective

Treesearch

J. P. Roccaforte; P. Z. Fule

2008-01-01

(Please note, this is an abstract only) We modeled crown fire behavior and assessed changes in canopy fuels before and after the implementation of restoration treatments in a ponderosa pine landscape at Mt. Trumbull, Arizona. We measured 117 permanent plots before (1996/1997) and after (2003) thinning and burning treatments. The plots are evenly distributed across the...

Residents' responses to wildland fire programs: a review of cognitive and behavioral studies

Treesearch

James D. Absher; Jerry J. Vaske; Lori B. Shelby

2009-01-01

During the past 8 years the U.S. Forest Service’s Pacific Southwest Research Station, in cooperation with Colorado State University has conducted 4 research projects aimed at developing a theoretical and practical understanding of homeowners’ attitudes and behaviors in the Wildland Urban Interface in relation to the threat from wildland fires. Initial work focused on...

Fuel Consumption and Fire Emissions Estimates in Siberia: Impact of Vegetation Types, Meteorological Conditions, Forestry Practices and Fire Regimes

NASA Astrophysics Data System (ADS)

Kukavskaya, Elena; Conard, Susan; Ivanova, Galina; Buryak, Ludmila; Soja, Amber; Zhila, Sergey

2015-04-01

Boreal forests play a crucial role in carbon budgets with Siberian carbon fluxes and pools making a major contribution to the regional and global carbon cycle. Wildfire is the main ecological disturbance in Siberia that leads to changes in forest species composition and structure and in carbon storage, as well as direct emissions of greenhouse gases and aerosols to the atmosphere. At present, the global scientific community is highly interested in quantitative and accurate estimates of fire emissions. Little research on wildland fuel consumption and carbon emission estimates has been carried out in Russia until recently. From 2000 to 2007 we conducted a series of experimental fires of varying fireline intensity in light-coniferous forest of central Siberia to obtain quantitative and qualitative data on fire behavior and carbon emissions due to fires of known behavior. From 2009 to 2013 we examined a number of burned logged areas to assess the potential impact of forest practices on fire emissions. In 2013-2014 burned areas in dark-coniferous and deciduous forests were examined to determine fuel consumption and carbon emissions. We have combined and analyzed the scarce data available in the literature with data obtained in the course of our long-term research to determine the impact of various factors on fuel consumption and to develop models of carbon emissions for different ecosystems of Siberia. Carbon emissions varied drastically (from 0.5 to 40.9 tC/ha) as a function of vegetation type, weather conditions, anthropogenic effects and fire behavior characteristics and periodicity. Our study provides a basis for better understanding of the feedbacks between wildland fire emissions and changing anthropogenic disturbance patterns and climate. The data obtained could be used by air quality agencies to calculate local emissions and by managers to develop strategies to mitigate negative smoke impacts on the environmentand human health.

Integrating remote sensing and terrain data in forest fire modeling

NASA Astrophysics Data System (ADS)

Medler, Michael Johns

Forest fire policies are changing. Managers now face conflicting imperatives to re-establish pre-suppression fire regimes, while simultaneously preventing resource destruction. They must, therefore, understand the spatial patterns of fires. Geographers can facilitate this understanding by developing new techniques for mapping fire behavior. This dissertation develops such techniques for mapping recent fires and using these maps to calibrate models of potential fire hazards. In so doing, it features techniques that strive to address the inherent complexity of modeling the combinations of variables found in most ecological systems. Image processing techniques were used to stratify the elements of terrain, slope, elevation, and aspect. These stratification images were used to assure sample placement considered the role of terrain in fire behavior. Examination of multiple stratification images indicated samples were placed representatively across a controlled range of scales. The incorporation of terrain data also improved preliminary fire hazard classification accuracy by 40%, compared with remotely sensed data alone. A Kauth-Thomas transformation (KT) of pre-fire and post-fire Thematic Mapper (TM) remotely sensed data produced brightness, greenness, and wetness images. Image subtraction indicated fire induced change in brightness, greenness, and wetness. Field data guided a fuzzy classification of these change images. Because fuzzy classification can characterize a continuum of a phenomena where discrete classification may produce artificial borders, fuzzy classification was found to offer a range of fire severity information unavailable with discrete classification. These mapped fire patterns were used to calibrate a model of fire hazards for the entire mountain range. Pre-fire TM, and a digital elevation model produced a set of co-registered images. Training statistics were developed from 30 polygons associated with the previously mapped fire severity. Fuzzy classifications of potential burn patterns were produced from these images. Observed field data values were displayed over the hazard imagery to indicate the effectiveness of the model. Areas that burned without suppression during maximum fire severity are predicted best. Areas with widely spaced trees and grassy understory appear to be misrepresented, perhaps as a consequence of inaccuracies in the initial fire mapping.

Behavioral technology and its application to fire toxicology research

NASA Technical Reports Server (NTRS)

Russo, D. M.

1978-01-01

The application of behavioral technology to the toxicity testing of pyrolysis/combustion (P/C) products is discussed and two categories of behavioral tests commonly employed in fire toxicology programs are reviewed. Data are presented from a comparison of carbon monoxide (CO) induced incapacitation in rats performing in a rotating wheel or under a Sidmon free-operant schedule of shock avoidance. Rats performing in the rotating wheel were behaviorally incapacitated at CO concentrations and carboxyhemoglobin levels significantly lower than those which incapacitated operant avoidance animals. It is concluded that different measures of behavioral incapacitation may vary since incapacitation is a function of the particular toxic mechanism at work and the behavioral requirements of the specific task employed in the test procedure.

Stem mortality in surface fires: Part II, experimental methods for characterizing the thermal response of tree stems to heating by fires

Treesearch

D. M. Jimenez; B. W. Butler; J. Reardon

2003-01-01

Current methods for predicting fire-induced plant mortality in shrubs and trees are largely empirical. These methods are not readily linked to duff burning, soil heating, and surface fire behavior models. In response to the need for a physics-based model of this process, a detailed model for predicting the temperature distribution through a tree stem as a function of...

Risk perceptions and behavioral context: U.S. Forest Service fire management professionals

USGS Publications Warehouse

Taylor, Jonathan G.; Carpenter, Edwin H.; Cortner, Hanna J.; Cleaves, David A.

1989-01-01

Fire managers from the U.S. Forest Service were surveyed to determine which decision factors most strongly influenced their fire‐risk decisions. Safety, the resources at risk, public opinion, and the reliability of information were important influences on these decisions. This research allowed direct comparison between fire managers’ perceptions of factor importance and how their fire‐risk decisions changed in response to those factors. These risk decisions were highly responsive to changes in context (an escaped wildfire decision versus a prescribed burning decision) as well as to changing factors. The results demonstrate the utility of using scenarios in risk research and the vital importance of context in studying risk‐taking behavior. Research which attempts to remove risk decisions from their real‐world context may well distort the nature of risk‐taking behavior.

Hands-on learning: Its effectiveness in teaching the public about wildland fire

Treesearch

Tamara M. Parkinson; Jo Ellen Force; Jane Kapler Smith

2003-01-01

This study evaluated workshops for the adult public featuring experiential learning about wildland fire. Participants used hands-on activities to investigate fire behavior and ecology and to assess hazards in the wildland-urban interface. Effectiveness was examined using a pretest, a posttest following the program, and another posttest 30 days later. Participants’...

Response of northern bats (Myotis septentrionalis) to prescribed fires in eastern Kentucky forests

Treesearch

Michael J. Lacki; Daniel R. Cox; Luke E. Dodd; Matthew B. Dickinson

2009-01-01

Prescribed fire is becoming a common management tool for restoring forests of North America; however, effects of prescribed fire on forest-dwelling bats remain unclear. During 2006 and 2007, we monitored prey availability, diet, foraging behavior, and roost selection of adult female northern bats (Myotis septentrionalis) before and after 2 prescribed...

Fire behavior and effects: Principles for archaeologists [Chapter 2

Treesearch

Kevin C. Ryan; Cassandra Koerner

2012-01-01

Fire is a natural component of earth's ecosystems. Fire has impacted most landscapes of the Americas, having left evidence of its passing in trees, soils, fossils, and cultural artifacts (Andreae 1991; Benton and Reardon 2006; Biswell 1989; Bowman and others 2009; Boyd and others 2005; Cochrane and others 1999; DeBano and others 1998; Jurney and others 2004;...

Fuel treatment effects on modeled landscape level fire behavior in the northern Sierra Nevada

Treesearch

J.J. Moghaddas; B.M. Collins; K. Menning; E.E.Y. Moghaddas; S.L. Stephens

2010-01-01

Across the western United States, decades of fire exclusion combined with past management history have contributed to the current condition of extensive areas of high-density, shade-tolerant coniferous stands that are increasingly prone to high-severity fires. Here, we report the modeled effects of constructed defensible fuel profile zones and group selection...

Atmospheric moisture's influence on fire behavior: surface moisture and plume dynamics.

Treesearch

Brian E. Potter; Joseph J. Charney; Lesley A. Fusina

2006-01-01

Nine measures of atmospheric surface moisture are tested for statistical relationships with fire size and number of fires using data from the Great Lakes region of the United States. The measures include relative humidity, water vapor mixing ratio, mixing ratio deficit, vapor pressure, vapor pressure deficit, dew point temperature, dew point depression, wet bulb...

Evaluating crown fire rate of spread predictions from physics-based models

Treesearch

C. M. Hoffman; J. Ziegler; J. Canfield; R. R. Linn; W. Mell; C. H. Sieg; F. Pimont

2015-01-01

Modeling the behavior of crown fires is challenging due to the complex set of coupled processes that drive the characteristics of a spreading wildfire and the large range of spatial and temporal scales over which these processes occur. Detailed physics-based modeling approaches such as FIRETEC and the Wildland Urban Interface Fire Dynamics Simulator (WFDS) simulate...

Spatial controls of occurrence and spread of wildfires in the Missouri Ozark Highlands

Treesearch

Jian Yang; Hong S. He; Stephen R. Shifley

2008-01-01

Understanding spatial controls on wildfires is important when designing adaptive fire management plans and optimizing fuel treatment locations on a forest landscape. Previous research about this topic focused primarily on spatial controls for fire origin locations alone. Fire spread and behavior were largely overlooked. This paper contrasts the relative importance of...

Not Getting Burned: The Importance of Fire

Treesearch

Gregory S. Amacher; Arun S. Malik; Robert G. Haight

2005-01-01

We extend existing stand-level models of forest landowner behavior in the presence of fire risk to include the level and timing of fuel management activities. These activities reduce losses if a stand ignites. Based on simulations, we find the standard result that fire risk reduces the optimal rotation age does not hold when landowners use fuel management. Instead,...

Evaluating fuel complexes for fire hazard mitigation planning in the southeastern United States

Treesearch

Anne G. Andreu; Dan Shea; Bernard R. Parresol; Roger D. Ottmar

2012-01-01

Fire hazard mitigation planning requires an accurate accounting of fuel complexes to predict potential fire behavior and effects of treatment alternatives. In the southeastern United States, rapid vegetation growth coupled with complex land use history and forest management options requires a dynamic approach to fuel characterization. In this study we assessed...

Microbial response to high severity wildfire in the southwest United States

Treesearch

Steven T. Overby; Stephen C. Hart; Gregory S. Newman; Dana Erickson

2006-01-01

Southwest United States ponderosa pine (Pinus ponderosa Dougl. ex Laws) ecosystems have received great attention due to fuel conditions that increase the likelihood of large-scale wildfires with severe fire behavior. The fire season of 2002 demonstrated these extreme fuel load conditions with the largest fires in southwest history. The Jemez District of the Santa Fe...

Potential fire behavior in California: an atlas and guide for forest and brushland managers

Treesearch

Bill C. Ryan

1984-01-01

Potential fire characteristics can be estimated as functions of weather, fuel, and terrain slope. Such information is needed by forest and other land managers--especially for anticipating fire suppression needs and planning prescribed burns. To provide this information, an Atlas has been developed for California. The Atlas includes statistical analyses of spread...

Social validation and training of emergency fire safety skills for potential injury prevention and life saving.

PubMed Central

Jones, R T; Kazdin, A E; Haney, J I

1981-01-01

A multifaceted behavioral program designed to teach emergency fire escape procedures to children was evaluated in a multiple-baseline design. Five children were trained to respond correctly to nine home emergency fire situations under simulated conditions. The situations and responses focused upon in training were identified by a social validation procedure involving consultation with several safety agencies, including the direct input of firefighters. Training, carried out in simulated bedrooms at school, resulted in significant improvements in both overt behavior and self-report of fire safety skills. The gains were maintained at a post-check assessment 2 weeks after training had been terminated. The results are discussed in relation both to the importance of social validation of targets and outcomes and the implications for further research in assessing and developing emergency response skills. PMID:7298537

Electroantennogram and behavioral responses of the imported fire ant, Solenopsis invicta Buren, to an alarm pheromone component and its analogues.

PubMed

Guan, Di; Lu, Yong-Yue; Liao, Xiao-Lan; Wang, Lei; Chen, Li

2014-12-10

A characteristic behavior in ants is to move rapidly to emission sources of alarm pheromones. The addition of ant alarm pheromones to bait is expected to enhance its attractiveness. To search for candidate compounds for bait enhancement in fire ant control, 13 related alkylpyrazine analogues in addition to synthetic alarm pheromone component were evaluated for electroantennogram (EAG) and behavioral activities in Solenopsis invicta. Most compounds elicited dose-dependent EAG and behavioral responses. There exists a correlation between the EAG and behavioral responses. Among the 14 tested alkylpyrazines, three compounds, 2-ethyl-3,6(5)-dimethyl pyrazine (1), 2,3,5-trimethylpyrazine (7), and 2,3-diethyl-5-methylpyrazine (12), elicited significant alarm responses at a dose range of 0.1-1000 ng. Further bait discovery bioassay with the three most active alkylpyrazines demonstrated that food bait accompanied by sample-treated filter paper disk attracted significantly more fire ant workers in the first 15 min period. EAG and behavioral bioassays with pure pheromone isomers accumulated by semi-preparative high-performance liquid chromatography demonstrated that 2-ethyl-3,6-dimethylpyrazine was significantly more active than 2-ethyl-3,5-dimethylpyrazine.

Pathway-Specific Striatal Substrates for Habitual Behavior.

PubMed

O'Hare, Justin K; Ade, Kristen K; Sukharnikova, Tatyana; Van Hooser, Stephen D; Palmeri, Mark L; Yin, Henry H; Calakos, Nicole

2016-02-03

The dorsolateral striatum (DLS) is implicated in habit formation. However, the DLS circuit mechanisms underlying habit remain unclear. A key role for DLS is to transform sensorimotor cortical input into firing of output neurons that project to the mutually antagonistic direct and indirect basal ganglia pathways. Here we examine whether habit alters this input-output function. By imaging cortically evoked firing in large populations of pathway-defined striatal projection neurons (SPNs), we identify features that strongly correlate with habitual behavior on a subject-by-subject basis. Habitual behavior correlated with strengthened DLS output to both pathways as well as a tendency for action-promoting direct pathway SPNs to fire before indirect pathway SPNs. In contrast, habit suppression correlated solely with a weakened direct pathway output. Surprisingly, all effects were broadly distributed in space. Together, these findings indicate that the striatum imposes broad, pathway-specific modulations of incoming activity to render learned motor behaviors habitual. Copyright © 2016 Elsevier Inc. All rights reserved.

Behavior-dependent specialization of identified hippocampal interneurons

PubMed Central

Lapray, Damien; Lasztoczi, Balint; Lagler, Michael; Viney, Tim James; Katona, Linda; Valenti, Ornella; Hartwich, Katja; Borhegyi, Zsolt; Somogyi, Peter; Klausberger, Thomas

2012-01-01

A large variety of GABAergic interneurons control information processing in hippocampal circuits governing the formation of neuronal representations. Whether distinct hippocampal interneuron types contribute differentially to information-processing during behavior is not known. We employed a novel technique for recording and labeling interneurons and pyramidal cells in drug-free, freely-moving rats. Recorded parvalbumin-expressing basket interneurons innervate somata and proximal pyramidal cell dendrites, whereas nitric-oxide-synthase- and neuropeptide-Y-expressing ivy cells provide synaptic and extrasynaptic dendritic modulation. Basket and ivy cells showed distinct spike timing dynamics, firing at different rates and times during theta and ripple oscillations. Basket but not ivy cells changed their firing rates during movement, sleep and quiet wakefulness, suggesting that basket cells coordinate cell assemblies in a behavioral state-contingent manner, whereas persistently-firing ivy cells might control network excitability and homeostasis. Different interneuron types provide GABA to specific subcellular domains at defined times and rates, thus differentially controlling network activity during behavior. PMID:22864613

BK Channels Are Required for Multisensory Plasticity in the Oculomotor System.

PubMed

Nelson, Alexandra B; Faulstich, Michael; Moghadam, Setareh; Onori, Kimberly; Meredith, Andrea; du Lac, Sascha

2017-01-04

Neural circuits are endowed with several forms of intrinsic and synaptic plasticity that could contribute to adaptive changes in behavior, but circuit complexities have hindered linking specific cellular mechanisms with their behavioral consequences. Eye movements generated by simple brainstem circuits provide a means for relating cellular plasticity to behavioral gain control. Here we show that firing rate potentiation, a form of intrinsic plasticity mediated by reductions in BK-type calcium-activated potassium currents in spontaneously firing neurons, is engaged during optokinetic reflex compensation for inner ear dysfunction. Vestibular loss triggers transient increases in postsynaptic excitability, occlusion of firing rate potentiation, and reductions in BK currents in vestibular nucleus neurons. Concurrently, adaptive increases in visually evoked eye movements rapidly restore oculomotor function in wild-type mice but are profoundly impaired in BK channel-null mice. Activity-dependent regulation of intrinsic excitability may be a general mechanism for adaptive control of behavioral output in multisensory circuits. Copyright © 2017 Elsevier Inc. All rights reserved.

Dorsomedial Prefrontal Cortex Contribution to Behavioral and Nucleus Accumbens Neuronal Responses to Incentive Cues

PubMed Central

Ishikawa, Akinori; Ambroggi, Frederic; Nicola, Saleem M.; Fields, Howard L.

2008-01-01

Cue-elicited phasic changes in firing of nucleus accumbens (NAc) neurons can facilitate reward-seeking behavior. Here, we test the hypothesis that the medial prefrontal cortex (mPFC), which sends a dense glutamatergic projection to the NAc core, contributes to NAc neuronal firing responses to reward-predictive cues. Rats trained to perform an operant response to a cue for sucrose were implanted with recording electrodes in the core of the NAc and microinjection cannulas in the dorsal mPFC (dmPFC). The cue-evoked firing of NAc neurons was reduced by bilateral injection of GABAA and GABAB agonists into the dmPFC concomitant with loss of behavioral responding to the cue. In addition, unilateral dmPFC inactivation reduced ipsilateral cue excitations and contralateral cue inhibitions. These findings indicate that cue-evoked excitations and inhibitions of NAc core neurons depend on dmPFC projections to the NAc and that these phasic changes contribute to the behavioral response to reward-predictive cues. PMID:18463262

Neural activity in the prelimbic and infralimbic cortices of freely moving rats during social interaction: Effect of isolation rearing.

PubMed

Minami, Chihiro; Shimizu, Tomoko; Mitani, Akira

2017-01-01

Sociability promotes a sound daily life for individuals. Reduced sociability is a central symptom of various neuropsychiatric disorders, and yet the neural mechanisms underlying reduced sociability remain unclear. The prelimbic cortex (PL) and infralimbic cortex (IL) have been suggested to play an important role in the neural mechanisms underlying sociability because isolation rearing in rats results in impairment of social behavior and structural changes in the PL and IL. One possible mechanism underlying reduced sociability involves dysfunction of the PL and IL. We made a wireless telemetry system to record multiunit activity in the PL and IL of pairs of freely moving rats during social interaction and examined the influence of isolation rearing on this activity. In group-reared rats, PL neurons increased firing when the rat showed approaching behavior and also contact behavior, especially when the rat attacked the partner. Conversely, IL neurons increased firing when the rat exhibited leaving behavior, especially when the partner left on its own accord. In social interaction, the PL may be involved in active actions toward others, whereas the IL may be involved in passive relief from cautionary subjects. Isolation rearing altered social behavior and neural activity. Isolation-reared rats showed an increased frequency and decreased duration of contact behavior. The increased firing of PL neurons during approaching and contact behavior, observed in group-reared rats, was preserved in isolation-reared rats, whereas the increased firing of IL neurons during leaving behavior, observed in group-reared rats, was suppressed in isolation-reared rats. This result indicates that isolation rearing differentially alters neural activity in the PL and IL during social behavior. The differential influence of isolation rearing on neural activity in the PL and IL may be one of the neural bases of isolation rearing-induced behavior.

Concomitant behavioral and PFC neuronal activity recorded following dose-response protocol of MPD in adult male rats.

PubMed

Venkataraman, Sidish S; Claussen, Catherine; Joseph, Michael; Dafny, Nachum

2017-04-01

The use of methylphenidate (MPD), a commonly prescribed drug to treat attention-deficit hyperactivity disorder (ADHD), has steadily increased over the past 25 years. This trend has been accompanied by more MPD abuse by ordinary individuals for its cognitive enhancing effects. Therefore, understanding the effects of MPD on the prefrontal cortex (PFC), a brain area involved in higher cortical processing such as executive function, language, planning, and attention regulation, is of particular importance. The goal of this study is to investigate the effects of acute and chronic dose-response characteristics following MPD exposure on both the PFC neuronal population and behavioral activity in freely behaving animals implanted previously with permanent electrodes within the PFC. Four groups of animals were used: saline (control), 0.6, 2.5, and 10.0mg/kg MPD. It was observed that the same dose of either 0.6, 2.5, or 10.0mg/kg repetitive (chronic) MPD exposure elicited behavioral sensitization in some animals and behavioral tolerance in others, and that the majority of PFC units recorded from animals expressing behavioral sensitization to chronic MPD exposure responded to MPD by increasing their neuronal firing rate, whereas the majority of PFC neurons recorded from animals expressing behavioral tolerance in response to chronic MPD responded by decreasing their neuronal firing rate. This data suggests that in animals that display behavioral sensitization, chronic MPD exposure causes an increase in the number of post-synaptic D1 dopamine receptors leading to an increase in behavioral and neuronal firing rate, while in animals that display behavioral tolerance, chronic MPD exposure causes an increase in the number of post-synaptic D2 dopamine receptors leading to a decrease in behavioral and neuronal firing rate. This dichotomy needs to be further investigated. Copyright © 2017 Elsevier Inc. All rights reserved.

Environmental disturbance increases social connectivity in a passerine bird.

PubMed

Lantz, Samantha M; Karubian, Jordan

2017-01-01

Individual level response to natural and anthropogenic disturbance represents an increasingly important, but as yet little understood, component of animal behavior. Disturbance events often alter habitat, which in turn can modify behaviors of individuals in affected areas, including changes in habitat use and associated changes in social structure. To better understand these relationships, we investigated aspects of habitat selection and social connectivity of a small passerine bird, the red-backed fairywren (Malurus melanocephalus), before vs. after naturally occurring fire disturbance in Northern Territory, Australia. We utilized a social network framework to evaluate changes in social dynamics pre- vs. post-fire. Our study covered the non-breeding season in two consecutive years in which fires occurred, and individuals whose habitat was affected and those that were not affected by fire. Individuals in habitat affected by fires had stronger social ties (i.e. higher weighted degree) after fires, while those that were in areas that were not affected by fire actually had lower weighted degree. We suggest that this change in social connections may be linked to habitat. Before fires, fairywrens used habitat that had similar grass cover to available habitat plots randomly generated within our study site. Fire caused a reduction in grass cover, and fairywrens responded by selecting habitat with higher grass cover relative to random plots. This study demonstrates how changes in habitat and/or resource availability caused by disturbance can lead to substantive changes in the social environment that individuals experience.

Environmental disturbance increases social connectivity in a passerine bird

PubMed Central

Lantz, Samantha M.; Karubian, Jordan

2017-01-01

Individual level response to natural and anthropogenic disturbance represents an increasingly important, but as yet little understood, component of animal behavior. Disturbance events often alter habitat, which in turn can modify behaviors of individuals in affected areas, including changes in habitat use and associated changes in social structure. To better understand these relationships, we investigated aspects of habitat selection and social connectivity of a small passerine bird, the red-backed fairywren (Malurus melanocephalus), before vs. after naturally occurring fire disturbance in Northern Territory, Australia. We utilized a social network framework to evaluate changes in social dynamics pre- vs. post-fire. Our study covered the non-breeding season in two consecutive years in which fires occurred, and individuals whose habitat was affected and those that were not affected by fire. Individuals in habitat affected by fires had stronger social ties (i.e. higher weighted degree) after fires, while those that were in areas that were not affected by fire actually had lower weighted degree. We suggest that this change in social connections may be linked to habitat. Before fires, fairywrens used habitat that had similar grass cover to available habitat plots randomly generated within our study site. Fire caused a reduction in grass cover, and fairywrens responded by selecting habitat with higher grass cover relative to random plots. This study demonstrates how changes in habitat and/or resource availability caused by disturbance can lead to substantive changes in the social environment that individuals experience. PMID:28854197

An examination of the sensitivity of numerically simulated wildfires to low-level atmospheric stability and moisture, and the consequences for the Haines Index

Treesearch

Mary Ann Jenkins

2002-01-01

The Haines Index, an operational fire-weather index introduced in 1988 and based on the observed stability and moisture content of the near-surface atmosphere, has been a useful indicator of the potential for high-risk fires in low wind conditions and flat terrain. The Haines Index is of limited use, however, as a predictor of actual fire behavior. To develop a fire-...

Historical and current forest landscapes in eastern Oregon and Washington Part II: Linking vegetation characteristics to potential fire behavior and related smoke production.

Treesearch

Mark H. Huff; Roger D. Ottmar; Ernesto Alvarado; Robert E. Vihnanek; John F. Lehmkuhl; Paul F. Hessburg; Richard L. Everett

1995-01-01

We compared the potential fire behavior and smoke production of historical and current time periods based on vegetative conditions in forty-nine 5100- to 13 5OO-hectare watersheds in six river basins in eastern Oregon and Washington. Vegetation composition, structure, and patterns were attributed and mapped from aerial photographs taken from 1932 to 1959 (historical)...

Fuels and fire behavior in chipped and unchipped plots: implications for land management near the wildland/urban interface

Treesearch

Jeff S. Glitzenstein; Donna R. Streng; Gary L. Achtemeier; Luke P. Naeher; Dale D. Wade

2006-01-01

Fire behavior was measured and modeled from eight 1 ha experimental plots located in the Francis Marion National Forest, South Carolina, during prescribed burns on February 12 and February 20, 2003. Four of the plots had been subjected to mechanical chipping during 2002 to remove woody understory growth and to reduce large downed woody debris from the aftermath of...

The effects of bark beetle outbreaks on forest development, fuel loads and potential fire behavior in salvage logged and untreated lodgepole pine forests

Treesearch

B. J. Collins; C. C. Rhoades; M. A. Battaglia; R. M. Hubbard

2012-01-01

Recent mountain pine beetle infestations have resulted in widespread tree mortality and the accumulation of dead woody fuels across the Rocky Mountain region, creating concerns over future forest stand conditions and fire behavior. We quantified how salvage logging influenced tree regeneration and fuel loads relative to nearby, uncut stands for 24 lodgepole pine...

Experimental Study of Fire Hazards of Thermal-Insulation Material in Diesel Locomotive: Aluminum-Polyurethane.

PubMed

Zhang, Taolin; Zhou, Xiaodong; Yang, Lizhong

2016-03-05

This work investigated experimentally and theoretically the fire hazards of thermal-insulation materials used in diesel locomotives under different radiation heat fluxes. Based on the experimental results, the critical heat flux for ignition was determined to be 6.15 kW/m² and 16.39 kW/m² for pure polyurethane and aluminum-polyurethane respectively. A theoretical model was established for both to predict the fire behaviors under different circumstances. The fire behavior of the materials was evaluated based on the flashover and the total heat release rate (HRR). The fire hazards levels were classified based on different experimental results. It was found that the fire resistance performance of aluminum-polyurethane is much better than that of pure-polyurethane under various external heat fluxes. The concentration of toxic pyrolysis volatiles generated from aluminum-polyurethane materials is much higher than that of pure polyurethane materials, especially when the heat flux is below 50 kW/m². The hazard index HI during peak width time was proposed based on the comprehensive impact of time and concentrations. The predicted HI in this model coincides with the existed N-gas and FED models which are generally used to evaluate the fire gas hazard in previous researches. The integrated model named HNF was proposed as well to estimate the fire hazards of materials by interpolation and weighted average calculation.

Experimental Study of Fire Hazards of Thermal-Insulation Material in Diesel Locomotive: Aluminum-Polyurethane

PubMed Central

Zhang, Taolin; Zhou, Xiaodong; Yang, Lizhong

2016-01-01

This work investigated experimentally and theoretically the fire hazards of thermal-insulation materials used in diesel locomotives under different radiation heat fluxes. Based on the experimental results, the critical heat flux for ignition was determined to be 6.15 kW/m2 and 16.39 kW/m2 for pure polyurethane and aluminum-polyurethane respectively. A theoretical model was established for both to predict the fire behaviors under different circumstances. The fire behavior of the materials was evaluated based on the flashover and the total heat release rate (HRR). The fire hazards levels were classified based on different experimental results. It was found that the fire resistance performance of aluminum-polyurethane is much better than that of pure-polyurethane under various external heat fluxes. The concentration of toxic pyrolysis volatiles generated from aluminum-polyurethane materials is much higher than that of pure polyurethane materials, especially when the heat flux is below 50 kW/m2. The hazard index HI during peak width time was proposed based on the comprehensive impact of time and concentrations. The predicted HI in this model coincides with the existed N-gas and FED models which are generally used to evaluate the fire gas hazard in previous researches. The integrated model named HNF was proposed as well to estimate the fire hazards of materials by interpolation and weighted average calculation. PMID:28773295

Juvenile firesetting in Italy: relationship to aggression, psychopathology, personality, self-efficacy, and school functioning.

PubMed

Del Bove, Giannetta; Caprara, Gian Vittorio; Pastorelli, Concetta; Paciello, Marinella

2008-06-01

Despite the fact that juvenile fire involvement is associated with significant injuries and is highly correlated with diverse maladjustment characteristics, firesetting has never been empirically evaluated in Italy. Participants included 567 youth between 11 and 18 years of age. This investigation attempted to address four gaps in the literature. The first objective was to examine how common firesetting behavior is among Italian youth. The second goal was to explore whether in Italy firesetting is associated with other types of psychopathology and later maladjustment. Thirdly, this study sought to extend our knowledge of the personal characteristics of firesetters. Finally, the relationship between firesetting and aggression remains an empirical question. Results suggested that almost one in three Italian youth reported engaging in fire involvement. Moreover, firesetting in Italian youth is associated with significant levels of antisocial behavior and psychopathology. In fact, firesetters-only demonstrated higher levels of most measures of maladjustment than did aggressive-only youth. Finally, the findings of this study suggest that aggressive firesetters are not at higher risk than nonaggressive firesetters. Instead, fire involvement appears to be the most important variable when predicting serious behavioral difficulties and anti-sociality. This highlights the importance of fire involvement in both the assessment and prediction of antisocial behavior and psychosocial adjustment in adolescence.

Understanding the Factors that Influence Perceptions of Post-Wildfire Landscape Recovery Across 25 Wildfires in the Northwestern United States.

PubMed

Kooistra, C; Hall, T E; Paveglio, T; Pickering, M

2018-01-01

Disturbances such as wildfire are important features of forested landscapes. The trajectory of changes following wildfires (often referred to as landscape recovery) continues to be an important research topic among ecologists and wildfire scientists. However, the landscape recovery process also has important social dimensions that may or may not correspond to ecological or biophysical perspectives. Perceptions of landscape recovery may affect people's attitudes and behaviors related to forest and wildfire management. We explored the variables that influence people's perceptions of landscape recovery across 25 fires that occurred in 2011 or 2012 in the United States of Washington, Oregon, Idaho, and Montana and that represented a range of fire behavior characteristics and landscape impacts. Residents near each of the 25 fires were randomly selected to receive questionnaires about their experiences with the nearby fire, including perceived impacts and how the landscape had recovered since the fire. People generally perceived landscapes as recovering, even though only one to two years had passed. Regression analysis suggested that perceptions of landscape recovery were positively related to stronger beliefs about the ecological role of fire and negatively related to loss of landscape attachment, concern about erosion, increasing distance from the fire perimeter, and longer lasting fires. Hierarchical linear modeling (HLM) analysis indicated that the above relationships were largely consistent across fires. These findings highlight that perceptions of post-fire landscape recovery are influenced by more than vegetation changes and include emotional and cognitive factors. We discuss the management implications of these findings.

Understanding the Factors that Influence Perceptions of Post-Wildfire Landscape Recovery Across 25 Wildfires in the Northwestern United States

NASA Astrophysics Data System (ADS)

Kooistra, C.; Hall, T. E.; Paveglio, T.; Pickering, M.

2018-01-01

Disturbances such as wildfire are important features of forested landscapes. The trajectory of changes following wildfires (often referred to as landscape recovery) continues to be an important research topic among ecologists and wildfire scientists. However, the landscape recovery process also has important social dimensions that may or may not correspond to ecological or biophysical perspectives. Perceptions of landscape recovery may affect people's attitudes and behaviors related to forest and wildfire management. We explored the variables that influence people's perceptions of landscape recovery across 25 fires that occurred in 2011 or 2012 in the United States of Washington, Oregon, Idaho, and Montana and that represented a range of fire behavior characteristics and landscape impacts. Residents near each of the 25 fires were randomly selected to receive questionnaires about their experiences with the nearby fire, including perceived impacts and how the landscape had recovered since the fire. People generally perceived landscapes as recovering, even though only one to two years had passed. Regression analysis suggested that perceptions of landscape recovery were positively related to stronger beliefs about the ecological role of fire and negatively related to loss of landscape attachment, concern about erosion, increasing distance from the fire perimeter, and longer lasting fires. Hierarchical linear modeling (HLM) analysis indicated that the above relationships were largely consistent across fires. These findings highlight that perceptions of post-fire landscape recovery are influenced by more than vegetation changes and include emotional and cognitive factors. We discuss the management implications of these findings.

Fire risk in San Diego County, California: A weighted Bayesian model approach

USGS Publications Warehouse

Kolden, Crystal A.; Weigel, Timothy J.

2007-01-01

Fire risk models are widely utilized to mitigate wildfire hazards, but models are often based on expert opinions of less understood fire-ignition and spread processes. In this study, we used an empirically derived weights-of-evidence model to assess what factors produce fire ignitions east of San Diego, California. We created and validated a dynamic model of fire-ignition risk based on land characteristics and existing fire-ignition history data, and predicted ignition risk for a future urbanization scenario. We then combined our empirical ignition-risk model with a fuzzy fire behavior-risk model developed by wildfire experts to create a hybrid model of overall fire risk. We found that roads influence fire ignitions and that future growth will increase risk in new rural development areas. We conclude that empirically derived risk models and hybrid models offer an alternative method to assess current and future fire risk based on management actions.

Examination of Poststroke Alteration in Motor Unit Firing Behavior Using High-Density Surface EMG Decomposition.

PubMed

Li, Xiaoyan; Holobar, Ales; Gazzoni, Marco; Merletti, Roberto; Rymer, William Zev; Zhou, Ping

2015-05-01

Recent advances in high-density surface electromyogram (EMG) decomposition have made it a feasible task to discriminate single motor unit activity from surface EMG interference patterns, thus providing a noninvasive approach for examination of motor unit control properties. In the current study, we applied high-density surface EMG recording and decomposition techniques to assess motor unit firing behavior alterations poststroke. Surface EMG signals were collected using a 64-channel 2-D electrode array from the paretic and contralateral first dorsal interosseous (FDI) muscles of nine hemiparetic stroke subjects at different isometric discrete contraction levels between 2 to 10 N with a 2 N increment step. Motor unit firing rates were extracted through decomposition of the high-density surface EMG signals and compared between paretic and contralateral muscles. Across the nine tested subjects, paretic FDI muscles showed decreased motor unit firing rates compared with contralateral muscles at different contraction levels. Regression analysis indicated a linear relation between the mean motor unit firing rate and the muscle contraction level for both paretic and contralateral muscles (p < 0.001), with the former demonstrating a lower increment rate (0.32 pulses per second (pps)/N) compared with the latter (0.67 pps/N). The coefficient of variation (averaged over the contraction levels) of the motor unit firing rates for the paretic muscles (0.21 ± 0.012) was significantly higher than for the contralateral muscles (0.17 ± 0.014) (p < 0.05). This study provides direct evidence of motor unit firing behavior alterations poststroke using surface EMG, which can be an important factor contributing to hemiparetic muscle weakness.

Examination of Post-stroke Alteration in Motor Unit Firing Behavior Using High Density Surface EMG Decomposition

PubMed Central

Li, Xiaoyan; Holobar, Aleš; Gazzoni, Marco; Merletti, Roberto; Rymer, William Z.; Zhou, Ping

2014-01-01

Recent advances in high density surface electromyogram (EMG) decomposition have made it a feasible task to discriminate single motor unit activity from surface EMG interference patterns, thus providing a noninvasive approach for examination of motor unit control properties. In the current study we applied high density surface EMG recording and decomposition techniques to assess motor unit firing behavior alterations post-stroke. Surface EMG signals were collected using a 64-channel 2-dimensional electrode array from the paretic and contralateral first dorsal interosseous (FDI) muscles of nine hemiparetic stroke subjects at different isometric discrete contraction levels between 2 N to 10 N with a 2 N increment step. Motor unit firing rates were extracted through decomposition of the high density surface EMG signals, and compared between paretic and contralateral muscles. Across the nine tested subjects, paretic FDI muscles showed decreased motor unit firing rates compared with contralateral muscles at different contraction levels. Regression analysis indicated a linear relation between the mean motor unit firing rate and the muscle contraction level for both paretic and contralateral muscles (p < 0.001), with the former demonstrating a lower increment rate (0.32 pulses per second (pps)/N) compared with the latter (0.67 pps/N). The coefficient of variation (CoV, averaged over the contraction levels) of the motor unit firing rates for the paretic muscles (0.21 ± 0.012) was significantly higher than for the contralateral muscles (0.17 ± 0.014) (p < 0.05). This study provides direct evidence of motor unit firing behavior alterations post-stroke using surface EMG, which can be an important factor contributing to hemiparetic muscle weakness. PMID:25389239

Limitations imposed on fire PRA methods as the result of incomplete and uncertain fire event data.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nowlen, Steven Patrick; Hyslop, J. S.

2010-04-01

Fire probabilistic risk assessment (PRA) methods utilize data and insights gained from actual fire events in a variety of ways. For example, fire occurrence frequencies, manual fire fighting effectiveness and timing, and the distribution of fire events by fire source and plant location are all based directly on the historical experience base. Other factors are either derived indirectly or supported qualitatively based on insights from the event data. These factors include the general nature and intensity of plant fires, insights into operator performance, and insights into fire growth and damage behaviors. This paper will discuss the potential methodology improvements thatmore » could be realized if more complete fire event reporting information were available. Areas that could benefit from more complete event reporting that will be discussed in the paper include fire event frequency analysis, analysis of fire detection and suppression system performance including incipient detection systems, analysis of manual fire fighting performance, treatment of fire growth from incipient stages to fully-involved fires, operator response to fire events, the impact of smoke on plant operations and equipment, and the impact of fire-induced cable failures on plant electrical circuits.« less

Nociceptor Sensitization Depends on Age and Pain Chronicity123

PubMed Central

Dodge, Amanda K.

2016-01-01

Abstract Peripheral inflammation causes mechanical pain behavior and increased action potential firing. However, most studies examine inflammatory pain at acute, rather than chronic time points, despite the greater burden of chronic pain on patient populations, especially aged individuals. Furthermore, there is disagreement in the field about whether primary afferents contribute to chronic pain. Therefore, we sought to evaluate the contribution of nociceptor activity to the generation of pain behaviors during the acute and chronic phases of inflammation in both young and aged mice. We found that both young (2 months old) and aged (>18 months old) mice exhibited prominent pain behaviors during both acute (2 day) and chronic (8 week) inflammation. However, young mice exhibited greater behavioral sensitization to mechanical stimuli than their aged counterparts. Teased fiber recordings in young animals revealed a twofold mechanical sensitization in C fibers during acute inflammation, but an unexpected twofold reduction in firing during chronic inflammation. Responsiveness to capsaicin and mechanical responsiveness of A-mechanonociceptor (AM) fibers were also reduced chronically. Importantly, this lack of sensitization in afferent firing during chronic inflammation occurred even as these inflamed mice exhibited continued behavioral sensitization. Interestingly, C fibers from inflamed aged animals showed no change in mechanical firing compared with controls during either the acute or chronic inflammatory phases, despite strong behavioral sensitization to mechanical stimuli at these time points. These results reveal the following two important findings: (1) nociceptor sensitization to mechanical stimulation depends on age and the chronicity of injury; and (2) maintenance of chronic inflammatory pain does not rely on enhanced peripheral drive. PMID:26866058

Fighting fire with fire: estimating the efficacy of wildfire mitigation programs using propensity scores

Treesearch

David T. Butry

2009-01-01

This paper examines the effect wildfire mitigation has on broad-scale wildfire behavior. Each year, hundreds of million of dollars are spent on fire suppression and fuels management applications, yet little is known, quantitatively, of the returns to these programs in terms of their impact on wildfire extent and intensity. This is especially true when considering that...

Longleaf pine forests and woodlands: old growth under fire!

Treesearch

Joan L. Walker

1999-01-01

The author discusses a once widespread forest type of the Southeast – longleaf pine dominated forests and woodlands. This system depends on fire – more or less frequent, and often of low intensity. Because human-mediated landscape fragmentation has drastically changed the behavior of fire on longleaf pine dominated landscapes, these forests and woodlands will never be...

Variability and persistence of post-fire biological legacies in jack pine-dominated ecosystems of northern Lower Michigan

Treesearch

Daniel Kashian; Gregory Corace; Lindsey Shartell; Deahn M. Donner; Philip Huber

2011-01-01

Stand-replacing wildfires have historically shaped the forest structure of dry, sandy jack pine-dominated ecosystems at stand and landscape scales in northern Lower Michigan. Unique fire behavior during large wildfire events often preserves long strips of unburned trees arranged perpendicular to the direction of fire spread. These biological legacies create...

Soil properties in fire-consumed log burnout openings in a Missouri oak savanna

Treesearch

Charles C. Rhoades; A. J. Meier; A. J. Rebertus

2004-01-01

Downed logs are known to increase species diversity in many forest ecosystems by increasing resource and structural complexity and by altering fire behavior in fire-prone ecosystems. In a frequently burned oak savanna in central Missouri, combustion of downed logs formed patches that have remained free of herbaceous vegetation for more than 3 years. To assess the...

Science basis for changing forest structure to modify wildfire behavior and severity

Treesearch

Russell T. Graham; Sarah McCaffrey; Theresa B. Jain

2004-01-01

Fire, other disturbances, physical setting, weather, and climate shape the structure and function of forests throughout the Western United States. More than 80 years of fire research have shown that physical setting, fuels, and weather combine to determine wildfire intensity (the rate at which it consumes fuel) and severity (the effect fire has on vegetation, soils,...

Fuel loadings in southwestern ecosystems of the United States

Treesearch

Stephen S. Sackett; Sally M Haase

1996-01-01

Natural forest fuel loadings cause extreme fire behavior during dry, windy weather experienced during most fire seasons in the Southwest. Fire severity is also exacerbated from burning heavy fuels, including heavy humus layers on the forest floor. Ponderosa pine and mixed conifer stands possess more than 21.7 and 44.1 tons per acre of total forest floor fuel,...

Forest fuel characterization using direct sampling in forest plantations

Treesearch

Eva Reyna Esmeralda Díaz García; Marco Aurelio González Tagle; Javier Jiménez Pérez; Eduardo JavierTreviño Garza; Diana Yemilet Ávila Flores

2013-01-01

One of the essential elements for a fire to occur is the flammable material. This is defined as the total biomass that has the ability to ignite and burn when exposed to a heat source. Fuel characterization in Mexican forest ecosystems is very scarce. However, this information is very important for estimating flammability and forest fire risk, fire behavior,...

Assessing three fuel classification systems and their maps using Forest Inventory and Analysis (FIA) surface fuel measurements

Treesearch

Robert E. Keane; Jason M. Herynk; Chris Toney; Shawn P. Urbanski; Duncan C. Lutes; Roger D. Ottmar

2015-01-01

Fuel classifications are integral tools in fire management and planning because they are used as inputs to fire behavior and effects simulation models. Fuel Loading Models (FLMs) and Fuel Characteristic Classification System (FCCSs) fuelbeds are the most popular classifications used throughout wildland fire science and management, but they have yet to be thoroughly...

The interannual variability of the Haines Index over North America

Treesearch

Lejiang Yu; Shiyuan Zhong; Xindi Bian; Warren E. Heilman; Joseph J. Charney

2013-01-01

The Haines index (HI) is a fire-weather index that is widely used as an indicator of the potential for dry, low-static-stability air in the lower atmosphere to contribute to erratic fire behavior or large fire growth. This study examines the interannual variability of HI over North America and its relationship to indicators of large-scale circulation anomalies. The...

Characteristics of burns conducted under modified prescriptions to mitigate limited fuels in a semi-arid grassland

Treesearch

David J. Augustine; Justin D. Derner; David P. Smith

2014-01-01

In semi-arid grasslands of the North American Great Plains, fire has traditionally been viewed as having few management applications, and quantitative measurements of fire behavior in the low fuel loads characteristic of this region are lacking. More recently, land managers have recognized potential applications of prescribed fire to control undesirable plant species...

Designing seasonal initial attack resource deployment and dispatch rules using a two-stage stochastic programming procedure

Treesearch

Yu Wei; Michael Bevers; Erin J. Belval

2015-01-01

Initial attack dispatch rules can help shorten fire suppression response times by providing easy-to-follow recommendations based on fire weather, discovery time, location, and other factors that may influence fire behavior and the appropriate response. A new procedure is combined with a stochastic programming model and tested in this study for designing initial attack...

Wildland fires and dwarf mistletoes: A literature review of ecology and prescribed burning

Treesearch

Martin E. Alexander; Frank G. Hawksworth

1975-01-01

Wildfires play a multiple role in the distribution of dwarf mistletoes - they may either inhibit or encourage these parasites depending primarily on the size and intensity of the burn. Many reports suggest that fire exclusion policies of the past half century have resulted in increased dwarf mistletoe levels as, well as increased fire behavior potential. Prescribed...

Factors influencing fire severity under moderate burning conditions in the Klamath Mountains, northern California, USA

Treesearch

Becky L. Estes; Eric E. Knapp; Carl N. Skinner; Jay D. Miller; Haiganoush K. Preisler

2017-01-01

Topography, weather, and fuels are known factors driving fire behavior, but the degree to which each contributes to the spatial pattern of fire severity under different conditions remains poorly understood. The variability in severity within the boundaries of the 2006 wildfires that burned in the Klamath Mountains, northern California, along with data on burn...

Effect of certain chemical attributes of vegetation on forest inflammability

Treesearch

Leon W. Richards

1940-01-01

Forest Service administrators and fire-research men have long felt the need of information concerning the effect of vegetation such as shrubs, grasses, and forbs (nongrasslike herbs) on the rate of spread of fires. To date, all knowledge of the subject has been acquired empirically in the field, or deduced from knowledge of fire behavior as influenced by the condition...

Fire behavior, fuel treatments, and fire suppression on the Hayman Fire - Part 6: Daily emissions

Treesearch

Wei Min Hao

2003-01-01

Biomass burning is a major source of many atmospheric trace gases and aerosol particles (Crutzen and Andreae 1990). These compounds and particulates affect public health, regional air quality, air chemistry, and global climate. It is difficult to assess quantitatively the impact wildfires have on the environment because of the uncertainty in determining the size of...

Faunal responses to fire in chaparral and sage scrub in California, USA

USGS Publications Warehouse

van Mantgem, Elizabeth; Keeley, Jon E.; Witter, Marti

2015-01-01

Impact of fire on California shrublands has been well studied but nearly all of this work has focused on plant communities. Impact on and recovery of the chaparral fauna has received only scattered attention; this paper synthesizes what is known in this regard for the diversity of animal taxa associated with California shrublands and outlines the primary differences between plant and animal responses to fire. We evaluated the primary faunal modes of resisting fire effects in three categories: 1) endogenous survival in a diapause or diapause-like stage, 2) sheltering in place within unburned refugia, or 3) fleeing and recolonizing. Utilizing these patterns in chaparral and sagescrub, as well as some studies on animals in other mediterranean-climate ecosystems, we derived generalizations about how plants and animals differ in their responses to fire impacts and their post fire recovery. One consequence of these differences is that variation in fire behavior has a much greater potential to affect animals than plants. For example, plants recover from fire endogenously from soil-stored seeds and resprouts, so fire size plays a limited role in determining recovery patterns. However, animals that depend on recolonization of burned sites from metapopulations may be greatly affected by fire size. Animal recolonization may also be greatly affected by regional land use patterns that affect colonization corridors, whereas such regional factors play a minimal role in plant community recovery. Fire characteristics such as rate of spread and fire intensity do not appear to play an important role in determining patterns of chaparral and sage scrub plant recovery after fire. However, these fire behavior characteristics may have a profound role in determining survivorship of some animal populations as slow-moving, smoldering combustion may limit survivorship of animals in burrows, whereas fast-moving, high intensity fires may affect survivorship of animals in above ground refugia or those attempting to flee. Thus, fire regime characteristics may have a much greater effect on postfire recovery of animal communities than plant communities in these shrubland ecosystems.

Fire safety knowledge and practices among residents of an assisted living facility.

PubMed

Jaslow, David; Ufberg, Jacob; Yoon, Russell; McQueen, Clay; Zecher, Derek; Jakubowski, Greg

2005-01-01

Assisted living facilities (ALFs) pose unique fire risks to the elderly that may be linked to specific fire safety (FS) practices. To evaluate self-reported FS practices among ALF residents. All residents of a small ALF were surveyed regarding actual and hypothetical FS behaviors, self-perceived fire risk, and FS preparedness. Fifty-eight ALF residents completed the survey. Thirty-three (58%) individuals reported one or more disabilities. Seven (12%) residents ignored the fire alarm and 21 (35%) could not hear it clearly. Sixteen (28%) residents would attempt to locate the source of a fire rather than escape from the building. Only 24 (42%) residents were familiar with the building fire plan. Twenty-three (40%) people surveyed believed that they were not at risk of fire in the study facility. Residents of an ALF may be at increased fire injury risk due to their FS practices and disabilities.

Wildfire spread, hazard and exposure metric raster grids for central Catalonia.

PubMed

Alcasena, Fermín J; Ager, Alan A; Salis, Michele; Day, Michelle A; Vega-Garcia, Cristina

2018-04-01

We provide 40 m resolution wildfire spread, hazard and exposure metric raster grids for the 0.13 million ha fire-prone Bages County in central Catalonia (northeastern Spain) corresponding to node influence grid (NIG), crown fraction burned (CFB) and fire transmission to residential houses (TR). Fire spread and behavior data (NIG, CFB and fire perimeters) were generated with fire simulation modeling considering wildfire season extreme fire weather conditions (97 th percentile). Moreover, CFB was also generated for prescribed fire (Rx) mild weather conditions. The TR smoothed grid was obtained with a geospatial analysis considering large fire perimeters and individual residential structures located within the study area. We made these raster grids available to assist in the optimization of wildfire risk management plans within the study area and to help mitigate potential losses from catastrophic events.

Forecasting distribution of numbers of large fires

USGS Publications Warehouse

Eidenshink, Jeffery C.; Preisler, Haiganoush K.; Howard, Stephen; Burgan, Robert E.

2014-01-01

Systems to estimate forest fire potential commonly utilize one or more indexes that relate to expected fire behavior; however they indicate neither the chance that a large fire will occur, nor the expected number of large fires. That is, they do not quantify the probabilistic nature of fire danger. In this work we use large fire occurrence information from the Monitoring Trends in Burn Severity project, and satellite and surface observations of fuel conditions in the form of the Fire Potential Index, to estimate two aspects of fire danger: 1) the probability that a 1 acre ignition will result in a 100+ acre fire, and 2) the probabilities of having at least 1, 2, 3, or 4 large fires within a Predictive Services Area in the forthcoming week. These statistical processes are the main thrust of the paper and are used to produce two daily national forecasts that are available from the U.S. Geological Survey, Earth Resources Observation and Science Center and via the Wildland Fire Assessment System. A validation study of our forecasts for the 2013 fire season demonstrated good agreement between observed and forecasted values.

Experimental study on flowing burning behaviors of a pool fire with dripping of melted thermoplastics.

PubMed

Xie, Qiyuan; Tu, Ran; Wang, Nan; Ma, Xin; Jiang, Xi

2014-02-28

The objective of this work is to quantitatively investigate the dripping-burning and flowing fire of thermoplastics. A new experimental setup is developed with a heating vessel and a T-trough. Hot thermoplastic liquids are generated in the vessel by electric heating. N2 gas is continuously injected into the vessel to avoid a sudden ignition of fuel in it. The detailed flowing burning behaviors of pool fire in the T-trough are analyzed through the measurements of the mass, heat flux and temperatures etc. The experimental results suggest that a continuous dripping of melted thermoplastic liquids in a nearly constant mass rate can be successfully made in the new setup. It also shows that the mass dripping rate of melted PS liquid is smaller than PP and PE since its large viscosity. In addition, the flame spread velocities of hot liquids of PS in the T-trough are also smaller than that of PP and PE because of its large viscosity. The mass burning rate of the PP and PE pool fire in T-trough are smaller than PS. Finally, considering the heating, melting, dripping and flowing burning behaviors of these polymers, it is suggested that the fire hazard of PE and PP are obviously higher than PS for their faster flowing burning. Copyright © 2013 Elsevier B.V. All rights reserved.

Development of Standard Fuel Models in Boreal Forests of Northeast China through Calibration and Validation

PubMed Central

Cai, Longyan; He, Hong S.; Wu, Zhiwei; Lewis, Benard L.; Liang, Yu

2014-01-01

Understanding the fire prediction capabilities of fuel models is vital to forest fire management. Various fuel models have been developed in the Great Xing'an Mountains in Northeast China. However, the performances of these fuel models have not been tested for historical occurrences of wildfires. Consequently, the applicability of these models requires further investigation. Thus, this paper aims to develop standard fuel models. Seven vegetation types were combined into three fuel models according to potential fire behaviors which were clustered using Euclidean distance algorithms. Fuel model parameter sensitivity was analyzed by the Morris screening method. Results showed that the fuel model parameters 1-hour time-lag loading, dead heat content, live heat content, 1-hour time-lag SAV(Surface Area-to-Volume), live shrub SAV, and fuel bed depth have high sensitivity. Two main sensitive fuel parameters: 1-hour time-lag loading and fuel bed depth, were determined as adjustment parameters because of their high spatio-temporal variability. The FARSITE model was then used to test the fire prediction capabilities of the combined fuel models (uncalibrated fuel models). FARSITE was shown to yield an unrealistic prediction of the historical fire. However, the calibrated fuel models significantly improved the capabilities of the fuel models to predict the actual fire with an accuracy of 89%. Validation results also showed that the model can estimate the actual fires with an accuracy exceeding 56% by using the calibrated fuel models. Therefore, these fuel models can be efficiently used to calculate fire behaviors, which can be helpful in forest fire management. PMID:24714164

Closing the wildland fire heat budget - measurements in the field at intermediate and operational scales

NASA Astrophysics Data System (ADS)

Dickinson, M.; Kremens, R.; Bova, A. S.

2012-12-01

Closing the wildland fire heat budget involves characterizing the heat source and energy dissipation across the range of variability in fuels and fire behavior. Meeting this challenge will lay the foundation for predicting direct ecological effects of fires and fire-atmosphere coupling. Here, we focus on the relationships between the fire radiation field, as measured from the zenith, fuel consumption, and the behavior of spreading flame fronts. Experiments were conducted in 8 m x 8 m outdoor plots using pre-conditioned wildland fuels characteristic of mixed-oak forests of the eastern United States. Using dual-band radiometers with a field of view of about 18.5 m^2 at a height of 4.2 m, we found a near-linear increase in fire radiative energy density (FRED) over a range of fuel consumption between 0.15 kg m^-2 to 3.25 kg m^-2. Using an integrated heat budget, we estimate that the fraction of total theoretical combustion energy density radiated from the plot averaged 0.17, the fraction of latent energy transported in the plume averaged 0.08, and the fraction accounted for by the combination of fire convective energy transport and soil heating averaged 0.72. Future work will require, at minimum, instantaneous and time-integrated estimates of energy transported by radiation, convection, and soil heating across a range of fuels. We introduce the Rx-CADRE project through which such measurements are being made.

In vivo analysis of Purkinje cell firing properties during postnatal mouse development

PubMed Central

Arancillo, Marife; White, Joshua J.; Lin, Tao; Stay, Trace L.

2014-01-01

Purkinje cell activity is essential for controlling motor behavior. During motor behavior Purkinje cells fire two types of action potentials: simple spikes that are generated intrinsically and complex spikes that are induced by climbing fiber inputs. Although the functions of these spikes are becoming clear, how they are established is still poorly understood. Here, we used in vivo electrophysiology approaches conducted in anesthetized and awake mice to record Purkinje cell activity starting from the second postnatal week of development through to adulthood. We found that the rate of complex spike firing increases sharply at 3 wk of age whereas the rate of simple spike firing gradually increases until 4 wk of age. We also found that compared with adult, the pattern of simple spike firing during development is more irregular as the cells tend to fire in bursts that are interrupted by long pauses. The regularity in simple spike firing only reached maturity at 4 wk of age. In contrast, the adult complex spike pattern was already evident by the second week of life, remaining consistent across all ages. Analyses of Purkinje cells in alert behaving mice suggested that the adult patterns are attained more than a week after the completion of key morphogenetic processes such as migration, lamination, and foliation. Purkinje cell activity is therefore dynamically sculpted throughout postnatal development, traversing several critical events that are required for circuit formation. Overall, we show that simple spike and complex spike firing develop with unique developmental trajectories. PMID:25355961

Triphasic behavioral response of motor units to submaximal fatiguing exercise.

PubMed

Dorfman, L J; Howard, J E; McGill, K C

1990-07-01

We have measured the firing rate and amplitude of 4551 motor unit action potentials (MUAPs) recorded with concentric needle electrodes from the brachial biceps muscles of 10 healthy young adults before, during, and after 45 minutes of intermittent isometric exercise at 20% of maximum voluntary contraction (MVC), using an automatic method for decomposition of electromyographic activity (ADEMG). During and after exercise, MUAPs derived from contractions of 30% MVC showed progressive increase in mean firing rate (P less than or equal to .01) and amplitude (P less than or equal to .05). The firing rate increase preceded the rise in mean amplitude, and was evident prior to the development of fatigue, defined as reduction of MVC. Analysis of individual potentials revealed that the increase in firing rate and in amplitude reflected different MUAP subpopulations. A short-term (less than 1 minute) reduction in MUAP firing rates (P less than or equal to .05) was also observed at the onset of each test contraction. These findings suggest that motor units exhibit a triphasic behavioral response to prolonged submaximal exercise: (1) short-term decline and stabilization of onset firing rates, followed by (2) gradual and progressive increase in firing rates and firing variability, and then by (3) recruitment of additional (larger) motor units. The (2) and (3) components presumably compensate for loss of force-generating capacity in the exercising muscle, and give rise jointly to the well-known increase in total surface EMG which accompanies muscle fatigue.

An overview of the fire and fuels extension to the forest vegetation simulator

Treesearch

Sarah J. Beukema; Elizabeth D. Reinhardt; Werner A. Kurz; Nicholas L. Crookston

2000-01-01

The Fire and Fuels Extension (FFE) to the Forest Vegetation Simulator (FVS) has been developed to assess the risk, behavior, and impact of fire in forest ecosystems. This extension to the widely-used stand-dynamics model FVS simulates the dynamics of snags and surface fuels as they are affected by stand management (of trees or fuels), live tree growth and mortality,...

Causes and behavior of a tornadic fire-whirlwind

Treesearch

Arthur R. Pirsko; Leo M. Sergius; Carl W. Hickerson

1965-01-01

A destructive whirlwind of tornadic force was formed in a 600-acre brush fire burning on the lee side of a ridge near Santa Barbara on March 7, 1964. The fire whirlwind, formed in a post-frontal unstable air mass, cut a mile long path, injured 4 people, destroyed 2 houses, a barn, and 4 automobiles, and wrecked a 100-tree avocado orchard.[higher-...

Incorporating field wind data into FIRETEC simulations of the International Crown Fire Modeling Experiment (ICFME): preliminary lessons learned

Treesearch

Rodman Linn; Kerry Anderson; Judith Winterkamp; Alyssa Broos; Michael Wotton; Jean-Luc Dupuy; Francois Pimont; Carleton Edminster

2012-01-01

Field experiments are one way to develop or validate wildland fire-behavior models. It is important to consider the implications of assumptions relating to the locality of measurements with respect to the fire, the temporal frequency of the measured data, and the changes to local winds that might be caused by the experimental configuration. Twenty FIRETEC simulations...

WindWizard: A New Tool for Fire Management Decision Support

Treesearch

Bret W. Butler; Mark Finney; Larry Bradshaw; Jason Forthofer; Chuck McHugh; Rick Stratton; Dan Jimenez

2006-01-01

A new software tool has been developed to simulate surface wind speed and direction at the 100m to 300 m scale. This tool is useful when trying to estimate fire behavior in mountainous terrain. It is based on widely used computational fluid dynamics technology and has been tested against measured wind flows. In recent years it has been used to support fire management...

Litter Species Composition and Topographic Effects on Fuels and Modeled Fire Behavior in an Oak-Hickory Forest in the Eastern USA

Treesearch

Matthew B. Dickinson; Todd F. Hutchinson; Mark Dietenberger; Frederick Matt; Matthew P. Peters; Jian Yang

2016-01-01

Mesophytic species (esp. Acer rubrum) are increasingly replacing oaks (Quercus spp.) in fire-suppressed, deciduous oak-hickory forests of the eastern US. A pivotal hypothesis is that fuel beds derived from mesophytic litter are less likely than beds derived from oak litter to carry a fire and, if they do, are more likely to...

Influence of vegetation moisture on combustion of pyrolysis gases in wildland fires

Treesearch

S.C. Dover; A.R. Dahale; B. Shotorban; S. Mahalingam; D.R. Weise

2011-01-01

Since wildland fires occur in living vegetation, the fuel moisture content must be considered in order to correctly predict the behavior of the fire. One facet of combustion of pyrolysis gases that has not been considered in previous research is the effect of moisture on the combustion process. This effect is investigated by using CHEMKIN software to study an opposed...

Considerations in the use of models available for fuel treatment analysis

Treesearch

Charles W. McHugh

2006-01-01

Fire managers are required to evaluate and justify the effectiveness of planned fuel treatments in modifying fire growth, behavior and effects on resources and assets. With the number of models currently available, today’s fire manager can become overwhelmed when deciding which model to use. Each model has a required level of expertise in order to develop the necessary...

A fuel treatment reduces potential fire severity and increases suppression efficiency in a Sierran mixed conifer forest

Treesearch

Jason J. Moghaddas

2006-01-01

Fuel treatments are being widely implemented on public and private lands across the western U.S. While scientists and managers have an understanding of how fuel treatments can modify potential fire behavior under modeled conditions, there is limited information on how treatments perform under real wildfire conditions in Sierran mixed conifer forests. The Bell Fire...

Optogenetic Modulation and Multi-Electrode Analysis of Cerebellar Networks In Vivo

PubMed Central

Kruse, Wolfgang; Krause, Martin; Aarse, Janna; Mark, Melanie D.; Manahan-Vaughan, Denise; Herlitze, Stefan

2014-01-01

The firing patterns of cerebellar Purkinje cells (PCs), as the sole output of the cerebellar cortex, determine and tune motor behavior. PC firing is modulated by various inputs from different brain regions and by cell-types including granule cells (GCs), climbing fibers and inhibitory interneurons. To understand how signal integration in PCs occurs and how subtle changes in the modulation of PC firing lead to adjustment of motor behaviors, it is important to precisely record PC firing in vivo and to control modulatory pathways in a spatio-temporal manner. Combining optogenetic and multi-electrode approaches, we established a new method to integrate light-guides into a multi-electrode system. With this method we are able to variably position the light-guide in defined regions relative to the recording electrode with micrometer precision. We show that PC firing can be precisely monitored and modulated by light-activation of channelrhodopsin-2 (ChR2) expressed in PCs, GCs and interneurons. Thus, this method is ideally suited to investigate the spatio/temporal modulation of PCs in anesthetized and in behaving mice. PMID:25144735

Spatial fuel data products of the LANDFIRE Project

USGS Publications Warehouse

Reeves, M.C.; Ryan, K.C.; Rollins, M.G.; Thompson, T.G.

2009-01-01

The Landscape Fire and Resource Management Planning Tools (LANDFIRE) Project is mapping wildland fuels, vegetation, and fire regime characteristics across the United States. The LANDFIRE project is unique because of its national scope, creating an integrated product suite at 30-m spatial resolution and complete spatial coverage of all lands within the 50 states. Here we describe development of the LANDFIRE wildland fuels data layers for the conterminous 48 states: surface fire behavior fuel models, canopy bulk density, canopy base height, canopy cover, and canopy height. Surface fire behavior fuel models are mapped by developing crosswalks to vegetation structure and composition created by LANDFIRE. Canopy fuels are mapped using regression trees relating field-referenced estimates of canopy base height and canopy bulk density to satellite imagery, biophysical gradients and vegetation structure and composition data. Here we focus on the methods and data used to create the fuel data products, discuss problems encountered with the data, provide an accuracy assessment, demonstrate recent use of the data during the 2007 fire season, and discuss ideas for updating, maintaining and improving LANDFIRE fuel data products.

Predictions of fire behavior and resistance to control: for use with photo series for the ponderosa pine type, ponderosa pine and associated species type, and lodgepole pine type.

Treesearch

Franklin R. Ward; David V. Sandberg

1981-01-01

This publication presents tables on the behavior of fire and the resistance of fuels to control. The information is to be used with the publication, "Photo Series for Quantifying Forest Residues in the Ponderosa Pine Type, Ponderosa Pine and Associated Species Type, Lodgepole Pine Type" (Maxwell, Wayne G.; Ward, Franklin R. 1976. Gen. Tech. Rep. PNW-GTR-052....

Predictions of fire behavior and resistance to control: for use with photo series for the sierra mixed conifer type and the sierra true fir type.

Treesearch

Franklin R. Ward; David V. Sandberg

1981-01-01

This publication presents tables on the behavior of fire and the resistance: of fuels to control. The information is to be used with the photos in the publication, "Photo Series for Quantifying Forest Residues in the Sierra Mixed Conifer Type, Sierra True Fir Type" (Maxwell, Wayne G.; Ward, Franklin R. 1979. Gen. Tech. Rep. PNW-GTR-095. Portland, OR: U.S....

Modeling fire occurrence as a function of landscape

NASA Astrophysics Data System (ADS)

Loboda, T. V.; Carroll, M.; DiMiceli, C.

2011-12-01

Wildland fire is a prominent component of ecosystem functioning worldwide. Nearly all ecosystems experience the impact of naturally occurring or anthropogenically driven fire. Here, we present a spatially explicit and regionally parameterized Fire Occurrence Model (FOM) aimed at developing fire occurrence estimates at landscape and regional scales. The model provides spatially explicit scenarios of fire occurrence based on the available records from fire management agencies, satellite observations, and auxiliary geospatial data sets. Fire occurrence is modeled as a function of the risk of ignition, potential fire behavior, and fire weather using internal regression tree-driven algorithms and empirically established, regionally derived relationships between fire occurrence, fire behavior, and fire weather. The FOM presents a flexible modeling structure with a set of internal globally available default geospatial independent and dependent variables. However, the flexible modeling environment adapts to ingest a variable number, resolution, and content of inputs provided by the user to supplement or replace the default parameters to improve the model's predictive capability. A Southern California FOM instance (SC FOM) was developed using satellite assessments of fire activity from a suite of Landsat and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data, Monitoring Trends in Burn Severity fire perimeters, and auxiliary geospatial information including land use and ownership, utilities, transportation routes, and the Remote Automated Weather Station data records. The model was parameterized based on satellite data acquired between 2001 and 2009 and fire management fire perimeters available prior to 2009. SC FOM predictive capabilities were assessed using observed fire occurrence available from the MODIS active fire product during 2010. The results show that SC FOM provides a realistic estimate of fire occurrence at the landscape level: the fraction of area impacted by fire from the total available area within a given value of the Fire Occurrence Index (FOI) increased from 9.e-06 at FOI < 3 to 28.e-06 at 25 < FOI <= 28. Additionally, the model has revealed a new important relationship between fire occurrence, anthropogenic activity, and fire weather. Data analysis has demonstrated that human activity can alter the expected weather/fire occurrence relationships and result in considerable modifications of fire regimes contrary to the assumed ecological parameters. Specifically, between 2001 and 2009 over 50% of total fire impacted area burned during the low fire danger conditions (Canadian Fire Weather Index < 5). These findings and the FOM capabilities offer a new theoretical construct and an advanced tool for assessing the potential impacts of climate changes on fire regimes, particularly within landscapes which are impacted strongly by human activities. Future development of the FOM will focus on ingesting and internal downscaling of climate variables produced by General or Regional Circulation Models to develop scenarios of potential future change in fire occurrence under the influence of projected climate change at the appropriate regional or landscape scales.

Simulating statistics of lightning-induced and man made fires

NASA Astrophysics Data System (ADS)

Krenn, R.; Hergarten, S.

2009-04-01

The frequency-area distributions of forest fires show power-law behavior with scaling exponents α in a quite narrow range, relating wildfire research to the theoretical framework of self-organized criticality. Examples of self-organized critical behavior can be found in computer simulations of simple cellular automata. The established self-organized critical Drossel-Schwabl forest fire model (DS-FFM) is one of the most widespread models in this context. Despite its qualitative agreement with event-size statistics from nature, its applicability is still questioned. Apart from general concerns that the DS-FFM apparently oversimplifies the complex nature of forest dynamics, it significantly overestimates the frequency of large fires. We present a straightforward modification of the model rules that increases the scaling exponent α by approximately 1•3 and brings the simulated event-size statistics close to those observed in nature. In addition, combined simulations of both the original and the modified model predict a dependence of the overall distribution on the ratio of lightning induced and man made fires as well as a difference between their respective event-size statistics. The increase of the scaling exponent with decreasing lightning probability as well as the splitting of the partial distributions are confirmed by the analysis of the Canadian Large Fire Database. As a consequence, lightning induced and man made forest fires cannot be treated separately in wildfire modeling, hazard assessment and forest management.

Application of the relative energy release criteria to enclosure fire testing. [aircraft compartments

NASA Technical Reports Server (NTRS)

Roschke, E. J.; Coulbert, C. D.

1979-01-01

The five relative energy release criteria (RERC) which are a first step towards formulating a unified concept that can be applied to the development of fires in enclosures, place upper bounds on the rate and amount of energy released during a fire. They are independent, calculated readily, and may be applied generally to any enclosure regardless of size. They are useful in pretest planning and for interpreting experimental data. Data from several specific fire test programs were examined to evaluate the potential use of RERC to provide test planning guidelines. The RERC were compared with experimental data obtained in full-scale enclosures. These results confirm that in general the RERC do identify the proper limiting constraints on enclosure fire development and determine the bounds of the fire development envelope. Plotting actual fire data against the RERC reveals new valid insights into fire behavior and reveals the controlling constraints in fire development. The RERC were calculated and plotted for several descrpitions of full-scale fires in various aircraft compartments.

Curve Number and Peakflow Responses Following the Cerro Grande Fire on a Small Watershed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Springer, E. P.; Hawkins, Richard H.

The Curve Number (CN) method is routinely used to estimate runoff and peakflows following forest fires, but there has been essentially no literature on the estimated value and temporal variation of CNs following wildland fires. In May 2000, the Cerro Grande Fire burned the headwaters of the major watersheds that cross Los Alamos National Laboratory, and a stream gauging network presented an opportunity to assess CNs following the fire. Analysis of rainfall-runoff events indicated that the pre-fire watershed response was complacent or limited watershed area contributed to runoff. The post-fire response indicated that the complacent behavior continued so the watershedmore » response was not dramatically changed. Peakflows did increase by 2 orders of magnitude following the fire, and this was hypothesized to be a function of increase in runoff volume and changes in watershed network allowing more efficient delivery of runoff. More observations and analyses following fires are needed to support definition of CNs for post-fire response and mitigation efforts.« less

Cellular mechanisms underlying behavioral state-dependent bidirectional modulation of motor cortex output.

PubMed

Schiemann, Julia; Puggioni, Paolo; Dacre, Joshua; Pelko, Miha; Domanski, Aleksander; van Rossum, Mark C W; Duguid, Ian

2015-05-26

Neuronal activity in primary motor cortex (M1) correlates with behavioral state, but the cellular mechanisms underpinning behavioral state-dependent modulation of M1 output remain largely unresolved. Here, we performed in vivo patch-clamp recordings from layer 5B (L5B) pyramidal neurons in awake mice during quiet wakefulness and self-paced, voluntary movement. We show that L5B output neurons display bidirectional (i.e., enhanced or suppressed) firing rate changes during movement, mediated via two opposing subthreshold mechanisms: (1) a global decrease in membrane potential variability that reduced L5B firing rates (L5Bsuppressed neurons), and (2) a coincident noradrenaline-mediated increase in excitatory drive to a subpopulation of L5B neurons (L5Benhanced neurons) that elevated firing rates. Blocking noradrenergic receptors in forelimb M1 abolished the bidirectional modulation of M1 output during movement and selectively impaired contralateral forelimb motor coordination. Together, our results provide a mechanism for how noradrenergic neuromodulation and network-driven input changes bidirectionally modulate M1 output during motor behavior. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

A bio-inspired auditory perception model for amplitude-frequency clustering (keynote Paper)

NASA Astrophysics Data System (ADS)

Arena, Paolo; Fortuna, Luigi; Frasca, Mattia; Ganci, Gaetana; Patane, Luca

2005-06-01

In this paper a model for auditory perception is introduced. This model is based on a network of integrate-and-fire and resonate-and-fire neurons and is aimed to control the phonotaxis behavior of a roving robot. The starting point is the model of phonotaxis in Gryllus Bimaculatus: the model consists of four integrate-and-fire neurons and is able of discriminating the calling song of male cricket and orienting the robot towards the sound source. This paper aims to extend the model to include an amplitude-frequency clustering. The proposed spiking network shows different behaviors associated with different characteristics of the input signals (amplitude and frequency). The behavior implemented on the robot is similar to the cricket behavior, where some frequencies are associated with the calling song of male crickets, while other ones indicate the presence of predators. Therefore, the whole model for auditory perception is devoted to control different responses (attractive or repulsive) depending on the input characteristics. The performance of the control system has been evaluated with several experiments carried out on a roving robot.

Intraspecific Variation among Social Insect Colonies: Persistent Regional and Colony-Level Differences in Fire Ant Foraging Behavior

PubMed Central

Bockoven, Alison A.; Wilder, Shawn M.; Eubanks, Micky D.

2015-01-01

Individuals vary within a species in many ecologically important ways, but the causes and consequences of such variation are often poorly understood. Foraging behavior is among the most profitable and risky activities in which organisms engage and is expected to be under strong selection. Among social insects there is evidence that within-colony variation in traits such as foraging behavior can increase colony fitness, but variation between colonies and the potential consequences of such variation are poorly documented. In this study, we tested natural populations of the red imported fire ant, Solenopsis invicta, for the existence of colony and regional variation in foraging behavior and tested the persistence of this variation over time and across foraging habitats. We also reared single-lineage colonies in standardized environments to explore the contribution of colony lineage. Fire ants from natural populations exhibited significant and persistent colony and regional-level variation in foraging behaviors such as extra-nest activity, exploration, and discovery of and recruitment to resources. Moreover, colony-level variation in extra-nest activity was significantly correlated with colony growth, suggesting that this variation has fitness consequences. Lineage of the colony had a significant effect on extra-nest activity and exploratory activity and explained approximately half of the variation observed in foraging behaviors, suggesting a heritable component to colony-level variation in behavior. PMID:26197456

[Research progress in post-fire debris flow].

PubMed

Di, Xue-ying; Tao, Yu-zhu

2013-08-01

The occurrence of the secondary disasters of forest fire has significant impacts on the environment quality and human health and safety. Post-fire debris flow is one of the most hazardous secondary disasters of forest fire. To understand the occurrence conditions of post-fire debris flow and to master its occurrence situation are the critical elements in post-fire hazard assessment. From the viewpoints of vegetation, precipitation threshold and debris flow material sources, this paper elaborated the impacts of forest fire on the debris flow, analyzed the geologic and geomorphic conditions, precipitation and slope condition that caused the post-fire debris flow as well as the primary mechanisms of debris-flow initiation caused by shallow landslide or surface runoff, and reviewed the research progress in the prediction and forecast of post-fire debris flow and the related control measures. In the future research, four aspects to be focused on were proposed, i. e., the quantification of the relationships between the fire behaviors and environmental factors and the post-fire debris flow, the quantitative research on the post-fire debris flow initiation and movement processes, the mechanistic model of post-fire debris flow, and the rapid and efficient control countermeasures of post-fire debris flow.

Modeling task-specific neuronal ensembles improves decoding of grasp

NASA Astrophysics Data System (ADS)

Smith, Ryan J.; Soares, Alcimar B.; Rouse, Adam G.; Schieber, Marc H.; Thakor, Nitish V.

2018-06-01

Objective. Dexterous movement involves the activation and coordination of networks of neuronal populations across multiple cortical regions. Attempts to model firing of individual neurons commonly treat the firing rate as directly modulating with motor behavior. However, motor behavior may additionally be associated with modulations in the activity and functional connectivity of neurons in a broader ensemble. Accounting for variations in neural ensemble connectivity may provide additional information about the behavior being performed. Approach. In this study, we examined neural ensemble activity in primary motor cortex (M1) and premotor cortex (PM) of two male rhesus monkeys during performance of a center-out reach, grasp and manipulate task. We constructed point process encoding models of neuronal firing that incorporated task-specific variations in the baseline firing rate as well as variations in functional connectivity with the neural ensemble. Models were evaluated both in terms of their encoding capabilities and their ability to properly classify the grasp being performed. Main results. Task-specific ensemble models correctly predicted the performed grasp with over 95% accuracy and were shown to outperform models of neuronal activity that assume only a variable baseline firing rate. Task-specific ensemble models exhibited superior decoding performance in 82% of units in both monkeys (p  <  0.01). Inclusion of ensemble activity also broadly improved the ability of models to describe observed spiking. Encoding performance of task-specific ensemble models, measured by spike timing predictability, improved upon baseline models in 62% of units. Significance. These results suggest that additional discriminative information about motor behavior found in the variations in functional connectivity of neuronal ensembles located in motor-related cortical regions is relevant to decode complex tasks such as grasping objects, and may serve the basis for more reliable and accurate neural prosthesis.

Effects of prescribed fire, supplemental feeding, and mammalian predator exclusion on hispid cotton rat populations.

PubMed

Morris, Gail; Hostetler, Jeffrey A; Conner, L Mike; Oli, Madan K

2011-12-01

Predation and food resources can strongly affect small mammal population dynamics directly by altering vital rates or indirectly by influencing behaviors. Fire may also strongly influence population dynamics of species inhabiting fire-adapted habitats because fire can alter food and cover availability. We used capture-mark-recapture and radio-telemetry studies to experimentally examine how supplemental feeding, mammalian predator exclusion, and prescribed fire affected survival, abundance, and reproduction of hispid cotton rats (Sigmodon hispidus) in southwestern Georgia, USA. Prescribed fire reduced survival, abundance, and rates of transitions to reproductive states. Food supplementation increased survival, transitions to reproductive states, and abundance, but was not sufficient to prevent post-fire declines in any of these parameters. Mammalian predator exclusion did not strongly affect any of the considered parameters. Our results show that fire strongly influenced cotton rat populations in our study site, primarily by reducing cover and increasing predation risk from non-mammalian predators.

Unprecedented remote sensing data over King and Rim megafires in the Sierra Nevada Mountains of California.

PubMed

Stavros, E Natasha; Tane, Zachary; Kane, Van R; Veraverbeke, Sander; McGaughey, Robert J; Lutz, James A; Ramirez, Carlos; Schimel, David

2016-11-01

Megafires have lasting social, ecological, and economic impacts and are increasing in the western contiguous United States. Because of their infrequent nature, there is a limited sample of megafires to investigate their unique behavior, drivers, and relationship to forest management practices. One approach is to characterize critical information pre-, during, and post-fire using remote sensing. In August 2013, the Rim Fire burned 104,131 ha and in September 2014, the King Fire burned 39,545 ha. Both fires occurred in California's Sierra Nevada. The areas burned by these fires were fortuitously surveyed by airborne campaigns, which provided the most recent remote sensing technologies not currently available from satellite. Technologies include an imaging spectrometer spanning the visible to shortwave infrared (0.38-2.5 μm), a multispectral, high-spatial resolution thermal infrared (3.5-13 μm) spectroradiometer, and Light Detection and Ranging that provide spatial resolutions of pixels from 1 × 1 m to 35 × 35 m. Because of the unique information inherently derived from these technologies before the fires, the areas were subsequently surveyed after the fires. We processed and provide free dissemination of these airborne datasets as products of surface reflectance, spectral metrics and forest structural metrics ( http://dx.doi.org/10.3334/ORNLDAAC/1288). These data products provide a unique opportunity to study relationships among and between remote sensing observations and fuel and fire characteristics (e.g., fuel type, condition, structure, and fire severity). The novelty of these data is not only in the unprecedented types of information available from them before, during, and after two megafires, but also in the synergistic use of multiple state of the art technologies for characterizing the environment. The synergy of these data can provide novel information that can improve maps of fuel type, structure, abundance, and condition that may improve predictions of megafire behavior and effects, thus aiding management before, during, and after such events. Key questions that these data could address include: What drives, extinguishes, and results from megafires? How does megafire behavior relate to fire and fuel management? How does the size and severity of a megafire affect the ecological recovery of the system? © 2016 by the Ecological Society of America.

Water source protection funds as a tool to address climate adaptation and resiliency in southwestern forests

Treesearch

Laura Falk McCarthy

2014-01-01

Wildfire intensity in the Southwestern United States has increased over the last decade corresponding with dense fuels and higher temperatures. For example, in New Mexico on the 2011 Las Conchas fire, intense fire and wind-driven fire behavior resulted in large areas of moderate and high severity burn (42 percent of burned area) with roughly 65,000 acres (26,300 ha)...

Economic information on the historical behavior of forest fires in the forest lands in the state of Parana, Brazil

Treesearch

Vitor Afonso Hoeflich; Alexandre França Tetto; Antonio Carlos Batista

2013-01-01

It is widely acknowledged that the fires have caused severe impact in the world, and their frequency and intensity tend to increase as a result of ongoing climate changes which have occurred over the past decades. It should be also noted that the urban-rural interface has attracted the attention of governments by the concentration of the number of fire...

Long-term dead wood changes in a Sierra Nevada mixed conifer forest: habitat and fire hazard implications

Treesearch

Eric E. Knapp

2015-01-01

Dead trees play an important role in forests, with snags and coarse woody debris (CWD) used by many bird and mammal species for nesting, resting, or foraging. However, too much dead wood can also contribute to extreme fire behavior. This tension between dead wood as habitat and dead wood as fuel has raised questions about appropriate quantities in fire-dependent...

Characteristics and behavior of a cool-season prescribed fire in the oak savannas of the Southwestern Borderlands

Treesearch

Karen A. Koestner; Daniel G. Neary; Gerald J. Gottfired; Ruben Morales

2008-01-01

Oak-savannas and woodlands comprise over 80,000 km2 (31,000 mi2) in the mountains and high valleys of the southwestern United States and northern Mexico (Figure 1). Fire, which was once the most important natural disturbance in this system, has been excluded due to over-grazing and fire suppression practices. This has resulted in ecosystem changes and fuel...

Orbitofrontal participation in sign- and goal-tracking conditioned responses: Effects of nicotine.

PubMed

Stringfield, Sierra J; Palmatier, Matthew I; Boettiger, Charlotte A; Robinson, Donita L

2017-04-01

Pavlovian conditioned stimuli can acquire incentive motivational properties, and this phenomenon can be measured in animals using Pavlovian conditioned approach behavior. Drugs of abuse can influence the expression of this behavior, and nicotine in particular exhibits incentive amplifying effects. Both conditioned approach behavior and drug abuse rely on overlapping corticolimbic circuitry. We hypothesize that the orbitofrontal cortex (OFC) regulates conditioned approach, and that one site of nicotine action is in the OFC where it reduces cortical output. To test this, we repeatedly exposed rats to 0.4 mg/kg nicotine (s.c.) during training and then pharmacologically inactivated the lateral OFC or performed in vivo electrophysiological recordings of lateral OFC neurons in the presence or absence of nicotine. In Experiment 1, animals were trained in a Pavlovian conditioning paradigm and behavior was evaluated after inactivation of the OFC by microinfusion of the GABA agonists baclofen and muscimol. In Experiment 2, we monitored phasic firing of OFC neurons during Pavlovian conditioning sessions. Nicotine reliably enhanced conditioned responding to the conditioned cue, and inactivation of the OFC reduced conditioned responding, especially the sign-tracking response. OFC neurons exhibited phasic excitations to cue presentation and during goal tracking, and nicotine acutely blunted this phasic neuronal firing. When nicotine was withheld, both conditioned responding and phasic firing in the OFC returned to the level of controls. These results suggest that the OFC is recruited for the expression of conditioned responses, and that nicotine acutely influences this behavior by reducing phasic firing in the OFC. Copyright © 2016 Elsevier Ltd. All rights reserved.

Predictions of fire behavior and resistance to control: for use with photo series for the Douglas fir-hemlock type and the coastal Douglas-fir-hardwood type.

Treesearch

David V. SANDBERG; Franklin R. Ward

1981-01-01

This publication presents tables on the behavior of fire and the resistance of fuels to control. The information is to be used with the photos in the publication, "Photo Series for Quantifying Forest Residues in the Coastal Douglas-fir—Hemlock Type, Coastal Douglas-fir—Hardwood Type" (Maxwell, Wayne G.; Ward, Franklin R. 1976. Gen. Tech. Rep. PNW-GTR-051....

Prospect Theory and Interval-Valued Hesitant Set for Safety Evacuation Model

NASA Astrophysics Data System (ADS)

Kou, Meng; Lu, Na

2018-01-01

The study applies the research results of prospect theory and multi attribute decision making theory, combined with the complexity, uncertainty and multifactor influence of the underground mine fire system and takes the decision makers’ psychological behavior of emotion and intuition into full account to establish the intuitionistic fuzzy multiple attribute decision making method that is based on the prospect theory. The model established by this method can explain the decision maker’s safety evacuation decision behavior in the complex system of underground mine fire due to the uncertainty of the environment, imperfection of the information and human psychological behavior and other factors.

The impact of wildland fires on calcareous Mediterranean pedosystems (Sardinia, Italy) - An integrated multiple approach.

PubMed

Capra, Gian Franco; Tidu, Simona; Lovreglio, Raffaella; Certini, Giacomo; Salis, Michele; Bacciu, Valentina; Ganga, Antonio; Filzmoser, Peter

2018-05-15

Sardinia (Italy), the second largest island of the Mediterranean Sea, is a fire-prone land. Most Sardinian environments over time were shaped by fire, but some of them are too intrinsically fragile to withstand the currently increasing fire frequency. Calcareous pedoenvironments represent a significant part of Mediterranean areas, and require important efforts to prevent long-lasting degradation from fire. The aim of this study was to assess through an integrated multiple approach the impact of a single and highly severe wildland fire on limestone-derived soils. For this purpose, we selected two recently burned sites, Sant'Antioco and Laconi. Soil was sampled from 80 points on a 100×100m grid - 40 in the burned area and 40 in unburned one - and analyzed for particle size fractions, pH, electrical conductivity, organic carbon, total N, total P, and water repellency (WR). Fire behavior (surface rate of spread (ROS), fireline intensity (FLI), flame length (FL)) was simulated by BehavePlus 5.0.5 software. Comparisons between burned and unburned areas were done through ANOVA as well as deterministic and stochastic interpolation techniques; multiple correlations among parameters were evaluated by principal factor analysis (PFA) and differences/similarities between areas by principal component analysis (PCA). In both sites, fires were characterized by high severity and determined significant changes to some soil properties. The PFA confirmed the key ecological role played by fire in both sites, with the variability of a four-modeled components mainly explained by fire parameters, although the induced changes on soils were mainly site-specific. The PCA revealed the presence of two main "driving factors": slope (in Sant'Antioco), which increased the magnitude of ROS and FLI; and soil properties (in Laconi), which mostly affected FL. In both sites, such factors played a direct role in differentiating fire behavior and sites, while they played an indirect role in determining some effects on soil. Copyright © 2017 Elsevier B.V. All rights reserved.

Specific role of VTA dopamine neuronal firing rates and morphology in the reversal of anxiety-related, but not depression-related behavior in the ClockΔ19 mouse model of mania.

PubMed

Coque, Laurent; Mukherjee, Shibani; Cao, Jun-Li; Spencer, Sade; Marvin, Marian; Falcon, Edgardo; Sidor, Michelle M; Birnbaum, Shari G; Graham, Ami; Neve, Rachael L; Gordon, Elizabeth; Ozburn, Angela R; Goldberg, Matthew S; Han, Ming-Hu; Cooper, Donald C; McClung, Colleen A

2011-06-01

Lithium has been used extensively for mood stabilization, and it is particularly efficacious in the treatment of bipolar mania. Like other drugs used in the treatment of psychiatric diseases, it has little effect on the mood of healthy individuals. Our previous studies found that mice with a mutation in the Clock gene (ClockΔ19) have a complete behavioral profile that is very similar to human mania, which can be reversed with chronic lithium treatment. However, the cellular and physiological effects that underlie its targeted therapeutic efficacy remain unknown. Here we find that ClockΔ19 mice have an increase in dopaminergic activity in the ventral tegmental area (VTA), and that lithium treatment selectively reduces the firing rate in the mutant mice with no effect on activity in wild-type mice. Furthermore, lithium treatment reduces nucleus accumbens (NAc) dopamine levels selectively in the mutant mice. The increased dopaminergic activity in the Clock mutants is associated with cell volume changes in dopamine neurons, which are also rescued by lithium treatment. To determine the role of dopaminergic activity and morphological changes in dopamine neurons in manic-like behavior, we manipulated the excitability of these neurons by overexpressing an inwardly rectifying potassium channel subunit (Kir2.1) selectively in the VTA of ClockΔ19 mice and wild-type mice using viral-mediated gene transfer. Introduction of this channel mimics the effects of lithium treatment on the firing rate of dopamine neurons in ClockΔ19 mice and leads to a similar change in dopamine cell volume. Furthermore, reduction of dopaminergic firing rates in ClockΔ19 animals results in a normalization of locomotor- and anxiety-related behavior that is very similar to lithium treatment; however, it is not sufficient to reverse depression-related behavior. These results suggest that abnormalities in dopamine cell firing and associated morphology underlie alterations in anxiety-related behavior in bipolar mania, and that the therapeutic effects of lithium come from a reversal of these abnormal phenotypes.

Postfire logging in riparian areas.

PubMed

Reeves, Gordon H; Bisson, Peter A; Rieman, Bruce E; Benda, Lee E

2006-08-01

We reviewed the behavior of wildfire in riparian zones, primarily in the western United States, and the potential ecological consequences of postfire logging. Fire behavior in riparian zones is complex, but many aquatic and riparian organisms exhibit a suite of adaptations that allow relatively rapid recovery after fire. Unless constrained by other factors, fish tend to rebound relatively quickly, usually within a decade after a wildfire. Additionally, fire and subsequent erosion events contribute wood and coarse sediment that can create and maintain productive aquatic habitats over time. The potential effects of postfire logging in riparian areas depend on the landscape context and disturbance history of a site; however available evidence suggests two key management implications: (1) fire in riparian areas creates conditions that may not require intervention to sustain the long-term productivity of the aquatic network and (2) protection of burned riparian areas gives priority to what is left rather than what is removed. Research is needed to determine how postfire logging in riparian areas has affected the spread of invasive species and the vulnerability of upland forests to insect and disease outbreaks and how postfire logging will affect the frequency and behavior of future fires. The effectiveness of using postfire logging to restore desired riparian structure and function is therefore unproven, but such projects are gaining interest with the departure of forest conditions from those that existed prior to timber harvest, fire suppression, and climate change. In the absence of reliable information about the potential consequence of postfire timber harvest, we conclude that providing postfire riparian zones with the same environmental protections they received before they burned isjustified ecologically Without a commitment to monitor management experiments, the effects of postfire riparian logging will remain unknown and highly contentious.

Impact of reduced ignition propensity cigarette regulation on consumer smoking behavior and quit intentions: evidence from 6 waves (2004–11) of the ITC Four Country Survey

PubMed Central

2013-01-01

Background Although on the decline, smoking-related fires remain a leading cause of fire death in the United States and United Kingdom and account for over 10% of fire-related deaths worldwide. This has prompted lawmakers to enact legislation requiring manufacturers to implement reduced ignition propensity (RIP) safety standards for cigarettes. The current research evaluates how implementation of RIP safety standards in different countries influenced smokers’ perceptions of cigarette self-extinguishment, frequency of extinguishment, and the impact on consumer smoking behaviors, including cigarettes smoked per day and planning to quit. Methods Participants for this research come from Waves 3 through 8 of the International Tobacco Control (ITC) Four Country Survey conducted longitudinally from 2004 through 2011 in the United States, United Kingdom, Australia, and Canada. Results Perceptions of cigarette self-extinguishment and frequency of extinguishment increased concurrently with an increase in the prevalence of RIP safety standards for cigarettes. Presence of RIP safety standards was also associated with a greater intention to quit smoking, but was not associated with the number of cigarettes smoked per day. Intention to quit was higher among those who were more likely to report that their cigarettes self-extinguish sometimes and often, but we found no evidence of an interaction between frequency of extinguishment and RIP safety standards on quit intentions. Conclusions Overall, because these standards largely do not influence consumer smoking behavior, RIP implementation may significantly reduce the number of cigarette-related fires and the associated death and damages. Further research should assess how implementation of RIP safety standards has influenced smoking-related fire incidence, deaths, and other costs associated with smoking-related fires. PMID:24359292

Impact of reduced ignition propensity cigarette regulation on consumer smoking behavior and quit intentions: evidence from 6 waves (2004-11) of the ITC Four Country Survey.

PubMed

Adkison, Sarah E; O'Connor, Richard J; Borland, Ron; Yong, Hua-Hie; Cummings, K Michael; Hammond, David; Fong, Geoffrey T

2013-12-21

Although on the decline, smoking-related fires remain a leading cause of fire death in the United States and United Kingdom and account for over 10% of fire-related deaths worldwide. This has prompted lawmakers to enact legislation requiring manufacturers to implement reduced ignition propensity (RIP) safety standards for cigarettes. The current research evaluates how implementation of RIP safety standards in different countries influenced smokers' perceptions of cigarette self-extinguishment, frequency of extinguishment, and the impact on consumer smoking behaviors, including cigarettes smoked per day and planning to quit. Participants for this research come from Waves 3 through 8 of the International Tobacco Control (ITC) Four Country Survey conducted longitudinally from 2004 through 2011 in the United States, United Kingdom, Australia, and Canada. Perceptions of cigarette self-extinguishment and frequency of extinguishment increased concurrently with an increase in the prevalence of RIP safety standards for cigarettes. Presence of RIP safety standards was also associated with a greater intention to quit smoking, but was not associated with the number of cigarettes smoked per day. Intention to quit was higher among those who were more likely to report that their cigarettes self-extinguish sometimes and often, but we found no evidence of an interaction between frequency of extinguishment and RIP safety standards on quit intentions. Overall, because these standards largely do not influence consumer smoking behavior, RIP implementation may significantly reduce the number of cigarette-related fires and the associated death and damages. Further research should assess how implementation of RIP safety standards has influenced smoking-related fire incidence, deaths, and other costs associated with smoking-related fires.

Mapping the Daily Progression of Large Wildland Fires Using MODIS Active Fire Data

NASA Technical Reports Server (NTRS)

Veraverbeke, Sander; Sedano, Fernando; Hook, Simon J.; Randerson, James T.; Jin, Yufang; Rogers, Brendan

2013-01-01

High temporal resolution information on burned area is a prerequisite for incorporating bottom-up estimates of wildland fire emissions in regional air transport models and for improving models of fire behavior. We used the Moderate Resolution Imaging Spectroradiometer (MODIS) active fire product (MO(Y)D14) as input to a kriging interpolation to derive continuous maps of the evolution of nine large wildland fires. For each fire, local input parameters for the kriging model were defined using variogram analysis. The accuracy of the kriging model was assessed using high resolution daily fire perimeter data available from the U.S. Forest Service. We also assessed the temporal reporting accuracy of the MODIS burned area products (MCD45A1 and MCD64A1). Averaged over the nine fires, the kriging method correctly mapped 73% of the pixels within the accuracy of a single day, compared to 33% for MCD45A1 and 53% for MCD64A1.

Disentangling the drivers of coarse woody debris behavior and carbon gas emissions during fire

NASA Astrophysics Data System (ADS)

Zhao, Weiwei; van der Werf, Guido R.; van Logtestijn, Richard S. P.; van Hal, Jurgen R.; Cornelissen, Johannes H. C.

2016-04-01

The turnover of coarse woody debris, a key terrestrial carbon pool, plays fundamental roles in global carbon cycling. Biological decomposition and fire are two main fates for dead wood turnover. Compared to slow decomposition, fire rapidly transfers organic carbon from the earth surface to the atmosphere. Both a-biotic environmental factors and biotic wood properties determine coarse wood combustion and thereby its carbon gas emissions during fire. Moisture is a key inhibitory environmental factor for fire. The properties of dead wood strongly affect how it burns either directly or indirectly through interacting with moisture. Coarse wood properties vary between plant species and between various decay stages. Moreover, if we put a piece of dead wood in the context of a forest fuel bed, the soil and wood contact might also greatly affect their fire behavior. Using controlled laboratory burns, we disentangled the effects of all these driving factors: tree species (one gymnosperms needle-leaf species, three angiosperms broad-leaf species), wood decay stages (freshly dead, middle decayed, very strongly decayed), moisture content (air-dried, 30% moisture content in mass), and soil-wood contact (on versus 3cm above the ground surface) on dead wood flammability and carbon gas efflux (CO2 and CO released in grams) during fire. Wood density was measured for all coarse wood samples used in our experiment. We found that compared to other drivers, wood decay stages have predominant positive effects on coarse wood combustion (for wood mass burned, R2=0.72 when air-dried and R2=0.52 at 30% moisture content) and associated carbon gas emissions (for CO2andCO (g) released, R2=0.55 when air-dried and R2=0.42 at 30% moisture content) during fire. Thus, wood decay accelerates wood combustion and its CO2 and CO emissions during fire, which can be mainly attributed to the decreasing wood density (for wood mass burned, R2=0.91 when air-dried and R2=0.63 at 30% moisture content) as wood becomes more decomposed. Our results provide quantitative experimental evidence for how several key abiotic and biotic factors, especially moisture content and the key underlying trait wood density, as well as their interactions, together drive coarse wood carbon turnover through fire. Our experimental data on coarse wood behavior and gas efflux during fire will help to improve the predictive power of global vegetation climate models on dead wood turnover and its feedback to climate.

Quantifying and predicting fuels and the effects of reduction treatments along successional and invasion gradients in sagebrush habitats

USGS Publications Warehouse

Shinneman, Douglas; Pilliod, David S.; Arkle, Robert; Glenn, Nancy F.

2015-01-01

Sagebrush shrubland ecosystems in the Great Basin are prime examples of how altered successional trajectories can create dynamic fuel conditions and, thus, increase uncertainty about fire risk and behavior. Although fire is a natural disturbance in sagebrush, post-fire environments are highly susceptible to conversion to an invasive grass-fire regime (often referred to as a “grass-fire cycle”). After fire, native shrub-steppe plants are often slow to regenerate, whereas nonnative annuals, especially cheatgrass (Bromus tectorum) and medusahead (Taeniatherum caput-medusae), can establish quickly and outcompete native species. Once fire-prone annuals become established, fire occurrences increase, further promoting dominance of nonnative species. The invasive grass-fire regime also alters nutrient and hydrologic cycles, pushing ecosystems beyond ecological thresholds toward steady-state, fire-prone, nonnative communities. These changes affect millions of hectares in the Great Basin and increase fire risk, decrease habitat quality and biodiversity, accelerate soil erosion, and degrade rangeland resources for livestock production. In many sagebrush landscapes, constantly changing plant communities and fuel conditions hinder attempts by land managers to predict and control fire behavior, restore native communities, and provide ecosystem services (e.g., forage production for livestock). We investigated successional and nonnative plant invasion states and associated fuel loads in degraded sagebrush habitat in a focal study area, the Morley Nelson Snake River Birds of Prey National Conservation Area (hereafter the NCA), in the Snake River Plain Ecoregion of southern Idaho. We expanded our inference by comparing our findings to similar data collected throughout seven major land resource areas (MLRAs) across the Great Basin (JFSP Project “Fire Rehabilitation Effectiveness: A Chronosequence Approach for the Great Basin” [09-S-02-1]). 4 We used a combination of field-sampling, experimental treatments, and remotely sensed data to address the following questions: (1) How do fuel loads change along gradients of succession and invasion in sagebrush ecological sites? (2) How do fuel reduction treatments influence fuels in invaded areas formerly dominated by sagebrush? (3) How do fuel loads vary across landscapes and which remote sensing techniques are effective for characterizing them?

Fire and Smoke Model Evaluation Experiment: Coordination of a study to improve smoke modeling for fire operations within the United States

NASA Astrophysics Data System (ADS)

French, N. H. F.; Ottmar, R. D.; Brown, T. J.; Larkin, N. K.

2017-12-01

The Fire and Smoke Model Evaluation Experiment (FASMEE) is an integrative research effort to identify and collect critical measurements to improve operational wildland fire and smoke prediction systems. FASMEE has two active phases and one suggested phase. Phase 1 is the analysis and planning process to assess the current state of fire-plume-smoke modeling and to determine the critical measurements required to evaluate and improve these operational fire and smoke models. As the major deliverable for Phase 1, a study plan has been completed that describes the measurement needs, field campaigns, and command, safety and air space de-confliction plans necessary to complete the FASMEE project. Phase 2 is a set of field campaigns to collect data during 2019-2022. Future Improvements would be a set of analyses and model improvements based on the data collected within Phase 2 that is dependent on identifying future funding sources. In this presentation, we will review the FASMEE Study Plan and detailed measurements and conditions expected for the four to five proposed research burns. The recommended measurements during Phase 2 span the four interrelated disciplines of FASMEE: fuels and consumption, fire behavior and energy, plume dynamics and meteorology, and smoke emissions, chemistry, and transport. Fuel type, condition, and consumption during wildland fire relates to several fire impacts including radiative heating, which provides the energy that drives fire dynamics. Local-scale meteorology is an important factor which relates to atmospheric chemistry, dispersion, and transport. Plume dynamics provide the connection between fire behavior and far-field smoke dispersion, because it determines the vertical distribution of the emissions. Guided by the data needs and science questions generated during Phase 1, three wildland fire campaigns were selected. These included the western wildfire campaign (rapid deployment aimed at western wildfires supporting NOAA, NASA, and NSF smoke flights), southwestern campaign (targeting high intensity prescribed fires), and southeastern campaign (targeting large and higher than average fuel loadings with important smoke management relevancy).

Analytical approximations of the firing rate of an adaptive exponential integrate-and-fire neuron in the presence of synaptic noise.

PubMed

Hertäg, Loreen; Durstewitz, Daniel; Brunel, Nicolas

2014-01-01

Computational models offer a unique tool for understanding the network-dynamical mechanisms which mediate between physiological and biophysical properties, and behavioral function. A traditional challenge in computational neuroscience is, however, that simple neuronal models which can be studied analytically fail to reproduce the diversity of electrophysiological behaviors seen in real neurons, while detailed neuronal models which do reproduce such diversity are intractable analytically and computationally expensive. A number of intermediate models have been proposed whose aim is to capture the diversity of firing behaviors and spike times of real neurons while entailing the simplest possible mathematical description. One such model is the exponential integrate-and-fire neuron with spike rate adaptation (aEIF) which consists of two differential equations for the membrane potential (V) and an adaptation current (w). Despite its simplicity, it can reproduce a wide variety of physiologically observed spiking patterns, can be fit to physiological recordings quantitatively, and, once done so, is able to predict spike times on traces not used for model fitting. Here we compute the steady-state firing rate of aEIF in the presence of Gaussian synaptic noise, using two approaches. The first approach is based on the 2-dimensional Fokker-Planck equation that describes the (V,w)-probability distribution, which is solved using an expansion in the ratio between the time constants of the two variables. The second is based on the firing rate of the EIF model, which is averaged over the distribution of the w variable. These analytically derived closed-form expressions were tested on simulations from a large variety of model cells quantitatively fitted to in vitro electrophysiological recordings from pyramidal cells and interneurons. Theoretical predictions closely agreed with the firing rate of the simulated cells fed with in-vivo-like synaptic noise.

An Information Perception-Based Emotion Contagion Model for Fire Evacuation

NASA Astrophysics Data System (ADS)

Liu, Ting Ting; Liu, Zhen; Ma, Minhua; Xuan, Rongrong; Chen, Tian; Lu, Tao; Yu, Lipeng

2017-03-01

In fires, people are easier to lose their mind. Panic will lead to irrational behavior and irreparable tragedy. It has great practical significance to make contingency plans for crowd evacuation in fires. However, existing studies about crowd simulation always paid much attention on the crowd density, but little attention on emotional contagion that may cause a panic. Based on settings about information space and information sharing, this paper proposes an emotional contagion model for crowd in panic situations. With the proposed model, a behavior mechanism is constructed for agents in the crowd and a prototype of system is developed for crowd simulation. Experiments are carried out to verify the proposed model. The results showed that the spread of panic not only related to the crowd density and the individual comfort level, but also related to people's prior knowledge of fire evacuation. The model provides a new way for safety education and evacuation management. It is possible to avoid and reduce unsafe factors in the crowd with the lowest cost.

Sleep and Movement Differentiates Actions of Two Types of Somatostatin-Expressing GABAergic Interneuron in Rat Hippocampus

PubMed Central

Katona, Linda; Lapray, Damien; Viney, Tim J.; Oulhaj, Abderrahim; Borhegyi, Zsolt; Micklem, Benjamin R.; Klausberger, Thomas; Somogyi, Peter

2014-01-01

Summary Neuropeptides acting on pre- and postsynaptic receptors are coreleased with GABA by interneurons including bistratified and O-LM cells, both expressing somatostatin but innervating segregated dendritic domains of pyramidal cells. Neuropeptide release requires high-frequency action potentials, but the firing patterns of most peptide/GABA-releasing interneurons during behavior are unknown. We show that behavioral and network states differentiate the activities of bistratified and O-LM cells in freely moving rats. Bistratified cells fire at higher rates during sleep than O-LM cells and, unlike O-LM cells, strongly increase spiking during sharp wave-associated ripples (SWRs). In contrast, O-LM interneurons decrease firing during sleep relative to awake states and are mostly inhibited during SWRs. During movement, both cell types fire cooperatively at the troughs of theta oscillations but with different frequencies. Somatostatin and GABA are differentially released to distinct dendritic zones of CA1 pyramidal cells during sleep and wakefulness to coordinate segregated glutamatergic inputs from entorhinal cortex and CA3. PMID:24794095

Multiplexing of Motor Information in the Discharge of a Collision Detecting Neuron during Escape Behaviors

PubMed Central

Fotowat, Haleh; Harrison, Reid R; Gabbiani, Fabrizio

2010-01-01

Locusts possess an identified neuron, the descending contralateral movement detector (DCMD), conveying visual information about impending collision from the brain to thoracic motor centers. We built a telemetry system to simultaneously record, in freely behaving animals, the activity of the DCMD and of motoneurons involved in jump execution. Co-contraction of antagonistic leg muscles, a required preparatory phase, was triggered after the DCMD firing rate crossed a threshold. Thereafter, the number of DCMD spikes predicted precisely motoneuron activity and jump occurrence. Additionally, the time of DCMD peak firing rate predicted that of jump. Ablation experiments suggest that the DCMD, together with a nearly identical ipsilateral descending neuron, is responsible for the timely execution of the escape. Thus, three distinct features that are multiplexed in a single neuron’s sensory response to impending collision – firing rate threshold, peak firing time, and spike count – likely control three distinct motor aspects of escape behaviors. PMID:21220105

Distinct Developmental Origins Manifest in the Specialized Encoding of Movement by Adult Neurons of the External Globus Pallidus

PubMed Central

Dodson, Paul D.; Larvin, Joseph T.; Duffell, James M.; Garas, Farid N.; Doig, Natalie M.; Kessaris, Nicoletta; Duguid, Ian C.; Bogacz, Rafal; Butt, Simon J.B.; Magill, Peter J.

2015-01-01

Summary Transcriptional codes initiated during brain development are ultimately realized in adulthood as distinct cell types performing specialized roles in behavior. Focusing on the mouse external globus pallidus (GPe), we demonstrate that the potential contributions of two GABAergic GPe cell types to voluntary action are fated from early life to be distinct. Prototypic GPe neurons derive from the medial ganglionic eminence of the embryonic subpallium and express the transcription factor Nkx2-1. These neurons fire at high rates during alert rest, and encode movements through heterogeneous firing rate changes, with many neurons decreasing their activity. In contrast, arkypallidal GPe neurons originate from lateral/caudal ganglionic eminences, express the transcription factor FoxP2, fire at low rates during rest, and encode movements with robust increases in firing. We conclude that developmental diversity positions prototypic and arkypallidal neurons to fulfil distinct roles in behavior via their disparate regulation of GABA release onto different basal ganglia targets. PMID:25843402

Fire danger rating and fire behavior prediction in the United States

Treesearch

Patricia L. Andrews

2005-01-01

For the seven year period from 1998 to 2004, an average of almost 79,000 fires per year on U.S. Federal and State land burned a yearly average of over 22,000 km2. An average of 1 billion US dollars was spent on suppression each year by the Federal agencies alone. Variation in climate, vegetation, and population across the U.S. leads to significant differences in the...

Fuel consumption and fire characteristics during understory burning in a mixed white pine-hardwood stand in the Southern Appalachians.

Treesearch

Barton D. Clinton; James M. Vose; Wayne T. Swank; Erik C. Berg; David L. Loftis

1998-01-01

We characterized tire behavior and fuel consumption resulting from an understory prescribed burn in a mixed eastern white pine-hardwood stand in the Southern Appalachians. These stands were used for the treatment. Flame lengths, ranging from 0.3 to 1.5 meters (m) for backing fires and from 1.2 to 4.5 m for head fires, reached maximum heights where evergreen understory...

Fire and Thinning in an Ohio Oak Forest: Grid-Based Analyses of Fire Behavior, Environmental Conditions, and Tree Regeneration Across a Topographic Moisture Gradient

Treesearch

Louis Iverson; Anantha Prasad; Todd Hutchinson; Joanne Rebbeck; Daniel A. Yaussy

2004-01-01

Prescribed fire alone and in combination with thinning were accomplished in late 2000 to spring 2001 at Zaleski State Forest in southern Ohio. Sites were monitored before and after the treatments were applied. Light was assessed via hemispherical photographs taken in July 2000 and 2001. Oak and hickory seedlings and saplings were sampled during those same time periods...

Using a prescribed fire to test custom and standard fuel models for fire behaviour prediction in a non-native, grass-invaded tropical dry shrubland

Treesearch

Andrew D. Pierce; Sierra McDaniel; Mark Wasser; Alison Ainsworth; Creighton M. Litton; Christian P. Giardina; Susan Cordell; Ralf Ohlemuller

2014-01-01

Questions: Do fuel models developed for North American fuel types accurately represent fuel beds found in grass-invaded tropical shrublands? Do standard or custom fuel models for firebehavior models with in situ or RAWS measured fuel moistures affect the accuracy of predicted fire behavior in grass-invaded tropical shrublands? Location: Hawai’i Volcanoes National...

Economic vulnerability of timber resources to forest fires.

PubMed

y Silva, Francisco Rodríguez; Molina, Juan Ramón; González-Cabán, Armando; Machuca, Miguel Ángel Herrera

2012-06-15

The temporal-spatial planning of activities for a territorial fire management program requires knowing the value of forest ecosystems. In this paper we extend to and apply the economic valuation principle to the concept of economic vulnerability and present a methodology for the economic valuation of the forest production ecosystems. The forest vulnerability is analyzed from criteria intrinsically associated to the forest characterization, and to the potential behavior of surface fires. Integrating a mapping process of fire potential and analytical valuation algorithms facilitates the implementation of fire prevention planning. The availability of cartography of economic vulnerability of the forest ecosystems is fundamental for budget optimization, and to help in the decision making process. Published by Elsevier Ltd.

Optimal firing rate estimation

NASA Technical Reports Server (NTRS)

Paulin, M. G.; Hoffman, L. F.

2001-01-01

We define a measure for evaluating the quality of a predictive model of the behavior of a spiking neuron. This measure, information gain per spike (Is), indicates how much more information is provided by the model than if the prediction were made by specifying the neuron's average firing rate over the same time period. We apply a maximum Is criterion to optimize the performance of Gaussian smoothing filters for estimating neural firing rates. With data from bullfrog vestibular semicircular canal neurons and data from simulated integrate-and-fire neurons, the optimal bandwidth for firing rate estimation is typically similar to the average firing rate. Precise timing and average rate models are limiting cases that perform poorly. We estimate that bullfrog semicircular canal sensory neurons transmit in the order of 1 bit of stimulus-related information per spike.

Basal Ganglia Outputs Map Instantaneous Position Coordinates during Behavior

PubMed Central

Barter, Joseph W.; Li, Suellen; Sukharnikova, Tatyana; Rossi, Mark A.; Bartholomew, Ryan A.

2015-01-01

The basal ganglia (BG) are implicated in many movement disorders, yet how they contribute to movement remains unclear. Using wireless in vivo recording, we measured BG output from the substantia nigra pars reticulata (SNr) in mice while monitoring their movements with video tracking. The firing rate of most nigral neurons reflected Cartesian coordinates (either x- or y-coordinates) of the animal's head position during movement. The firing rates of SNr neurons are either positively or negatively correlated with the coordinates. Using an egocentric reference frame, four types of neurons can be classified: each type increases firing during movement in a particular direction (left, right, up, down), and decreases firing during movement in the opposite direction. Given the high correlation between the firing rate and the x and y components of the position vector, the movement trajectory can be reconstructed from neural activity. Our results therefore demonstrate a quantitative and continuous relationship between BG output and behavior. Thus, a steady BG output signal from the SNr (i.e., constant firing rate) is associated with the lack of overt movement, when a stable posture is maintained by structures downstream of the BG. Any change in SNr firing rate is associated with a change in position (i.e., movement). We hypothesize that the SNr output quantitatively determines the direction, velocity, and amplitude of voluntary movements. By changing the reference signals to downstream position control systems, the BG can produce transitions in body configurations and initiate actions. PMID:25673860

Acute ethanol effects on neural encoding of reward size and delay in the nucleus accumbens

PubMed Central

Gutman, Andrea L.

2016-01-01

Acute ethanol administration can cause impulsivity, resulting in increased preference for immediately available rewards over delayed but more valuable alternatives. The manner in which reward size and delay are represented in neural firing is not fully understood, and very little is known about ethanol effects on this encoding. To address this issue, we used in vivo electrophysiology to characterize neural firing in the core of the nucleus accumbens (NAcc) in rats responding for rewards that varied in size or delay after vehicle or ethanol administration. The NAcc is a central element in the circuit that governs decision-making and importantly, promotes choice of delayed rewards. We found that NAcc firing in response to reward-predictive cues encoded anticipated reward value after vehicle administration, but ethanol administration disrupted this encoding, resulting in a loss of discrimination between immediate and delayed rewards in cue-evoked neural responses. In addition, NAcc firing occurring at the time of the operant response (lever pressing) was inversely correlated with behavioral response latency, such that increased firing rates were associated with decreased latencies to lever press. Ethanol administration selectively attenuated this lever press-evoked firing when delayed but not immediate rewards were expected. These effects on neural firing were accompanied by increased behavioral latencies to respond for delayed rewards. Our results suggest that ethanol effects on NAcc cue- and lever press-evoked encoding may contribute to ethanol-induced impulsivity. PMID:27169507

PYRONES: pyro-modeling and evacuation simulation system

NASA Astrophysics Data System (ADS)

Kanellos, Tassos; Doulgerakis, Adam; Georgiou, Eftichia; Kountouriotis, Vassilios I.; Paterakis, Manolis; Thomopoulos, Stelios C. A.; Pappou, Theodora; Vrahliotis, Socrates I.; Rekouniotis, Thrasos; Protopsaltis, Byron; Rozenberg, Ofir; Livneh, Ofer

2016-05-01

Structural fires continue to pose a great threat towards human life and property. Due to the complexity and non-deterministic characteristics of a building fire disaster, it is not a straightforward task to assess the effectiveness of fire protection measures embedded in the building design, planned evacuation strategies and potential modes of response for mitigating the fire's consequences. Additionally, there is a lack of means that realistically and accurately recreate the conditions of building fire disasters for the purpose of training personnel in order to be sufficiently prepared when vis-a-vis with such an environment. The propagation of fire within a building, the diffusion of its volatile products, the behavior of the occupants and the sustained injuries not only exhibit non-linear behaviors as individual phenomena, but are also intertwined in a web of co-dependencies. The PYRONES system has been developed to address all these aspects through a comprehensive approach that relies on accurate and realistic computer simulations of the individual phenomena and their interactions. PYRONES offers innovative tools and services to strategically targeted niches in two market domains. In the domain of building design and engineering, PYRONES is seamlessly integrated within existing engineering Building Information Modelling (BIM) workflows and serves as a building performance assessment platform, able to evaluate fire protection systems. On another front, PYRONES penetrates the building security management market, serving as a holistic training platform for specialists in evacuation strategy planning, firefighters and first responders, both at a Command and Control and at an individual trainee level.

Gas emissions, minerals, and tars associated with three coal fires, Powder River Basin, USA.

PubMed

Engle, Mark A; Radke, Lawrence F; Heffern, Edward L; O'Keefe, Jennifer M K; Hower, James C; Smeltzer, Charles D; Hower, Judith M; Olea, Ricardo A; Eatwell, Robert J; Blake, Donald R; Emsbo-Mattingly, Stephen D; Stout, Scott A; Queen, Gerald; Aggen, Kerry L; Kolker, Allan; Prakash, Anupma; Henke, Kevin R; Stracher, Glenn B; Schroeder, Paul A; Román-Colón, Yomayra; ter Schure, Arnout

2012-03-15

Ground-based surveys of three coal fires and airborne surveys of two of the fires were conducted near Sheridan, Wyoming. The fires occur in natural outcrops and in abandoned mines, all containing Paleocene-age subbituminous coals. Diffuse (carbon dioxide (CO(2)) only) and vent (CO(2), carbon monoxide (CO), methane, hydrogen sulfide (H(2)S), and elemental mercury) emission estimates were made for each of the fires. Additionally, gas samples were collected for volatile organic compound (VOC) analysis and showed a large range in variation between vents. The fires produce locally dangerous levels of CO, CO(2), H(2)S, and benzene, among other gases. At one fire in an abandoned coal mine, trends in gas and tar composition followed a change in topography. Total CO(2) fluxes for the fires from airborne, ground-based, and rate of fire advancement estimates ranged from 0.9 to 780mg/s/m(2) and are comparable to other coal fires worldwide. Samples of tar and coal-fire minerals collected from the mouth of vents provided insight into the behavior and formation of the coal fires. Published by Elsevier B.V.

Neural control of muscle force: indications from a simulation model

PubMed Central

Luca, Carlo J. De

2013-01-01

We developed a model to investigate the influence of the muscle force twitch on the simulated firing behavior of motoneurons and muscle force production during voluntary isometric contractions. The input consists of an excitatory signal common to all the motor units in the pool of a muscle, consistent with the “common drive” property. Motor units respond with a hierarchically structured firing behavior wherein at any time and force, firing rates are inversely proportional to recruitment threshold, as described by the “onion skin” property. Time- and force-dependent changes in muscle force production are introduced by varying the motor unit force twitches as a function of time or by varying the number of active motor units. A force feedback adjusts the input excitation, maintaining the simulated force at a target level. The simulations replicate motor unit behavior characteristics similar to those reported in previous empirical studies of sustained contractions: 1) the initial decrease and subsequent increase of firing rates, 2) the derecruitment and recruitment of motor units throughout sustained contractions, and 3) the continual increase in the force fluctuation caused by the progressive recruitment of larger motor units. The model cautions the use of motor unit behavior at recruitment and derecruitment without consideration of changes in the muscle force generation capacity. It describes an alternative mechanism for the reserve capacity of motor units to generate extraordinary force. It supports the hypothesis that the control of motoneurons remains invariant during force-varying and sustained isometric contractions. PMID:23236008

Validation of coupled atmosphere-fire behavior models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bossert, J.E.; Reisner, J.M.; Linn, R.R.

1998-12-31

Recent advances in numerical modeling and computer power have made it feasible to simulate the dynamical interaction and feedback between the heat and turbulence induced by wildfires and the local atmospheric wind and temperature fields. At Los Alamos National Laboratory, the authors have developed a modeling system that includes this interaction by coupling a high resolution atmospheric dynamics model, HIGRAD, with a fire behavior model, BEHAVE, to predict the spread of wildfires. The HIGRAD/BEHAVE model is run at very high resolution to properly resolve the fire/atmosphere interaction. At present, these coupled wildfire model simulations are computationally intensive. The additional complexitymore » of these models require sophisticated methods for assuring their reliability in real world applications. With this in mind, a substantial part of the research effort is directed at model validation. Several instrumented prescribed fires have been conducted with multi-agency support and participation from chaparral, marsh, and scrub environments in coastal areas of Florida and inland California. In this paper, the authors first describe the data required to initialize the components of the wildfire modeling system. Then they present results from one of the Florida fires, and discuss a strategy for further testing and improvement of coupled weather/wildfire models.« less

Locomotor effects of a low-frequency fire alarm on C57BL/6 male mice: a preliminary study.

PubMed

Povroznik, Jessica M; Faith, Robert E; Kessler, Matthew J; Ali, Frank N; Kosik, James; Prince, Stephen; Engler-Chiurazzi, Elizabeth B

2017-12-01

Maintaining appropriate acoustic conditions for animal welfare and data collection are crucial in biomedical research facilities. Negative impacts of disruptive sound are known and can include auditory damage, immune function changes, and behavioral alterations. One type of disruptive sound occurring in research facilities is that of fire alarms. To ameliorate this problem, many facilities have incorporated the use of low-frequency fire alarms that emit tones outside the rodent audible range. The impact of these devices has been assumed to be negligible. However, this has yet to be evaluated with controlled behavioral experiments. Thus, our objective was to investigate the impact of low-frequency fire alarm exposure on locomotor behavior in the open field, a test sensitive to acoustic stimuli disruption. Male mice were randomized to three alarm exposure groups (No-Alarm; Alarm-During; and Alarm-After) and placed in individual photobeam-activated locomotor chambers. The Alarm-During group displayed significantly reduced horizontal locomotion, with a trend towards reduced vertical locomotion. These data suggest that a low-frequency brief alarm tone can temporarily disrupt movement, a valuable insight should an alarm be deployed. Further, findings support close collaboration between researchers and institutional facility staff to ensure appropriate acoustic conditions are maintained, whenever possible, for research animals.

Cortical firing and sleep homeostasis.

PubMed

Vyazovskiy, Vladyslav V; Olcese, Umberto; Lazimy, Yaniv M; Faraguna, Ugo; Esser, Steve K; Williams, Justin C; Cirelli, Chiara; Tononi, Giulio

2009-09-24

The need to sleep grows with the duration of wakefulness and dissipates with time spent asleep, a process called sleep homeostasis. What are the consequences of staying awake on brain cells, and why is sleep needed? Surprisingly, we do not know whether the firing of cortical neurons is affected by how long an animal has been awake or asleep. Here, we found that after sustained wakefulness cortical neurons fire at higher frequencies in all behavioral states. During early NREM sleep after sustained wakefulness, periods of population activity (ON) are short, frequent, and associated with synchronous firing, while periods of neuronal silence are long and frequent. After sustained sleep, firing rates and synchrony decrease, while the duration of ON periods increases. Changes in firing patterns in NREM sleep correlate with changes in slow-wave activity, a marker of sleep homeostasis. Thus, the systematic increase of firing during wakefulness is counterbalanced by staying asleep.