Fire Range Research Articles

Contribution of regional-scale fire events to ozone and PM2.5 air quality estimated by photochemical modeling approaches

Two specific fires from 2011 are tracked for local to regional scale contribution to ozone (O3) and fine particulate matter (PM2.5) using a freely available regulatory modeling system that includes the BlueSky wildland fire emissions tool, Spare Matrix Operator Kernel Emissions (SMOKE) model, Weather and Research Forecasting (WRF) meteorological model, and Community Multiscale Air Quality (CMAQ) photochemical grid model. The modeling system was applied to track the contribution from a wildfire (Wallow) and prescribed fire (Flint Hills) using both source sensitivity and source apportionment approaches. The model estimated fire contribution to primary and secondary pollutants are comparable using source sensitivity (brute-force zero out) and source apportionment (Integrated Source Apportionment Method) approaches. Model estimated O3 enhancement relative to CO is similar to values reported in literature indicating the modeling system captures the range of O3 inhibition possible near fires and O3 production both near the fire and downwind. O3 and peroxyacetyl nitrate (PAN) are formed in the fire plume and transported downwind along with highly reactive VOC species such as formaldehyde and acetaldehyde that are both emitted by the fire and rapidly produced in the fire plume by VOC oxidation reactions. PAN and aldehydes contribute to continued downwind O3 production. The transport and thermal decomposition of PAN to nitrogen oxides (NOX) enables O3 production in areas limited by NOX availability and the photolysis of aldehydes to produce free radicals (HOX) causes increased O3 production in NOX rich areas. The modeling system tends to overestimate hourly surface O3 at routine rural monitors in close proximity to the fires when the model predicts elevated fire impacts on O3 and Hazard Mapping System (HMS) data indicates possible fire impact. A sensitivity simulation in which solar radiation and photolysis rates were more aggressively attenuated by aerosol in the plume reduced model O3 but does not eliminate this bias. A comparison of model predicted daily average speciated PM2.5 at surface rural routine network sites when the model predicts fire impacts from either of these fires shows a tendency toward overestimation of PM2.5 organic aerosol in close proximity to these fires. The standard version of the CMAQ treats primarily emitted organic aerosol as non-volatile. An alternative approach for treating organic aerosol as semi-volatile resulted in lower PM2.5 organic aerosol from these fires but does not eliminate the bias. Future work should focus on modeling specific fire events that are well characterized in terms of size, emissions, and have extensive measurements taken near the fire and downwind to better constrain model representation of important physical and chemical processes (e.g. aerosol photolysis attenuation and organic aerosol treatment) related to wild and prescribed fires.

DETERMINING THE FIRE RATING OF CONCRETE STRUCTURES, Case study of using a probabilistic approach and travelling fires

As part of a refurbishment the height of a building in London is to be increased resulting in a change of the fire rating of the existing level from R60 to R90 as per prescriptive guidance. To investigate whether the inherent fire resistance of the structure would be sufficient a state-of-the-art probabilistic approach was adopted, with the approach extended to consider 2D heat-transfer to concrete elements. After determining the required reliability of the structure based on an acceptable risk level, a Monte-Carlo assessment was conducted. This considered for the proposed internal layouts and determined the range of input parameters to be randomly varied in order to define the required range of design fires analysed. The assessment demonstrated that the inherent structural fire resistance would provide sufficient structural reliability for the new use of the building and that no additional fire protection was required to the concrete frame.

Novel Testing to Study the Performance of Intumescent Coatings under Non-Standard Heating Regimes

Intumescent coatings (also called reactive coatings) are widely used to protect structural steel from fire. These thin coatings swell on heating to form a highly insulating char, protecting steel members and preventing them from reaching critical temperatures that could cause them to fail. As is the case for most structural materials and assemblies, intumescent coatings for use in buildings are typically developed and certified solely according to the standard cellulosic fire resistance test by exposure within a fire testing furnace. Reliance on furnace testing is expensive, non-representative of realistic fire conditions, and insufficiently versatile to gather detailed performance information on the response of reactive coatings under the full range of design fires which might be considered during a rational, performance-based design assessment. This paper presents a novel testing methodology for studying the performance of reactive coatings when subjected to non-standard heating regimes. The new approach is calibrated and validated using furnace test data, and is shown to offer considerable advantages over furnace testing in terms of reliability, repeatability, versatility, speed and cost. An investigation is then presented to study the effective variable thermal conductivity of a commercially available reactive coating when subjected to various timehistories of heat flux. It is shown that the heating rate and dry film thickness of the coating do not drastically affect the development of effective thermal conductivity with substrate temperature, leading to a proposal for a simplified method for specifying coating requirements and/or performing heat transfer design calculations when designing to non-standard heating regimes.

Space-use and habitat associations of Black-backed Woodpeckers (Picoides arcticus) occupying recently disturbed forests in the Black Hills, South Dakota

Black-backed Woodpeckers (Picoides arcticus) are a disturbance-dependent species that occupy recently burned forest and mountain pine beetle (MPB) infestations. Forest management practices that reduce the amount of disturbed forest may lead to habitat loss for Black-backed Woodpeckers, which have recently been petitioned for listing under the Endangered Species Act. We studied home range size and resource selection of Black-backed Woodpeckers occupying habitat created by summer wildfire, fall prescribed fire, and MPB infestations in the Black Hills, South Dakota. We studied home range size and resource selection by attaching radio-transmitters to adult Black-backed Woodpeckers. We estimated home range size using fixed kernel density techniques (n=28 in habitat created by summer wildfire, n=19 in habitat created by fall prescribed fire, and n=27 in MPB infestations). We evaluated resource selection with a random-effects discrete choice model in a Bayesian framework (n=5 in habitat created by summer wildfire, n=16 in habitat created by fall prescribed fire, and n=8 in habitat created by MPB infestations). Home range size was smallest in 1–2year post summer wildfire habitat (mean home range size=79ha) and 2-year post fall prescribed fire habitat (mean home range size=143ha). Home range size was intermediate in MPB infestations (mean home range size=307ha) and was greatest in 3–4year post fire habitat (mean summer wildfire home range size=430 hectares, mean fall prescribed fire home range size=460ha). The relative probability that a Black-backed Woodpecker used a tree increased with increasing diameter at breast height (DBH) and basal area and was greatest on disturbance-killed trees. These results suggest 1–2year post summer wildfire habitat may have the greatest relative value to Black-backed Woodpeckers and that MPB infestations may be more important as post-fire habitats age. We recommend retaining patches of 1–2year post summer wildfire habitat that are at least 200ha by exempting portions of recently burned forest from salvage logging. This recommendation can be accomplished by exempting salvage logging in summer wildfires <200ha and retaining at least 50% of summer wildfires >400ha. Ideally, recently burned forest patches should be composed of ⩾27m2 basal area/ha of trees that burned at moderate or high severity, with at least 40% of the basal area composed of trees ⩾27cm DBH.

Prescribed burning in Italy: issues, advances and challenges

Abstract: Prescribed burning has been carried out since the late 1970s in several southern European countries. Italy hosted some pioneer experiences in the early ’80s, but these did not follow up into practical implementation, and few studies and applications were carried out in subsequent years. In the last decade, a new interest arose and several experiences were carried out. We aim to illustrate the limitations, advances and challenges of prescribed burning in Italy by reviewing the national literature of the last 40 years on this subject. Unfavorable land characteristics, conflicting management goals, a hostile socio-cultural environment, and an inadequate regulatory framework have supposedly limited the application of prescribed burning in Italy. Nevertheless, in the last 20 years the legislation at the regional level has been updated to consider the use of fire, and new procedures to authorize prescribed fires allowed for experiments and application, even within National Parks. From 2005 to 2012, prescribed burning programs for fire hazard reduction, forest and range management, biodiversity conservation and firefighter training were implemented throughout Italy. Several vegetation and fuel types were involved (e.g., broadleaved and coniferous forests, Mediterranean and continental shrubland, grassland, slash). Studies on fire behavior and effects helped to set prescriptions for specific objectives and environments. Results were transferred to professionals through training sessions. Some of the challenges ahead are improving the legislative framework, e.g., by introducing a certification for the use of fire, and addressing issues of pastoral fire through conflict resolution programs. Prescribed burning in Italy could be developed by committing to carry out ecological studies on its implications to silviculture, range management and habitat conservation.

Fire growth simulation in passenger rail vehicles using a simplified flame spread model for integration with CFD analysis

Few robust engineering approaches currently exist to assess flame spread performance of interior finish materials for a range of source fires, in support of compartment fire hazard analysis. As a step toward closing this gap, a simplified approach for assessing (a) the propensity for a material to support self-propagating flame spread and (b) the extent of flame spread for a range of source fire conditions has been developed. In addition, a general approach for integrating the output of the simplified flame spread analysis into a computational fluid dynamics (CFD) model has been developed to predict the overall fire growth and spread hazard for a passenger rail vehicle compartment. Language: en

An overview of flame retardancy of polymeric materials: application, technology, and future directions

SUMMARYFlame retardancy of polymeric materials is conducted to provide fire protection to flammable consumer goods, as well as to mitigate fire growth in a wide range of fires. This paper is a general overview of commercial flame retardant technology. It covers the drivers behind why flame retardants are used today, the current technologies in use, how they are applied, and where the field of flame retardant research is headed. The paper is not a full review of the technology, but rather a general overview of this entire field of applied science and is designed to get the reader started on the fundamentals behind this technology. This paper is based upon presentations given by the authors in late 2009 at the Flame Retardants and Fire Fighters meeting held at NIST. Copyright © 2012 John Wiley &amp; Sons, Ltd.

Fire Pattern Repeatability: A Study in Uncertainty

Abstract The National Institute of Standards and Technology (NIST) is conducting a multi-year study, with the support of the National Institute of Justice (NIJ) and the NIST Office of Law Enforcement Standards (OLES), to examine the repeatability of fire patterns. The primary objective of the study is assessing the repeatability of fire patterns on gypsum board exposed to a limited range of source fires. The focus of this paper is an overview of the uncertainties of the measurements. The study required the use of a variety of measurements to determine the repeatability of the source fires in terms of heat release rate, temperature, heat flux, and flame height. Replicate source fire experiments were conducted in an oxygen consumption calorimeter in order to examine the repeatability of the fires in terms of the heat release rate. The flame movement and height for each fire were recorded with photographs and videos. The fire pattern experiments were conducted in a three-walled structure with a full floor and partial ceiling constructed from wood framing and lined with painted gypsum board. The source fires were positioned against the rear wall, midway along its length. Replicate experiments were conducted with each fuel. The fire patterns were documented and analyzed for repeatability. The fire pattern height results are then compared to the mean flame height results to examine the level of agreement.

An Experimental Study on the Thermal Properties of Concrete under the Load Ratio Condition in a Fire

When a fire occurs, the strength of the concrete structure deteriorates due to temperature rise under the condition of constant load. The deterioration in strength causes the change in axial load ratio, so the structure is deformed. In this study, loaded heating test of concrete lining was conducted to realize the condition of an actual fire outbreak in a tunnel where heating and loading affect the structure simultaneously. The shape of the specimens was planned in compliance with the standard for small scale test prescribed in the EFNARC and 24 MPa, 40 MPa and 50MPa were used to analyze the thermal properties associated with different concrete strengths. Constant loading condition was provided based on the load ratios equivalent to 20 % and 40 % of the sectional stress in the concrete and the MHC fire scenario was selected to realize the thermal impact on the concrete by rapid temperature rise. Under each load ratio, more cracks were observed in higher strength and spalling occurred in 50MPa. In terms of fire damage range, 50mm points from heated surface of the 200mm lining did not satisfy the ITA standard for concrete lining upon a fire.

Tall building collapse mechanisms initiated by fire: Mechanisms and design methodology

A methodology for assessing the vulnerability of tall buildings to fire on multiple floors is presented. It is based upon numerical modelling of real and imagined tall building structures. Key results from the modelling work are also presented here to introduce and illustrate two potential failure mechanisms for tall buildings in multiple floor fires. Events leading up to the failure of an external column are described for the two collapse mechanisms identified, namely, a weak floor failure mechanism and a strong floor failure mechanism.In the weak floor mechanism failure initiates in a non-fire floor and spreads progressively to adjacent floors above and below the fire affected floors. Failure is first initiated in the nearest floor below the fire affected floor which experiences large axial or membrane compressions giving rise to large P-δ moments (in addition to the pre-existing load induced moments) leading either to a buckling or a flexure failure. If the floors do not fail then the strong floor failure mechanism can occur caused by large P-δ moments in the column as a result of the inward deflection of the column in the region of the fire floors. These mechanisms are discussed in detail to understand the structural behaviour before and during collapse, following which a summary of additional numerical work to further illustrate the failure mechanisms is presented.Following discussion of the failure mechanisms, a simple design assessment methodology is proposed which could potentially offer engineers a useful tool for estimating the upper bound collapse mechanisms for tall buildings subjected to a range of multiple floor fires without resorting to complex and labour-intensive finite element models. The methodology is first demonstrated in comparison with the results obtained for the two collapse mechanisms discussed in detail in the numerical modelling part of the paper, and then it is compared with the summary of a series of numerical results from a parametric analysis to ensure that the method produces conservative results.

Preparation and properties of crystallizable Glass/Al2O3 composites for LTCC material

The investigated low temperature Co fired ceramics(LTCC) composite of 60wt% CaO-Al2O3-B2O3-SiO2 glass and 40wt% α-Al2O3 as a filler is a non-reactive system, which is a critical part of the low temperature Co fired ceramics process. Through a study on densification process, the phase transformation and microstructure can be revealed. Its composites typically consist of CaO-Al2O3-B2O3-SiO2 glass and α-Al2O3 powders of average particle size (D50=3.49 μm). The sintering behavior, phase evaluation, sintered morphology, and microwave dielectric properties were investigated. In the fire range of 800 to 900 °C, the composites were crystallized after completion of densification. It is found that the composites start to densify at 825 °C, simultaneously, the dielectric constant (ɛr) reaches its maximum. With increasing heat-treatment temperatures, due to the loose microstructure of the material, tanδ increases slightly. The last of the sintered samples were identified as partly Anorthite at 850 °C. At that temperature it has ɛr of 7.9 and tanδ less than 1×10−3, and can be used as a promising LTCC material.

Old Smokey coal fire, Floyd County, Kentucky: Estimates of gaseous emission rates

Abstract Vent emissions of the Old Smokey coal fire, Floyd County, Kentucky, were studied in May and July, 2010. Vent emissions were generally lower in July, perhaps due to a shift in the fire front, change in vent structure, or another unidentified factor. Volatile organics in the vent gasses contain dangerous levels of toxic, carcinogenic, and other hazardous compounds. Benzene ranges to nearly 400 parts per billion (volume) at one vent. Toluene exceeds 104 parts per billion (volume) at the same vent. Flux rates for CO 2 and CO range to 85,000 mg/s/m 2 and 89 mg/s/m 2 , respectively, for various vents for the two measuring times. Estimates of total CO 2 emissions, possibly less than 1000 t/year, are within the range of other eastern Kentucky coal fires.

Fire Ant Decapitating Fly Cooperative Release Programs (1994–2008): TwoPseudacteonSpecies,P. tricuspisandP. curvatus, Rapidly Expand Across Imported Fire Ant Populations in the Southeastern United States

Natural enemies of the imported fire ants, Solenopsis invicta Buren S. richteri Forel (Hymenoptera: Formicidae), and their hybrid, include a suite of more than 20 fire ant decapitating phorid flies from South America in the genus Pseudacteon. Over the past 12 years, many researchers and associates have cooperated in introducing several species as classical or self-sustaining biological control agents in the United States. As a result, two species of flies, Pseudacteon tricuspis Borgmeier and P. curvatus Borgmeier (Diptera: Phoridae), are well established across large areas of the southeastern United States. Whereas many researchers have published local and state information about the establishment and spread of these flies, here distribution data from both published and unpublished sources has been compiled for the entire United States with the goal of presenting confirmed and probable distributions as of the fall of 2008. Documented rates of expansion were also used to predict the distribution of these flies three years later in the fall of 2011. In the fall of 2008, eleven years after the first successful release, we estimate that P. tricuspis covered about 50% of the fire ant quarantined area and that it will occur in almost 65% of the quarantine area by 2011. Complete coverage of the fire ant quarantined area will be delayed or limited by this species' slow rate of spread and frequent failure to establish in more northerly portions of the fire ant range and also, perhaps, by its preference for red imported fire ants (S. invicta). Eight years after the first successful release of P. curvatus, two biotypes of this species (one biotype occurring predominantly in the black and hybrid imported fire ants and the other occurring in red imported fire ants) covered almost 60% of the fire ant quarantined area. We estimate these two biotypes will cover almost 90% of the quarantine area by 2011 and 100% by 2012 or 2013. Strategic selection of several distributional gaps for future releases will accelerate complete coverage of quarantine areas. However, some gaps may be best used for the release of additional species of decapitating flies because establishment rates may be higher in areas without competing species.

Simplified Approach for Assessing Initial Fire Development and Spread in Passenger Rail Vehicles

Whether a fire in a passenger rail vehicle remains small or grows to encompass the vehicle and how large the fire may become largely depend on the initiation fire, vehicle interior lining materials and contents, vehicle configuration, and ventilation. Assuming fixed configuration and ventilation, the initiation fire, interior materials, and contents are critical variables. Evaluation of the fire hazards represented by different interior lining materials when exposed to various initiation fire scenarios can be costly and time-consuming with full-scale fire tests. However, small-scale fire tests are less expensive, and numerous tests can be performed in a short time. Small-scale test data coupled with initiation fire data and computational modeling can be used to cost-effectively assess a wide range of scenarios and material combinations for existing and proposed vehicle designs. This paper proposes a simplified approach for characterizing initiation fires and predicting the potential for flame spread on the basis of data that can be obtained from small-scale fire tests. Through the application of a simple screening tool, it is possible to quickly assess a material's propensity to spread flames over a range of initiation fires. This approach can be used to support threat, risk, and vulnerability assessments of existing rail stock and to screen materials for new vehicle design. In conjunction with additional assessment of initial flame spread characteristics, the screening tool can be used with computational fluid dynamics fire-modeling tools to predict the overall development and spread hazard of the fire for specific vehicle configurations and resultant infrastructure impacts.

Estimating burn severity from Landsat dNBR and RdNBR indices across western Canada

National parks in western Canada experience wildland fire events at differing frequencies, intensities, and burn severities. These episodic disturbances have varying implications for various biotic and abiotic processes and patterns. To predict burn severity, the differenced Normalized Burn Ratio (dNBR) algorithm, derived from Landsat imagery, has been used extensively throughout the wildland fire community. In Canada, few accuracy assessments have been undertaken to compare the accuracy of the dNBR algorithm to its relative form (RdNBR). To investigate the accuracies of these two algorithms in Canada's National Parks, we hypothesized that RdNBR would outperform dNBR in two specific applications based on former research by Miller and Thode (2007). The first was the capacity of the RdNBR to produce more accurate results than dNBR over a wide range of fires and secondly in pre-fire landscapes with low canopy closure and high heterogeneity. To investigate these questions, dNBR and RdNBR indices were extracted from Landsat imagery and compared to the measurements of the Composite Burn Index (Key & Benson, 2006). Following this, best fit models were developed and statistically tested at the individual, regional, overall, and vegetative levels. We then developed confusion matrices to assess the relative strength and weakness of each model. As an additional means of comparing model accuracy, we tested Hall et al.'s (2008) non-linear model in estimating burn severity for the study's western boreal region and individual fires. The results indicate that across all fires, the RdNBR-derived model did not estimate burn severity more accurately than dNBR (65.2% versus 70.2% classification accuracy, respectively) nor in the heterogeneous and low canopy cover landscapes. In addition, we conclude that RdNBR is no more effective than dNBR at the regional, individual, and fine-scale vegetation levels. The Hall et al. (2008) model was found to estimate burn severity in the western boreal region with a higher overall kappa than both the dNBR and RdNBR study models. The results herein support the continued research and pursuit of developing regional remote sensing derived models in western Canada.

Immobilization of arsenic in soils by stabilized nanoscale zero-valent iron, iron sulfide (FeS), and magnetite (Fe3O4) particles

Arsenic is a widespread contaminant in soils and groundwater. While various iron-based materials have been studied for immobilizing arsenic in contaminated soils, the feasibility of stabilized iron-based nanoparticles has not been reported. This study investigates the effectiveness of using three types of starch-stabilized iron-based nanoparticles, including zero-valent iron (ZVI), iron sulfide (FeS), and magnetite (Fe3O4), for immobilization of arsenic in two representative As-contaminated soils (an orchard soil and a fire range soil). To test the effect of the nanoparticles on the arsenic leachability, As-contaminated soils were amended with the nanoparticles at various Fe/As molar ratios (5:1–100:1) and contact time (3 and 7 d). After three days’ treatments of a field-contaminated sandy soil, the PBET-based bioaccessibility of As decreased from an initial (71.3±3.1)% (mean±SD) to (30.9±3.2)% with ZVI, (37.6±1.2)% with FeS, and (29.8± 3.1)% with Fe3O4 at an Fe/As molar ratio of 100:1. The TCLP-based leachability of arsenic in a spiked fire range soil decreased from an initial (0.51±0.11)% to (0.24±0.03)%, (0.27±0.04)% and (0.17±0.04)% by ZVI, FeS, and Fe3O4 nanoparticles, respectively. The Fe3O4 nanoparticles appeared to be more effective (5% or more) than other nanoparticles for immobilizing arsenic. When the two soils were compared, the treatment is more effective on the orchard soil that has a lower iron content and higher initial leachability than on the range soil that already has a high iron content. These results suggest that these innocuous iron-based nanoparticles may serve as effective media for immobilization of As in iron-deficient soils, sediments or solid wastes.

Species traits affect the performance of species distribution models for plants in southern California

Questions: To what extent do plant species traits, including life history, life form, and disturbance response characteristics, affect the degree to which species distributions are determined by physical environmental factors? Is the strength of the relationship between species distribution and environment stronger in some disturbance-response types than in others? Location: California southwest ecoregion, USA. Methods: We developed species distribution models (SDMs) for 45 plant species using three primary modeling methods (GLMs, GAMs, and Random Forests). Using AUC as a performance measure of prediction accuracy, and measure of the strength of species–environment correlations, we used regression analyses to compare the effects of fire disturbance response type, longevity, dispersal mechanism, range size, cover, species prevalence, and model type. Results: Fire disturbance response type explained more variation in model performance than any other variable, but other species and range characteristics were also significant. Differences in prediction accuracy reflected variation in species life history, disturbance response, and rarity. AUC was significantly higher for longer-lived species, found at intermediate levels of abundance, and smaller range sizes. Models performed better for shrubs than sub-shrubs and perennial herbs. The disturbance response type with the highest SDM accuracy was obligate-seeding shrubs with ballistic dispersal that regenerate via fire-cued germination from a dormant seed bank. Conclusions: The effect of species characteristics on predictability of species distributions overrides any differences in modeling technique. Prediction accuracy may be related to how a suite of species characteristics co-varies along environmental gradients. Including disturbance response was important because SDMs predict the realized niche. Classification of plant species into disturbance response types may provide a strong framework for evaluating performance of SDMs.

Quantitative Assessment of Building Fire Risk to Life Safety

This article presents a quantitative risk assessment framework for evaluating fire risk to life safety. Fire risk is divided into two parts: probability and corresponding consequence of every fire scenario. The time-dependent event tree technique is used to analyze probable fire scenarios based on the effect of fire protection systems on fire spread and smoke movement. To obtain the variation of occurrence probability with time, Markov chain is combined with a time-dependent event tree for stochastic analysis on the occurrence probability of fire scenarios. To obtain consequences of every fire scenario, some uncertainties are considered in the risk analysis process. When calculating the onset time to untenable conditions, a range of fires are designed based on different fire growth rates, after which uncertainty of onset time to untenable conditions can be characterized by probability distribution. When calculating occupant evacuation time, occupant premovement time is considered as a probability distribution. Consequences of a fire scenario can be evaluated according to probability distribution of evacuation time and onset time of untenable conditions. Then, fire risk to life safety can be evaluated based on occurrence probability and consequences of every fire scenario. To express the risk assessment method in detail, a commercial building is presented as a case study. A discussion compares the assessment result of the case study with fire statistics.

Forest and Field Fire Search System Using MODIS Data

Tokyo University of Information Sciences receives MODIS (Moderate Resolution Imaging Spectroradiometer) data from NASA’s Terra and Aqua satellites, and provides the processed data to universities and research institutes as part of the academic frontier project. This paper considers the utilization of MODIS data for a system to search for fire regions in forests and fields. For the search system to be effective, the system must be able to extract the location, range and distribution of fires in forests and fields from a large scale image database quickly with high accuracy. In order to achieve high search response time and to improve the accuracy of the analysis, we propose a forest and field fire search system which implements a) a parallel distributed system configuration using multiple PC clusters, and b) MOD02, MOD03 and MOD09 process levels of MODIS data for input data which provide higher resolution and more accurate readings than the standard MOD14 process level data.

Decision analysis on fire safety design based on evaluating building fire risk to life

This study presents a framework of decision analysis on fire safety design alternatives based on evaluating building fire risk to life. A probabilistic risk assessment method for occupant life is presented with consideration of some uncertainties of evacuation process and fire development at first. For occupant evacuation time assessment, occupant pre-movement time is characterized by normal distribution. For onset time to untenable conditions assessment, its uncertainty is considered as probability distribution according to the range of design fires. Based on event tree technique, probable fire scenarios are analyzed with consideration of the effect of fire protection systems, employees extinguishing, etc. It is difficult to make a precise assessment on probability and consequence of every fire scenario, but their lower bound and upper bound can be achieved based on statistical data. Therefore, Supersoft Decision Theory [Malmnäs, P.E., 1995. Methods of Evaluation in Supersoft Decision Theory. Department of Philosophy, Stockholm University, 365 Stockholm; Johansson, H., Malmnäs, P.E., 2000. Application of supersoft decision theory in fire risk assessment. Journal of Fire Protection Engineering 14, 55–84] that allows decision maker to utilize vague statement is utilized to integrate with risk assessment to make decision on different fire safety design alternatives. To express how to make decision on different fire safety design alternatives based on evaluating building fire risk to life, two hypothetical fire safety design alternatives for a commercial building are presented.