[Estimating Biomass Burned Areas from Multispectral Dataset Detected by Multiple-Satellite].

PubMed

Yu, Chao; Chen, Liang-fu; Li, Shen-shen; Tao, Jin-hua; Su, Lin

2015-03-01

Biomass burning makes up an important part of both trace gases and particulate matter emissions, which can efficiently degrade air quality and reduce visibility, destabilize the global climate system at regional to global scales. Burned area is one of the primary parameters necessary to estimate emissions, and considered to be the largest source of error in the emission inventory. Satellite-based fire observations can offer a reliable source of fire occurrence data on regional and global scales, a variety of sensors have been used to detect and map fires in two general approaches: burn scar mapping and active fire detection. However, both of the two approaches have limitations. In this article, we explore the relationship between hotspot data and burned area for the Southeastern United States, where a significant amount of biomass burnings from both prescribed and wild fire took place. MODIS (Moderate resolution imaging spectrometer) data, which has high temporal-resolution, can be used to monitor ground biomass. burning in time and provided hot spot data in this study. However, pixel size of MODIS hot spot can't stand for the real ground burned area. Through analysis of the variation of vegetation band reflectance between pre- and post-burn, we extracted the burned area from Landsat-5 TM (Thematic Mapper) images by using the differential normalized burn ratio (dNBR) which is based on TM band4 (0.84 μm) and TM band 7(2.22 μm) data. We combined MODIS fire hot spot data and Landsat-5 TM burned scars data to build the burned area estimation model, results showed that the linear correlation coefficient is 0.63 and the relationships vary as a function of vegetation cover. Based on the National Land Cover Database (NLCD), we built burned area estimation model over different vegetation cover, and got effective burned area per fire pixel, values for forest, grassland, shrub, cropland and wetland are 0.69, 1.27, 0.86, 0.72 and 0.94 km2 respectively. We validated the burned area estimates by using the ground survey data from National interagency Fire Center (NIFC), our results are more close to the ground survey data than burned area from Global Fire Emissions Database (GFED) and MODIS burned area product (MCD45), which omitted many small prescribed fires. We concluded that our model can provide more accurate burned area parameters for developing fire emission inventory, and be better for estimating emissions from biomass burning.

Meteorological Controls on Biomass Burning During Santa Ana Events in Southern California

NASA Technical Reports Server (NTRS)

Veraverbeke, Sander; Capps, Scott; Hook, Simon J.; Randerson, James T.; Jin, Yufang; Hall, Alex

2013-01-01

Fires occurring during Santa Ana (SA) events in southern California are driven by extreme fire weather characterized by high temperatures, low humidities, and high wind speeds. We studied the controls on burned area and carbon emissions during two intensive SA burning periods in 2003 and 2007. We therefore used remote sensing data in parallel with fire weather simulations of the Weather and Regional Forecast model. Total carbon emissions were approximately 1800 gigagrams in 2003 and 900 gigagrams in 2007, based on a daily burned area and a fire emission model that accounted for spatial variability in fuel loads and combustion completeness. On a regional scale, relatively strong positive correlations were found between the daily Fosberg fire weather index and burned area/emissions (probability is less than 0.01). Our analysis provides a quantitative assessment of relationships between fire activity and weather during severe SA fires in southern California.

Avian response to fire in pine–oak forests of Great Smoky Mountains National Park following decades of fire suppression

USGS Publications Warehouse

Rose, Eli T.; Simons, Theodore R.

2016-01-01

Fire suppression in southern Appalachian pine–oak forests during the past century dramatically altered the bird community. Fire return intervals decreased, resulting in local extirpation or population declines of many bird species adapted to post-fire plant communities. Within Great Smoky Mountains National Park, declines have been strongest for birds inhabiting xeric pine–oak forests that depend on frequent fire. The buildup of fuels after decades of fire suppression led to changes in the 1996 Great Smoky Mountains Fire Management Plan. Although fire return intervals remain well below historic levels, management changes have helped increase the amount of fire within the park over the past 20 years, providing an opportunity to study patterns of fire severity, time since burn, and bird occurrence. We combined avian point counts in burned and unburned areas with remote sensing indices of fire severity to infer temporal changes in bird occurrence for up to 28 years following fire. Using hierarchical linear models that account for the possibility of a species presence at a site when no individuals are detected, we developed occurrence models for 24 species: 13 occurred more frequently in burned areas, 2 occurred less frequently, and 9 showed no significant difference between burned and unburned areas. Within burned areas, the top models for each species included fire severity, time since burn, or both, suggesting that fire influenced patterns of species occurrence for all 24 species. Our findings suggest that no single fire management strategy will suit all species. To capture peak occupancy for the entire bird community within xeric pine–oak forests, at least 3 fire regimes may be necessary; one applying frequent low severity fire, another using infrequent low severity fire, and a third using infrequently applied high severity fire.

Potential shifts in dominant forest cover in interior Alaska driven by variations in fire severity

Treesearch

K. Barrett; A.D. McGuire; E.E. Hoy; E.S. Kasischke

2011-01-01

Large fire years in which >1% of the landscape burns are becoming more frequent in the Alaskan (USA) interior, with four large fire years in the past 10 years, and 79000 km2 (17% of the region) burned since 2000. We modeled fire severity conditions for the entire area burned in large fires during a large fire year (2004) to determine the...

Human impact on wildfires varies between regions and with vegetation productivity

NASA Astrophysics Data System (ADS)

Lasslop, Gitta; Kloster, Silvia

2017-11-01

We assess the influence of humans on burned area simulated with a dynamic global vegetation model. The human impact in the model is based on population density and cropland fraction, which were identified as important drivers of burned area in analyses of global datasets, and are commonly used in global models. After an evaluation of the sensitivity to these two variables we extend the model by including an additional effect of the cropland fraction on the fire duration. The general pattern of human influence is similar in both model versions: the strongest human impact is found in regions with intermediate productivity, where fire occurrence is not limited by fuel load or climatic conditions. Human effects in the model increases burned area in the tropics, while in temperate regions burned area is reduced. While the population density is similar on average for the tropical and temperate regions, the cropland fraction is higher in temperate regions, and leads to a strong suppression of fire. The model shows a low human impact in the boreal region, where both population density and cropland fraction is very low and the climatic conditions, as well as the vegetation productivity limit fire. Previous studies attributed a decrease in fire activity found in global charcoal datasets to human activity. This is confirmed by our simulations, which only show a decrease in burned area when the human influence on fire is accounted for, and not with only natural effects on fires. We assess how the vegetation-fire feedback influences the results, by comparing simulations with dynamic vegetation biogeography to simulations with prescribed vegetation. The vegetation-fire feedback increases the human impact on burned area by 10% for present day conditions. These results emphasize that projections of burned area need to account for the interactions between fire, climate, vegetation and humans.

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.

A second-order impact model for forest fire regimes.

PubMed

Maggi, Stefano; Rinaldi, Sergio

2006-09-01

We present a very simple "impact" model for the description of forest fires and show that it can mimic the known characteristics of wild fire regimes in savannas, boreal forests, and Mediterranean forests. Moreover, the distribution of burned biomasses in model generated fires resemble those of burned areas in numerous large forests around the world. The model has also the merits of being the first second-order model for forest fires and the first example of the use of impact models in the study of ecosystems.

Improving global fire carbon emissions estimates by combining moderate resolution burned area and active fire observations

NASA Astrophysics Data System (ADS)

Randerson, J. T.; Chen, Y.; Giglio, L.; Rogers, B. M.; van der Werf, G.

2011-12-01

In several important biomes, including croplands and tropical forests, many small fires exist that have sizes that are well below the detection limit for the current generation of burned area products derived from moderate resolution spectroradiometers. These fires likely have important effects on greenhouse gas and aerosol emissions and regional air quality. Here we developed an approach for combining 1km thermal anomalies (active fires; MOD14A2) and 500m burned area observations (MCD64A1) to estimate the prevalence of these fires and their likely contribution to burned area and carbon emissions. We first estimated active fires within and outside of 500m burn scars in 0.5 degree grid cells during 2001-2010 for which MCD64A1 burned area observations were available. For these two sets of active fires we then examined mean fire radiative power (FRP) and changes in enhanced vegetation index (EVI) derived from 16-day intervals immediately before and after each active fire observation. To estimate the burned area associated with sub-500m fires, we first applied burned area to active fire ratios derived solely from within burned area perimeters to active fires outside of burn perimeters. In a second step, we further modified our sub-500m burned area estimates using EVI changes from active fires outside and within of burned areas (after subtracting EVI changes derived from control regions). We found that in northern and southern Africa savanna regions and in Central and South America dry forest regions, the number of active fires outside of MCD64A1 burned areas increased considerably towards the end of the fire season. EVI changes for active fires outside of burn perimeters were, on average, considerably smaller than EVI changes associated with active fires inside burn scars, providing evidence for burn scars that were substantially smaller than the 25 ha area of a single 500m pixel. FRP estimates also were lower for active fires outside of burn perimeters. In our analysis we quantified how including sub-500m burned area influenced global burned area, carbon emissions, and net ecosystem exchange (NEE) in different continental regions using the Global Fire Emissions Database (GFED) biogeochemical model. We conclude by discussing validation needs using higher resolution visible and thermal imagery.

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...

Static and dynamic controls on fire activity at moderate spatial and temporal scales in the Alaskan boreal forest

USGS Publications Warehouse

Barrett, Kirsten; Loboda, Tatiana; McGuire, A. David; Genet, Hélène; Hoy, Elizabeth; Kasischke, Eric

2016-01-01

Wildfire, a dominant disturbance in boreal forests, is highly variable in occurrence and behavior at multiple spatiotemporal scales. New data sets provide more detailed spatial and temporal observations of active fires and the post-burn environment in Alaska. In this study, we employ some of these new data to analyze variations in fire activity by developing three explanatory models to examine the occurrence of (1) seasonal periods of elevated fire activity using the number of MODIS active fire detections data set (MCD14DL) within an 11-day moving window, (2) unburned patches within a burned area using the Monitoring Trends in Burn Severity fire severity product, and (3) short-to-moderate interval (<60 yr) fires using areas of burned area overlap in the Alaska Large Fire Database. Explanatory variables for these three models included dynamic variables that can change over the course of the fire season, such as weather and burn date, as well as static variables that remain constant over a fire season, such as topography, drainage, vegetation cover, and fire history. We found that seasonal periods of high fire activity are associated with both seasonal timing and aggregated weather conditions, as well as the landscape composition of areas that are burning. Important static inputs to the model of seasonal fire activity indicate that when fire weather conditions are suitable, areas that typically resist fire (e.g., deciduous stands) may become more vulnerable to burning and therefore less effective as fire breaks. The occurrence of short-to-moderate interval fires appears to be primarily driven by weather conditions, as these were the only relevant explanatory variables in the model. The unique importance of weather in explaining short-to-moderate interval fires implies that fire return intervals (FRIs) will be sensitive to projected climate changes in the region. Unburned patches occur most often in younger stands, which may be related to a greater deciduous fraction of vegetation as well as lower fuel loads compared with mature stands. The fraction of unburned patches may therefore increase in response to decreasing FRIs and increased deciduousness in the region, or these may decrease if fire weather conditions become more severe.

Regional patterns of cropland and pasture burning: Statistical separation of signals from remote sensing products

NASA Astrophysics Data System (ADS)

Rabin, S. S.; Pacala, S. W.; Magi, B. I.; Shevliakova, E.

2013-12-01

The use of fire in agriculture--to manage crop residues and pastoral grasses, and for clearing land--has consequences worldwide for air quality, human health, and climate. Airborne particulate matter from such burning aggravates respiratory ailments and can influence regional precipitation, while associated greenhouse gases and aerosols affect global climate. Little research, however, has focused on understanding patterns of cropland and pasture fire use with an eye towards simulation at global scales. Previous work by these authors showed that the separate seasonal trends of agricultural and non-agricultural fire could be extracted from large-scale fire observation and land use datasets. This study builds on that research, describing the derivation and application of a statistical method to estimate both the seasonality and amount of cropland, pasture, and other fire based on observations from satellite-based remote sensing products. We demonstrate that our approach is flexible enough to allow the incorporation of alternative high-quality observations of fire and/or land use that might be available only for certain regions. Results for a number of large regions around the world show that these two kinds of agricultural fire often differ in their extent and seasonality from each other and from burning on other land in ways that reflect known management practices. For example, we find that pasture in north-central sub-Saharan Africa tends to burn earlier than non-agricultural land; this can be attributed to pastoralists preventively burning their land early in the dry season so as to avoid severe, uncontrolled burns under more dangerous fire conditions later. Both the timing and extent of agricultural fires prove to be regionally specific; our method allows these geographically distinct patterns to be fully appreciated. The local and global differences in seasonality and amount of fire between different land-use types suggest that dynamic global vegetation models (DGVMs) should simulate fires on cropland and pasture fire independently from burning on other lands and take a regional approach in doing so. For example, pastoral burning dominates across large parts of the African region described above, where a fire model focused only on non-agricultural burning would therefore be inaccurate. On the other hand, in southern Africa those two types of fire more closely parallel each other. While a pure application of our analytical method is based exclusively on the relative distributions of fire activity and land use types, we demonstrate its incorporation into a more process-based fire model to capture the influence of seasonal and interannual variations in climate and ecosystem characteristics on burning. Such a model, the ultimate goal of our research, will help improve DGVM simulations--and therefore scientific understanding--of past, present, and future distributions of fire.

Integrating satellite imagery with simulation modeling to improve burn severity mapping

Treesearch

Eva C. Karau; Pamela G. Sikkink; Robert E. Keane; Gregory K. Dillon

2014-01-01

Both satellite imagery and spatial fire effects models are valuable tools for generating burn severity maps that are useful to fire scientists and resource managers. The purpose of this study was to test a new mapping approach that integrates imagery and modeling to create more accurate burn severity maps. We developed and assessed a statistical model that combines the...

Influence of fire frequency on carbon consumption in Alaskan blackspruce forests

NASA Astrophysics Data System (ADS)

Hoy, E.; Kasischke, E. S.

2014-12-01

Increasing temperatures and drier conditions within the boreal forests of Alaska have resulted in increases in burned area and fire frequency, which alter carbon storage and emissions. In particular, analyses of satellite remote sensing data showed that >20% of the area impacted by fires in interior Alaska occurred in areas that had previously burned since 1950 (e.g., short to intermediate interval fires). Field studies showed that in immature black spruce forests ~ 35 to 55 years old organic layers experienced deep burning regardless of topographic position or seasonality of burning, factors that control depth of burning in mature black spruce forests. Here, refinements were made to a carbon consumption model to account for variations in fuel loads and fraction of carbon consumed associated with fire frequency based on quantifying burned area in recently burned sites using satellite imagery. An immature black spruce (Picea mariana) fuel type (including stands of ~0-50 years) was developed which contains new ground-layer carbon consumption values in order to more accurately account for differences between various age classes of black spruce forest. Both versions of the model were used to assess carbon consumption during 100 fire events (over 4.4 x 10^6 ha of burned area) from two recent ultra-large fire years (2004 and 2005). Using the improved model to better attribute fuel type and consumption resulted in higher ground-layer carbon consumption (4.9% in 2004 and 6.8% in 2005) than previously estimated. These adjustments in ground-layer burning resulted in total carbon consumption within 2004 and 2005 of 63.5 and 42.0 Tg of carbon, respectively. Results from this research could be incorporated into larger scale modeling efforts to better assess changes in the climate-fire-vegetation dynamics in interior Alaskan boreal forests, and to understand the impacts of these changes on carbon consumption and emissions.

Use of artificial landscapes to isolate controls on burn probability

Treesearch

Marc-Andre Parisien; Carol Miller; Alan A. Ager; Mark A. Finney

2010-01-01

Techniques for modeling burn probability (BP) combine the stochastic components of fire regimes (ignitions and weather) with sophisticated fire growth algorithms to produce high-resolution spatial estimates of the relative likelihood of burning. Despite the numerous investigations of fire patterns from either observed or simulated sources, the specific influence of...

Biomass Combustions and Burning Emissions Inferred from GOES Fire Radiative Power

NASA Astrophysics Data System (ADS)

Zhang, X.; Kondragunta, S.; Schmidt, C.

2007-12-01

Biomass burning significantly affects air quality and climate changes. Current estimates of burning emissions are rather imprecise and vary markedly with different methodologies. This paper investigates biomass burning consumption and emissions using GOES (Geostationary Operational Environmental Satellites) WF_ABBA (Wildfire Automated Biomass Burning Algorithm) fire product. In doing this, we establish a set of representatives in diurnal patterns of half-hourly GOES Fire Radiative Power (FRP) for various ecosystems. The representative patterns are used to fill the missed and poor observations of half hourly FRP in GOES fire data for individual fire pixels. The simulated FRP is directly applied to the calculation of the biomass combusted during fire activities. The FRP-based biomass combustion is evaluated using the estimates using a traditional model which integrates burned area, fuel loading, and combustion factor. In the traditional model calculation, we derive burned areas from GOES WF_ABBA fire size. Fuel loading includes three different types (1) MODIS Vegetation Property-based Fuel System (MVPFS), (2) National Dangerous Rating Systems (NFDRS), and (3) the Fuel Characteristic Classification System (FCCS). By comparing the biomass combustions across the Contiguous United States (CONUS) from 2003-2005, we conclude that FRP is an effective tool to estimate the biomass burning emissions. Finally, we examine the temporal and spatial patterns in biomass combustions and emissions (PM2.5, CO, NH3) across the CONUS.

Data Filtering of Western Hemisphere GOES Wildfire ABBA Products

NASA Astrophysics Data System (ADS)

Theisen, M.; Prins, E.; Schmidt, C.; Reid, J. S.; Hunter, J.; Westphal, D.

2002-05-01

The Fire Locating and Modeling of Burning Emissions (FLAMBE') project was developed to model biomass burning emissions, transport, and radiative effects in real time. The model relies on data from the Geostationary Operational Environment Satellites (GOES-8, GOES-10), that is generated by the Wildfire Automated Biomass Burning Algorithm (WF ABBA). In an attempt to develop the most accurate modeling system the data set needs to be filtered to distinguish the true fire pixels from false alarms. False alarms occur due to reflection of solar radiation off of standing water, surface structure variances, and heat anomalies. The Reoccurring Fire Filtering algorithm (ReFF) was developed to address such false alarms by filtering data dependent on reoccurrence, location in relation to region and satellite, as well as heat intensity. WF ABBA data for the year 2000 during the peak of the burning season were analyzed using ReFF. The analysis resulted in a 45% decrease in North America and only a 15% decrease in South America, respectively, in total fire pixel occurrence. The lower percentage decrease in South America is a result of fires burning for longer periods of time, less surface variance, as well as an increase in heat intensity of fires for that region. Also fires are so prevalent in the region that multiple fires may coexist in the same 4-kilometer pixel.

The Fire INventory from NCAR (FINN): a high resolution global model to estimate the emissions from open burning

Treesearch

C. Wiedinmyer; S. K. Akagi; R. J. Yokelson; L. K. Emmons; J. A. Al-Saadi; J. J. Orlando; A. J. Soja

2010-01-01

The Fire INventory from NCAR version 1.0 (FINNv1) provides daily, 1 km resolution, global estimates of the trace gas and particle emissions from open burning of biomass, which includes wildfire, agricultural fires, and prescribed burning and does not include 5 biofuel use and trash burning. Emission factors used in the calculations have been updated with recent data,...

Modeling Fire Severity in Black Spruce Stands in the Alaskan Boreal Forest Using Spectral and Non-Spectral Geospatial Data

NASA Technical Reports Server (NTRS)

Barrett, K.; Kasischke, E. S.; McGuire, A. D.; Turetsky, M. R.; Kane, E. S.

2010-01-01

Biomass burning in the Alaskan interior is already a major disturbance and source of carbon emissions, and is likely to increase in response to the warming and drying predicted for the future climate. In addition to quantifying changes to the spatial and temporal patterns of burned areas, observing variations in severity is the key to studying the impact of changes to the fire regime on carbon cycling, energy budgets, and post-fire succession. Remote sensing indices of fire severity have not consistently been well-correlated with in situ observations of important severity characteristics in Alaskan black spruce stands, including depth of burning of the surface organic layer. The incorporation of ancillary data such as in situ observations and GIS layers with spectral data from Landsat TM/ETM+ greatly improved efforts to map the reduction of the organic layer in burned black spruce stands. Using a regression tree approach, the R2 of the organic layer depth reduction models was 0.60 and 0.55 (pb0.01) for relative and absolute depth reduction, respectively. All of the independent variables used by the regression tree to estimate burn depth can be obtained independently of field observations. Implementation of a gradient boosting algorithm improved the R2 to 0.80 and 0.79 (pb0.01) for absolute and relative organic layer depth reduction, respectively. Independent variables used in the regression tree model of burn depth included topographic position, remote sensing indices related to soil and vegetation characteristics, timing of the fire event, and meteorological data. Post-fire organic layer depth characteristics are determined for a large (N200,000 ha) fire to identify areas that are potentially vulnerable to a shift in post-fire succession. This application showed that 12% of this fire event experienced fire severe enough to support a change in post-fire succession. We conclude that non-parametric models and ancillary data are useful in the modeling of the surface organic layer fire depth. Because quantitative differences in post-fire surface characteristics do not directly influence spectral properties, these modeling techniques provide better information than the use of remote sensing data alone.

Modeling fire severity in black spruce stands in the Alaskan boreal forest using spectral and non-spectral geospatial data

USGS Publications Warehouse

Barrett, Kirsten M.; Kasischke, E.S.; McGuire, A.D.; Turetsky, M.R.; Kane, E.S.

2010-01-01

Biomass burning in the Alaskan interior is already a major disturbance and source of carbon emissions, and is likely to increase in response to the warming and drying predicted for the future climate. In addition to quantifying changes to the spatial and temporal patterns of burned areas, observing variations in severity is the key to studying the impact of changes to the fire regime on carbon cycling, energy budgets, and post-fire succession. Remote sensing indices of fire severity have not consistently been well-correlated with in situ observations of important severity characteristics in Alaskan black spruce stands, including depth of burning of the surface organic layer. The incorporation of ancillary data such as in situ observations and GIS layers with spectral data from Landsat TM/ETM+ greatly improved efforts to map the reduction of the organic layer in burned black spruce stands. Using a regression tree approach, the R2 of the organic layer depth reduction models was 0.60 and 0.55 (pb0.01) for relative and absolute depth reduction, respectively. All of the independent variables used by the regression tree to estimate burn depth can be obtained independently of field observations. Implementation of a gradient boosting algorithm improved the R2 to 0.80 and 0.79 (pb0.01) for absolute and relative organic layer depth reduction, respectively. Independent variables used in the regression tree model of burn depth included topographic position, remote sensing indices related to soil and vegetation characteristics, timing of the fire event, and meteorological data. Post-fire organic layer depth characteristics are determined for a large (N200,000 ha) fire to identify areas that are potentially vulnerable to a shift in post-fire succession. This application showed that 12% of this fire event experienced fire severe enough to support a change in post-fire succession. We conclude that non-parametric models and ancillary data are useful in the modeling of the surface organic layer fire depth. Because quantitative differences in post-fire surface characteristics do not directly influence spectral properties, these modeling techniques provide better information than the use of remote sensing data alone.

ESA fire_cci product assessment

NASA Astrophysics Data System (ADS)

Heil, Angelika; Yue, Chao; Mouillot, Florent; Storm, Thomas; Chuvieco, Emilio; Ramo Sanchez, Ruben; Kaiser, Johannes W.

2017-04-01

Vegetation fires are a major disturbance in the Earth System. Fires change the biophysical properties and dynamics of ecosystems and alter terrestrial carbon pools. By altering the atmosphere's composition, fire emissions exert a significant climate forcing. To realistically model past and future changes of the Earth System, fire disturbances must be taken into account. Related modelling efforts require consistent global burned area observations covering at least 10 to 20 years. Guided by the specific requirements of a wide range of end users, the ESA fire_cci project has computed a new global burned area dataset. It applies a newly developed spectral change detection algorithm upon the ENVISAT-MERIS archive. The algorithm relies on MODIS active fire information as "seed". It comprises a pixel burned area product (spatial resolution of 333 m) with date detection information and a biweekly grid product at 0.25 degree spatial resolution. We compare fire_cci burned area with other global burned area products (MCD64 Collection 6, MCD45, GFED4, GFED4s and GEOLAND) and a set of active fires data (hotspots from MODIS, TRMM, AATSR and fire radiative power from GFAS). The analysis of patterns of agreement and disagreement between fire_cci and other products provides a better understanding of product characteristics and uncertainties. The intercomparison of the 2005-2011 fire_cci time series shows a close agreement with GFED4 data in terms of global burned area and the general spatial and temporal patterns. Pronounced differences, however, emerge for specific regions or fire events. Burned area mapped by fire_cci tends to be notably higher in regions where small agricultural fires predominate. The improved detection of small agricultural fires by fire_cci can be related to the increased spatial resolution of the MERIS sensor (333 m compared to 500 in MODIS). This is illustrated in detail using the example of the extreme 2006 spring fires in Eastern Europe.

Effects of ignition location models on the burn patterns of simulated wildfires

USGS Publications Warehouse

Bar-Massada, A.; Syphard, A.D.; Hawbaker, T.J.; Stewart, S.I.; Radeloff, V.C.

2011-01-01

Fire simulation studies that use models such as FARSITE often assume that ignition locations are distributed randomly, because spatially explicit information about actual ignition locations are difficult to obtain. However, many studies show that the spatial distribution of ignition locations, whether human-caused or natural, is non-random. Thus, predictions from fire simulations based on random ignitions may be unrealistic. However, the extent to which the assumption of ignition location affects the predictions of fire simulation models has never been systematically explored. Our goal was to assess the difference in fire simulations that are based on random versus non-random ignition location patterns. We conducted four sets of 6000 FARSITE simulations for the Santa Monica Mountains in California to quantify the influence of random and non-random ignition locations and normal and extreme weather conditions on fire size distributions and spatial patterns of burn probability. Under extreme weather conditions, fires were significantly larger for non-random ignitions compared to random ignitions (mean area of 344.5 ha and 230.1 ha, respectively), but burn probability maps were highly correlated (r = 0.83). Under normal weather, random ignitions produced significantly larger fires than non-random ignitions (17.5 ha and 13.3 ha, respectively), and the spatial correlations between burn probability maps were not high (r = 0.54), though the difference in the average burn probability was small. The results of the study suggest that the location of ignitions used in fire simulation models may substantially influence the spatial predictions of fire spread patterns. However, the spatial bias introduced by using a random ignition location model may be minimized if the fire simulations are conducted under extreme weather conditions when fire spread is greatest. ?? 2010 Elsevier Ltd.

Impact of fire disturbance on soil thermal and carbon dynamics in Alaskan Tundra and Boreal forest ecosystems

NASA Astrophysics Data System (ADS)

Jiang, Y.; Rastetter, E.; Shaver, G. R.; Rocha, A. V.

2012-12-01

In Alaska, fire disturbance is a major component influencing the soil water and energy balance in both tundra and boreal forest ecosystems. Fire-caused changes in soil environment further affect both above- and below-ground carbon cycles depending on different fire severities. Understanding the effects of fire disturbance on soil thermal change requires implicit modeling work on the post-fire soil thawing and freezing processes. In this study, we model the soil temperature profiles in multiple burned and non-burned sites using a well-developed soil thermal model which fully couples soil water and heat transport. The subsequent change in carbon dynamics is analyzed based on site level observations and simulations from the Multiple Element Limitation (MEL) model. With comparison between burned and non-burned sites, we compare and contrast fire effects on soil thermal and carbon dynamics in continuous permafrost (Anaktuvik fire in north slope), discontinuous permafrost (Erickson Creek fire at Hess Creek) and non-permafrost zone (Delta Junction fire in interior Alaska). Then we check the post-fire recovery of soil temperature profiles at sites with different fire severities in both tundra and boreal forest fire areas. We further project the future changes in soil thermal and carbon dynamics using projected climate data from Scenarios Network for Alaska & Arctic Planning (SNAP). This study provides information to improve the understanding of fire disturbance on soil thermal and carbon dynamics and the consequent response under a warming climate.

Sensitivity of global terrestrial carbon cycle dynamics to variability in satellite-observed burned area

NASA Astrophysics Data System (ADS)

Poulter, Benjamin; Cadule, Patricia; Cheiney, Audrey; Ciais, Philippe; Hodson, Elke; Peylin, Philippe; Plummer, Stephen; Spessa, Allan; Saatchi, Sassan; Yue, Chao; Zimmermann, Niklaus E.

2015-02-01

Fire plays an important role in terrestrial ecosystems by regulating biogeochemistry, biogeography, and energy budgets, yet despite the importance of fire as an integral ecosystem process, significant advances remain to improve its prognostic representation in carbon cycle models. To recommend and to help prioritize model improvements, this study investigates the sensitivity of a coupled global biogeography and biogeochemistry model, LPJ, to observed burned area measured by three independent satellite-derived products, GFED v3.1, L3JRC, and GlobCarbon. Model variables are compared with benchmarks that include pantropical aboveground biomass, global tree cover, and CO2 and CO trace gas concentrations. Depending on prescribed burned area product, global aboveground carbon stocks varied by 300 Pg C, and woody cover ranged from 50 to 73 Mkm2. Tree cover and biomass were both reduced linearly with increasing burned area, i.e., at regional scales, a 10% reduction in tree cover per 1000 km2, and 0.04-to-0.40 Mg C reduction per 1000 km2. In boreal regions, satellite burned area improved simulated tree cover and biomass distributions, but in savanna regions, model-data correlations decreased. Global net biome production was relatively insensitive to burned area, and the long-term land carbon sink was robust, 2.5 Pg C yr-1, suggesting that feedbacks from ecosystem respiration compensated for reductions in fuel consumption via fire. CO2 transport provided further evidence that heterotrophic respiration compensated any emission reductions in the absence of fire, with minor differences in modeled CO2 fluxes among burned area products. CO was a more sensitive indicator for evaluating fire emissions, with MODIS-GFED burned area producing CO concentrations largely in agreement with independent observations in high latitudes. This study illustrates how ensembles of burned area data sets can be used to diagnose model structures and parameters for further improvement and also highlights the importance in considering uncertainties and variability in observed burned area data products for model applications.

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,...

Assessing the response of area burned to changing climate in western boreal North America using a Multivariate Adaptive Regression Splines (MARS) approach

USGS Publications Warehouse

Balshi, M. S.; McGuire, A.D.; Duffy, P.; Flannigan, M.; Walsh, J.; Melillo, J.

2009-01-01

Fire is a common disturbance in the North American boreal forest that influences ecosystem structure and function. The temporal and spatial dynamics of fire are likely to be altered as climate continues to change. In this study, we ask the question: how will area burned in boreal North America by wildfire respond to future changes in climate? To evaluate this question, we developed temporally and spatially explicit relationships between air temperature and fuel moisture codes derived from the Canadian Fire Weather Index System to estimate annual area burned at 2.5?? (latitude ?? longitude) resolution using a Multivariate Adaptive Regression Spline (MARS) approach across Alaska and Canada. Burned area was substantially more predictable in the western portion of boreal North America than in eastern Canada. Burned area was also not very predictable in areas of substantial topographic relief and in areas along the transition between boreal forest and tundra. At the scale of Alaska and western Canada, the empirical fire models explain on the order of 82% of the variation in annual area burned for the period 1960-2002. July temperature was the most frequently occurring predictor across all models, but the fuel moisture codes for the months June through August (as a group) entered the models as the most important predictors of annual area burned. To predict changes in the temporal and spatial dynamics of fire under future climate, the empirical fire models used output from the Canadian Climate Center CGCM2 global climate model to predict annual area burned through the year 2100 across Alaska and western Canada. Relative to 1991-2000, the results suggest that average area burned per decade will double by 2041-2050 and will increase on the order of 3.5-5.5 times by the last decade of the 21st century. To improve the ability to better predict wildfire across Alaska and Canada, future research should focus on incorporating additional effects of long-term and successional vegetation changes on area burned to account more fully for interactions among fire, climate, and vegetation dynamics. ?? 2009 The Authors Journal compilation ?? 2009 Blackwell Publishing Ltd.

South American smoke coverage and flux estimations from the Fire Locating and Modeling of Burning Emissions (FLAMBE') system.

NASA Astrophysics Data System (ADS)

Reid, J. S.; Westphal, D. L.; Christopher, S. A.; Prins, E. M.; Gasso, S.; Reid, E.; Theisen, M.; Schmidt, C. C.; Hunter, J.; Eck, T.

2002-05-01

The Fire Locating and Modeling of Burning Emissions (FLAMBE') project is a joint Navy, NOAA, NASA and university project to integrate satellite products with numerical aerosol models to produce a real time fire and emissions inventory. At the center of the program is the Wildfire Automated Biomass Burning Algorithm (WF ABBA) which provides real-time fire products and the NRL Aerosol Analysis and Prediction System to model smoke transport. In this presentation we give a brief overview of the system and methods, but emphasize new estimations of smoke coverage and emission fluxes from the South American continent. Temporal and smoke patterns compare reasonably well with AERONET and MODIS aerosol optical depth products for the 2000 and 2001 fire seasons. Fluxes are computed by relating NAAPS output fields and MODIS optical depth maps with modeled wind fields. Smoke emissions and transport fluxes out of the continent can then be estimated by perturbing the modeled emissions to gain agreement with the satellite and wind products. Regional smoke emissions are also presented for grass and forest burning.

Relative importance of fuel management, ignition management and weather for area burned: Evidence from five landscape-fire-succession models

Treesearch

Geoffrey J. Cary; Mike D. Flannigan; Robert E. Keane; Ross A. Bradstock; Ian D. Davies; James M. Lenihan; Chao Li; Kimberley A. Logan; Russell A. Parsons

2009-01-01

The behaviour of five landscape fire models (CAFE, FIRESCAPE, LAMOS(HS), LANDSUM and SEMLAND) was compared in a standardised modelling experiment. The importance of fuel management approach, fuel management effort, ignition management effort and weather in determining variation in area burned and number of edge pixels burned (a measure of potential impact on assets...

Contrasting fire responses to climate and management: insights from two Australian ecosystems.

PubMed

King, Karen J; Cary, Geoffrey J; Bradstock, Ross A; Marsden-Smedley, Jonathan B

2013-04-01

This study explores effects of climate change and fuel management on unplanned fire activity in ecosystems representing contrasting extremes of the moisture availability spectrum (mesic and arid). Simulation modelling examined unplanned fire activity (fire incidence and area burned, and the area burned by large fires) for alternate climate scenarios and prescribed burning levels in: (i) a cool, moist temperate forest and wet moorland ecosystem in south-west Tasmania (mesic); and (ii) a spinifex and mulga ecosystem in central Australia (arid). Contemporary fire activity in these case study systems is limited, respectively, by fuel availability and fuel amount. For future climates, unplanned fire incidence and area burned increased in the mesic landscape, but decreased in the arid landscape in accordance with predictions based on these limiting factors. Area burned by large fires (greater than the 95th percentile of historical, unplanned fire size) increased with future climates in the mesic landscape. Simulated prescribed burning was more effective in reducing unplanned fire activity in the mesic landscape. However, the inhibitory effects of prescribed burning are predicted to be outweighed by climate change in the mesic landscape, whereas in the arid landscape prescribed burning reinforced a predicted decline in fire under climate change. The potentially contrasting direction of future changes to fire will have fundamentally different consequences for biodiversity in these contrasting ecosystems, and these will need to be accommodated through contrasting, innovative management solutions. © 2012 Blackwell Publishing Ltd.

Land surface temperature as potential indicator of burn severity in forest Mediterranean ecosystems

NASA Astrophysics Data System (ADS)

Quintano, C.; Fernández-Manso, A.; Calvo, L.; Marcos, E.; Valbuena, L.

2015-04-01

Forest fires are one of the most important causes of environmental alteration in Mediterranean countries. Discrimination of different degrees of burn severity is critical for improving management of fire-affected areas. This paper aims to evaluate the usefulness of land surface temperature (LST) as potential indicator of burn severity. We used a large convention-dominated wildfire, which occurred on 19-21 September, 2012 in Northwestern Spain. From this area, a 1-year series of six LST images were generated from Landsat 7 Enhanced Thematic Mapper (ETM+) data using a single channel algorithm. Further, the Composite Burn Index (CBI) was measured in 111 field plots to identify the burn severity level (low, moderate, and high). Evaluation of the potential relationship between post-fire LST and ground measured CBI was performed by both correlation analysis and regression models. Correlation coefficients were higher in the immediate post-fire LST images, but decreased during the fall of 2012 and increased again with a second maximum value in summer, 2013. A linear regression model between post-fire LST and CBI allowed us to represent spatially predicted CBI (R-squaredadj > 85%). After performing an analysis of variance (ANOVA) between post-fire LST and CBI, a Fisher's least significant difference test determined that two burn severity levels (low-moderate and high) could be statistically distinguished. The identification of such burn severity levels is sufficient and useful to forest managers. We conclude that summer post-fire LST from moderate resolution satellite data may be considered as a valuable indicator of burn severity for large fires in Mediterranean forest ecosytems.

Use of multi-sensor active fire detections to map fires in the United States: the future of monitoring trends in burn severity

USGS Publications Warehouse

Picotte, Joshua J.; Coan, Michael; Howard, Stephen M.

2014-01-01

The effort to utilize satellite-based MODIS, AVHRR, and GOES fire detections from the Hazard Monitoring System (HMS) to identify undocumented fires in Florida and improve the Monitoring Trends in Burn Severity (MTBS) mapping process has yielded promising results. This method was augmented using regression tree models to identify burned/not-burned pixels (BnB) in every Landsat scene (1984–2012) in Worldwide Referencing System 2 Path/Rows 16/40, 17/39, and 1839. The burned area delineations were combined with the HMS detections to create burned area polygons attributed with their date of fire detection. Within our study area, we processed 88,000 HMS points (2003–2012) and 1,800 Landsat scenes to identify approximately 300,000 burned area polygons. Six percent of these burned area polygons were larger than the 500-acre MTBS minimum size threshold. From this study, we conclude that the process can significantly improve understanding of fire occurrence and improve the efficiency and timeliness of assessing its impacts upon the landscape.

What Fraction of Global Fire Activity Can Be Forecast Using Sea Surface Temperatures?

NASA Astrophysics Data System (ADS)

Chen, Y.; Randerson, J. T.; Morton, D. C.; Andela, N.; Giglio, L.

2015-12-01

Variations in sea surface temperatures (SSTs) can influence climate dynamics in local and remote land areas, and thus influence fire-climate interactions that govern burned area. SST information has been recently used in statistical models to create seasonal outlooks of fire season severity in South America and as the initial condition for dynamical model predictions of fire activity in Indonesia. However, the degree to which large-scale ocean-atmosphere interactions can influence burned area in other continental regions has not been systematically explored. Here we quantified the amount of global burned area that can be predicted using SSTs in 14 different oceans regions as statistical predictors. We first examined lagged correlations between GFED4s burned area and the 14 ocean climate indices (OCIs) individually. The maximum correlations from different OCIs were used to construct a global map of fire predictability. About half of the global burned area can be forecast by this approach 3 months before the peak burning month (with a Pearson's r of 0.5 or higher), with the highest levels of predictability in Central America and Equatorial Asia. Several hotspots of predictability were identified using k-means cluster analysis. Within these regions, we tested the improvements of the forecast by using two OCIs from different oceans. Our forecast models were based on near-real-time SST data and may therefore support the development of new seasonal outlooks for fire activity that can aid the sustainable management of these fire-prone ecosystems.

Evaluating spatially explicit burn probabilities for strategic fire management planning

Treesearch

C. Miller; M.-A. Parisien; A. A. Ager; M. A. Finney

2008-01-01

Spatially explicit information on the probability of burning is necessary for virtually all strategic fire and fuels management planning activities, including conducting wildland fire risk assessments, optimizing fuel treatments, and prevention planning. Predictive models providing a reliable estimate of the annual likelihood of fire at each point on the landscape have...

Fire-mediated dieback and compositional cascade in an Amazonian forest.

PubMed

Barlow, Jos; Peres, Carlos A

2008-05-27

The only fully coupled land-atmosphere global climate model predicts a widespread dieback of Amazonian forest cover through reduced precipitation. Although these predictions are controversial, the structural and compositional resilience of Amazonian forests may also have been overestimated, as current vegetation models fail to consider the potential role of fire in the degradation of forest ecosystems. We examine forest structure and composition in the Arapiuns River basin in the central Brazilian Amazon, evaluating post-fire forest recovery and the consequences of recurrent fires for the patterns of dominance of tree species. We surveyed tree plots in unburned and once-burned forests examined 1, 3 and 9 years after an unprecedented fire event, in twice-burned forests examined 3 and 9 years after fire and in thrice-burned forests examined 5 years after the most recent fire event. The number of trees recorded in unburned primary forest control plots was stable over time. However, in both once- and twice-burned forest plots, there was a marked recruitment into the 10-20cm diameter at breast height tree size classes between 3 and 9 years post-fire. Considering tree assemblage composition 9 years after the first fire contact, we observed (i) a clear pattern of community turnover among small trees and the most abundant shrubs and saplings, and (ii) that species that were common in any of the four burn treatments (unburned, once-, twice- and thrice-burned) were often rare or entirely absent in other burn treatments. We conclude that episodic wildfires can lead to drastic changes in forest structure and composition, with cascading shifts in forest composition following each additional fire event. Finally, we use these results to evaluate the validity of the savannization paradigm.

Modeling of multi-strata forest fire severity using Landsat TM data

Treesearch

Q. Meng; R.K. Meentemeyer

2011-01-01

Most of fire severity studies use field measures of composite burn index (CBI) to represent forest fire severity and fit the relationships between CBI and Landsat imagery derived differenced normalized burn ratio (dNBR) to predict and map fire severity at unsampled locations. However, less attention has been paid on the multi-strata forest fire severity, which...

Allowing a wildfire to burn: estimating the effect on future fire suppression costs

Treesearch

Rachel M. Houtman; Claire A. Montgomery; Aaron R. Gagnon; David E. Calkin; Thomas G. Dietterich; Sean McGregor; Mark Crowley

2013-01-01

Where a legacy of aggressive wildland fire suppression has left forests in need of fuel reduction, allowing wildland fire to burn may provide fuel treatment benefits, thereby reducing suppression costs from subsequent fires. The least-cost-plus-net-value-change model of wildland fire economics includes benefits of wildfire in a framework for evaluating suppression...

Modeling post-fire hydro-geomorphic recovery in the Waldo Canyon Fire

NASA Astrophysics Data System (ADS)

Kinoshita, Alicia; Nourbakhshbeidokhti, Samira; Chin, Anne

2016-04-01

Wildfire can have significant impacts on watershed hydrology and geomorphology by changing soil properties and removing vegetation, often increasing runoff and soil erosion and deposition, debris flows, and flooding. Watershed systems may take several years or longer to recover. During this time, post-fire channel changes have the potential to alter hydraulics that influence characteristics such as time of concentration and increase time to peak flow, flow capacity, and velocity. Using the case of the 2012 Waldo Canyon Fire in Colorado (USA), this research will leverage field-based surveys and terrestrial Light Detection and Ranging (LiDAR) data to parameterize KINEROS2 (KINematic runoff and EROSion), an event oriented, physically-based watershed runoff and erosion model. We will use the Automated Geospatial Watershed Assessment (AGWA) tool, which is a GIS-based hydrologic modeling tool that uses commonly available GIS data layers to parameterize, execute, and spatially visualize runoff and sediment yield for watersheds impacted by the Waldo Canyon Fire. Specifically, two models are developed, an unburned (Bear Creek) and burned (Williams) watershed. The models will simulate burn severity and treatment conditions. Field data will be used to validate the burned watersheds for pre- and post-fire changes in infiltration, runoff, peak flow, sediment yield, and sediment discharge. Spatial modeling will provide insight into post-fire patterns for varying treatment, burn severity, and climate scenarios. Results will also provide post-fire managers with improved hydro-geomorphic modeling and prediction tools for water resources management and mitigation efforts.

ESA Fire CCI product assessment

NASA Astrophysics Data System (ADS)

Heil, Angelika; Yue, Chao; Mouillot, Florent; Storm, Thomas; Chuvieco, Emilio; Kaiser, Johannes

2016-04-01

Vegetation fires are a major disturbance in the Earth System. Fires change the biophysical properties and dynamics of ecosystems and alter terrestrial carbon pools. By altering the atmosphere's composition, fire emissions exert a significant climate forcing. To realistically model past and future changes of the Earth System, fire disturbances must be taken into account. Related modelling efforts require consistent global burned area observations covering at least 10 to 20 years. Guided by the specific requirements of a wide range of end users, the ESA fire_cci project is currently computing a new global burned area dataset. It applies a newly developed spectral change detection algorithm upon the full ENVISAT-MERIS archive (2002 to 2012). The algorithm relies on MODIS active fire information as "seed". A first, formally validated version has been released for the period 2006 to 2008. It comprises a pixel burned area product (spatial resolution of 333 m) with date detection information and a biweekly grid product at 0.5 degree spatial resolution. We compare fire_cci burned area with other global burned area products (MCD64, GFED4(s), GEOLAND) and a set of active fires data (hotspots from MODIS, TRMM, AATSR and fire radiative power from GFAS). Output from the ongoing processing of the full MERIS timeseries will be incorporated into the study, as far as available. The analysis of patterns of agreement and disagreement between fire_cci and other products provides a better understanding of product characteristics and uncertainties. The intercomparison of the 2006-2008 fire_cci time series shows a close agreement with GFED4 data in terms of global burned area and the general spatial and temporal patterns. Pronounced differences, however, emerge for specific regions or fire events. Burned area mapped by fire_cci tends to be notably higher in regions where small agricultural fires predominate. The improved detection of small agricultural fires by fire_cci can be related to the increased spatial resolution of the MERIS sensor (333 m compared to 500 in MODIS). This is illustrated in detail using the example of the extreme 2006 spring fires in Eastern Europe.

Lightning Forcing in Global Fire Models: The Importance of Temporal Resolution

NASA Astrophysics Data System (ADS)

Felsberg, A.; Kloster, S.; Wilkenskjeld, S.; Krause, A.; Lasslop, G.

2018-01-01

In global fire models, lightning is typically prescribed from observational data with monthly mean temporal resolution while meteorological forcings, such as precipitation or temperature, are prescribed in a daily resolution. In this study, we investigate the importance of the temporal resolution of the lightning forcing for the simulation of burned area by varying from daily to monthly and annual mean forcing. For this, we utilize the vegetation fire model JSBACH-SPITFIRE to simulate burned area, forced with meteorological and lightning data derived from the general circulation model ECHAM6. On a global scale, differences in burned area caused by lightning forcing applied in coarser temporal resolution stay below 0.55% compared to the use of daily mean forcing. Regionally, however, differences reach up to 100%, depending on the region and season. Monthly averaged lightning forcing as well as the monthly lightning climatology cause differences through an interaction between lightning ignitions and fire prone weather conditions, accounted for by the fire danger index. This interaction leads to decreased burned area in the boreal zone and increased burned area in the Tropics and Subtropics under the coarser temporal resolution. The exclusion of interannual variability, when forced with the lightning climatology, has only a minor impact on the simulated burned area. Annually averaged lightning forcing causes differences as a direct result of the eliminated seasonal characteristics of lightning. Burned area is decreased in summer and increased in winter where fuel is available. Regions with little seasonality, such as the Tropics and Subtropics, experience an increase in burned area.

Impacts of air pollutants from fire and non-fire emissions on the regional air quality in Southeast Asia

NASA Astrophysics Data System (ADS)

Lee, Hsiang-He; Iraqui, Oussama; Gu, Yefu; Hung-Lam Yim, Steve; Chulakadabba, Apisada; Yiu-Ming Tonks, Adam; Yang, Zhengyu; Wang, Chien

2018-05-01

Severe haze events in Southeast Asia caused by particulate pollution have become more intense and frequent in recent years. Widespread biomass burning occurrences and particulate pollutants from human activities other than biomass burning play important roles in degrading air quality in Southeast Asia. In this study, numerical simulations have been conducted using the Weather Research and Forecasting (WRF) model coupled with a chemistry component (WRF-Chem) to quantitatively examine the contributions of aerosols emitted from fire (i.e., biomass burning) versus non-fire (including fossil fuel combustion, and road dust, etc.) sources to the degradation of air quality and visibility over Southeast Asia. These simulations cover a time period from 2002 to 2008 and are driven by emissions from (a) fossil fuel burning only, (b) biomass burning only, and (c) both fossil fuel and biomass burning. The model results reveal that 39 % of observed low-visibility days (LVDs) can be explained by either fossil fuel burning or biomass burning emissions alone, a further 20 % by fossil fuel burning alone, a further 8 % by biomass burning alone, and a further 5 % by a combination of fossil fuel burning and biomass burning. Analysis of an 24 h PM2.5 air quality index (AQI) indicates that the case with coexisting fire and non-fire PM2.5 can substantially increase the chance of AQI being in the moderate or unhealthy pollution level from 23 to 34 %. The premature mortality in major Southeast Asian cities due to degradation of air quality by particulate pollutants is estimated to increase from ˜ 4110 per year in 2002 to ˜ 6540 per year in 2008. In addition, we demonstrate the importance of certain missing non-fire anthropogenic aerosol sources including anthropogenic fugitive and industrial dusts in causing urban air quality degradation. An experiment of using machine learning algorithms to forecast the occurrence of haze events in Singapore is also explored in this study. All of these results suggest that besides minimizing biomass burning activities, an effective air pollution mitigation policy for Southeast Asia needs to consider controlling emissions from non-fire anthropogenic sources.

A human-driven decline in global burned area

NASA Astrophysics Data System (ADS)

Andela, N.; Morton, D. C.; Chen, Y.; van der Werf, G.; Giglio, L.; Kasibhatla, P. S.; Randerson, J. T.

2016-12-01

Fire is an important and dynamic ecosystem process that influences many aspects of the global Earth system. Here, we used several different satellite datasets to assess trends in global burned area during 1998 to 2014. Global burned area decreased by about 21.6 ± 8.5% over the period from 1998-2014, with large regional declines observed in savanna and grassland ecosystems in northern Africa, Eurasia, and South America. The decrease in burned area remained robust after removing the influence of climate (16.0 ± 6.0%), implicating human activity as a likely driver. To further investigate the mechanisms contributing to regional and global trends, we conducted several kinds of analysis, including separation of burned area into ignition and fire size components and geospatial analysis of fire trends in relationship with demographic and land use variables. We found that fire number was a more important factor contributing to burned area trends than fire size, suggesting a reduction in the use of fire for management purposes. Concurrent decreases in fire size also contributed to the trend outside of North and South America, suggesting a role for greater landscape fragmentation. From our geospatial analysis, we developed a conceptual model that incorporates a range of drivers for human-driven changes in biomass burning that can be used to guide global fire models, currently unable to reproduce these large scale recent trends. Patterns of agricultural expansion and land use intensification are likely to further contribute to declining burned area trends in future decades, with important consequences for Earth system processes mediated by surface albedo, greenhouse gas emissions, and aerosols. Our results also highlight the vulnerability of savannas and grassland to land use changes with unprecedented global scale consequences for vegetation structure and the carbon cycle.

Modeling In-Stream Hydro-Geomorphic Processes After 2012 Waldo Canyon Fire, Colorado

NASA Astrophysics Data System (ADS)

Nourbakhshbeidokhti, S.; Kinoshita, A. M.; Chin, A.

2016-12-01

Wildfires can have significant impacts on hydrologic and geomorphic processes. Post-fire sediment transport and runoff generation vary by burn severity, precipitation, and vegetation. A need exists to understand these variable relationships and improve parameterization of post-fire hydro-geomorphic models. This research aims to model pre-fire geomorphic and hydrologic processes in Williams Canyon, a watershed burned by the 2012 Waldo Canyon Fire in Colorado. We develop the KINematic Runoff and EROSion (KINEROS) model with Geographical Information System (GIS)-based information, including a Digital Elevation Model, land cover, soil classification, precipitation, and soil burn severity for a local reference watershed that is unburned. We transfer these parameters to a channel reach in Williams Canyon (Williams Downstream) and adjust them toward post-fire conditions. We model runoff and sediment yield for several storms following the fire. Three post-fire terrestrial Light Detection and Ranging (LiDAR) images (21 April 2013, 14 September 2013, and 16 September 2014) are used to estimate total erosion and deposition at the reach scale. We use the LiDAR-based information to calibrate the post-fire model. Preliminary modeling results indicate 3870-125 kg/ha of sediment in the Williams Downstream reach. The uncalibrated model overestimated (410% in the first year) and underestimated (87.2% in the second year) the erosion. Model calibration reduced the Root Mean Square Error (RMSE) of sediment to 0.016% for the first year and 0.09% for the second year. The parameters calibrated for the Williams Downstream channel reach will be used to develop models for seven other channel reaches within the area burned by the Waldo Canyon Fire, where the performance can be evaluated with LiDAR estimates. Results of this research will enhance our understanding of wildfire disturbance on coupled hydrologic and geomorphic processes. Findings will also improve model parameterization that can be used to guide post-fire management and predictions.

Modeling the spreading of large-scale wildland fires

Treesearch

Mohamed Drissi

2015-01-01

The objective of the present study is twofold. First, the last developments and validation results of a hybrid model designed to simulate fire patterns in heterogeneous landscapes are presented. The model combines the features of a stochastic small-world network model with those of a deterministic semi-physical model of the interaction between burning and non-burning...

Fine scale vegetation classification and fuel load mapping for prescribed burning

Treesearch

Andrew D. Bailey; Robert Mickler

2007-01-01

Fire managers in the Coastal Plain of the Southeastern United States use prescribed burning as a tool to reduce fuel loads in a variety of vegetation types, many of which have elevated fuel loads due to a history of fire suppression. While standardized fuel models are useful in prescribed burn planning, those models do not quantify site-specific fuel loads that reflect...

Near real-time estimation of burned area using VIIRS 375 m active fire product

NASA Astrophysics Data System (ADS)

Oliva, P.; Schroeder, W.

2016-12-01

Every year, more than 300 million hectares of land burn globally, causing significant ecological and economic consequences, and associated climatological effects as a result of fire emissions. In recent decades, burned area estimates generated from satellite data have provided systematic global information for ecological analysis of fire impacts, climate and carbon cycle models, and fire regimes studies, among many others. However, there is still need of near real-time burned area estimations in order to assess the impacts of fire and estimate smoke and emissions. The enhanced characteristics of the Visible Infrared Imaging Radiometer Suite (VIIRS) 375 m channels on board the Suomi National Polar-orbiting Partnesship (S-NPP) make possible the use of near real-time active fire detection data for burned area estimation. In this study, consecutive VIIRS 375 m active fire detections were aggregated to produce the VIIRS 375 m burned area (BA) estimation over ten ecologically diverse study areas. The accuracy of the BA estimations was assessed by comparison with Landsat-8 supervised burned area classification. The performance of the VIIRS 375 m BA estimates was dependent on the ecosystem characteristics and fire behavior. Higher accuracy was observed in forested areas characterized by large long-duration fires, while grasslands, savannas and agricultural areas showed the highest omission and commission errors. Complementing those analyses, we performed the burned area estimation of the largest fires in Oregon and Washington states during 2015 and the Fort McMurray fire in Canada 2016. The results showed good agreement with NIROPs airborne fire perimeters proving that the VIIRS 375 m BA estimations can be used for near real-time assessments of fire effects.

A human-driven decline in global burned area.

PubMed

Andela, N; Morton, D C; Giglio, L; Chen, Y; van der Werf, G R; Kasibhatla, P S; DeFries, R S; Collatz, G J; Hantson, S; Kloster, S; Bachelet, D; Forrest, M; Lasslop, G; Li, F; Mangeon, S; Melton, J R; Yue, C; Randerson, J T

2017-06-30

Fire is an essential Earth system process that alters ecosystem and atmospheric composition. Here we assessed long-term fire trends using multiple satellite data sets. We found that global burned area declined by 24.3 ± 8.8% over the past 18 years. The estimated decrease in burned area remained robust after adjusting for precipitation variability and was largest in savannas. Agricultural expansion and intensification were primary drivers of declining fire activity. Fewer and smaller fires reduced aerosol concentrations, modified vegetation structure, and increased the magnitude of the terrestrial carbon sink. Fire models were unable to reproduce the pattern and magnitude of observed declines, suggesting that they may overestimate fire emissions in future projections. Using economic and demographic variables, we developed a conceptual model for predicting fire in human-dominated landscapes. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

FEMME- post-Fire Emergency ManageMEnt tool.

NASA Astrophysics Data System (ADS)

Vieira, Diana; Serpa, Dalila; Rocha, João; Nunes, João; Keizer, Jacob

2017-04-01

Wildfires can have important impacts on hydrological and soil erosion processes in forest catchments, due to the destruction of vegetation cover and changes to soil properties. The involved processes however, are non-linear and not fully understood. This has severely limited the understanding on the impacts of wildfires, and, as a consequence, current runoff-erosion models are poorly adapted to recently burned forest conditions. Furthermore, while post-fire forestry operations and, to a lesser extent, post-fire soil conservation measures are commonly applied, their hydrological and erosion impacts continue poorly known, hampering decision-making by land owners and managers. Past post-wildfire research in Portugal has involved simple adaptations of plot-scale runoff-erosion models to post-fire conditions. This follow-up study focusses on model adaptation to selected post-fire soil conservation measures. To this end, full stock is taken of various datasets collected by several (past and ongoing research projects. The selected model is the Morgan-Morgan-Finney model (MMF, Morgan,2001), which already proved its suitability for post-fire conditions in Portugal (Vieira et al, 2010, 2014) as well as NW-Spain ( Fernández et al., 2010). The present results concerned runoff and erosion different burn severities and various post-fire mitigation treatments (mulch, hydromulch, needle cast, barriers), focussing on the plot and field scale. The results for both the first and the second year following the wildfire revealed good model efficiency, not only for burned and untreated conditions but also for burned and treated conditions. These results thus reinforced earlier findings that MMF is a suitable model for the envisaged post-fire soil erosion assessment tool, coined "FEMME". The data used for post-fire soil erosion calibration with the MMF already allows the delineation of the post-fire management FEMME tool. Nevertheless, further model assessment will address additional post-fire forestry operations (e.g. plowing) as well as upscaling to the catchment scale with the MMF model and compare it with the SWAT model.

Characterization and evaluation of controls on post-fire streamflow response across western US watersheds

NASA Astrophysics Data System (ADS)

Saxe, Samuel; Hogue, Terri S.; Hay, Lauren

2018-02-01

This research investigates the impact of wildfires on watershed flow regimes, specifically focusing on evaluation of fire events within specified hydroclimatic regions in the western United States, and evaluating the impact of climate and geophysical variables on response. Eighty-two watersheds were identified with at least 10 years of continuous pre-fire daily streamflow records and 5 years of continuous post-fire daily flow records. Percent change in annual runoff ratio, low flows, high flows, peak flows, number of zero flow days, baseflow index, and Richards-Baker flashiness index were calculated for each watershed using pre- and post-fire periods. Independent variables were identified for each watershed and fire event, including topographic, vegetation, climate, burn severity, percent area burned, and soils data. Results show that low flows, high flows, and peak flows increase in the first 2 years following a wildfire and decrease over time. Relative response was used to scale response variables with the respective percent area of watershed burned in order to compare regional differences in watershed response. To account for variability in precipitation events, runoff ratio was used to compare runoff directly to PRISM precipitation estimates. To account for regional differences in climate patterns, watersheds were divided into nine regions, or clusters, through k-means clustering using climate data, and regression models were produced for watersheds grouped by total area burned. Watersheds in Cluster 9 (eastern California, western Nevada, Oregon) demonstrate a small negative response to observed flow regimes after fire. Cluster 8 watersheds (coastal California) display the greatest flow responses, typically within the first year following wildfire. Most other watersheds show a positive mean relative response. In addition, simple regression models show low correlation between percent watershed burned and streamflow response, implying that other watershed factors strongly influence response. Spearman correlation identified NDVI, aridity index, percent of a watershed's precipitation that falls as rain, and slope as being positively correlated with post-fire streamflow response. This metric also suggested a negative correlation between response and the soil erodibility factor, watershed area, and percent low burn severity. Regression models identified only moderate burn severity and watershed area as being consistently positively/negatively correlated, respectively, with response. The random forest model identified only slope and percent area burned as significant watershed parameters controlling response. Results will help inform post-fire runoff management decisions by helping to identify expected changes to flow regimes, as well as facilitate parameterization for model application in burned watersheds.

Studying the effects of fuel treatment based on burn probability on a boreal forest landscape.

PubMed

Liu, Zhihua; Yang, Jian; He, Hong S

2013-01-30

Fuel treatment is assumed to be a primary tactic to mitigate intense and damaging wildfires. However, how to place treatment units across a landscape and assess its effectiveness is difficult for landscape-scale fuel management planning. In this study, we used a spatially explicit simulation model (LANDIS) to conduct wildfire risk assessments and optimize the placement of fuel treatments at the landscape scale. We first calculated a baseline burn probability map from empirical data (fuel, topography, weather, and fire ignition and size data) to assess fire risk. We then prioritized landscape-scale fuel treatment based on maps of burn probability and fuel loads (calculated from the interactions among tree composition, stand age, and disturbance history), and compared their effects on reducing fire risk. The burn probability map described the likelihood of burning on a given location; the fuel load map described the probability that a high fuel load will accumulate on a given location. Fuel treatment based on the burn probability map specified that stands with high burn probability be treated first, while fuel treatment based on the fuel load map specified that stands with high fuel loads be treated first. Our results indicated that fuel treatment based on burn probability greatly reduced the burned area and number of fires of different intensities. Fuel treatment based on burn probability also produced more dispersed and smaller high-risk fire patches and therefore can improve efficiency of subsequent fire suppression. The strength of our approach is that more model components (e.g., succession, fuel, and harvest) can be linked into LANDIS to map the spatially explicit wildfire risk and its dynamics to fuel management, vegetation dynamics, and harvesting. Copyright © 2012 Elsevier Ltd. All rights reserved.

North African savanna fires and atmospheric carbon dioxide

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

Iacobellis, S.F.; Frouni, Razafimpaniolo, H.

1994-04-20

The effect of north African savanna fires on atmospheric CO{sub 2} is investigated using a tracer transport model. The model uses winds from operational numerical weather prediction analyses and provides CO{sub 2} concentrations as a function of space and time. After a spin-up period of several years, biomass-burning sources are added, and model experiments are run for an additional year, utilizing various estimates of CO{sub 2} sources. The various model experiments show that biomass burning in the north African savannas significantly affects CO{sub 2} concentrations in South America. The effect is more pronounced during the period from January through March,more » when biomass burning in South America is almost nonexistent. During this period, atmospheric CO{sub 2} concentrations in parts of South America typically may increase by 0.5 to 0.75 ppm at 970 mbar, the average pressure of the lowest model layer. These figures are above the probable uncertainty level, as model runs with biomass-burning sources estimated from independent studies using distinct data sets and techniques indicate. From May through September, when severe biomass burning occurs in South America, the effect of north African savanna fires over South America has become generally small at 970 mbar, but north of the equator it may be of the same magnitude or larger than the effect of South American fires. The CO{sub 2} concentration increase in the extreme northern and southern portions of South America, however, is mostly due to southern African fires, whose effect may be 2-3 times larger than the effect of South American fires at 970 mbar. Even in the central part of the continent, where local biomass-burning emissions are maximum, southern African fires contribute to at least 15% of the CO{sub 2} concentration increase at 970 mbar. 20 refs., 15 figs., 1 tab.« less

Avian community responses to post-fire forest structure: Implications for fire management in mixed conifer forests

USGS Publications Warehouse

White, Angela M.; Manley, Patricia N.; Tarbill, Gina; Richardson, T.L.; Russell, Robin E.; Safford, Hugh D.; Dobrowski, Solomon Z.

2015-01-01

Fire is a natural process and the dominant disturbance shaping plant and animal communities in many coniferous forests of the western US. Given that fire size and severity are predicted to increase in the future, it has become increasingly important to understand how wildlife responds to fire and post-fire management. The Angora Fire burned 1243 hectares of mixed conifer forest in South Lake Tahoe, California. We conducted avian point counts for the first 3 years following the fire in burned and unburned areas to investigate which habitat characteristics are most important for re-establishing or maintaining the native avian community in post-fire landscapes. We used a multi-species occurrence model to estimate how avian species are influenced by the density of live and dead trees and shrub cover. While accounting for variations in the detectability of species, our approach estimated the occurrence probabilities of all species detected including those that were rare or observed infrequently. Although all species encountered in this study were detected in burned areas, species-specific modeling results predicted that some species were strongly associated with specific post-fire conditions, such as a high density of dead trees, open-canopy conditions or high levels of shrub cover that occur at particular burn severities or at a particular time following fire. These results indicate that prescribed fire or managed wildfire which burns at low to moderate severity without at least some high-severity effects is both unlikely to result in the species assemblages that are unique to post-fire areas or to provide habitat for burn specialists. Additionally, the probability of occurrence for many species was associated with high levels of standing dead trees indicating that intensive post-fire harvest of these structures could negatively impact habitat of a considerable proportion of the avian community.

Assessing the predictability of fire occurrence and area burned across phytoclimatic regions in Spain

NASA Astrophysics Data System (ADS)

Bedia, J.; Herrera, S.; Gutiérrez, J. M.

2014-01-01

Most fire protection agencies throughout the world have developed forest fire risk forecast systems, usually building upon existing fire danger indices and meteorological forecast data. In this context, the daily predictability of wildfires is of utmost importance in order to allow the fire protection agencies to issue timely fire hazard alerts. In this study, we address the predictability of daily fire occurrence using the components of the Canadian Fire Weather Index (FWI) System and related variables calculated from the latest ECMWF (European Centre for Medium Range Weather Forecasts) reanalysis, ERA-Interim. We develop daily fire occurrence models in peninsular Spain for the period 1990-2008 and, considering different minimum burned area thresholds for fire definition, assess their ability to reproduce the inter-annual fire frequency variability. We based the analysis on a phytoclimatic classification aiming the stratification of the territory into homogeneous units in terms of climatic and fuel type characteristics, allowing to test model performance under different climate/fuel conditions. We then extend the analysis in order to assess the predictability of monthly burned areas. The sensitivity of the models to the level of spatial aggregation of the data is also evaluated. Additionally, we investigate the gain in model performance with the inclusion of socioeconomic and land use/land cover (LULC) covariates in model formulation. Fire occurrence models have attained good performance in most of the phytoclimatic zones considered, being able to faithfully reproduce the inter-annual variability of fire frequency. Total area burned has exhibited some dependence on the meteorological drivers, although model performance was poor in most cases. We identified temperature and some FWI system components as the most important explanatory variables, highlighting the adequacy of the FWI system for fire occurrence prediction in the study area. The results were improved when using aggregated data across regions compared to when data were sampled at the grid-box level. The inclusion of socioeconomic and LULC covariates contributed marginally to the improvement of the models, and in most cases attained no relevant contribution to total explained variance - excepting northern Spain, where anthropogenic factors are known to be the major driver of fires. Models of monthly fire counts performed better in the case of fires larger than 0.1 ha, and for the rest of the thresholds (1, 10 and 100 ha) the daily occurrence models improved the predicted inter-annual variability, indicating the added value of daily models. Fire frequency predictions may provide a preferable basis for past fire history reconstruction, long-term monitoring and the assessment of future climate impacts on fire regimes across regions, posing several advantages over burned area as a response variable. Our results leave the door open to the development a more complex modelling framework based on daily data from numerical climate model outputs based on the FWI system.

Detecting post-fire burn severity and vegetation recovery using multitemporal remote sensing spectral indices and field-collected composite burn index data in a ponderosa pine forest

USGS Publications Warehouse

Chen, Xuexia; Vogelmann, James E.; Rollins, Matt; Ohlen, Donald; Key, Carl H.; Yang, Limin; Huang, Chengquan; Shi, Hua

2011-01-01

It is challenging to detect burn severity and vegetation recovery because of the relatively long time period required to capture the ecosystem characteristics. Multitemporal remote sensing data can providemultitemporal observations before, during and after a wildfire, and can improve the change detection accuracy. The goal of this study is to examine the correlations between multitemporal spectral indices and field-observed burn severity, and to provide a practical method to estimate burn severity and vegetation recovery. The study site is the Jasper Fire area in the Black Hills National Forest, South Dakota, that burned during August and September 2000. Six multitemporal Landsat images acquired from 2000 (pre-fire), 2001 (post-fire), 2002, 2003, 2005 and 2007 were used to assess burn severity. The normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), normalized burn ratio (NBR), integrated forest index (IFI) and the differences of these indices between the pre-fire and post-fire years were computed and analysed with 66 field-based composite burn index (CBI) plots collected in 2002. Results showed that differences of NDVI and differences of EVI between the pre-fire year and the first two years post-fire were highly correlated with the CBI scores. The correlations were low beyond the second year post-fire. Differences of NBR had good correlation with CBI scores in all study years. Differences of IFI had low correlation with CBI in the first year post-fire and had good correlation in later years. A CBI map of the burnt area was produced using regression tree models and the multitemporal images. The dynamics of four spectral indices from 2000 to 2007 indicated that both NBR and IFI are valuable for monitoring long-term vegetation recovery. The high burn severity areas had a much slower recovery than the moderate and low burn areas.

Daily and 3-hourly Variability in Global Fire Emissions and Consequences for Atmospheric Model Predictions of Carbon Monoxide

NASA Technical Reports Server (NTRS)

Mu, M.; Randerson, J. T.; vanderWerf, G. R.; Giglio, L.; Kasibhatla, P.; Morton, D.; Collatz, G. J.; DeFries, R. S.; Hyer, E. J.; Prins, E. M.;

How Much Global Burned Area Can Be Forecast on Seasonal Time Scales Using Sea Surface Temperatures?

NASA Technical Reports Server (NTRS)

Chen, Yang; Morton, Douglas C.; Andela, Niels; Giglio, Louis; Randerson, James T.

2016-01-01

Large-scale sea surface temperature (SST) patterns influence the interannual variability of burned area in many regions by means of climate controls on fuel continuity, amount, and moisture content. Some of the variability in burned area is predictable on seasonal timescales because fuel characteristics respond to the cumulative effects of climate prior to the onset of the fire season. Here we systematically evaluated the degree to which annual burned area from the Global Fire Emissions Database version 4 with small fires (GFED4s) can be predicted using SSTs from 14 different ocean regions. We found that about 48 of global burned area can be forecast with a correlation coefficient that is significant at a p < 0.01 level using a single ocean climate index (OCI) 3 or more months prior to the month of peak burning. Continental regions where burned area had a higher degree of predictability included equatorial Asia, where 92% of the burned area exceeded the correlation threshold, and Central America, where 86% of the burned area exceeded this threshold. Pacific Ocean indices describing the El Nino-Southern Oscillation were more important than indices from other ocean basins, accounting for about 1/3 of the total predictable global burned area. A model that combined two indices from different oceans considerably improved model performance, suggesting that fires in many regions respond to forcing from more than one ocean basin. Using OCI-burned area relationships and a clustering algorithm, we identified 12 hotspot regions in which fires had a consistent response to SST patterns. Annual burned area in these regions can be predicted with moderate confidence levels, suggesting operational forecasts may be possible with the aim of improving ecosystem management.

Differences in Human Versus Lightning Fires with Human Proximity at Two Spatial Scales in Interior Alaska

NASA Astrophysics Data System (ADS)

Calef, M. P.; Varvak, A.; McGuire, A. D.

2017-12-01

The boreal forest contains significant amounts of carbon in its biomass and soils and is currently responding to a rapidly changing climate. This is leading to warmer temperatures, drier conditions and larger and more frequent wildfires in western North America. However, the fire regime is also affected by direct human activities through suppression, ignition, and land use changes. Models are important predictive tools for understanding future conditions but they are based on regional generalizations of wildfire behavior and do not account for the complexity of human-fire interactions. In order to achieve a better understanding of the human influence on fires and how human fires differ from lightning fires, we analyzed both in regard to human proximity at two spatial scales (the Fairbanks subregion and Interior Alaska) using ArcGIS and quantitative analysis methods. We found that area burned is increasing across the region at 3% per year and is driven by increase in area burned by lightning while human-caused area burned has been decreasing recently especially in the WUI near Fairbanks. Human fires differed from lightning fires in several ways: they occurred significantly closer to settlements and highways, burned for a shorter duration, and were not as restricted to a brief seasonal window. The fire regime in the much more populated Fairbanks subregion has been altered by human activity: it experienced substantially more human fire ignitions along with a larger area burned though the human influence decreases with distance. This study provides important insights into spatial patterns of human influences on fires and provides useful information for fire modeling and fire management.

Predicted effects of prescribed burning and harvesting on forest recovery and sustainability in southwest Georgia, USA.

PubMed

Garten, Charles T

2006-12-01

A model-based analysis of the effect of prescribed burning and forest thinning or clear-cutting on stand recovery and sustainability was conducted at Fort Benning, GA, in the southeastern USA. Two experiments were performed with the model. In the first experiment, forest recovery from degraded soils was predicted for 100 years with or without prescribed burning. In the second experiment simulations began with 100 years of predicted stand growth, then forest sustainability was predicted for an additional 100 years under different combinations of prescribed burning and forest harvesting. Three levels of fire intensity (low, medium, and high), that corresponded to 17%, 33%, and 50% consumption of the forest floor C stock by fire, were evaluated at 1-, 2-, and 3-year fire return intervals. Relative to the control (no fire), prescribed burning with a 2- or 3-year return interval caused only a small reduction in predicted steady state soil C stocks (< or =25%) and had no effect on steady state tree wood biomass, regardless of fire intensity. Annual high intensity burns did adversely impact forest recovery and sustainability (after harvesting) on less sandy soils, but not on more sandy soils that had greater N availability. Higher intensity and frequency of ground fires increased the chance that tree biomass would not return to pre-harvest levels. Soil N limitation was indicated as the cause of unsustainable forests when prescribed burns were too frequent or too intense to permit stand recovery.

The Fire Locating and Modeling of Burning Emissions (FLAMBE) Project

NASA Astrophysics Data System (ADS)

Reid, J. S.; Prins, E. M.; Westphal, D.; Richardson, K.; Christopher, S.; Schmidt, C.; Theisen, M.; Eck, T.; Reid, E. A.

2001-12-01

The Fire Locating and Modeling of Burning Emissions (FLAMBE) project was initiated by NASA, the US Navy and NOAA to monitor biomass burning and burning emissions on a global scale. The idea behind the mission is to integrate remote sensing data with global and regional transport models in real time for the purpose of providing the scientific community with smoke and fire products for planning and research purposes. FLAMBE is currently utilizing real time satellite data from GOES satellites, fire products based on the Wildfire Automated Biomass Burning Algorithm (WF_ABBA) are generated for the Western Hemisphere every 30 minutes with only a 90 minute processing delay. We are currently collaborating with other investigators to gain global coverage. Once generated, the fire products are used to input smoke fluxes into the NRL Aerosol Analysis and Prediction System, where advection forecasts are performed for up to 6 days. Subsequent radiative transfer calculations are used to estimate top of atmosphere and surface radiative forcing as well as surface layer visibility. Near real time validation is performed using field data collected by Aerosol Robotic Network (AERONET) Sun photometers. In this paper we fully describe the FLAMBE project and data availability. Preliminary result from the previous year will also be presented, with an emphasis on the development of algorithms to determine smoke emission fluxes from individual fire products. Comparisons to AERONET Sun photometer data will be made.

Evaluation of a post-fire tree mortality model for western US conifers

Treesearch

Sharon M. Hood; Charles W McHugh; Kevin C. Ryan; Elizabeth Reinhardt; Sheri L. Smith

2007-01-01

Accurately predicting fire-caused mortality is essential to developing prescribed fire burn plans and post-fire salvage marking guidelines. The mortality model included in the commonly used USA fire behaviour and effects models, the First Order Fire Effects Model (FOFEM), BehavePlus, and the Fire and Fuels Extension to the Forest Vegetation Simulator (FFE-FVS), has not...

Waterfowl populations are resilient to immediate and lagged impacts of wildfires in the boreal forest

USGS Publications Warehouse

Lewis, Tyler; Schmutz, Joel A.; Amundson, Courtney L.; Lindberg, Mark S.

2016-01-01

Summary 1. Wildfires are the principal disturbance in the boreal forest, and their size and frequency are increasing as the climate warms. Impacts of fires on boreal wildlife are largely unknown, especially for the tens of millions of waterfowl that breed in the region. This knowledge gap creates significant barriers to the integrative management of fires and waterfowl, leading to fire policies that largely disregard waterfowl. 2. Waterfowl populations across the western boreal forest of North America have been monitored annually since 1955 by the Waterfowl Breeding Population and Habitat Survey (BPOP), widely considered the most extensive wildlife survey in the world. Using these data, we examined impacts of forest fires on abundance of two waterfowl guilds – dabblers and divers. We modelled waterfowl abundance in relation to fire extent (i.e. amount of survey transect burned) and time since fire, examining both immediate and lagged fire impacts. 3. From 1955 to 2014, >1100 fires in the western boreal forest intersected BPOP survey transects, and many transects burned multiple times. Nonetheless, fires had no detectable impact on waterfowl abundance; annual transect counts of dabbler and diver pairs remained stable from the pre- to post-fire period. 4. The absence of fire impacts on waterfowl abundance extended from the years immediately following the fire to those more than a decade afterwards. Likewise, the amount of transect burned did not influence waterfowl abundance, with similar pair counts from the pre- to post-fire period for small (1–20% burned), medium (21–60%) and large (>60%) burns. 5. Policy implications. Waterfowl populations appear largely resilient to forest fires, providing initial evidence that current policies of limited fire suppression, which predominate throughout much of the boreal forest, have not been detrimental to waterfowl populations. Likewise, fire-related management actions, such as prescribed burning or targeted suppression, seem to have limited impacts on waterfowl abundance and productivity. For waterfowl managers, our results suggest that adaptive models of waterfowl harvest, which annually guide hunting quotas, do not need to emphasize fires when integrating climate change effects.

Modeling Multiple-Core Updraft Plume Rise for an Aerial Ignition Prescribed Burn by Coupling Daysmoke with a Cellular Automata Fire Model

Treesearch

G. L Achtemeier; S. L. Goodrick; Y. Liu

2012-01-01

Smoke plume rise is critically dependent on plume updraft structure. Smoke plumes from landscape burns (forest and agricultural burns) are typically structured into “sub-plumes” or multiple-core updrafts with the number of updraft cores depending on characteristics of the landscape, fire, fuels, and weather. The number of updraft cores determines the efficiency of...

Importance of transboundary transport of biomass burning emissions to regional air quality in Southeast Asia during a high fire event

NASA Astrophysics Data System (ADS)

Aouizerats, B.; van der Werf, G. R.; Balasubramanian, R.; Betha, R.

2015-01-01

Smoke from biomass and peat burning has a notable impact on ambient air quality and climate in the Southeast Asia (SEA) region. We modeled a large fire-induced haze episode in 2006 stemming mostly from Indonesia using the Weather Research and Forecasting model coupled with chemistry (WRF-Chem). We focused on the evolution of the fire plume composition and its interaction with the urbanized area of the city state of Singapore, and on comparisons of modeled and measured aerosol and carbon monoxide (CO) concentrations. Two simulations were run with WRF-Chem using the complex volatility basis set (VBS) scheme to reproduce primary and secondary aerosol evolution and concentration. The first simulation referred to as WRF-FIRE included anthropogenic, biogenic and biomass burning emissions from the Global Fire Emissions Database (GFED3) while the second simulation referred to as WRF-NOFIRE was run without emissions from biomass burning. To test model performance, we used three independent data sets for comparison including airborne measurements of particulate matter (PM) with a diameter of 10 μm or less (PM10) in Singapore, CO measurements in Sumatra, and aerosol optical depth (AOD) column observations from four satellite-based sensors. We found reasonable agreement between the model runs and both ground-based measurements of CO and PM10. The comparison with AOD was less favorable and indicated the model underestimated AOD, although the degree of mismatch varied between different satellite data sets. During our study period, forest and peat fires in Sumatra were the main cause of enhanced aerosol concentrations from regional transport over Singapore. Analysis of the biomass burning plume showed high concentrations of primary organic aerosols (POA) with values up to 600 μg m-3 over the fire locations. The concentration of POA remained quite stable within the plume between the main burning region and Singapore while the secondary organic aerosol (SOA) concentration slightly increased. However, the absolute concentrations of SOA (up to 20 μg m-3) were much lower than those from POA, indicating a minor role of SOA in these biomass burning plumes. Our results show that about 21% of the total mass loading of ambient PM10 during the July-October study period in Singapore was due to biomass and peat burning in Sumatra, but this contribution increased during high burning periods. In total, our model results indicated that during 35 days aerosol concentrations in Singapore were above the threshold of 50 μg m-3 day-1 indicating poor air quality. During 17 days this was due to fires, based on the difference between the simulations with and without fires. Local pollution in combination with recirculation of air masses was probably the main cause of poor air quality during the other 18 days, although fires from Sumatra and probably also from Kalimantan (Indonesian part of the island of Borneo) added to the enhanced PM10 concentrations. The model versus measurement comparisons highlighted that for our study period and region the GFED3 biomass burning aerosol emissions were more in line with observations than found in other studies. This indicates that care should be taken when using AOD to constrain emissions or estimate ground-level air quality. This study also shows the need for relatively high resolution modeling to accurately reproduce the advection of air masses necessary to quantify the impacts and feedbacks on regional air quality.

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.

Improved estimates of biomass burning emissions in the southeast United States

NASA Astrophysics Data System (ADS)

Nowell, H.; Holmes, C.; Elsner, J.; Hiers, J. K.; Robertson, K.

2017-12-01

Biomass burning is a major source of gas and particle emissions that affects air quality, human health, and climate. Prescribed burns in the southeastern United States consume more biomass and cover a larger area than fires in the rest of the United States combined. Although fires can be detected remotely from thermal infrared emission and changes to surface reflectance, there are multiple issues that make satellite detections difficult in the eastern United States. These include small fire sizes, short duration, low intensity, canopy coverage, and rapid vegetation regrowth. Some attempts have been made to compensate for this bias, for example the small fire product in the Global Fire Emission Database (GFED4.1s) product. The accuracy of GFED and other remotely sensed global fire emission inventories are largely unknown, outside of a few field studies, mainly because there are few independent datasets of fire extent. The Florida Forest Service (FFS) has extensive records on fire type, size, location, and time for both prescribed and wild fires, which have not previously been used to evaluate fire area and emissions. For our study period of 2004 to 2016, we compared FFS burn authorization data against GFED4.1s burned area. When averaged across the state of Florida, there is 4 times more land burned than detected from satellite sensors. When comparing FFS data against high quality records from Apalachicola National Forest, Avon Park Air Force Range, Eglin Air Force Base, Tall Timbers Research Station, and Tyndall Air Force base, the areal discrepancy between these records and FFS reports are +/- 15%, well below the 4 times detection discrepancy between satellites and FFS reports. We have developed a method to statistically correct this satellite bias in fire detections. Treating the FFS burn authorizations as accurate, we have found this bias ratio can be predicted from fire size, land cover type, leaf area, and month. The regression model incorporating these factors can predict greater than 80% of variance in bias ratio across Florida during the summer months with correlations around 0.6 on average. This improved estimate of burned area in Florida will be used in global circulation models to determine the true contribution of prescribed wild fires in the southeast United States to gas and particle emissions.

Climate Change Transforms Fire Regimes but Does not Eliminate Forest Carbon Sequestration in the Greater Yellowstone Ecosystem

NASA Astrophysics Data System (ADS)

Henne, P. D.; Hawbaker, T. J.; Berryman, E.

2017-12-01

Annual area burned in the Rocky Mountains varies with climatic conditions. However, projecting long-term changes in wildfire presents an enduring challenge because climate also constrains vegetation and fuel availability. We combined an aridity-threshold fire model with the Landis-II dynamic landscape vegetation model (NECN extension) to project climate change impacts on vegetation, area burned, and ecosystem carbon balance in the Greater Yellowstone Ecosystem (GYE). We developed a fire model that relates drought stress to area burned by quantifying an aridity threshold separating large and small years in 15 ecoregions in the Intermountain West. A significant positive correlation (r2 = 0.97) exists between mean fire-season aridity and ecoregion-specific aridity thresholds. We simulated vegetation and fire dynamics in the GYE at 250 m spatial resolution with Landis-II, using projections from five climate models and two emissions scenarios for the period 1980-2100 AD. We determined if each simulation year exceeded the regional aridity threshold, then randomly drew the number of fires and size of individual fires from fire-size distributions from large or small fire years. Burned area increases dramatically in most climate scenarios, especially after 2060, when most years exceed the aridity threshold. Productivity gains due to rising temperatures partially offset biomass lost to fire, but C stocks plateau or decline after 2060 in most simulations as burned area increases, and drought stress causes post-fire regeneration to decline at low elevations. However, species level changes (e.g. expansion by drought-tolerant Pseuodotsuga menziesii) help maintain productivity in sites where water becomes limiting. Fire-adapted Pinus contorta occupies less total area, but a greater proportion of remaining forests, and Picea engelmannii and Abies lasiocarpa significantly decline. Although fire and climate change will alter species distributions and forest structure, our results suggest that the GYE can maintain a C sink through 2100. However, C stocks will likely shift to higher elevations, and forests will be less resilient to disturbance, in a warmer future. Our landscape-level approach identifies regions likely to maintain high conservation value and ecosystem services under multiple climate scenarios.

Potential shifts in dominant forest cover in interior Alaska driven by variations in fire severity

USGS Publications Warehouse

Barrett, K.; McGuire, A. David; Hoy, E.E.; Kasischke, E.S.

2011-01-01

Large fire years in which >1% of the landscape burns are becoming more frequent in the Alaskan (USA) interior, with four large fire years in the past 10 years, and 79 000 km2 (17% of the region) burned since 2000. We modeled fire severity conditions for the entire area burned in large fires during a large fire year (2004) to determine the factors that are most important in estimating severity and to identify areas affected by deep‐burning fires. In addition to standard methods of assessing severity using spectral information, we incorporated information regarding topography, spatial pattern of burning, and instantaneous characteristics such as fire weather and fire radiative power. Ensemble techniques using regression trees as a base learner were able to determine fire severity successfully using spectral data in concert with other relevant geospatial data. This method was successful in estimating average conditions, but it underestimated the range of severity.This new approach was used to identify black spruce stands that experienced intermediate‐ to high‐severity fires in 2004 and are therefore susceptible to a shift in regrowth toward deciduous dominance or mixed dominance. Based on the output of the severity model, we estimate that 39% (∼4000 km2) of all burned black spruce stands in 2004 had <10 cm of residual organic layer and may be susceptible a postfire shift in plant functional type dominance, as well as permafrost loss. If the fraction of area susceptible to deciduous regeneration is constant for large fire years, the effect of such years in the most recent decade has been to reduce black spruce stands by 4.2% and to increase areas dominated or co‐dominated by deciduous forest stands by 20%. Such disturbance‐driven modifications have the potential to affect the carbon cycle and climate system at regional to global scales.

Potential shifts in dominant forest cover in interior Alaska driven by variations in fire severity.

PubMed

Barrett, K; McGuire, A D; Hoy, E E; Kasischke, E S

2011-10-01

Large fire years in which >1% of the landscape burns are becoming more frequent in the Alaskan (USA) interior, with four large fire years in the past 10 years, and 79 000 km2 (17% of the region) burned since 2000. We modeled fire severity conditions for the entire area burned in large fires during a large fire year (2004) to determine the factors that are most important in estimating severity and to identify areas affected by deep-burning fires. In addition to standard methods of assessing severity using spectral information, we incorporated information regarding topography, spatial pattern of burning, and instantaneous characteristics such as fire weather and fire radiative power. Ensemble techniques using regression trees as a base learner were able to determine fire severity successfully using spectral data in concert with other relevant geospatial data. This method was successful in estimating average conditions, but it underestimated the range of severity. This new approach was used to identify black spruce stands that experienced intermediate- to high-severity fires in 2004 and are therefore susceptible to a shift in regrowth toward deciduous dominance or mixed dominance. Based on the output of the severity model, we estimate that 39% (approximately 4000 km2) of all burned black spruce stands in 2004 had <10 cm of residual organic layer and may be susceptible a postfire shift in plant functional type dominance, as well as permafrost loss. If the fraction of area susceptible to deciduous regeneration is constant for large fire years, the effect of such years in the most recent decade has been to reduce black spruce stands by 4.2% and to increase areas dominated or co-dominated by deciduous forest stands by 20%. Such disturbance-driven modifications have the potential to affect the carbon cycle and climate system at regional to global scales.

A combustion model of vegetation burning in "Tiger" fire propagation tool

NASA Astrophysics Data System (ADS)

Giannino, F.; Ascoli, D.; Sirignano, M.; Mazzoleni, S.; Russo, L.; Rego, F.

2017-11-01

In this paper, we propose a semi-physical model for the burning of vegetation in a wildland fire. The main physical-chemical processes involved in fire spreading are modelled through a set of ordinary differential equations, which describe the combustion process as linearly related to the consumption of fuel. The water evaporation process from leaves and wood is also considered. Mass and energy balance equations are written for fuel (leaves and wood) assuming that combustion process is homogeneous in space. The model is developed with the final aim of simulating large-scale wildland fires which spread on heterogeneous landscape while keeping the computation cost very low.

Modeling of marginal burning state of fire spread in live chaparral shrub fuel bed

Treesearch

X. Zhou; S. Mahalingam; D. Weise

2005-01-01

Prescribed burning in chaparral, currently used to manage wildland fuels and reduce wildfire hazard, is often conducted under marginal burning conditions. The relative importance of the fuel and environmental variables that determine fire spread success in chaparral fuels is not quantitatively understood. Based on extensive experimental study, a two-dimensional...

North African savanna fires and atmospheric carbon dioxide

NASA Technical Reports Server (NTRS)

Iacobellis, Sam F.; Frouin, Robert; Razafimpanilo, Herisoa; Somerville, Richard C. J.; Piper, Stephen C.

1994-01-01

The effect of north African savanna fires on atmospheric CO2 is investigated using a tracer transport model. The model uses winds from operational numerical weather prediction analyses and provides CO2 concentrations as a function of space and time. After a spin-up period of several years, biomass-burning sources are added, and model experiments are run for an additional year, utilizing various estimates of CO2 sources. The various model experiments show that biomass burning in the north African savannas significantly affects CO2 concentrations in South America. The effect is more pronounced during the period from January through March, when biomass burning in South America is almost nonexistent. During this period, atmospheric CO2 concentrations in parts of South America typically may increase by 0.5 to 0.75 ppm at 970 mbar, the average pressure of the lowest model layer. These figures are above the probable uncertainty level, as model runs with biomass-burning sources estimated from independent studies using distinct data sets and techniques indicate. From May through September, when severe biomass burning occurs in South America, the effect of north African savanna fires over South America has become generally small at 970 mbar, but north of the equator it may be of the same magnitude or larger than the effect of South American fires. The CO2 concentration increase in the extreme northern and southern portions of South America, however, is mostly due to southern African fires, whose effect may be 2-3 times larger than the effect of South American fires at 970 mbar. Even in the central part of the continent, where local biomass-burning emissions are maximum, southern African fires contribute to at least 15% of the CO2 concentration increase at 970 mbar. At higher levels in the atmosphere, less CO2 emitted by north African savanna fires reaches South America, and at 100 mbar no significant amount of CO2 is transported across the Atlantic Ocean. The vertical structure of the CO2 concentration increase due to biomass burning differs substantially, depending on whether sources are local or remote. A prominent maximum of CO2 concentration increase in the lower layers characterizes the effect of local sources, whereas a more homogeneous profile of CO2 concentration increase characterizes the effect of remote sources. The results demonstrate the strong remote effects of African biomoass burning which, owing to the general circulation of the atmosphere, are felt as far away as South America.

Comparison of the sensitivity of landscape-fire-succession models to variation in terrain, fuel pattern, climate and weather

Treesearch

Geoffrey J. Cary; Robert E. Keane; Robert H. Gardner; Sandra Lavorel; Mike D. Flannigan; Ian D. Davies; Chao Li; James M. Lenihan; T. Scott Rupp; Florent Mouillot

2006-01-01

The relative importance of variables in determining area burned is an important management consideration although gaining insights from existing empirical data has proven difficult. The purpose of this study was to compare the sensitivity of modeled area burned to environmental factors across a range of independently-developed landscape-fire-succession models. The...

Comparison of the sensitivity of landscape-fire-succession models to variation in terrain, fuel pattern, climate and weather

Treesearch

Geoffrey J. Cary; Robert E. Keane; Robert H. Gardner; Sandra Lavorel; Michael D. Flannigan; Ian D. Davies; Chao Li; James M. Lenihan; T. Scott Rupp; Florent Mouillot

2006-01-01

The purpose of this study was to compare the sensitivity of modelled area burned to environmental factors across a range of independently-developed landscape-fire-succession models. The sensitivity of area burned to variation in four factors, namely terrain (flat, undulating and mountainous), fuel pattern (finely and coarsely clumped), climate (observed, warmer &...

Comparison of GFED3, QFED2 and FEER1 Biomass Burning Emissions Datasets in a Global Model

NASA Technical Reports Server (NTRS)

Pan, Xiaohua; Ichoku, Charles; Bian, Huisheng; Chin, Mian; Ellison, Luke; da Silva, Arlindo; Darmenov, Anton

2015-01-01

Biomass burning contributes about 40% of the global loading of carbonaceous aerosols, significantly affecting air quality and the climate system by modulating solar radiation and cloud properties. However, fire emissions are poorly constrained in models on global and regional levels. In this study, we investigate 3 global biomass burning emission datasets in NASA GEOS5, namely: (1) GFEDv3.1 (Global Fire Emissions Database version 3.1); (2) QFEDv2.4 (Quick Fire Emissions Dataset version 2.4); (3) FEERv1 (Fire Energetics and Emissions Research version 1.0). The simulated aerosol optical depth (AOD), absorption AOD (AAOD), angstrom exponent and surface concentrations of aerosol plumes dominated by fire emissions are evaluated and compared to MODIS, OMI, AERONET, and IMPROVE data over different regions. In general, the spatial patterns of biomass burning emissions from these inventories are similar, although the strength of the emissions can be noticeably different. The emissions estimates from QFED are generally larger than those of FEER, which are in turn larger than those of GFED. AOD simulated with all these 3 databases are lower than the corresponding observations in Southern Africa and South America, two of the major biomass burning regions in the world.

Normalized burn ratios link fire severity with patterns of avian occurrence

USGS Publications Warehouse

Rose, Eli T.; Simons, Theodore R.; Klein, Rob; McKerrow, Alexa

2016-01-01

ContextRemotely sensed differenced normalized burn ratios (DNBR) provide an index of fire severity across the footprint of a fire. We asked whether this index was useful for explaining patterns of bird occurrence within fire adapted xeric pine-oak forests of the southern Appalachian Mountains.ObjectivesWe evaluated the use of DNBR indices for linking ecosystem process with patterns of bird occurrence. We compared field-based and remotely sensed fire severity indices and used each to develop occupancy models for six bird species to identify patterns of bird occurrence following fire.MethodsWe identified and sampled 228 points within fires that recently burned within Great Smoky Mountains National Park. We performed avian point counts and field-assessed fire severity at each bird census point. We also used Landsat™ imagery acquired before and after each fire to quantify fire severity using DNBR. We used non-parametric methods to quantify agreement between fire severity indices, and evaluated single season occupancy models incorporating fire severity summarized at different spatial scales.ResultsAgreement between field-derived and remotely sensed measures of fire severity was influenced by vegetation type. Although occurrence models using field-derived indices of fire severity outperformed those using DNBR, summarizing DNBR at multiple spatial scales provided additional insights into patterns of occurrence associated with different sized patches of high severity fire.ConclusionsDNBR is useful for linking the effects of fire severity to patterns of bird occurrence, and informing how high severity fire shapes patterns of bird species occurrence on the landscape.

Simulating Building Fires for Movies

NASA Technical Reports Server (NTRS)

Rodriguez, Ricardo C.; Johnson, Randall P.

1987-01-01

Fire scenes for cinematography staged at relatively low cost in method that combines several existing techniques. Nearly realistic scenes, suitable for firefighter training, produced with little specialized equipment. Sequences of scenes set up quickly and easily, without compromising safety because model not burned. Images of fire, steam, and smoke superimposed on image of building to simulate burning of building.

Spreaders, igniters, and burning shrubs: plant flammability explains novel fire dynamics in grass-invaded deserts.

PubMed

Fuentes-Ramirez, Andres; Veldman, Joseph W; Holzapfel, Claus; Moloney, Kirk A

2016-10-01

Novel fire regimes are an important cause and consequence of global environmental change that involve interactions among biotic, climatic, and human components of ecosystems. Plant flammability is key to these interactions, yet few studies directly measure flammability or consider how multiple species with different flammabilities interact to produce novel fire regimes. Deserts of the southwestern United States are an ideal system for exploring how novel fire regimes can emerge when fire-promoting species invade ecosystems comprised of species that did not evolve with fire. In these deserts, exotic annual grasses provide fuel continuity across landscapes that did not historically burn. These fires often ignite a keystone desert shrub, the fire-intolerant creosote bush, Larrea tridentata (DC.) Coville. Ignition of Larrea is likely catalyzed by fuels produced by native plants that grow beneath the shrubs. We hypothesize that invasive and native species exhibit distinct flammability characteristics that in combination determine spatial patterns of fire spread and intensity. We measured flammability metrics of Larrea, two invasive grasses, Schismus arabicus and Bromus madritensis, and two native plants, the sub-shrub Ambrosia dumosa and the annual herb Amsinckia menziesii. Results of laboratory experiments show that the grasses carry fire quickly (1.32 cm/s), but burn for short duration (0.5 min) at low temperatures. In contrast, native plants spread fire slowly (0.12 cm/s), but burn up to eight times longer (4 min) and produced hotter fires. Additional experiments on the ignition requirements of Larrea suggest that native plants burn with sufficient temperature and duration to ignite dead Larrea branches (time to ignition, 2 min; temperature at ignition 692°C). Once burning, these dead branches ignite living branches in the upper portions of the shrub. Our study provides support for a conceptual model in which exotic grasses are "spreaders" of fire and native plants growing beneath shrubs are "igniters" of dead Larrea branches. Once burning, flames produced by dead branches engulf the entire shrub, resulting in locally intense fires without historical precedent in this system. We suggest that fire models and conservation-focused management could be improved by incorporating the distinct flammability characteristics and spatial distributions of spreaders, igniters, and keystone shrubs. © 2016 by the Ecological Society of America.

Importance of transboundary transport of biomass burning emissions to regional air quality in Southeast Asia

NASA Astrophysics Data System (ADS)

Aouizerats, B.; van der Werf, G. R.; Balasubramanian, R.; Betha, R.

2014-05-01

Smoke from biomass and peat burning has a notable impact on ambient air quality and climate in the Southeast Asia (SEA) region. We modeled the largest fire-induced haze episode in the past decade (2006) in Indonesia using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). We focused mainly on the evolution of the fire plume composition and its interaction with the urbanized area of the city-state of Singapore, and on comparisons of modeled and measured aerosol and CO concentrations. Two simulations were run with the model using the complex Volatility Basis Set (VBS) scheme to reproduce primary and secondary aerosol evolution and concentration. The first simulation referred to as WRF-FIRE included anthropogenic, biogenic, and b iomass burning emissions from the Global Fire Emissions Database (GFED3) while the second simulation referred to as WRF-NOFIRE was run without emissions from biomass burning. To test model performance, we used three independent datasets for comparison including airborne measurements of Particulate Matter with a diameter of 10 μm or less (PM10) in Singapore, CO measurements in Sumatra, and Aerosol Optical Depth (AOD) column observations from 4 satellite-based sensors. We found reasonable agreement of the model runs with both ground-based measurements of CO and PM10. The comparison with AOD was less favorable and indicated the model underestimated AOD, although the degree of mismatch varied between different satellite data sets. During our study period, forest and peat fires in Sumatra were the main cause of enhanced aerosol concentrations from regional transport over Singapore. Analysis of the biomass burning plume showed high concentrations of primary organic aerosols (POA) with values up to 600 μg m-3 over the fire locations. The concentration of POA remained quite stable within the plume between the main burning region and Singapore while secondary organic aerosol (SOA) concentration slightly increased. The absolute values of SOA (up to 20 μg m-3) were much lower than those from POA, indicating a minor role of SOA in biomass burning plumes. Our results show that about 21% of the total mass loading of ambient PM10 during the July-October study period in Singapore was due to biomass and peat burning in Sumatra, but this contribution increased during high burning periods. In total, our model results indicated that during 35 days aerosol concentrations in Singapore were above the threshold of 50 μg m-3 day-1 indicating poor air quality. During 17 days this was due to fires, based on the difference between the simulations with and without fires. Local pollution in combination with recirculation of air masses was probably the main cause of poor air quality during the other 18 days, although fires from Sumatra and probably also from Borneo added to the enhanced PM10 concentrations. The model vs. measurement comparisons highlighted that for our study period and region the GFED3 biomass burning aerosol emissions were more in line with observations than found in other studies. This indicates that care should be taken when using AOD to constrain emissions or estimate ground-level air quality. This study also shows the need for relatively high resolution modeling to accurately reproduce the advection of air masses necessary to quantify the impacts and feedbacks on air quality.

Using RAQMS Chemical Transport Model, Aircraft In-situ and Satellite Data to Verify Ground-based Biomass Burning Emissions from the Extreme Fire Event in Boreal Alaska 2004

NASA Astrophysics Data System (ADS)

Soja, A. J.; Pierce, R. B.; Al-Saadi, J. A.; Alvarado, E.; Sandberg, D. V.; Ottmar, R. D.; Kittaka, C.; McMillian, W. W.; Sachse, G. W.; Warner, J. X.; Szykman, J. J.

2006-12-01

Current climate change scenarios are predicted to result in increased biomass burning, particularly in boreal regions. Biomass burning events feedback to the climate system by altering albedo (affecting the energy balance) and by direct and indirect fire emissions. Additionally, fire emissions influence air quality and human health downwind of burning. Biomass burning emission estimates are difficult to quantify in near-real-time and accurate estimates are useful for large-scale chemical transport models, which could be used to warn the public of potential health risks and for climate modeling. In this talk, we describe a methodology to quantify emissions, validate those emission estimates, transport the emissions and verify the resultant CO plume 100's of kilometers from the fire events using aircraft in-situ and satellite data. First, we developed carbon consumption estimates that are specifically designed for near-real-time use in conjunction with satellite-derived fire data for regional- to global-chemical transport models. Large-scale carbon consumption estimates are derived for 10 ecozones across North America and each zone contains 3 classes of severity. The estimates range is from a low severity 3.11 t C ha-1 estimate from the Western Taiga Shield to a high severity 59.83 t C ha-1 estimate from the Boreal Cordillera. These estimates are validated using extensive supplementary ground-based Alaskan data. Then, the RAQMS chemical transport model ingests these data and transports CO from the Alaskan 2004 fires across North America, where results are compared with in-situ flight CO data measured during INTEX-A and satellite-based CO data (AIRS and MOPITT). Ground-based CO is 6 to 14 times greater than the typically modeled fire climatology. RAQMS often overestimates CO in the biomass plumes in comparison to satellite- derived CO data and we suspect this may be due to the satellite instruments low sensitivity to planetary boundary layer CO, which is prevalent in the near field plumes, and also the assumption of high-severity fires throughout the burning season. RAQMS underestimates biomass CO in comparison to in-situ CO data (146 out of 148 ascents and descents), and we suspect this may be due to RAQMS difficulty in defining narrow fire plumes due to the 1.4° x 1.4° resolution.

Estimating future burned areas under changing climate in the EU-Mediterranean countries.

PubMed

Amatulli, Giuseppe; Camia, Andrea; San-Miguel-Ayanz, Jesús

2013-04-15

The impacts of climate change on forest fires have received increased attention in recent years at both continental and local scales. It is widely recognized that weather plays a key role in extreme fire situations. It is therefore of great interest to analyze projected changes in fire danger under climate change scenarios and to assess the consequent impacts of forest fires. In this study we estimated burned areas in the European Mediterranean (EU-Med) countries under past and future climate conditions. Historical (1985-2004) monthly burned areas in EU-Med countries were modeled by using the Canadian Fire Weather Index (CFWI). Monthly averages of the CFWI sub-indices were used as explanatory variables to estimate the monthly burned areas in each of the five most affected countries in Europe using three different modeling approaches (Multiple Linear Regression - MLR, Random Forest - RF, Multivariate Adaptive Regression Splines - MARS). MARS outperformed the other methods. Regression equations and significant coefficients of determination were obtained, although there were noticeable differences from country to country. Climatic conditions at the end of the 21st Century were simulated using results from the runs of the regional climate model HIRHAM in the European project PRUDENCE, considering two IPCC SRES scenarios (A2-B2). The MARS models were applied to both scenarios resulting in projected burned areas in each country and in the EU-Med region. Results showed that significant increases, 66% and 140% of the total burned area, can be expected in the EU-Med region under the A2 and B2 scenarios, respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

PyrE, an interactive fire module within the NASA-GISS Earth System Model

NASA Astrophysics Data System (ADS)

Mezuman, K.; Bauer, S. E.; Tsigaridis, K.

2017-12-01

Fires directly affect the composition of the atmosphere and Earth's radiation balance by emitting a suite of reactive gases and particles. Having an interactive fire module in an Earth System Model allows us to study the natural and anthropogenic drivers, feedbacks, and interactions of biomass burning in different time periods. To do so we have developed PyrE, the NASA-GISS interactive fire emissions model. PyrE uses the flammability, ignition, and suppression parameterization proposed by Pechony and Shindell (2009), and is coupled to a burned area and surface recovery parameterization. The burned area calculation follows CLM's approach (Li et al., 2012), paired with an offline recovery scheme based on Ent's Terrestrial Biosphere Model (Ent TBM) carbon pool turnover time. PyrE is driven by environmental variables calculated by climate simulations, population density data, MODIS fire counts and LAI retrievals, as well as GFED4s emissions. Since the model development required extensive use of reference datasets, in addition to comparing it to GFED4s BA, we evaluate it by studying the effect of fires on atmospheric composition and climate. Our results show good agreement globally, with some regional differences. Finally, we quantify the present day fire radiative forcing. The development of PyrE allowed us for the first time to interactively simulate climate and fire activity with GISS-ModelE3

Permafrost as an additional driving factor for the extreme fire event in the boreal Baikal region in 2003

NASA Astrophysics Data System (ADS)

Forkel, M.; Thonicke, K.; Beer, C.; Cramer, W.; Bartalev, S.; Schmullius, C.

2012-04-01

Wildfires are a natural and important element in the functioning of boreal forests. However, in some years, fires with extreme spread and severity occur. Such severe fires degrade the forest, affect human values, emit huge amount of carbon and aerosols and alter the land surface albedo. Usually, wind, slope, and dry conditions have been recognized as factors determining fire spread. In the Baikal region, 127,000 km2 burned in 2003, while the annual average burned area is approx. 8100 km2. In average years, 16% of the burned area occurred in the continuous permafrost zone but in 2003, 33% of these burned areas coincide with the existence of permanently frozen grounds. Permafrost and the associated upper active layer, which thaws during summer and refreezes during winter, is an important supply for soil moisture in boreal ecosystems. This leads to the question if permafrost hydrology is a potential additional driving factor for extreme fire events in boreal forests. Using temperature and precipitation data, we calculated the Nesterov index as indicator for fire weather conditions. Further, we used satellite observations of burned area and surface moisture, a digital elevation model, a land cover and a permafrost map to evaluate drivers for the temporal dynamic and spatial variability of surface moisture conditions and burned area in spring 2003. On the basis of time series decomposition, we separated the effect of drivers for fire activity on different time scales. We next computed cross-correlations to identify potential time lags between weather conditions, surface moisture and fire activity. Finally, we assessed the predictive capability of different combinations of driving variables for surface moisture conditions and burned area using multivariate spatial-temporal regression models. The results from this study demonstrate that permafrost in larch-dominated ecosystems regulates the inter-annual variability of surface moisture and thus increases the inter-annual variability of burned area. The drought conditions in spring 2003 were accelerated by the presence of permafrost because less water was stored in the upper active layer from the dry previous summer 2002 and the permafrost table prevents vegetative water uptake from deeper layers. In contrast, weather conditions (precipitation anomaly, Nesterov index) are weaker predictors for the 2003 fire event. Our analysis advances the understanding of complex interactions between the atmosphere, vegetation and soil on how feedback mechanisms can lead to extreme fire events. These findings emphasize the importance of a mechanistic coupling of soil thermodynamics, hydrology, and fire activity in earth system models for projecting climate change impacts over the next century.

A data-driven approach to identify controls on global fire activity from satellite and climate observations (SOFIA V1)

NASA Astrophysics Data System (ADS)

Forkel, Matthias; Dorigo, Wouter; Lasslop, Gitta; Teubner, Irene; Chuvieco, Emilio; Thonicke, Kirsten

2017-12-01

Vegetation fires affect human infrastructures, ecosystems, global vegetation distribution, and atmospheric composition. However, the climatic, environmental, and socioeconomic factors that control global fire activity in vegetation are only poorly understood, and in various complexities and formulations are represented in global process-oriented vegetation-fire models. Data-driven model approaches such as machine learning algorithms have successfully been used to identify and better understand controlling factors for fire activity. However, such machine learning models cannot be easily adapted or even implemented within process-oriented global vegetation-fire models. To overcome this gap between machine learning-based approaches and process-oriented global fire models, we introduce a new flexible data-driven fire modelling approach here (Satellite Observations to predict FIre Activity, SOFIA approach version 1). SOFIA models can use several predictor variables and functional relationships to estimate burned area that can be easily adapted with more complex process-oriented vegetation-fire models. We created an ensemble of SOFIA models to test the importance of several predictor variables. SOFIA models result in the highest performance in predicting burned area if they account for a direct restriction of fire activity under wet conditions and if they include a land cover-dependent restriction or allowance of fire activity by vegetation density and biomass. The use of vegetation optical depth data from microwave satellite observations, a proxy for vegetation biomass and water content, reaches higher model performance than commonly used vegetation variables from optical sensors. We further analyse spatial patterns of the sensitivity between anthropogenic, climate, and vegetation predictor variables and burned area. We finally discuss how multiple observational datasets on climate, hydrological, vegetation, and socioeconomic variables together with data-driven modelling and model-data integration approaches can guide the future development of global process-oriented vegetation-fire models.

The BlueSky Smoke Modeling Framework: Recent Developments

NASA Astrophysics Data System (ADS)

Sullivan, D. C.; Larkin, N.; Raffuse, S. M.; Strand, T.; ONeill, S. M.; Leung, F. T.; Qu, J. J.; Hao, X.

2012-12-01

BlueSky systems—a set of decision support tools including SmartFire and the BlueSky Framework—aid public policy decision makers and scientific researchers in evaluating the air quality impacts of fires. Smoke and fire managers use BlueSky systems in decisions about prescribed burns and wildland firefighting. Air quality agencies use BlueSky systems to support decisions related to air quality regulations. We will discuss a range of recent improvements to the BlueSky systems, as well as examples of applications and future plans. BlueSky systems have the flexibility to accept basic fire information from virtually any source and can reconcile multiple information sources so that duplication of fire records is eliminated. BlueSky systems currently apply information from (1) the National Oceanic and Atmospheric Administration's (NOAA) Hazard Mapping System (HMS), which represents remotely sensed data from the Moderate Resolution Imaging Spectroradiometer (MODIS), Advanced Very High Resolution Radiometer (AVHRR), and Geostationary Operational Environmental Satellites (GOES); (2) the Monitoring Trends in Burn Severity (MTBS) interagency project, which derives fire perimeters from Landsat 30-meter burn scars; (3) the Geospatial Multi-Agency Coordination Group (GeoMAC), which produces helicopter-flown burn perimeters; and (4) ground-based fire reports, such as the ICS-209 reports managed by the National Wildfire Coordinating Group. Efforts are currently underway to streamline the use of additional ground-based systems, such as states' prescribed burn databases. BlueSky systems were recently modified to address known uncertainties in smoke modeling associated with (1) estimates of biomass consumption derived from sparse fuel moisture data, and (2) models of plume injection heights. Additional sources of remotely sensed data are being applied to address these issues as follows: - The National Aeronautics and Space Administration's (NASA) Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis Real-Time (TMPA-RT) data set is being used to improve dead fuel moisture estimates. - EastFire live fuel moisture estimates, which are derived from NASA's MODIS direct broadcast, are being used to improve live fuel moisture estimates. - NASA's Multi-angle Imaging Spectroradiometer (MISR) stereo heights are being used to improve estimates of plume injection heights. Further, the Fire Location and Modeling of Burning Emissions (FLAMBÉ) model was incorporated into the BlueSky Framework as an alternative means of calculating fire emissions. FLAMBÉ directly estimates emissions on the basis of fire detections and radiance measures from NASA's MODIS and NOAA's GOES satellites. (The authors gratefully acknowledge NASA's Applied Sciences Program [Grant Nos. NN506AB52A and NNX09AV76G)], the USDA Forest Service, and the Joint Fire Science Program for their support.)

An evaluation of the uncertainties in biomass burning emissions

NASA Astrophysics Data System (ADS)

Yano, A.; Garcia Menendez, F.; Hu, Y.; Odman, M.

2012-12-01

The contribution of biomass burning emissions to the atmospheric loads of gases and aerosols can lead to major air quality problems and have significant climate impacts. Whether from wildfires, natural or human-induced, or controlled burns, biomass burning emissions are an important source of air pollutants regionally in certain parts of the world as well as globally. There are two common ways of estimating biomass burning emissions: by using either ground-based information or satellite observations. When there is sufficient local information about the burn area, the types of fuels and their consumption amounts, and the progression of the fire, ground-based estimation is preferred. For controlled burns a.k.a. prescribed burns and wildfires in places where land management is practiced to a certain extent there is typically sufficient ground-based information for emissions estimation. However, for remote regions where no ground-based information is available on the size, intensity, or the spread of the fire, estimates based on satellite observations are preferred. For example, burn location, size and timing information can be obtained from satellite retrievals of thermal anomalies and fuel loading information can be obtained from satellite products of vegetation cover. In both cases, reasonable emission estimates for a variety of pollutants can be obtained by using emission factors (mass of pollutant released per unit mass of fuel consumed) derived from field or laboratory studies. Here, emissions from a controlled burn and a wildfire are estimated using both ground-based information and satellite observations. The controlled burn was conducted on 17 November 2009 near Santa Barbara, California over 80 ha of land covered with chaparral. An aircraft tracked the smoke plume and measured CO2, light scattering, as well as meteorological parameters during the burn (Akagi et al., 2011). The wildfire is from the summer of 2008 when tens of thousands hectares of wild land burned in Northern California causing unprecedented damage. NASA Aircraft commissioned for the ARCTAS campaign at the time flew over the fires and collected data detailing composition of gases and aerosols in the fire plumes (Singh et al., 2012). We model the fires using a newly developed system consisting of a plume rise and dispersion model specifically designed for wild-land fire plumes (Daysmoke; Achtemeier et al., 2011) coupled with a regional-scale chemistry-transport model (CMAQ). Wind fields generated by a weather prediction model (WRF) are adjusted locally to match the aircraft measurements of wind speed and direction. The fires are simulated using both ground-based and satellite-based estimates of emissions. Predicted concentrations of gases and aerosols are compared to corresponding aircraft measurements. Satellite retrievals of aerosol optical depth are also used in evaluating model predictions. The new modeling system along with the wind adjustments reduces several of the uncertainties inherent to regional-scale modeling of plume transport. This allows for a more reliable analysis of the uncertainties related to emissions. Uncertainties in the magnitudes and timings of emissions, and in plume injection heights with respect to boundary layer heights are investigated. Uncertainties associated with ground-based and satellite-based emissions estimation methods are compared to each other.

Lessons from the fires of 2000: Post-fire heterogeneity in ponderosa pine forests

USGS Publications Warehouse

Kotliar, Natasha B.; Haire, Sandra L.; Key, Carl H.; Omni, Phillip N.; Joyce, Linda A.

2003-01-01

We evaluate burn-severity patterns for six burns that occurred in the southern Rocky Mountains and the Colorado Plateau in 2000. We compare the results of two data sources: Burned Area Rehabilitations Teams (BAER) and a spatial burnseverity model derived from satellite imagery (the Normalized Burn Ratio; NBR). BAER maps tended to overestimate area of severe burns and underestimate area of moderate-severity burns relative to NBR maps. Low elevation and more southern ponderosa pine burns were predominantly understory burns, whereas burns at higher elevations and farther north had a greater component of high-severity burns. Thus, much, if not most, of the area covered by these burns appears to be consistent with historic burns and contributes to healthy functioning ecosystems.

Land cover change interacts with drought severity to change fire regimes in Western Amazonia.

PubMed

Gutiérrez-Vélez, Víctor H; Uriarte, María; DeFries, Ruth; Pinedo-Vásquez, Miguel; Fernandes, Katia; Ceccato, Pietro; Baethgen, Walter; Padoch, Christine

Fire is becoming a pervasive driver of environmental change in Amazonia and is expected to intensify, given projected reductions in precipitation and forest cover. Understanding of the influence of post-deforestation land cover change on fires in Amazonia is limited, even though fires in cleared lands constitute a threat for ecosystems, agriculture, and human health. We used MODIS satellite data to map burned areas annually between 2001 and 2010. We then combined these maps with land cover and climate information to understand the influence of land cover change in cleared lands and dry-season severity on fire occurrence and spread in a focus area in the Peruvian Amazon. Fire occurrence, quantified as the probability of burning of individual 232-m spatial resolution MODIS pixels, was modeled as a function of the area of land cover types within each pixel, drought severity, and distance to roads. Fire spread, quantified as the number of pixels burned in 3 × 3 pixel windows around each focal burned pixel, was modeled as a function of land cover configuration and area, dry-season severity, and distance to roads. We found that vegetation regrowth and oil palm expansion are significantly correlated with fire occurrence, but that the magnitude and sign of the correlation depend on drought severity, successional stage of regrowing vegetation, and oil palm age. Burning probability increased with the area of nondegraded pastures, fallow, and young oil palm and decreased with larger extents of degraded pastures, secondary forests, and adult oil palm plantations. Drought severity had the strongest influence on fire occurrence, overriding the effectiveness of secondary forests, but not of adult plantations, to reduce fire occurrence in severely dry years. Overall, irregular and scattered land cover patches reduced fire spread but irregular and dispersed fallows and secondary forests increased fire spread during dry years. Results underscore the importance of land cover management for reducing fire proliferation in this landscape. Incentives for promoting natural regeneration and perennial crops in cleared lands might help to reduce fire risk if those areas are protected against burning in early stages of development and during severely dry years.

Simulating high spatial resolution high severity burned area in Sierra Nevada forests for California Spotted Owl habitat climate change risk assessment and management.

NASA Astrophysics Data System (ADS)

Keyser, A.; Westerling, A. L.; Jones, G.; Peery, M. Z.

2017-12-01

Sierra Nevada forests have experienced an increase in very large fires with significant areas of high burn severity, such as the Rim (2013) and King (2014) fires, that have impacted habitat of endangered species such as the California spotted owl. In order to support land manager forest management planning and risk assessment activities, we used historical wildfire histories from the Monitoring Trends in Burn Severity project and gridded hydroclimate and land surface characteristics data to develope statistical models to simulate the frequency, location and extent of high severity burned area in Sierra Nevada forest wildfires as functions of climate and land surface characteristics. We define high severity here as BA90 area: the area comprising patches with ninety percent or more basal area killed within a larger fire. We developed a system of statistical models to characterize the probability of large fire occurrence, the probability of significant BA90 area present given a large fire, and the total extent of BA90 area in a fire on a 1/16 degree lat/lon grid over the Sierra Nevada. Repeated draws from binomial and generalized pareto distributions using these probabilities generated a library of simulated histories of high severity fire for a range of near (50 yr) future climate and fuels management scenarios. Fuels management scenarios were provided by USFS Region 5. Simulated BA90 area was then downscaled to 30 m resolution using a statistical model we developed using Random Forest techniques to estimate the probability of adjacent 30m pixels burning with ninety percent basal kill as a function of fire size and vegetation and topographic features. The result is a library of simulated high resolution maps of BA90 burned areas for a range of climate and fuels management scenarios with which we estimated conditional probabilities of owl nesting sites being impacted by high severity wildfire.

Tundra fire disturbance homogonizes belowground food web structure, function and dynamics

NASA Astrophysics Data System (ADS)

Moore, J. C.; Pressler, Y.; Koltz, A.; Asmus, A.; Simpson, R.

2016-12-01

Tundra fires on Alaska's North Slope are on the rise due to increased lightning strikes since 2000. On July 16, 2007 lightning ignited the Anaktuvuk River fire, burning a 40-by-10 mile swath of tundra about 24 miles north of Toolik Field Station. The fire burned 401 square miles, was visible from space, and released more than 2.3 million tons of carbon into the atmosphere. A large amount of the organic layer of the soil was burned, changing the over all composition of the site and exposing deeper soil horizons. Due to fundamental transitions in soil characteristics and vegetation we hypothesized that the belowground food web community would be affected both in terms of biomass and location within the soil profile. Microbial biomass was reduced with burn severity. In the lower organic horizon there was a significant reduction in fungal biomass but we did not observe this effect in the upper organic soil. We did not observe a significant effect of burn severity on individual group biomass within higher trophic levels. Canonical Discriminant Analysis using the biomass estimates of the functional groups in the food webs found that the webs are becoming increasingly homogenized in the severely burned site compared to the moderately burned and unburned sites. The unburned soils differed significantly from soil at both burn sites; the greatest effects on food web structure were at the lower organic depth, whereas. We modeled the effects of the fire on soil organic matter processing rates and energy flow through the three food webs. The model estimated a decrease in C and N mineralization with fire severity, due in large part to the loss of organic material. While the organic horizon at the unburned site had 12 times greater C and N mineralization than the mineral soils, we observed little to no difference in C and N mineralization between the organic and mineral soil horizons in the moderately and severely burned sites. Our results show that the fire significantly altered the trophic structure of the soil food web, with loss of trophic complexity with increasing fire severity, which correlated strongly with C and N processing and food web stability.

Mapping burned areas using dense time-series of Landsat data

USGS Publications Warehouse

Hawbaker, Todd J.; Vanderhoof, Melanie; Beal, Yen-Ju G.; Takacs, Joshua; Schmidt, Gail L.; Falgout, Jeff T.; Williams, Brad; Brunner, Nicole M.; Caldwell, Megan K.; Picotte, Joshua J.; Howard, Stephen M.; Stitt, Susan; Dwyer, John L.

2017-01-01

Complete and accurate burned area data are needed to document patterns of fires, to quantify relationships between the patterns and drivers of fire occurrence, and to assess the impacts of fires on human and natural systems. Unfortunately, in many areas existing fire occurrence datasets are known to be incomplete. Consequently, the need to systematically collect burned area information has been recognized by the United Nations Framework Convention on Climate Change and the Intergovernmental Panel on Climate Change, which have both called for the production of essential climate variables (ECVs), including information about burned area. In this paper, we present an algorithm that identifies burned areas in dense time-series of Landsat data to produce the Landsat Burned Area Essential Climate Variable (BAECV) products. The algorithm uses gradient boosted regression models to generate burn probability surfaces using band values and spectral indices from individual Landsat scenes, lagged reference conditions, and change metrics between the scene and reference predictors. Burn classifications are generated from the burn probability surfaces using pixel-level thresholding in combination with a region growing process. The algorithm can be applied anywhere Landsat and training data are available. For this study, BAECV products were generated for the conterminous United States from 1984 through 2015. These products consist of pixel-level burn probabilities for each Landsat scene, in addition to, annual composites including: the maximum burn probability and a burn classification. We compared the BAECV burn classification products to the existing Global Fire Emissions Database (GFED; 1997–2015) and Monitoring Trends in Burn Severity (MTBS; 1984–2013) data. We found that the BAECV products mapped 36% more burned area than the GFED and 116% more burned area than MTBS. Differences between the BAECV products and the GFED were especially high in the West and East where the BAECV products mapped 32% and 88% more burned area, respectively. However, the BAECV products found less burned area than the GFED in regions with frequent agricultural fires. Compared to the MTBS data, the BAECV products identified 31% more burned area in the West, 312% more in the Great Plains, and 233% more in the East. Most pixels in the MTBS data were detected by the BAECV, regardless of burn severity. The BAECV products document patterns of fire similar to those in the GFED but also showed patterns of fire that are not well characterized by the existing MTBS data. We anticipate the BAECV products will be useful to studies that seek to understand past patterns of fire occurrence, the drivers that created them, and the impacts fires have on natural and human systems.

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.

Transboundary Transport of Biomass Burning Emissions in Southeast Asia and Contribution to Local Air Quality During the 2006 Fire Event

NASA Astrophysics Data System (ADS)

Aouizerats, B.; van der Werf, G.; Balasubramanian, R.; Betha, R.

2014-12-01

Smoke from biomass and peat burning has a notable impact on ambient air quality and climate in the Southeast Asia (SEA) region. We modeled the largest fire-induced haze episode in the past decade (2006) that originated in Indonesia using WRF-Chem. Our study addressed 3 research questions: (1) Can the WRF-Chem model reproduce observations of both aerosol and CO concentrations in this complex region? (2) What is the evolution in the chemical composition of the aerosol fire plume during its atmospheric transport? and (3) What is the relative contribution of these fires to air quality in the urbanized area of the city-state of Singapore? To test model performance, we used three independent datasets for comparison (PM10 in Singapore, CO measurements in Sumatra, and AOD column observations from 4 satellite-based sensors). We found reasonable agreement of the model runs with ground-based measurements of both CO and PM10. However, the comparison with AOD was less favorable and indicated the model underestimated AOD. In the past, modeling studies using only AOD as a constraint have often boosted fire emissions to get a better agreement with observations. In our case, this approach would seriously deteriorate the difference with ground-based observations. Finally, our results show that about 21% of the total mass loading of ambient PM10 during the July-October study period in Singapore was due to the influence of biomass and peat burning in Sumatra, with an increased contribution during high burning periods. The composition of this biomass burning plume was largely dominated by primary organic carbon. In total, our model results indicated that during 35 days aerosol concentrations in Singapore were above the threshold of 50 μg m-3 day-1 (WHO threshold). During 17 days this deterioration was due to Indonesian fires, based on the difference between the simulations with and without fires. Local air pollution in combination with recirculation of air masses was probably the main cause of the lack of good air quality during the other 18 days. This finding is mostly due to the relatively fine scale of our model set-up; coarser resolution models would have likely attributed the increased aerosol loads to burning in Borneo from which plumes were advected close to Singapore, but did not contribute to local pollution according to our model.

Prescribed fire applications in Forest and Woodlands: Integration of models and field studies to guide fire use

Treesearch

Kevin C. Ryan; Eric Rigolot; Francisco C. Rego; Herminio Botelho; Jose A. Vega; Paulo M. Fernandes; Tatiana M. Sofronova

2010-01-01

Globally prescribed burning is widely used for agro-forestry, restoration, and conservation to modify species composition and stand structure. Commonly stated goals of prescribed burns include to reduce hazardous fuels, improve species’ habitat, reduce the potential for severe fires in the wildland urban interface or protect municipal watersheds. Treatments may focus...

Modeling relationships among 217 fires using remote sensing of burn severity in southern pine forests

Treesearch

Sparkle L. Malone; Leda N. Kobziar; Christina L. Staudhammer; Amr Abd-Elrahman

2011-01-01

Pine flatwoods forests in the southeastern US have experienced severe wildfires over the past few decades, often attributed to fuel load build-up. These forest communities are fire dependent and require regular burning for ecosystem maintenance and health. Although prescribed fire has been used to reduce wildfire risk and maintain ecosystem integrity, managers are...

Comparative Evaluation of Five Fire Emissions Datasets Using the GEOS-5 Model

NASA Astrophysics Data System (ADS)

Ichoku, C. M.; Pan, X.; Chin, M.; Bian, H.; Darmenov, A.; Ellison, L.; Kucsera, T. L.; da Silva, A. M., Jr.; Petrenko, M. M.; Wang, J.; Ge, C.; Wiedinmyer, C.

2017-12-01

Wildfires and other types of biomass burning affect most vegetated parts of the globe, contributing 40% of the annual global atmospheric loading of carbonaceous aerosols, as well as significant amounts of numerous trace gases, such as carbon dioxide, carbon monoxide, and methane. Many of these smoke constituents affect the air quality and/or the climate system directly or through their interactions with solar radiation and cloud properties. However, fire emissions are poorly constrained in global and regional models, resulting in high levels of uncertainty in understanding their real impacts. With the advent of satellite remote sensing of fires and burned areas in the last couple of decades, a number of fire emissions products have become available for use in relevant research and applications. In this study, we evaluated five global biomass burning emissions datasets, namely: (1) GFEDv3.1 (Global Fire Emissions Database version 3.1); (2) GFEDv4s (Global Fire Emissions Database version 4 with small fires); (3) FEERv1 (Fire Energetics and Emissions Research version 1.0); (4) QFEDv2.4 (Quick Fire Emissions Dataset version 2.4); and (5) Fire INventory from NCAR (FINN) version 1.5. Overall, the spatial patterns of biomass burning emissions from these inventories are similar, although the magnitudes of the emissions can be noticeably different. The inventories derived using top-down approaches (QFEDv2.4 and FEERv1) are larger than those based on bottom-up approaches. For example, global organic carbon (OC) emissions in 2008 are: QFEDv2.4 (51.93 Tg), FEERv1 (28.48 Tg), FINN v1.5 (19.48 Tg), GFEDv3.1 (15.65 Tg) and GFEDv4s (13.76 Tg); representing a factor of 3.7 difference between the largest and the least. We also used all five biomass-burning emissions datasets to conduct aerosol simulations using the NASA Goddard Earth Observing System Model, Version 5 (GEOS-5), and compared the resulting aerosol optical depth (AOD) output to the corresponding retrievals from MODIS and AERONET. Simulated AOD based on all five emissions inventories show significant underestimation in biomass burning dominated regions. Attributions of possible factors responsible for the differences among the inventories were further explored in Southern Africa and South America, two of the major biomass burning regions of the world.

Inundation and Fire Shape the Structure of Riparian Forests in the Pantanal, Brazil

PubMed Central

Arruda, Wellinton de Sá; Oldeland, Jens; Paranhos Filho, Antonio Conceição; Pott, Arnildo; Cunha, Nicolay L.; Ishii, Iria Hiromi; Damasceno-Junior, Geraldo Alves

2016-01-01

Inundation and fire can affect the structure of riparian vegetation in wetlands. Our aim was to verify if there are differences in richness, abundance, basal area, composition and topographic preference of woody species in riparian forests related to the fire history, flooding duration, or the interaction between both. The study was conducted in the riparian forests of the Paraguay River some of which were burned three times between 2001 and 2011. We sampled trees with a girth of at least 5 cm at breast height in 150 5 × 10 m plots (79 burned and 71 unburned). We also measured height of the flood mark and estimated the flooding duration of each plot. We performed Generalized Linear Mixed Models to verify differences in richness, basal area, and abundance of individuals associated to interaction of fire and inundation. We used an analysis of similarity (ANOSIM) and indicator species analysis to identify differences in composition of species and the association with burned and unburned area according to different levels of inundation. Finally, we used a hierarchical set of Generalized Linear Models (GLM), the so-called HOF models, to analyse each species’ specific response to inundation based on topography and to determine their preferred optimal topographic position for both burned as well as unburned areas. Richness was positively associated with elevation only in burned areas while abundance was negatively influenced by inundation only in burned areas. Basal area was negatively associated with time of inundation independent of fire history. There were 15 species which were significant indicators for at least one combination of the studied factors. We found nine species in burned areas and 15 in unburned areas, with response curves in HOF models along the inundation gradient. From these, five species shifted their optimal position along the inundation gradient in burned areas. The interaction of fire and inundation did not appear to affect the basal area, but it did affect the richness, number of individuals, success of some species, and seemed to shape the boundary of these forests as shown by the difference in the positioning of these species along the inundation gradient. PMID:27280879

Inundation and Fire Shape the Structure of Riparian Forests in the Pantanal, Brazil.

PubMed

Arruda, Wellinton de Sá; Oldeland, Jens; Paranhos Filho, Antonio Conceição; Pott, Arnildo; Cunha, Nicolay L; Ishii, Iria Hiromi; Damasceno-Junior, Geraldo Alves

2016-01-01

Inundation and fire can affect the structure of riparian vegetation in wetlands. Our aim was to verify if there are differences in richness, abundance, basal area, composition and topographic preference of woody species in riparian forests related to the fire history, flooding duration, or the interaction between both. The study was conducted in the riparian forests of the Paraguay River some of which were burned three times between 2001 and 2011. We sampled trees with a girth of at least 5 cm at breast height in 150 5 × 10 m plots (79 burned and 71 unburned). We also measured height of the flood mark and estimated the flooding duration of each plot. We performed Generalized Linear Mixed Models to verify differences in richness, basal area, and abundance of individuals associated to interaction of fire and inundation. We used an analysis of similarity (ANOSIM) and indicator species analysis to identify differences in composition of species and the association with burned and unburned area according to different levels of inundation. Finally, we used a hierarchical set of Generalized Linear Models (GLM), the so-called HOF models, to analyse each species' specific response to inundation based on topography and to determine their preferred optimal topographic position for both burned as well as unburned areas. Richness was positively associated with elevation only in burned areas while abundance was negatively influenced by inundation only in burned areas. Basal area was negatively associated with time of inundation independent of fire history. There were 15 species which were significant indicators for at least one combination of the studied factors. We found nine species in burned areas and 15 in unburned areas, with response curves in HOF models along the inundation gradient. From these, five species shifted their optimal position along the inundation gradient in burned areas. The interaction of fire and inundation did not appear to affect the basal area, but it did affect the richness, number of individuals, success of some species, and seemed to shape the boundary of these forests as shown by the difference in the positioning of these species along the inundation gradient.

Edge-preserving data assimilation for fire monitoring using optical data

NASA Astrophysics Data System (ADS)

Gomez-Dans, Jose; Lewis, Philip; Disney, Mathias; Roy, David; Quaife, Tristan; Wooster, Martin

2013-04-01

Monitoring fire using optical data from moderate spatial resolution sensors is in essence a change detection process, where changes in reflectance (or a vegetation index) within two dates or periods are interpreted as fires if the change meets a number of spectral rules. A major challenge in any of these algorithms is accounting for angular effects due to different acquistion/illumination geometry. The MODIS Coll5 algorithm for example, uses linear kernel models to forward predict observations, and based on a statistical test, decides whether a change has occurred and labels it as a potential fire. While the algorithm is successful in many regions, it has problems dealing with cloudy periods, and with limitations in the available observations. In this work, we propose a new approach based on (i) a more advanced signal tracking method using edge-preserving data assimilation techniques and (ii) an interpretation of the change signal using a spectral linear model. The signal tracking approach uses linear kernel models, but solves for them using regularisation in time as a prior. This allows for a transfer of information from data rich periods to other periods where data may be more sparse. To minimise information leaking over the actual fire, we implement an edge-preserving mechanism that limits the information transfer over the disturbance. The result of this is a complete time series of surface reflectance acquired with a constant geometry. Note that the system provides complete uncertainty estimates of the parameters, taking into account the initial level of uncertainty in the observations of surface reflectance. A second stage interprets post-fire reflectance as a mixture of a "typical burn signal" and an unburned component, which we assume to be the pre-fire reflectance. We propose a simple spectral model for the burn signal, a constrained quadratic function. This model is appropriate for a number of burned material spectrum. We demonstrate using the MODIS burned area product that the approach provides useful complementary information about fires, describing the spectral nature of the burn signal, as well as providing information on potentially the impact of the fire in the pixel. Both approaches are then combined into a multispectral burned area algorithm with MODIS land surface observations. We test the performance of the proposed method, compare to other well-established products, and show some of the shortcomings of the proposed algorithm.

Rapid Response Tools and Datasets for Post-fire Erosion Modeling: Lessons Learned from the Rock House and High Park Fires

NASA Astrophysics Data System (ADS)

Miller, Mary Ellen; Elliot, William E.; MacDonald, Lee H.

2013-04-01

Once the danger posed by an active wildfire has passed, land managers must rapidly assess the threat from post-fire runoff and erosion due to the loss of surface cover and fire-induced changes in soil properties. Increased runoff and sediment delivery are of great concern to both the pubic and resource managers. Post-fire assessments and proposals to mitigate these threats are typically undertaken by interdisciplinary Burned Area Emergency Response (BAER) teams. These teams are under very tight deadlines, so they often begin their analysis while the fire is still burning and typically must complete their plans within a couple of weeks. Many modeling tools and datasets have been developed over the years to assist BAER teams, but process-based, spatially explicit models are currently under-utilized relative to simpler, lumped models because they are more difficult to set up and require the preparation of spatially-explicit data layers such as digital elevation models, soils, and land cover. The difficulty of acquiring and utilizing these data layers in spatially-explicit models increases with increasing fire size. Spatially-explicit post-fire erosion modeling was attempted for a small watershed in the 1270 km2 Rock House fire in Texas, but the erosion modeling work could not be completed in time. The biggest limitation was the time required to extract the spatially explicit soils data needed to run the preferred post-fire erosion model (GeoWEPP with Disturbed WEPP parameters). The solution is to have the spatial soil, land cover, and DEM data layers prepared ahead of time, and to have a clear methodology for the BAER teams to incorporate these layers in spatially-explicit modeling interfaces like GeoWEPP. After a fire occurs the data layers can quickly be clipped to the fire perimeter. The soil and land cover parameters can then be adjusted according to the burn severity map, which is one of the first products generated for the BAER teams. Under a previous project for the U.S. Environmental Protection Agency this preparatory work was done for much of Colorado, and in June 2012 the High Park wildfire in north central Colorado burned over 340 km2. The data layers for the entire burn area were quickly assembled and the spatially explicit runoff and erosion modeling was completed in less than three days. The resulting predictions were then used by the BAER team to quantify downstream risks and delineate priority areas for different post-fire treatments. These two contrasting case studies demonstrate the feasibility and the value of preparing datasets and modeling tools ahead of time. In recognition of this, the U.S. National Aeronautic and Space Administration has agreed to fund a pilot project to demonstrate the utility of acquiring and preparing the necessary data layers for fire-prone wildlands across the western U.S. A similar modeling and data acquisition approach could be followed

Variable carbon losses from recurrent fires in drained tropical peatlands.

PubMed

Konecny, Kristina; Ballhorn, Uwe; Navratil, Peter; Jubanski, Juilson; Page, Susan E; Tansey, Kevin; Hooijer, Aljosja; Vernimmen, Ronald; Siegert, Florian

2016-04-01

Tropical peatland fires play a significant role in the context of global warming through emissions of substantial amounts of greenhouse gases. However, the state of knowledge on carbon loss from these fires is still poorly developed with few studies reporting the associated mass of peat consumed. Furthermore, spatial and temporal variations in burn depth have not been previously quantified. This study presents the first spatially explicit investigation of fire-driven tropical peat loss and its variability. An extensive airborne Light Detection and Ranging data set was used to develop a prefire peat surface modelling methodology, enabling the spatially differentiated quantification of burned area depth over the entire burned area. We observe a strong interdependence between burned area depth, fire frequency and distance to drainage canals. For the first time, we show that relative burned area depth decreases over the first four fire events and is constant thereafter. Based on our results, we revise existing peat and carbon loss estimates for recurrent fires in drained tropical peatlands. We suggest values for the dry mass of peat fuel consumed that are 206 t ha(-1) for initial fires, reducing to 115 t ha(-1) for second, 69 t ha(-1) for third and 23 t ha(-1) for successive fires, which are 58-7% of the current IPCC Tier 1 default value for all fires. In our study area, this results in carbon losses of 114, 64, 38 and 13 t C ha(-1) for first to fourth fires, respectively. Furthermore, we show that with increasing proximity to drainage canals both burned area depth and the probability of recurrent fires increase and present equations explaining burned area depth as a function of distance to drainage canal. This improved knowledge enables a more accurate approach to emissions accounting and will support IPCC Tier 2 reporting of fire emissions. © 2015 John Wiley & Sons Ltd.

A Five- Year CMAQ Model Performance for Wildfires and Prescribed Fires

EPA Science Inventory

Biomass burning has been identified as an important contributor to the degradation of air quality because of its impact on ozone and particulate matter. Two components of the biomass burning inventory, wildfires and prescribed fires are routinely estimated in the national emissio...

Burning rate of solid wood measured in a heat release rate calorimeter

Treesearch

H. C. Tran; R. H. White

1992-01-01

Burning rate is a key factor in modeling fire growth and fire endurance of wood structures. This study investigated the burning rate of selected wood materials as determined by heat release, mass loss and charring rates. Thick samples of redwood, southern pine, red oak and basswood were tested in a heat release rate calorimeter. Results on ignitability and average beat...

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.

Modeling prescribed burning experiments and assessing the fire impacts on local to regional air quality

NASA Astrophysics Data System (ADS)

Zhou, L.; Baker, K. R.; Napelenok, S. L.; Elleman, R. A.; Urbanski, S. P.

2016-12-01

Biomass burning, including wildfires and prescribed burns, strongly impact the global carbon cycle and are of increasing concern due to the potential impacts on ambient air quality. This modelling study focuses on the evolution of carbonaceous compounds during a prescribed burning experiment and assesses the impacts of burning on local to regional air quality. The Community Multiscale Air Quality (CMAQ) model is used to conduct 4 and 2 km grid resolution simulations of prescribed burning experiments in southeast Washington state and western Idaho state in summer 2013. The ground and airborne measurements from the field experiment are used to evaluate the model performance in capturing surface and aloft impacts from the burning events. Phase partitioning of organic compounds in the plume are studied as it is a crucial step towards understanding the fate of carbonaceous compounds. The sensitivities of ambient concentrations and deposition to emissions are conducted for organic carbon, elemental carbon and ozone to estimate the impacts of fire on air quality.

Burn Severity and Its Impact on Soil Properties: 2016 Erskine Fire in the Southern Sierra Nevada

NASA Astrophysics Data System (ADS)

Haake, S.; Guo, J.; Krugh, W. C.

2017-12-01

Wildfire frequency in the southern Sierra Nevada has increased over the past decades. The effects of wildfires on soils can increase the frequency of slope failure and debris flow events, which pose a greater risk to people, as human populations expand into foothill and mountainous communities of the Sierra Nevada. Alterations in the physical properties of burned soils are one such effect that can catalyze slope failure and debris flow events. Moreover, the degree of a soil's physical alteration resulting from wildfire is linked to fire intensity. The 2016 Erskine fire occurred in the southern Sierra Nevada, burning 48,019 acres, resulting in soils of unburned, low, moderate, and high burn severities. In this study, the physical properties of soils with varying degrees of burn severity are explored within the 2016 Erskine fire perimeter. The results constrain the effects of burn severity on soil's physical properties. Unburned, low, moderate, and high burn severity soil samples were collected within the Erskine fire perimeter. Alterations in soils' physical properties resulting from burn severity are explored using X-ray diffractometry analysis, liquid limit, plastic limit, and shear strength tests. Preliminary results from this study will be used to assess debris flow and slope failure hazard models within burned areas of the Kern River watershed in the southern Sierra Nevada.

Modeling the disturbance of vegetation by fire in the boreal forest

NASA Astrophysics Data System (ADS)

Crevoisier, C.; Shevliakova, E.; Gloor, M.; Wirth, C.

2006-12-01

Boreal regions are important for the global carbon cycle because it is the largest forested area on earth and there are large belowground carbon pools (~1000 PgC). It is also a region where largest warming trends on the globe over the last decades have been observed and changes of the land ecosystems have already started. A major factor that determines the structure and carbon dynamics of the boreal forest is fire. As fire frequency depends strongly on climate, increased fire occurrence and related losses to the atmosphere are likely, and have already been reported. In order to predict with more confidence the occurrence and effect of fire on forest ecosystems in the boreal region, we have developed a fire model that takes advantage of the large on-ground, remote sensing and climate data from Canada, Alaska and Siberia. This prognostic model estimates the monthly burned area in a grid cell of 2 by 2.5 degrees, from four climate (air temperature, air relative humidity, precipitation and soil water content) and one human-related (road density) variables. Parameters are estimated using a Markov Chain Monte Carlo method applied to a dataset of observed burned area for Canada. The model is able to reproduce the seasonality of fire, the interannual variability, as well as the location of fire events, not only for Canada (on which data the model is based), but also for Siberia and Alaska, for which the results compare well with remote sensing observation, and are in the range of various current estimations of burned area. The fire model is being implemented in LM3V, the new vegetation model of GFDL earth system model, in order to make prediction of future fire behavior in boreal regions, and the related disturbance of the vegetation and carbon emissions.

Comparison of the sensitivity of landscape-fire-succession models to variation in terrain, fuel pattern, climate and weather.

Treesearch

Geoffrey J. Cary; Robert E. Keane; Robert H. Gardner; Sandra Lavorel; Mike D. Flannigan; Ian D. Davies; Chao Li; James M. Lenihan; T. Scott Rupp; Florent Mouillot

2006-01-01

The purpose of this study was to compare the sensitivity of nlodelled area burned to environmental factors across a range of independently-developed landscape-fire-succession models. The sensitivity of area burned to variation in four factors, namely terrain (flat, undulating and mountainous), fuel pattern (finely and coarsely clumped), climate (observed, warmer &...

Effects of Climate and Fuels Management on Wildfire Occurrence, Size, Severity and Emissions in the Sierra Nevada

NASA Astrophysics Data System (ADS)

Westerling, A. L.; Fites, J. A.; Keyser, A.

2015-12-01

Annual wildfire burned area in federally managed Sierra Nevada forests has increased by more than 10,000 ha per decade since the early 1970s. At the same time, recent years have seen some extremely large fires compared to the historical record, with significant areas of moderate to high severity fire (e.g., McNally 2002, Rim 2013, King 2014 fires). Changes to fuels and fire regimes due to fire suppression and land use, as well as warming temperatures and the occurrence of drought, are thought to be significant factors contributing to increased risks of large, severe fires in Sierra Nevada forests. Over 70% of the vegetated area in federally managed forests in the Sierra Nevada is classified as having altered fuels and fire regimes, while average annual temperature in the Sierra Nevada has been above the long term mean for all but four years in the past two decades. As climate is expected to continue warming for decades to come, we explored fuels management scenarios as the primary tools available to modify risks of large, severe wildfires. We developed experimental statistical models of fire occurrence, fire size, and high severity burned area, to explore the interaction between climate and altered fuels conditions. These models were applied to historical climate conditions, a sample of future climate projections, and to both current fuels conditions and a range of scenarios for fuels treatments. Emissions from wildfires were estimated using the Fire Inventory from the National Center for Atmospheric Research. Our models project that average annual burned area in the Sierra Nevada will more than double by mid-century. Similarly, particulate and other pollution emissions from Sierra Nevada wildfires are projected to more than double, even if future fire severity does not change. Fuels treatment scenarios significantly reduced simulated future burned area and emissions below untreated projections. High severity burned area responded to both climate and fuels treatments. A sensitivity analysis indicated that in areas where the fraction of highly altered fuels is high, successfully restoring fuels to prehistoric conditions could more than compensate for expected climate change effects on fire severity by mid-century.

Photochemical model estimated fire impacts on ozone and aerosol evaluated with field studies and routine data sources

NASA Astrophysics Data System (ADS)

Baker, K. R.

2017-12-01

Highly instrumented field studies provide a unique opportunity to evaluate multiple aspects of photochemical grid model representation of fire emissions, dispersion, and chemical evolution. Fuel information and burn area for a specific fire coupled with near-fire and downwind chemical measurements provides information needed to constrain model predicted fire plume transport and chemical evolution of important pollutants such as ozone and particulate matter (PM2.5) that have deleterious health effects. Most local to regional scale field campaigns to date have made relatively few transects through plumes from fires with well characterized fuel type and consumption. While more comprehensive field studies are being planned for 2018 and beyond (WE-CAN, FIREX, FIRE-CHEM, and FASMEE), existing measurement data from multiple field campaigns including 2013 SEAC4RS, satellite data, and routine surface networks are used to assess how a regulatory modeling system captures fire impacts on local to regional scale ozone and PM2.5. Key aspects of the regulatory modeling system include fire location and burn area from SMARTFIRE2, emissions from BlueSky framework, and predictions of ambient O3 and PM2.5 from the Community Multiscale Air Quality (CMAQ) photochemical transport model. A comparison of model estimated O3 from specific fires with routine surface measurements at rural locations in proximity to the 2013 Rim fire, 2011 Wallow fire, and 2011 Flint Hills fires suggest the modeling system over-estimates smoke impacts on hourly ozone. Sensitivity simulations where solar radiation and photolysis rates are more aggressively attenuated by smoke reduced O3 predictions but did not ameliorate the over prediction bias. PM2.5 organic carbon tends to be overpredicted at rural surface sites downwind from the 2011 Flint Hills prescribed fires while results were mixed at rural sites downwind of the 2013 Rim fire and 2011 Wallow fire suggesting differences in fuel characterization (e.g., emission factors, emissions speciation, burn period, etc.) between these areas may contribute to differences in model prediction. Aircraft plume transects made downwind of the 2013 Rim fire and satellite information suggest the model does well at regional scale plume transport.

Future climate change drives increases in forest fires and summertime OC concentrations in the Western U.S.

NASA Astrophysics Data System (ADS)

Spracklen, D. V.; Logan, J. A.; Mickley, L. J.; Park, R. J.; Flannigan, M. D.; Westerling, A. L.

2006-12-01

Increased forest fire activity in the Western United States appears to be driven by increasing spring and summer temperatures. Here we make a first estimate of how climate-driven changes in fire activity will influence summertime organic carbon (OC) concentrations in the Western US. We use output from a general circulation model (GCM) combined with area burned regressions to predict how area burned will change between present day and 2050. Calculated area burned is used to create future emission estimates for the Western U.S. and we use a global chemical transport model (CTM) to predict future changes in OC concentrations. Stepwise linear regression is used to determine the best relationships between observed area burned for 1980- 2004 and variables chosen from temperature, relative humidity, wind speed, rainfall and drought indices from the Candaian Fire Weather Index Model. Best predictors are ecosytem dependent but typically include mean summer temperature and mean drought code. In forest ecosystems of the Western U.S. our regressions explain 50-60% of the variance in annual area burned. Between 2000 and 2050 increases in temperature and reductions in precipitation, as predicted by the GISS GCM, cause mean area burned in the western U.S. to increase by 30-55%. We use the GEOS-Chem CTM to show that these increased emissions result in an increase in summertime western U.S. OC concentrations by 55% over current concentrations. Our results show that the predicted increase in future wild fires will have important consequences for western US air quality and visibility.

Tree mortality following prescribed fire and a storm surge event in Slash Pine (pinus elliottii var. densa) forests in the Florida Keys, USA

USGS Publications Warehouse

Sah, Jay P.; Ross, Michael S.; Snyder, James R.; Ogurcak, Danielle E.

2010-01-01

In fire-dependent forests, managers are interested in predicting the consequences of prescribed burning on postfire tree mortality. We examined the effects of prescribed fire on tree mortality in Florida Keys pine forests, using a factorial design with understory type, season, and year of burn as factors. We also used logistic regression to model the effects of burn season, fire severity, and tree dimensions on individual tree mortality. Despite limited statistical power due to problems in carrying out the full suite of planned experimental burns, associations with tree and fire variables were observed. Post-fire pine tree mortality was negatively correlated with tree size and positively correlated with char height and percent crown scorch. Unlike post-fire mortality, tree mortality associated with storm surge from Hurricane Wilma was greater in the large size classes. Due to their influence on population structure and fuel dynamics, the size-selective mortality patterns following fire and storm surge have practical importance for using fire as a management tool in Florida Keys pinelands in the future, particularly when the threats to their continued existence from tropical storms and sea level rise are expected to increase.

Implications of emission inventory choice for modeling fire-related pollution in the U.S.

NASA Astrophysics Data System (ADS)

Koplitz, S. N.; Nolte, C. G.; Pouliot, G.

2017-12-01

Wildland fires are a major source of fine particulate matter (PM2.5), one of the most harmful ambient pollutants for human health globally. Within the U.S., wildland fires can account for more than 30% of total annual PM2.5 emissions. In order to represent the influence of fire emissions on atmospheric composition, regional and global chemical transport models (CTMs) rely on fire emission inventories developed from estimates of burned area (i.e. fire size and location). Burned area can be estimated using a range of top-down and bottom-up approaches, including satellite-derived remote sensing and on-the-ground incident reports. While burned area estimates agree with each other reasonably well in the western U.S. (within 20-30% for most years during 2002-2014), estimates for the southern U.S. vary by more than a factor of 3. Differences in burned area estimation methods lead to significant variability in the spatial and temporal allocation of emissions across fire emission inventory platforms. In this work, we implement fire emission estimates for 2011 from three different products - the USEPA National Emission Inventory (NEI), the Fire INventory of NCAR (FINN), and the Global Fire Emission Database (GFED4s) - into the Community Multiscale Air Quality (CMAQ) model to quantify and characterize differences in simulated fire-related PM2.5 and ozone concentrations across the contiguous U.S. due solely to the emission inventory used. Preliminary results indicate that the estimated contribution to national annual average PM2.5 from wildland fire in 2011 is highest using GFED4s emissions (1.0 µg m-3) followed by NEI (0.7 µg m-3) and FINN (0.3 µg m-3), with comparisons varying significantly by region and season. Understanding the sensitivity of modeling fire-related PM2.5 and ozone in the U.S. to fire emission inventory choice will inform future efforts to assess the implications of present and future fire activity for air quality and human health at national and global scales.

Continued warming could transform Greater Yellowstone fire regimes by mid-21st century

PubMed Central

Westerling, Anthony L.; Turner, Monica G.; Smithwick, Erica A. H.; Romme, William H.; Ryan, Michael G.

2011-01-01

Climate change is likely to alter wildfire regimes, but the magnitude and timing of potential climate-driven changes in regional fire regimes are not well understood. We considered how the occurrence, size, and spatial location of large fires might respond to climate projections in the Greater Yellowstone ecosystem (GYE) (Wyoming), a large wildland ecosystem dominated by conifer forests and characterized by infrequent, high-severity fire. We developed a suite of statistical models that related monthly climate data (1972–1999) to the occurrence and size of fires >200 ha in the northern Rocky Mountains; these models were cross-validated and then used with downscaled (∼12 km × 12 km) climate projections from three global climate models to predict fire occurrence and area burned in the GYE through 2099. All models predicted substantial increases in fire by midcentury, with fire rotation (the time to burn an area equal to the landscape area) reduced to <30 y from the historical 100–300 y for most of the GYE. Years without large fires were common historically but are expected to become rare as annual area burned and the frequency of regionally synchronous fires increase. Our findings suggest a shift to novel fire–climate–vegetation relationships in Greater Yellowstone by midcentury because fire frequency and extent would be inconsistent with persistence of the current suite of conifer species. The predicted new fire regime would transform the flora, fauna, and ecosystem processes in this landscape and may indicate similar changes for other subalpine forests. PMID:21788495

Two global data sets of daily fire emission injection heights since 2003

NASA Astrophysics Data System (ADS)

Rémy, Samuel; Veira, Andreas; Paugam, Ronan; Sofiev, Mikhail; Kaiser, Johannes W.; Marenco, Franco; Burton, Sharon P.; Benedetti, Angela; Engelen, Richard J.; Ferrare, Richard; Hair, Jonathan W.

2017-02-01

The Global Fire Assimilation System (GFAS) assimilates fire radiative power (FRP) observations from satellite-based sensors to produce daily estimates of biomass burning emissions. It has been extended to include information about injection heights derived from fire observations and meteorological information from the operational weather forecasts of ECMWF. Injection heights are provided by two distinct methods: the Integrated Monitoring and Modelling System for wildland fires (IS4FIRES) parameterisation and the one-dimensional plume rise model (PRM). A global database of daily biomass burning emissions and injection heights at 0.1° resolution has been produced for 2003-2015 and is continuously extended in near-real time with the operational GFAS service of the Copernicus Atmospheric Monitoring Service (CAMS). In this study, the two injection height data sets were compared with the new MPHP2 (MISR Plume Height Project 2) satellite-based plume height retrievals. The IS4FIRES parameterisation showed a better overall agreement than the observations, while the PRM was better at capturing the variability of injection heights. The performance of both parameterisations is also dependent on the type of vegetation. Furthermore, the use of biomass burning emission heights from GFAS in atmospheric composition forecasts was assessed in two case studies: the South AMerican Biomass Burning Analysis (SAMBBA) campaign which took place in September 2012 in Brazil, and a series of large fire events in the western USA in August 2013. For these case studies, forecasts of biomass burning aerosol species by the Composition Integrated Forecasting System (C-IFS) of CAMS were found to better reproduce the observed vertical distribution when using PRM injection heights from GFAS compared to aerosols emissions being prescribed at the surface. The globally available GFAS injection heights introduced and evaluated in this study provide a comprehensive data set for future fire and atmospheric composition modelling studies.

Post-fire vegetation recovery in Portugal based on spot/vegetation data

NASA Astrophysics Data System (ADS)

Gouveia, C.; Dacamara, C. C.; Trigo, R. M.

2010-04-01

A procedure is presented that allows identifying large burned scars and the monitoring of vegetation recovery in the years following major fire episodes. The procedure relies on 10-day fields of Maximum Value Composites of Normalized Difference Vegetation Index (MVC-NDVI), with a 1 km×1 km spatial resolution obtained from the VEGETATION instrument. The identification of fire scars during the extremely severe 2003 fire season is performed based on cluster analysis of NDVI anomalies that persist during the vegetative cycle of the year following the fire event. Two regions containing very large burned scars were selected, located in Central and Southwestern Portugal, respectively, and time series of MVC-NDVI analysed before the fire events took place and throughout the post-fire period. It is shown that post-fire vegetation dynamics in the two selected regions may be characterised based on maps of recovery rates as estimated by fitting a monoparametric model of vegetation recovery to MVC-NDVI data over each burned scar. Results indicated that the recovery process in the region located in Central Portugal is mostly related to fire damage rather than to vegetation density before 2003, whereas the latter seems to have a more prominent role than vegetation conditions after the fire episode, e.g. in the case of the region in Southwestern Portugal. These differences are consistent with the respective predominant types of vegetation. The burned area located in Central Portugal is dominated by Pinus Pinaster whose natural regeneration crucially depends on the destruction of seeds present on the soil surface during the fire, whereas the burned scar in Southwestern Portugal was populated by Eucalyptus that may quickly re-sprout from buds after fire. Besides its simplicity, the monoparametric model of vegetation recovery has the advantage of being easily adapted to other low-resolution satellite data, as well as to other types of vegetation indices.

Modelled vs. reconstructed past fire dynamics - how can we compare?

NASA Astrophysics Data System (ADS)

Brücher, Tim; Brovkin, Victor; Kloster, Silvia; Marlon, Jennifer R.; Power, Mitch J.

2015-04-01

Fire is an important process that affects climate through changes in CO2 emissions, albedo, and aerosols (Ward et al. 2012). Fire-history reconstructions from charcoal accumulations in sediment indicate that biomass burning has increased since the Last Glacial Maximum (Power et al. 2008; Marlon et al. 2013). Recent comparisons with transient climate model output suggest that this increase in global ?re activity is linked primarily to variations in temperature and secondarily to variations in precipitation (Daniau et al. 2012). In this study, we discuss the best way to compare global ?re model output with charcoal records. Fire models generate quantitative output for burned area and fire-related emissions of CO2, whereas charcoal data indicate relative changes in biomass burning for specific regions and time periods only. However, models can be used to relate trends in charcoal data to trends in quantitative changes in burned area or fire carbon emissions. Charcoal records are often reported as Z-scores (Power et al. 2008). Since Z-scores are non-linear power transformations of charcoal influxes, we must evaluate if, for example, a two-fold increase in the standardized charcoal reconstruction corresponds to a 2- or 200-fold increase in the area burned. In our study we apply the Z-score metric to the model output. This allows us to test how well the model can quantitatively reproduce the charcoal-based reconstructions and how Z-score metrics affect the statistics of model output. The Global Charcoal Database (GCD version 2.5; www.gpwg.org/gpwgdb.html) is used to determine regional and global paleofire trends from 218 sedimentary charcoal records covering part or all of the last 8 ka BP. To retrieve regional and global composites of changes in fire activity over the Holocene the time series of Z-scores are linearly averaged to achieve regional composites. A coupled climate-carbon cycle model, CLIMBA (Brücher et al. 2014), is used for this study. It consists of the CLIMBER-2 Earth system model of intermediate complexity and the JSBACH land component of the Max Planck Institute Earth System Model. The fire algorithm in JSBACH assumes a constant annual lightning cycle as the sole fire ignition mechanism (Arora and Boer 2005). To eliminate data processing differences as a source for potential discrepancies, the processing of both reconstructed and modeled data, including e.g. normalisation with respect to a given base period and aggregation of time series was done in exactly the same way. Here, we compare the aggregated time series on a hemispheric and regional scale.

Biomass Burning: The Cycling of Gases and Particulates from the Biosphere to the Atmosphere

NASA Astrophysics Data System (ADS)

Levine, J. S.

2003-12-01

Biomass burning is both a process of geochemical cycling of gases and particulates from the biosphere to the atmosphere and a process of global change. In the preface to the book, One Earth, One Future: Our Changing Global Environment (National Academy of Sciences, 1990), Dr. Frank Press, the President of the National Academy of Sciences, writes: "Human activities are transforming the global environment, and these global changes have many faces: ozone depletion, tropical deforestation, acid deposition, and increased atmospheric concentrations of gases that trap heat and may warm the global climate."It is interesting to note that all four global change "faces" identified by Dr. Press have a common thread - they are all caused by biomass burning.Biomass burning or vegetation burning is the burning of living and dead vegetation and includes human-initiated burning and natural lightning-induced burning. The bulk of the world's biomass burning occurs in the tropics - in the tropical forests of South America and Southeast Asia and in the savannasof Africa and South America. The majority of the biomass burning, primarily in the tropics (perhaps as much as 90%), is believed to be human initiated for land clearing and land-use change. Natural fires triggered by atmospheric lightning only accounts for ˜10% of all fires (Andreae, 1991). As will be discussed, a significant amount of biomass burning occurs in the boreal forests of Russia, Canada, and Alaska.Biomass burning is a significant source of gases and particulates to the regional and global atmosphere (Crutzen et al., 1979; Seiler and Crutzen, 1980; Crutzen and Andreae, 1990; Levine et al., 1995). Its burning is truly a multidiscipline subject, encompassing the following areas: fire ecology, fire measurements, fire modeling, fire combustion, remote sensing, fire combustion gaseous and particulate emissions, the atmospheric transport of these emissions, and the chemical and climatic impacts of these emissions. Recently, a series of dedicated books have documented much of our understanding of biomass burning in different ecosystems. These volumes include: Goldammer (1990), Levine (1991, 1996a, b), Crutzen and Goldammer (1993), Goldammer and Furyaev (1996), van Wilgen et al. (1997), Kasischke and Stocks (2000), Innes et al. (2000), and Eaton and Radojevic (2001).

A Five-Year CMAQ PM2.5 Model Performance for Wildfires and Prescribed Fires

NASA Astrophysics Data System (ADS)

Wilkins, J. L.; Pouliot, G.; Foley, K.; Rappold, A.; Pierce, T. E.

2016-12-01

Biomass burning has been identified as an important contributor to the degradation of air quality because of its impact on ozone and particulate matter. Two components of the biomass burning inventory, wildfires and prescribed fires are routinely estimated in the national emissions inventory. However, there is a large amount of uncertainty in the development of these emission inventory sectors. We have completed a 5 year set of CMAQ model simulations (2008-2012) in which we have simulated regional air quality with and without the wildfire and prescribed fire inventory. We will examine CMAQ model performance over regions with significant PM2.5 and Ozone contribution from prescribed fires and wildfires. We will also review plume rise to see how it affects model bias and compare CMAQ current fire emissions input to an hourly dataset from FLAMBE.

In situ Micrometeorological Measurements during RxCADRE

NASA Astrophysics Data System (ADS)

Clements, C. B.; Hiers, J. K.; Strenfel, S. J.

2009-12-01

The Prescribed Fire Combustion and Atmospheric Dynamics Research Experiment (RxCADRE) was a collaborative research project designed to fully instrument prescribed fires in the Southeastern United States. Data were collected on pre-burn fuel loads, post burn consumption, ambient weather, in situ atmospheric dynamics, plume dynamics, radiant heat release (both from in-situ and remote sensors), in-situ fire behavior, and select fire effects. The sampling was conducted at Eglin Air Force Base, Florida, and the Joseph W. Jones Ecological Research Center in Newton, Georgia, from February 29 to March 6, 2008. Data were collected on 5 prescribed burns, totaling 4458 acres. The largest aerial ignition totaled 2,290 acres and the smallest ground ignition totaled 104 acres. Quantifying fire-atmospheric interactions is critical for understanding wildland fire dynamics and enhancing modeling of smoke plumes. During Rx-CADRE, atmospheric soundings using radiosondes were made at each burn prior to ignition. In situ micrometeorological measurements were made within each burn unit using five portable, 10-m towers equipped with sonic and prop anemometers, fine-wire thermocouples, and a carbon dioxide probes. The towers were arranged within the burn units to capture the wind and temperature fields as the fire front and plume passed the towers. Due to the interaction of fire lines following ignition, several of the fire fronts that passed the towers were backing fires and thus less intense. Preliminary results indicate that the average vertical velocities associated with the fire front passage were on the order of 3-5 m s-1 and average plume temperatures were on the order of 30-50 °C above ambient. During two of the experimental burns, radiosondes were released into the fire plumes to determine the vertical structure of the plume temperature, humidity, and winds. A radiosonde released into the plume during the burn conducted on 3 March 2008 indicated a definite plume boundary in the potential temperature and dew point temperature structure. The plume height immediately downwind of the fire front was approximately 150 m AGL and heating within this layer was on the order of 3 K. One interesting feature of the plume was the enhanced wind velocity at the top of the plume. Winds increased by 2 m s-1 in a shallow layer at the very top of the plume boundary indicating enhanced acceleration due to the increase in buoyancy. This experience highlights the dynamism of interacting fire lines within prescribed burns as well as the difficulty of measuring fire-atmospheric interactions on large prescribed fire ignitions.

Global fire emissions estimates during 1997-2016

NASA Astrophysics Data System (ADS)

van der Werf, Guido R.; Randerson, James T.; Giglio, Louis; van Leeuwen, Thijs T.; Chen, Yang; Rogers, Brendan M.; Mu, Mingquan; van Marle, Margreet J. E.; Morton, Douglas C.; Collatz, G. James; Yokelson, Robert J.; Kasibhatla, Prasad S.

2017-09-01

Climate, land use, and other anthropogenic and natural drivers have the potential to influence fire dynamics in many regions. To develop a mechanistic understanding of the changing role of these drivers and their impact on atmospheric composition, long-term fire records are needed that fuse information from different satellite and in situ data streams. Here we describe the fourth version of the Global Fire Emissions Database (GFED) and quantify global fire emissions patterns during 1997-2016. The modeling system, based on the Carnegie-Ames-Stanford Approach (CASA) biogeochemical model, has several modifications from the previous version and uses higher quality input datasets. Significant upgrades include (1) new burned area estimates with contributions from small fires, (2) a revised fuel consumption parameterization optimized using field observations, (3) modifications that improve the representation of fuel consumption in frequently burning landscapes, and (4) fire severity estimates that better represent continental differences in burning processes across boreal regions of North America and Eurasia. The new version has a higher spatial resolution (0.25°) and uses a different set of emission factors that separately resolves trace gas and aerosol emissions from temperate and boreal forest ecosystems. Global mean carbon emissions using the burned area dataset with small fires (GFED4s) were 2.2 × 1015 grams of carbon per year (Pg C yr-1) during 1997-2016, with a maximum in 1997 (3.0 Pg C yr-1) and minimum in 2013 (1.8 Pg C yr-1). These estimates were 11 % higher than our previous estimates (GFED3) during 1997-2011, when the two datasets overlapped. This net increase was the result of a substantial increase in burned area (37 %), mostly due to the inclusion of small fires, and a modest decrease in mean fuel consumption (-19 %) to better match estimates from field studies, primarily in savannas and grasslands. For trace gas and aerosol emissions, differences between GFED4s and GFED3 were often larger due to the use of revised emission factors. If small fire burned area was excluded (GFED4 without the s for small fires), average emissions were 1.5 Pg C yr-1. The addition of small fires had the largest impact on emissions in temperate North America, Central America, Europe, and temperate Asia. This small fire layer carries substantial uncertainties; improving these estimates will require use of new burned area products derived from high-resolution satellite imagery. Our revised dataset provides an internally consistent set of burned area and emissions that may contribute to a better understanding of multi-decadal changes in fire dynamics and their impact on the Earth system. GFED data are available from http://www.globalfiredata.org.

Evaluating impacts of fire management strategies on native and invasive plants using an individual-based model

NASA Astrophysics Data System (ADS)

Gangur, Alexander N.; Fill, Jennifer M.; Northfield, Tobin D.; van de Wiel, Marco

2017-04-01

The capacity for species to coexist and potentially exclude one another can broadly be attributed to drivers that influence fitness differences (such as competitive ability) and niche differences (such as environmental change). These drivers, and thus the determinants of coexistence they influence, can interact and fluctuate both spatially and temporally. Understanding the spatiotemporal variation in niche and fitness differences in systems prone to fluctuating drivers, such as fire, can help to inform the management of invasive species. In the Cape floristic region of South Africa, invasive Pinus pinaster seedlings are strong competitors in the post-burn environment of the fire-driven Fynbos vegetation. In this, system native Protea spp. are especially vulnerable to unseasonal burns, but seasonal prescribed (Summer) burns are thought to present a high safety risk. Together, these issues have limited the appeal of prescribed burn management as an alternative to costly manual eradication of P. pinaster. Using a spatially-explicit field-of-neighbourhood individual-based model, we represent the drivers of spatiotemporal variation in niche differences (driven by fire regimes) and fitness differences (driven by competitive ability). In doing so, we evaluate optimal fire management strategies to a) control invasive P. pinaster in the Cape floristic region of South Africa, while b) minimizing deleterious effects of management on native Protea spp. The scarcity of appropriate data for model calibration has been problematic for models in invasion biology, but we use recent advances in Approximate Bayesian Computing techniques to overcome this limitation. We present early conclusions on the viability of prescribed burn management to control P. pinaster in South Africa.

Prescribed fire as a means of reducing forest carbon emissions in the western United States.

PubMed

Wiedinmyer, Christine; Hurteau, Matthew D

2010-03-15

Carbon sequestration by forested ecosystems offers a potential climate change mitigation benefit. However, wildfire has the potential to reverse this benefit In the western United States, climate change and land management practices have led to increases in wildfire intensity and size. One potential means of reducing carbon emissions from wildfire is the use of prescribed burning,which consumes less biomass and therefore releases less carbon to the atmosphere. This study uses a regional fire emissions model to estimate the potential reduction in fire emissions when prescribed burning is applied in dry, temperate forested systems of the western U.S. Daily carbon dioxide (CO(2)) fire emissions for 2001-2008 were calculated for the western U.S. for two cases: a default wildfire case and one in which prescribed burning was applied. Wide-scale prescribed fire application can reduce CO(2) fire emissions for the western U.S. by 18-25%1 in the western U.S., and by as much as 60% in specific forest systems. Although this work does not address important considerations such as the feasibility of implementing wide-scale prescribed fire management or the cumulative emissions from repeated prescribed burning, it does provide constraints on potential carbon emission reductions when prescribed burning is used.

Predicting post-fire tree mortality for 12 western US conifers using the First-Order Fire Effects Model (FOFEM)

Treesearch

Sharon Hood; Duncan Lutes

2017-01-01

Accurate prediction of fire-caused tree mortality is critical for making sound land management decisions such as developing burning prescriptions and post-fire management guidelines. To improve efforts to predict post-fire tree mortality, we developed 3-year post-fire mortality models for 12 Western conifer species - white fir (Abies concolor [Gord. &...

Landsat-Based Detection and Severity Analysis of Burned Sugarcane Plots in Tarlac, Philippines Using Differenced Normalized Burn Ratio (dNBR)

NASA Astrophysics Data System (ADS)

Baloloy, A. B.; Blanco, A. C.; Gana, B. S.; Sta. Ana, R. C.; Olalia, L. C.

2016-09-01

The Philippines has a booming sugarcane industry contributing about PHP 70 billion annually to the local economy through raw sugar, molasses and bioethanol production (SRA, 2012). Sugarcane planters adapt different farm practices in cultivating sugarcane, one of which is cane burning to eliminate unwanted plant material and facilitate easier harvest. Information on burned sugarcane extent is significant in yield estimation models to calculate total sugar lost during harvest. Pre-harvest burning can lessen sucrose by 2.7% - 5% of the potential yield (Gomez, et al 2006; Hiranyavasit, 2016). This study employs a method for detecting burn sugarcane area and determining burn severity through Differenced Normalized Burn Ratio (dNBR) using Landsat 8 Images acquired during the late milling season in Tarlac, Philippines. Total burned area was computed per burn severity based on pre-fire and post-fire images. Results show that 75.38% of the total sugarcane fields in Tarlac were burned with post-fire regrowth; 16.61% were recently burned; and only 8.01% were unburned. The monthly dNBR for February to March generated the largest area with low severity burn (1,436 ha) and high severity burn (31.14 ha) due to pre-harvest burning. Post-fire regrowth is highest in April to May when previously burned areas were already replanted with sugarcane. The maximum dNBR of the entire late milling season (February to May) recorded larger extent of areas with high and low post-fire regrowth compared to areas with low, moderate and high burn severity. Normalized Difference Vegetation Index (NDVI) was used to analyse vegetation dynamics between the burn severity classes. Significant positive correlation, rho = 0.99, was observed between dNBR and dNDVI at 5% level (p = 0.004). An accuracy of 89.03% was calculated for the Landsat-derived NBR validated using actual mill data for crop year 2015-2016.

Comparing fire severity models from post-fire and pre/post-fire differenced imagery

USDA-ARS?s Scientific Manuscript database

Wildland fires are common in rangelands worldwide. The potential for high severity fires to affect long-term changes in rangelands is considerable, and for this reason assessing fire severity shortly after the fire is critical. Such assessments are typically carried out following Burned Area Emergen...

SPITFIRE within the MPI Earth system model: Model development and evaluation

NASA Astrophysics Data System (ADS)

Lasslop, Gitta; Thonicke, Kirsten; Kloster, Silvia

2014-09-01

Quantification of the role of fire within the Earth system requires an adequate representation of fire as a climate-controlled process within an Earth system model. To be able to address questions on the interaction between fire and the Earth system, we implemented the mechanistic fire model SPITFIRE, in JSBACH, the land surface model of the MPI Earth system model. Here, we document the model implementation as well as model modifications. We evaluate our model results by comparing the simulation to the GFED version 3 satellite-based data set. In addition, we assess the sensitivity of the model to the meteorological forcing and to the spatial variability of a number of fire relevant model parameters. A first comparison of model results with burned area observations showed a strong correlation of the residuals with wind speed. Further analysis revealed that the response of the fire spread to wind speed was too strong for the application on global scale. Therefore, we developed an improved parametrization to account for this effect. The evaluation of the improved model shows that the model is able to capture the global gradients and the seasonality of burned area. Some areas of model-data mismatch can be explained by differences in vegetation cover compared to observations. We achieve benchmarking scores comparable to other state-of-the-art fire models. The global total burned area is sensitive to the meteorological forcing. Adjustment of parameters leads to similar model results for both forcing data sets with respect to spatial and seasonal patterns. This article was corrected on 29 SEP 2014. See the end of the full text for details.

New global fire emission estimates and evaluation of volatile organic compounds

Treesearch

C. Wiedinmyer; L. K. Emmons; S. K. Akagi; R. J. Yokelson; J. J. Orlando; J. A. Al-Saadi; A. J. Soja

2010-01-01

A daily, high-resolution, global fire emissions model has been built to estimate emissions from open burning for air quality modeling applications: The Fire INventory from NCAR (FINN version 1). The model framework uses daily fire detections from the MODIS instruments and updated emission factors, specifically for speciated non-methane organic compounds (NMOC). Global...

Analyzing wildfire exposure on Sardinia, Italy

NASA Astrophysics Data System (ADS)

Salis, Michele; Ager, Alan A.; Arca, Bachisio; Finney, Mark A.; Alcasena, Fermin; Bacciu, Valentina; Duce, Pierpaolo; Munoz Lozano, Olga; Spano, Donatella

2014-05-01

We used simulation modeling based on the minimum travel time algorithm (MTT) to analyze wildfire exposure of key ecological, social and economic features on Sardinia, Italy. Sardinia is the second largest island of the Mediterranean Basin, and in the last fifty years experienced large and dramatic wildfires, which caused losses and threatened urban interfaces, forests and natural areas, and agricultural productions. Historical fires and environmental data for the period 1995-2009 were used as input to estimate fine scale burn probability, conditional flame length, and potential fire size in the study area. With this purpose, we simulated 100,000 wildfire events within the study area, randomly drawing from the observed frequency distribution of burn periods and wind directions for each fire. Estimates of burn probability, excluding non-burnable fuels, ranged from 0 to 1.92x10-3, with a mean value of 6.48x10-5. Overall, the outputs provided a quantitative assessment of wildfire exposure at the landscape scale and captured landscape properties of wildfire exposure. We then examined how the exposure profiles varied among and within selected features and assets located on the island. Spatial variation in modeled outputs resulted in a strong effect of fuel models, coupled with slope and weather. In particular, the combined effect of Mediterranean maquis, woodland areas and complex topography on flame length was relevant, mainly in north-east Sardinia, whereas areas with herbaceous fuels and flat areas were in general characterized by lower fire intensity but higher burn probability. The simulation modeling proposed in this work provides a quantitative approach to inform wildfire risk management activities, and represents one of the first applications of burn probability modeling to capture fire risk and exposure profiles in the Mediterranean basin.

Sensitivity of ALOS/PALSAR imagery to forest degradation by fire in northern Amazon

NASA Astrophysics Data System (ADS)

Martins, Flora da Silva Ramos Vieira; dos Santos, João Roberto; Galvão, Lênio Soares; Xaud, Haron Abrahim Magalhães

2016-07-01

We evaluated the sensitivity of the full polarimetric Phased Array type L-band Synthetic Aperture Radar (PALSAR), onboard the Advanced Land Observing Satellite (ALOS), to forest degradation caused by fires in northern Amazon, Brazil. We searched for changes in PALSAR signal and tri-dimensional polarimetric responses for different classes of fire disturbance defined by fire frequency and severity. Since the aboveground biomass (AGB) is affected by fire, multiple regression models to estimate AGB were obtained for the whole set of coherent and incoherent attributes (general model) and for each set separately (specific models). The results showed that the polarimetric L-band PALSAR attributes were sensitive to variations in canopy structure and AGB caused by forest fire. However, except for the unburned and thrice burned classes, no single PALSAR attribute was able to discriminate between the intermediate classes of forest degradation by fire. Both the coherent and incoherent polarimetric attributes were important to explain AGB variations in tropical forests affected by fire. The HV backscattering coefficient, anisotropy, double-bounce component, orientation angle, volume index and HH-VV phase difference were PALSAR attributes selected from multiple regression analysis to estimate AGB. The general regression model, combining phase and power radar metrics, presented better results than specific models using coherent or incoherent attributes. The polarimetric responses indicated the dominance of VV-oriented backscattering in primary forest and lightly burned forests. The HH-oriented backscattering predominated in heavily and frequently burned forests. The results suggested a greater contribution of horizontally arranged constituents such as fallen trunks or branches in areas severely affected by fire.

Fire modeling in the Brazilian arc of deforestation through nested coupling of atmosphere, dynamic vegetation, LUCC and fire spread models

NASA Astrophysics Data System (ADS)

Tourigny, E.; Nobre, C.; Cardoso, M. F.

2012-12-01

Deforestation of tropical forests for logging and agriculture, associated to slash-and-burn practices, is a major source of CO2 emissions, both immediate due to biomass burning and future due to the elimination of a potential CO2 sink. Feedbacks between climate change and LUCC (Land-Use and Land-Cover Change) can potentially increase the loss of tropical forests and increase the rate of CO2 emissions, through mechanisms such as land and soil degradation and the increase in wildfire occurrence and severity. However, current understanding of the processes of fires (including ignition, spread and consequences) in tropical forests and climatic feedbacks are poorly understood and need further research. As the processes of LUCC and associated fires occur at local scales, linking them to large-scale atmospheric processes requires a means of up-scaling higher resolutions processes to lower resolutions. Our approach is to couple models which operate at various spatial and temporal scales: a Global Climate Model (GCM), Dynamic Global Vegetation Model (DGVM) and local-scale LUCC and fire spread model. The climate model resolves large scale atmospheric processes and forcings, which are imposed on the surface DGVM and fed-back to climate. Higher-resolution processes such as deforestation, land use management and associated (as well as natural) fires are resolved at the local level. A dynamic tiling scheme allows to represent local-scale heterogeneity while maintaining computational efficiency of the land surface model, compared to traditional landscape models. Fire behavior is modeled at the regional scale (~500m) to represent the detailed landscape using a semi-empirical fire spread model. The relatively coarse scale (as compared to other fire spread models) is necessary due to the paucity of detailed land-cover information and fire history (particularly in the tropics and developing countries). This work presents initial results of a spatially-explicit fire spread model coupled to the IBIS DGVM model. Our area of study comprises selected regions in and near the Brazilian "arc of deforestation". For model training and evaluation, several areas have been mapped using high-resolution imagery from the Landsat TM/ETM+ sensors (Figure 1). This high resolution reference data is used for local-scale simulations and also to evaluate the accuracy of the global MCD45 burned area product, which will be used in future studies covering the entire "arc of deforestation".; Area of study along the arc of deforestation and cerrado: landsat scenes used and burned area (2010) from MCD45 product.

Burn me twice, shame on who? Interactions between successive forest fires across a temperate mountain region.

PubMed

Harvey, Brian J; Donato, Daniel C; Turner, Monica G

2016-09-01

Increasing rates of natural disturbances under a warming climate raise important questions about how multiple disturbances interact. Escalating wildfire activity in recent decades has resulted in some forests re-burning in short succession, but how the severity of one wildfire affects that of a subsequent wildfire is not fully understood. We used a field-validated, satellite-derived, burn-severity atlas to assess interactions between successive wildfires across the US Northern Rocky Mountains a 300,000-km 2 region dominated by fire-prone forests. In areas that experienced two wildfires between 1984 and 2010, we asked: (1) How do overall frequency distributions of burn-severity classes compare between first and second fires? (2) In a given location, how does burn severity of the second fire relate to that of the first? (3) Do interactions between successive fires vary by forest zone or the interval between fires? (4) What factors increase the probability of burning twice as stand-replacing fire? Within the study area, 138,061 ha burned twice between 1984 and 2010. Overall, frequency distributions of burn severity classes (low, moderate, high; quantified using relativized remote sensing indices) were similar between the first and second fires; however burn severity was 5-13% lower in second fires on average. Negative interactions between fires were most pronounced in lower-elevation forests and woodlands, when fire intervals were <10 yr, and when burn severity was low in the first fire. When the first fire burned as high severity and fire intervals exceeded 10-12 yr, burn-severity interactions switched from negative to positive, with high-severity fire begetting subsequent high-severity fire. Locations most likely to experience successive stand-replacing fires were high-elevation forests, which are adapted to high-severity fire, and areas conducive to abundant post-fire tree regeneration. Broadly similar severities among short-interval "re-burns" and other wildfires indicate that positive severity feedbacks, an oft-posited agent of ecosystem decline or state shift, are not an inevitable outcome of re-burning. Nonetheless, context-dependent shifts in both the magnitude and direction of wildfire interactions (associated with forest zone, initial burn-severity, and disturbance interval) illustrate complexities in disturbance interactions and can inform management and predictions of future system dynamics. © 2016 by the Ecological Society of America.

Bat activity following restoration prescribed burning in the central Appalachian Upland and riparian habitats

USGS Publications Warehouse

Austin, Lauren V.; Silvis, Alexander; Ford, W. Mark; Muthersbaugh, Michael; Powers, Karen E.

2018-01-01

After decades of fire suppression in eastern North America, land managers now are prioritizing prescribed fire as a management tool to restore or maintain fire-adapted vegetation communities. However, in long—fire-suppressed landscapes, such as the central and southern Appalachians, it is unknown how bats will respond to prescribed fire in both riparian and upland forest habitats. To address these concerns, we conducted zero-crossing acoustic surveys of bat activity in burned, unburned, riparian, and non-riparian areas in the central Appalachians, Virginia, USA. Burn and riparian variables had model support (ΔAICc < 4) to explain activity of all bat species. Nonetheless, parameter estimates for these conditions were small and confidence intervals overlapped zero for all species, indicating effect sizes were marginal. Our results suggest that bats respond to fire differently between upland and riparian forest habitats, but overall, large landscape-level prescribed fire has a slightly positive to neutral impact on all bats species identified at our study site post—fire application.

Ecological and sampling constraints on defining landscape fire severity

USGS Publications Warehouse

Key, C.H.

2006-01-01

Ecological definition and detection of fire severity are influenced by factors of spatial resolution and timing. Resolution determines the aggregation of effects within a sampling unit or pixel (alpha variation), hence limiting the discernible ecological responses, and controlling the spatial patchiness of responses distributed throughout a burn (beta variation). As resolution decreases, alpha variation increases, extracting beta variation and complexity from the spatial model of the whole burn. Seasonal timing impacts the quality of radiometric data in terms of transmittance, sun angle, and potential contrast between responses within burns. Detection sensitivity candegrade toward the end of many fire seasons when low sun angles, vegetation senescence, incomplete burning, hazy conditions, or snow are common. Thus, a need exists to supersede many rapid response applications when remote sensing conditions improve. Lag timing, or timesince fire, notably shapes the ecological character of severity through first-order effects that only emerge with time after fire, including delayed survivorship and mortality. Survivorship diminishes the detected magnitude of severity, as burned vegetation remains viable and resprouts, though at first it may appear completely charred or consumed above ground. Conversely, delayed mortality increases the severity estimate when apparently healthy vegetation is in fact damaged by heat to the extent that it dies over time. Both responses dependon fire behavior and various species-specific adaptations to fire that are unique to the pre-firecomposition of each burned area. Both responses can lead initially to either over- or underestimating severity. Based on such implications, three sampling intervals for short-term burn severity are identified; rapid, initial, and extended assessment, sampled within about two weeks, two months, and depending on the ecotype, from three months to one year after fire, respectively. Spatial and temporal conditions of sampling strategies constrain data quality and ecological information obtained about fire severity. Though commonly overlooked, such considerations determine the objectives and hypotheses that are appropriate for each application, and are especially important when building comparative studies or long-term reference databases on fire severity.

Tundra fire alters stream water chemistry and benthic invertebrate communities, North Slope, Alaska

NASA Astrophysics Data System (ADS)

Allen, A. R.; Bowden, W. B.; Kling, G. W.; Schuett, E.; Kostrzewski, J. M.; Kolden Abatzoglou, C.; Findlay, R. H.

2010-12-01

Increased fire frequency and severity are potentially important consequences of climate change in high latitude ecosystems. The 2007 Anaktuvuk River fire, which burned from July until October, is the largest recorded tundra fire from Alaska's north slope (≈1,000 km2). The immediate effects of wildfire on water chemistry and biotic assemblages in tundra streams are heretofore unknown. We hypothesized that a tundra fire would increase inorganic nutrient inputs to P-limited tundra streams, increasing primary production and altering benthic macroinvertebrate community structure. We examined linkages among: 1) percentage of riparian zone and overall watershed vegetation burned, 2) physical, chemical and biological stream characteristics, and 3) macroinvertebrate communities in streams draining burned and unburned watersheds during the summers of 2008 and 2009. Streams in burned watersheds contained higher mean concentrations of soluble reactive phosphorus (SRP), ammonium (NH4+), and dissolved organic carbon (DOC). In contrast, stream nitrate (NO3-) concentrations were lower in burned watersheds. The net result was that the tundra fire did not affect concentrations of dissolved inorganic nitrogen (NH4+ + NO3-). In spite of increased SRP, benthic chlorophyll-a biomass was not elevated. Macroinvertebrate abundances were 1.5 times higher in streams draining burned watersheds; Chironomidae midges, Nematodes, and Nemoura stoneflies showed the greatest increases in abundance. Multivariate multiple regression identified environmental parameters associated with the observed changes in the macroinvertebrate communities. Since we identified stream latitude as a significant predictor variable, latitude was included in the model as a covariate. After removing the variation associated with latitude, 67.3 % of the variance in macroinvertebrate community structure was explained by a subset of 7 predictor variables; DOC, conductivity, mean temperature, NO3-, mean discharge, SRP and NH4+. The percentage of riparian vegetation burned, the percentage of watershed vegetation burned and total suspended solids were not included in the model as these parameters correlated with DOC concentration at r > 0.90. These results indicate that tundra fire not only alters stream water chemistry, it also affects benthic macroinvertebrate community structure.

Near-field emission profiling of tropical forest and Cerrado fires in Brazil during SAMBBA 2012

NASA Astrophysics Data System (ADS)

Hodgson, Amy K.; Morgan, William T.; O'Shea, Sebastian; Bauguitte, Stéphane; Allan, James D.; Darbyshire, Eoghan; Flynn, Michael J.; Liu, Dantong; Lee, James; Johnson, Ben; Haywood, Jim M.; Longo, Karla M.; Artaxo, Paulo E.; Coe, Hugh

2018-04-01

We profile trace gas and particulate emissions from near-field airborne measurements of discrete smoke plumes in Brazil during the 2012 biomass burning season. The South American Biomass Burning Analysis (SAMBBA) Project conducted during September and October 2012 sampled across two distinct fire regimes prevalent in the Amazon Basin. Combined measurements from a Compact Time-of-Flight Aerosol Mass Spectrometer (C-ToF-AMS) and a Single Particle Soot Photometer (SP2) are reported for the first time in a tropical biomass burning environment. Emissions from a mostly smouldering tropical forest wildfire in Rondônia state and numerous smaller flaming Cerrado fires in Tocantins state are presented. While the Cerrado fires appear to be representative of typical fire conditions in the existing literature, the tropical forest wildfire likely represents a more extreme example of biomass burning with a bias towards mostly smouldering emissions. We determined fire-integrated modified combustion efficiencies, emission ratios and emission factors for trace gas and particulate components for these two fire types, alongside aerosol microphysical properties. Seven times more black carbon was emitted from the Cerrado fires per unit of fuel combustion (EFBC of 0.13 ± 0.04 g kg-1) compared to the tropical forest fire (EFBC of 0.019 ± 0.006 g kg-1), and more than 6 times the amount of organic aerosol was emitted from the tropical forest fire per unit of fuel combustion (EFOM of 8.00 ± 2.53 g kg-1, EFOC of 5.00 ± 1.58 g kg-1) compared to the Cerrado fires (EFOM of 1.31 ± 0.42 g kg-1, EFOC of 0.82 ± 0.26 g kg-1). Particulate-phase species emitted from the fires sampled are generally lower than those reported in previous studies and in emission inventories, which is likely a combination of differences in fire combustion efficiency and fuel mixture, along with different measurement techniques. Previous modelling studies focussed on the biomass burning season in tropical South America have required significant scaling up of emissions to reproduce in situ and satellite aerosol concentrations over the region. Our results do not indicate that emission factors used in inventories are biased low, which could be one potential cause of the reported underestimates in modelling studies. This study supplements and updates trace gas and particulate emission factors for fire-type-specific biomass burning in Brazil for use in weather and climate models. The study illustrates that initial fire conditions can result in substantial differences in terms of their emitted chemical components, which can potentially perturb the Earth system.

Tree Mortality following Prescribed Fire and a Storm Surge Event in Slash Pine ( Pinus elliottii var. densa ) Forests in the Florida Keys, USA

DOE PAGES

Sah, Jay P.; Ross, Michael S.; Snyder, James R.; ...

2010-01-01

In fire-dependent forests, managers are interested in predicting the consequences of prescribed burning on postfire tree mortality. We examined the effects of prescribed fire on tree mortality in Florida Keys pine forests, using a factorial design with understory type, season, and year of burn as factors. We also used logistic regression to model the effects of burn season, fire severity, and tree dimensions on individual tree mortality. Despite limited statistical power due to problems in carrying out the full suite of planned experimental burns, associations with tree and fire variables were observed. Post-fire pine tree mortality was negatively correlated withmore » tree size and positively correlated with char height and percent crown scorch. Unlike post-fire mortality, tree mortality associated with storm surge from Hurricane Wilma was greater in the large size classes. Due to their influence on population structure and fuel dynamics, the size-selective mortality patterns following fire and storm surge have practical importance for using fire as a management tool in Florida Keys pinelands in the future, particularly when the threats to their continued existence from tropical storms and sea level rise are expected to increase.« less

Fires and Burns Involving Home Medical Oxygen

MedlinePlus

... nfpa.org Fires and Burns Involving Home Medical Oxygen The air is normally 21% oxygen. Oxygen is not flammable, but fire needs it to burn. ¾ When more oxygen is present, any fire that starts will burn ...

An Experimental Study on Burning Characteristics of n-Heptane/Ethanol Mixture Pool Fires in a Reduced Scaled Tunnel

NASA Astrophysics Data System (ADS)

Yozgatligil, Ahmet; Shafee, Sina

2016-11-01

Fire accidents in recent decades have drawn attention to safety issues associated with the design, construction and maintenance of tunnels. A reduced scale tunnel model constructed based on Froude scaling technique is used in the current work. Mixtures of n-heptane and ethanol are burned with ethanol volumetric fraction up to 30 percent and the longitudinal ventilation velocity varying from 0.5 to 2.5 m/s. The burning rates of the pool fires are measured using a precision load cell. The heat release rates of the fires are calculated according to oxygen calorimetry method and the temperature distributions inside the tunnel are also measured. Results of the experiments show that the ventilation velocity variation has a significant effect on the pool fire burning rate, smoke temperature and the critical ventilation velocity. With increased oxygen depletion in case of increased ethanol content of blended pool fires, the quasi-steady heat release rate values tend to increase as well as the ceiling temperatures while the combustion duration decreases.

The Big Burn: C Emissions from the Northern Rockies 1910 Fires

NASA Astrophysics Data System (ADS)

Walsh, E.; Hudiburg, T. W.

2017-12-01

The forest fires in August of 1910 were one of the greatest fire events in modern U.S. history. The Big Burn of northern Idaho and northwest Montana overwhelmed the burgeoning U.S. Forest Service suppression efforts and would ultimately harden the policy of fire suppression in the United States that prevails today. The fire burned 12k km2 (approximately the size of Connecticut) in two days with an estimated loss of 8 billion board feet of timber valued at $329 million (2016 dollars). Though one of the greatest natural events in U.S. history, little research has focused on the effect of the fires on CO2 emissions and forest successional pathways of this region. Based on fire extents and timber mortality reports, we estimate the fire resulted in 11 Mg/ha in dead woody biomass and potentially as much as 52 Tg C (191 Tg CO2) released as direct emissions. This is 58%-116% above the average yearly direct carbon emissions due to fire during 2002-2012 in the CONUS. We modeled the subsequent fires and change in species composition providing a measure of the observed shift from white pine (Pinus monticola), western larch (Larix occidentalis) and fir (Abies spp.) to lodgepole pine (Pinus contorta). These models can provide biogeochemical and forest successional pathway context for future changes in forest composition and fire severity/extent due to climate change.

The smoke-fireplume model : tool for eventual application to prescribed burns and wildland fires.

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

Brown, D. F.; Dunn, W. E.; Lazaro, M. A.

Land managers are increasingly implementing strategies that employ the use of fire in prescribed burns to sustain ecosystems and plan to sustain the rate of increase in its use over the next five years. In planning and executing expanded use of fire in wildland treatment it is important to estimate the human health and safety consequences, property damage, and the extent of visibility degradation from the resulting conflagration-pyrolysis gases, soot and smoke generated during flaming, smoldering and/or glowing fires. Traditional approaches have often employed the analysis of weather observations and forecasts to determine whether a prescribed burn will affect populations,more » property, or protected Class I areas. However, the complexity of the problem lends itself to advanced PC-based models that are simple to use for both calculating the emissions from the burning of wildland fuels and the downwind dispersion of smoke and other products of pyrolysis, distillation, and/or fuels combustion. These models will need to address the effects of residual smoldering combustion, including plume dynamics and optical effects. In this paper, we discuss a suite of tools that can be applied for analyzing dispersion. These tools include the dispersion models FIREPLUME and SMOKE, together with the meteorological preprocessor SEBMET.« less

USGS Wildland Fire Workshop, EROS Data Center, Sioux Falls, SD, July 9-10, 1997.

DTIC Science & Technology

1998-04-01

Montana , began by providing a brief over- view of research done at the U.S. Forest Service laborato- ries in East Lansing, Michigan and Seattle...Ecology and Fire Effects Panel; the Modeling: Fire Spread, Smoke Plume Panel; and the Postfire Rehabilitation, Hazards Assessment, and Habitat ...endangered species and criti- cal biological habitats . Ongoing research also is evaluat- ing the influences of seasonal burns, frequency of burns

Recent Progress and Emerging Issues in Measuring and Modeling Biomass Burning Emissions

NASA Astrophysics Data System (ADS)

Yokelson, R. J.; Stockwell, C.; Veres, P. R.; Hatch, L. E.; Barsanti, K. C.; Simpson, I. J.; Blake, D. R.; Alvarado, M.; Kreidenweis, S. M.; Robinson, A. L.; Akagi, S. K.; McMeeking, G. R.; Stone, E.; Gilman, J.; Warneke, C.; Sedlacek, A. J.; Kleinman, L. I.

2013-12-01

Nine recent multi-PI campaigns (6 airborne, 3 laboratory) have quantified biomass burning emissions and the subsequent smoke evolution in unprecedented detail. Among these projects were the Fourth Fire Lab at Missoula Experiment (FLAME-4) and the DOE airborne campaign BBOP (Biomass Burning Observation Project). Between 2009 and 2013 a large selection of fuels and ecosystems were probed including: (1) 21 US prescribed fires in pine forests, chaparral, and shrublands; (2) numerous wildfires in the Pacific Northwest of the US; (3) 77 lab fires burning fuels collected from the sites of the prescribed fires; and (4) 158 lab fires burning authentic fuels in traditional cooking fires and advanced stoves; peat from Indonesia, Canada, and North Carolina; savanna grasses from Africa; temperate grasses from the US; crop waste from the US; rice straw from Taiwan, China, Malaysia, and California; temperate and boreal forest fuels collected in Montana and Alaska; chaparral fuels from California; trash; and tires. Instrumentation for gases included: FTIR, PTR-TOF-MS, 2D-GC and whole air sampling. Particle measurements included filter sampling (with IC, elemental carbon (EC), organic carbon (OC), and GC-MS) and numerous real-time measurements such as: HR-AMS (high-resolution aerosol MS), SP-AMS (soot particle AMS), SP2 (single particle soot photometer), SP-MS (single particle MS), ice nuclei, CCN (cloud condensation nuclei), water soluble OC, size distribution, and optical properties in the UV-VIS. New data include: emission factors for over 400 gases, black carbon (BC), brown carbon (BrC), organic aerosol (OA), ions, metals, EC, and OC; and details of particle morphology, mixing state, optical properties, size distributions, and cloud nucleating activity. Large concentrations (several ppm) of monoterpenes were present in fresh smoke. About 30-70% of the initially emitted gas-phase non-methane organic compounds were semivolatile and could not be identified with current technology. The detection rate for the sampled US prescribed fires was zero by burned area and <30% by active fire detection. Smoke evolution was measured for numerous gas-phase precursors and products, ozone, OA, ions, and BC and BrC mixing state. BC particles were coated within one hour and the smoke evolution was, in general, strongly impacted by the unidentified low volatility gases. An informative synthesis of lab and field fire data with fuels from the same sites was carried out. A preliminary comparison of wildfire and prescribed fire emissions will be presented. Novel schemes are under development to summarize the new emissions data for models, with limited mechanisms and parameterize fast, sub-grid processes. Key current issues to be discussed include: packaging/parameterizing the recent explosion of emissions/evolution data for use in model mechanisms; addressing fires not detected from space; addressing the large amount of unidentified semi-volatile gases emitted by all fires; and developing appropriate airborne and ground-based sampling scales/strategies for local-global models. We briefly summarize a recently funded project that will sample emissions and quantify biomass consumption by peat fires in Indonesia and a pending proposal for comprehensive sampling of cooking fires, brick kilns, garbage burning, diesel super-emitters, etc. in South Asia.

Climate change and future wildfire in the western USA: what model projections do and don't tell us

NASA Astrophysics Data System (ADS)

Littell, J. S.; McKenzie, D.; Cushman, S. A.; Wan, H. Y.

2017-12-01

We developed statistical climate-fire models describing area burned for 70 ecosections in the western U.S. Historically, these ecosections collectively represent a gradient of climate-fire relationships from purely fuel limited (characterized by antecedent positive water balance anomalies and/or negative energy balance anomalies) to purely flammability limited (characterized by antecedent negative water balance anomalies and/or positive energy balance anomalies). Sixty-eight ecosection linear models included significant climate predictors, and 56 ecosections satisfied regression diagnostics, yielding acceptable climate-fire models. There is considerable diversity in seasonality, dominant variables, and prevalence of lagged climatic terms in the climate-fire regression models, indicating variation in mechanisms of climate-fire linkages across ecosystems. This diversity, however, is not random - there is a clear pattern in the fuzzy set membership of the relative dominance of regression predictor variables. This pattern defines a fuel-flammability gradient of limitations, with a tendency toward warm season drought on the flammability end and a tendency toward antecedent moisture on the fuel end. Projected area burned under a multi-model composite future climate scenarios varies, with increasing area burned in 41 ecosections in the West by 2030-2059 (median 132% among 10 purely flammability limited ecosections, median 240% among 25 flammability limited systems with a fuel limitation component, and median 43% among 6 systems with equal control) but decreasing (median -119% among 13 fuel limited systems with a flammability component). For the period 2070-2099, the projected area burned increases much more in the flammability (769%) and flammability-fuel hybrid (442%) systems than those with joint control (139%), and continues to decrease (-178%) in fuel-flammability hybrid systems. Filtering the projected results with fire rotation limits projections biased high by the static assumptions of the statistical models. Exceedence probabilities for 95th%ile fire years increases for the 2040s and 2080s and are largest in exclusively flammability limited ecosections compared with other fuel controls.

Additional historical solid rocket motor burns

NASA Astrophysics Data System (ADS)

Wiedemann, Carsten; Homeister, Maren; Oswald, Michael; Stabroth, Sebastian; Klinkrad, Heiner; Vörsmann, Peter

2009-06-01

The use of orbital solid rocket motors (SRM) is responsible for the release of a high number of slag and Al 2O 3 dust particles which contribute to the space debris environment. This contribution has been modeled for the ESA space debris model MASTER (Meteoroid and Space Debris Terrestrial Environment Reference). The current model version, MASTER-2005, is based on the simulation of 1076 orbital SRM firings which mainly contributed to the long-term debris environment. SRM firings on very low earth orbits which produce only short living particles are not considered. A comparison of the modeled flux with impact data from returned surfaces shows that the shape and quantity of the modeled SRM dust distribution matches that of recent Hubble Space Telescope (HST) solar array measurements very well. However, the absolute flux level for dust is under-predicted for some of the analyzed Long Duration Exposure Facility (LDEF) surfaces. This indicates that some past SRM firings are not included in the current event database. Thus it is necessary to investigate, if additional historical SRM burns, like the retro-burn of low orbiting re-entry capsules, may be responsible for these dust impacts. The most suitable candidates for these firings are the large number of SRM retro-burns of return capsules. This paper focuses on the SRM retro-burns of Russian photoreconnaissance satellites, which were used in high numbers during the time of the LDEF mission. It is discussed which types of satellites and motors may have been responsible for this historical contribution. Altogether, 870 additional SRM retro-burns have been identified. An important task is the identification of such missions to complete the current event data base. Different types of motors have been used to de-orbit both large satellites and small film return capsules. The results of simulation runs are presented.

Impacts of prescribed fires on air quality over the Southeastern United States in spring based on modeling and ground/satellite measurements.

PubMed

Zeng, Tao; Wang, Yuhang; Yoshida, Yasuko; Tian, Di; Russell, Amistead G; Barnard, William R

2008-11-15

Prescribed burning is a large aerosol source in the southeastern United States. Its air quality impact is investigated using 3-D model simulations and analysis of ground and satellite observations. Fire emissions for 2002 are calculated based on a recently developed VISTAS emission inventory. March was selected for the investigation because it is the most active prescribed fire month. Inclusion of fire emissions significantly improved model performance. Model results show that prescribed fire emissions lead to approximately 50% enhancements of mean OC and EC concentrations in the Southeast and a daily increase of PM2.5 up to 25 microg m(-3), indicating that fire emissions can lead to PM2.5 nonattainment in affected regions. Surface enhancements of CO up to 200 ppbv are found. Fire count measurements from the moderate resolution imaging spectroradiometer (MODIS) onboard the NASA Terra satellite show large springtime burning in most states, which is consistent with the emission inventory. These measurements also indicate that the inventory may underestimate fire emissions in the summer.

Evaluating the impact of improvements to the FLAMBE smoke source model on forecasts of aerosol distribution from NAAPS

NASA Astrophysics Data System (ADS)

Hyer, E. J.; Reid, J. S.

2006-12-01

As more forecast models aim to include aerosol and chemical species, there is a need for source functions for biomass burning emissions that are accurate, robust, and operable in real-time. NAAPS is a global aerosol forecast model running every six hours and forecasting distributions of biomass burning, industrial sulfate, dust, and sea salt aerosols. This model is run operationally by the U.S. Navy as an aid to planning. The smoke emissions used as input to the model are calculated from the data collected by the FLAMBE system, driven by near-real-time active fire data from GOES WF_ABBA and MODIS Rapid Response. The smoke source function uses land cover data to predict properties of detected fires based on literature data from experimental burns. This scheme is very sensitive to the choice of land cover data sets. In areas of rapid land cover change, the use of static land cover data can produce artifactual changes in emissions unrelated to real changes in fire patterns. In South America, this change may be as large as 40% over five years. We demonstrate the impact of a modified land cover scheme on FLAMBE emissions and NAAPS forecasts, including a fire size algorithm developed using MODIS burned area data. We also describe the effects of corrections to emissions estimates for cloud and satellite coverage. We outline areas where existing data sources are incomplete and improvements are required to achieve accurate modeling of biomass burning emissions in real time.

HESFIRE: a global fire model to explore the role of anthropogenic and weather drivers

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

Le Page, Yannick LB; Morton, Douglas; Bond-Lamberty, Benjamin

Vegetation fires are a major driver of ecosystem dynamics and greenhouse gas emissions. Anticipating potential changes in fire activity and their impacts relies first on a realistic model of fire activity (e.g., fire incidence and interannual variability) and second on a model accounting for fire impacts (e.g., mortality and emissions). In this paper, we focus on our understanding of fire activity and describe a new fire model, HESFIRE (Human–Earth System FIRE), which integrates the influence of weather, vegetation characteristics, and human activities on fires in a stand-alone framework. It was developed with a particular emphasis on allowing fires to spreadmore » over consecutive days given their major contribution to burned areas in many ecosystems. A subset of the model parameters was calibrated through an optimization procedure using observation data to enhance our knowledge of regional drivers of fire activity and improve the performance of the model on a global scale. Modeled fire activity showed reasonable agreement with observations of burned area, fire seasonality, and interannual variability in many regions, including for spatial and temporal domains not included in the optimization procedure. Significant discrepancies are investigated, most notably regarding fires in boreal regions and in xeric ecosystems and also fire size distribution. The sensitivity of fire activity to model parameters is analyzed to explore the dominance of specific drivers across regions and ecosystems. The characteristics of HESFIRE and the outcome of its evaluation provide insights into the influence of anthropogenic activities and weather, and their interactions, on fire activity.« less

HESFIRE: a global fire model to explore the role of anthropogenic and weather drivers

DOE PAGES

Le Page, Yannick LB; Morton, Douglas; Bond-Lamberty, Benjamin; ...

2015-02-13

Vegetation fires are a major driver of ecosystem dynamics and greenhouse gas emissions. Anticipating potential changes in fire activity and their impacts relies first on a realistic model of fire activity (e.g., fire incidence and interannual variability) and second on a model accounting for fire impacts (e.g., mortality and emissions). In this paper, we focus on our understanding of fire activity and describe a new fire model, HESFIRE (Human–Earth System FIRE), which integrates the influence of weather, vegetation characteristics, and human activities on fires in a stand-alone framework. It was developed with a particular emphasis on allowing fires to spreadmore » over consecutive days given their major contribution to burned areas in many ecosystems. A subset of the model parameters was calibrated through an optimization procedure using observation data to enhance our knowledge of regional drivers of fire activity and improve the performance of the model on a global scale. Modeled fire activity showed reasonable agreement with observations of burned area, fire seasonality, and interannual variability in many regions, including for spatial and temporal domains not included in the optimization procedure. Significant discrepancies are investigated, most notably regarding fires in boreal regions and in xeric ecosystems and also fire size distribution. The sensitivity of fire activity to model parameters is analyzed to explore the dominance of specific drivers across regions and ecosystems. The characteristics of HESFIRE and the outcome of its evaluation provide insights into the influence of anthropogenic activities and weather, and their interactions, on fire activity.« less

PROPAGATOR: a synchronous stochastic wildfire propagation model with distributed computation engine

NASA Astrophysics Data System (ADS)

D´Andrea, M.; Fiorucci, P.; Biondi, G.; Negro, D.

2012-04-01

PROPAGATOR is a stochastic model of forest fire spread, useful as a rapid method for fire risk assessment. The model is based on a 2D stochastic cellular automaton. The domain of simulation is discretized using a square regular grid with cell size of 20x20 meters. The model uses high-resolution information such as elevation and type of vegetation on the ground. Input parameters are wind direction, speed and the ignition point of fire. The simulation of fire propagation is done via a stochastic mechanism of propagation between a burning cell and a non-burning cell belonging to its neighbourhood, i.e. the 8 adjacent cells in the rectangular grid. The fire spreads from one cell to its neighbours with a certain base probability, defined using vegetation types of two adjacent cells, and modified by taking into account the slope between them, wind direction and speed. The simulation is synchronous, and takes into account the time needed by the burning fire to cross each cell. Vegetation cover, slope, wind speed and direction affect the fire-propagation speed from cell to cell. The model simulates several mutually independent realizations of the same stochastic fire propagation process. Each of them provides a map of the area burned at each simulation time step. Propagator simulates self-extinction of the fire, and the propagation process continues until at least one cell of the domain is burning in each realization. The output of the model is a series of maps representing the probability of each cell of the domain to be affected by the fire at each time-step: these probabilities are obtained by evaluating the relative frequency of ignition of each cell with respect to the complete set of simulations. Propagator is available as a module in the OWIS (Opera Web Interfaces) system. The model simulation runs on a dedicated server and it is remote controlled from the client program, NAZCA. Ignition points of the simulation can be selected directly in a high-resolution, three-dimensional graphical representation of the Italian territory within NAZCA. The other simulation parameters, namely wind speed and direction, number of simulations, computing grid size and temporal resolution, can be selected from within the program interface. The output of the simulation is showed in real-time during the simulation, and are also available off-line and on the DEWETRA system, a Web GIS-based system for environmental risk assessment, developed according to OGC-INSPIRE standards. The model execution is very fast, providing a full prevision for the scenario in few minutes, and can be useful for real-time active fire management and suppression.

Interactions among wildland fires in a long-established Sierra Nevada natural fire area

USGS Publications Warehouse

Collins, B.M.; Miller, J.D.; Thode, A.E.; Kelly, M.; van Wagtendonk, J.W.; Stephens, S.L.

2009-01-01

We investigate interactions between successive naturally occurring fires, and assess to what extent the environments in which fires burn influence these interactions. Using mapped fire perimeters and satellite-based estimates of post-fire effects (referred to hereafter as fire severity) for 19 fires burning relatively freely over a 31-year period, we demonstrate that fire as a landscape process can exhibit self-limiting characteristics in an upper elevation Sierra Nevada mixed conifer forest. We use the term 'self-limiting' to refer to recurring fire as a process over time (that is, fire regime) consuming fuel and ultimately constraining the spatial extent and lessening fire-induced effects of subsequent fires. When the amount of time between successive adjacent fires is under 9 years, and when fire weather is not extreme (burning index <34.9), the probability of the latter fire burning into the previous fire area is extremely low. Analysis of fire severity data by 10-year periods revealed a fair degree of stability in the proportion of area burned among fire severity classes (unchanged, low, moderate, high). This is in contrast to a recent study demonstrating increasing high-severity burning throughout the Sierra Nevada from 1984 to 2006, which suggests freely burning fires over time in upper elevation Sierra Nevada mixed conifer forests can regulate fire-induced effects across the landscape. This information can help managers better anticipate short- and long-term effects of allowing naturally ignited fires to burn, and ultimately, improve their ability to implement Wildland Fire Use programs in similar forest types. ?? 2008 Springer Science+Business Media, LLC.

Modelling the impacts of reoccurring fires in tropical savannahs using Biome-BGC.

NASA Astrophysics Data System (ADS)

Fletcher, Charlotte; Petritsch, Richard; Pietsch, Stephan

2010-05-01

Fires are a dominant feature of tropical savannahs and have occurred throughout history by natural as well as human-induced means. These fires have a profound influence on the landscape in terms of flux dynamics and vegetative species composition. This study attempts to understand the impacts of fire regimes on flux dynamics and vegetation composition in savannahs using the Biome-BGC model. The Batéké Plateau, Gabon - an area of savannah grasslands in the Congo basin, serves as a case-study. To achieve model validation for savannahs, data sets from stands with differing levels of past burning are used. It is hypothesised that the field measurements from those stands with lower-levels of past burning will correlate with the Biome-BGC model output, meaning that the model is validated for the savannah excluding fire regimes. However, in reality, fire is frequent in the savannah. Data on past fire events are available from the Moderate Resolution Imaging Spectroradiometer (MODIS) to provide the fire regimes of the model. As the field data-driven measurements of the burnt stands are influenced by fire in the savannah, this will therefore result in a Biome-BGC model validated for the impacts of fire on savannah ecology. The validated model can then be used to predict the savannah's flux dynamics under the fire scenarios expected with climate and/or human impact change.

Space-Based Sensorweb Monitoring of Wildfires in Thailand

NASA Technical Reports Server (NTRS)

Chien, Steve; Doubleday, Joshua; Mclaren, David; Davies, Ashley; Tran, Daniel; Tanpipat, Veerachai; Akaakara, Siri; Ratanasuwan, Anuchit; Mandl, Daniel

2011-01-01

We describe efforts to apply sensorweb technologies to the monitoring of forest fires in Thailand. In this approach, satellite data and ground reports are assimilated to assess the current state of the forest system in terms of forest fire risk, active fires, and likely progression of fires and smoke plumes. This current and projected assessment can then be used to actively direct sensors and assets to best acquire further information. This process operates continually with new data updating models of fire activity leading to further sensing and updating of models. As the fire activity is tracked, products such as active fire maps, burn scar severity maps, and alerts are automatically delivered to relevant parties.We describe the current state of the Thailand Fire Sensorweb which utilizes the MODIS-based FIRMS system to track active fires and trigger Earth Observing One / Advanced Land Imager to acquire imagery and produce active fire maps, burn scar severity maps, and alerts. We describe ongoing work to integrate additional sensor sources and generate additional products.

Using cellular automata to simulate forest fire propagation in Portugal

NASA Astrophysics Data System (ADS)

Freire, Joana; daCamara, Carlos

2017-04-01

Wildfires in the Mediterranean region have severe damaging effects mainly due to large fire events [1, 2]. When restricting to Portugal, wildfires have burned over 1:4 million ha in the last decade. Considering the increasing tendency in the extent and severity of wildfires [1, 2], the availability of modeling tools of fire episodes is of crucial importance. Two main types of mathematical models are generally available, namely deterministic and stochastic models. Deterministic models attempt a description of fires, fuel and atmosphere as multiphase continua prescribing mass, momentum and energy conservation, which typically leads to systems of coupled PDEs to be solved numerically on a grid. Simpler descriptions, such as FARSITE, neglect the interaction with atmosphere and propagate the fire front using wave techniques. One of the most important stochastic models are Cellular Automata (CA), in which space is discretized into cells, and physical quantities take on a finite set of values at each cell. The cells evolve in discrete time according to a set of transition rules, and the states of the neighboring cells. In the present work, we implement and then improve a simple and fast CA model designed to operationally simulate wildfires in Portugal. The reference CA model chosen [3] has the advantage of having been applied successfully in other Mediterranean ecosystems, namely to historical fires in Greece. The model is defined on a square grid with propagation to 8 nearest and next-nearest neighbors, where each cell is characterized by 4 possible discrete states, corresponding to burning, not-yet burned, fuel-free and completely burned cells, with 4 possible rules of evolution which take into account fuel properties, meteorological conditions, and topography. As a CA model, it offers the possibility to run a very high number of simulations in order to verify and apply the model, and is easily modified by implementing additional variables and different rules for the evolution of the fire spread. We present and discuss the application of the CA model to the "Tavira wildfire" in which approximately 24,800ha were burned. The event took place in summer 2012, between July 18 and 21, and spread in the Tavira and São Brás de Alportel municipalities of Algarve, a province in the southern coast of Portugal. [1] DaCamara et. al. (2014), International Journal of Wildland Fire 23. [2] Amraoui et. al. (2013), Forest Ecology and Management 294. [3] Alexandridis et. al. (2008), Applied Mathematics and Computation 204.

A Model-Based Approach to Infer Shifts in Regional Fire Regimes Over Time Using Sediment Charcoal Records

NASA Astrophysics Data System (ADS)

Itter, M.; Finley, A. O.; Hooten, M.; Higuera, P. E.; Marlon, J. R.; McLachlan, J. S.; Kelly, R.

2016-12-01

Sediment charcoal records are used in paleoecological analyses to identify individual local fire events and to estimate fire frequency and regional biomass burned at centennial to millenial time scales. Methods to identify local fire events based on sediment charcoal records have been well developed over the past 30 years, however, an integrated statistical framework for fire identification is still lacking. We build upon existing paleoecological methods to develop a hierarchical Bayesian point process model for local fire identification and estimation of fire return intervals. The model is unique in that it combines sediment charcoal records from multiple lakes across a region in a spatially-explicit fashion leading to estimation of a joint, regional fire return interval in addition to lake-specific local fire frequencies. Further, the model estimates a joint regional charcoal deposition rate free from the effects of local fires that can be used as a measure of regional biomass burned over time. Finally, the hierarchical Bayesian approach allows for tractable error propagation such that estimates of fire return intervals reflect the full range of uncertainty in sediment charcoal records. Specific sources of uncertainty addressed include sediment age models, the separation of local versus regional charcoal sources, and generation of a composite charcoal record The model is applied to sediment charcoal records from a dense network of lakes in the Yukon Flats region of Alaska. The multivariate joint modeling approach results in improved estimates of regional charcoal deposition with reduced uncertainty in the identification of individual fire events and local fire return intervals compared to individual lake approaches. Modeled individual-lake fire return intervals range from 100 to 500 years with a regional interval of roughly 200 years. Regional charcoal deposition to the network of lakes is correlated up to 50 kilometers. Finally, the joint regional charcoal deposition rate exhibits changes over time coincident with major climatic and vegetation shifts over the past 10,000 years. Ongoing work will use the regional charcoal deposition rate to estimate changes in biomass burned as a function of climate variability and regional vegetation pattern.

Vegetation management with fire modifies peatland soil thermal regime.

PubMed

Brown, Lee E; Palmer, Sheila M; Johnston, Kerrylyn; Holden, Joseph

2015-05-01

Vegetation removal with fire can alter the thermal regime of the land surface, leading to significant changes in biogeochemistry (e.g. carbon cycling) and soil hydrology. In the UK, large expanses of carbon-rich upland environments are managed to encourage increased abundance of red grouse (Lagopus lagopus scotica) by rotational burning of shrub vegetation. To date, though, there has not been any consideration of whether prescribed vegetation burning on peatlands modifies the thermal regime of the soil mass in the years after fire. In this study thermal regime was monitored across 12 burned peatland soil plots over an 18-month period, with the aim of (i) quantifying thermal dynamics between burned plots of different ages (from <2 to 15 + years post burning), and (ii) developing statistical models to determine the magnitude of thermal change caused by vegetation management. Compared to plots burned 15 + years previously, plots recently burned (<2-4 years) showed higher mean, maximum and range of soil temperatures, and lower minima. Statistical models (generalised least square regression) were developed to predict daily mean and maximum soil temperature in plots burned 15 + years prior to the study. These models were then applied to predict temperatures of plots burned 2, 4 and 7 years previously, with significant deviations from predicted temperatures illustrating the magnitude of burn management effects. Temperatures measured in soil plots burned <2 years previously showed significant statistical disturbances from model predictions, reaching +6.2 °C for daily mean temperatures and +19.6 °C for daily maxima. Soil temperatures in plots burnt 7 years previously were most similar to plots burned 15 + years ago indicating the potential for soil temperatures to recover as vegetation regrows. Our findings that prescribed peatland vegetation burning alters soil thermal regime should provide an impetus for further research to understand the consequences of thermal regime change for carbon processing and release, and hydrological processes, in these peatlands. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Transport of Cs-137 from Boreal Biomass Burning in Summer of 2010

NASA Technical Reports Server (NTRS)

Strode, Sarah; Ott, Lesley; Nielsen, Eric; Pawson, Steven

2010-01-01

The summer of 2010 was a severe fire season in western Russia. Wildfires were detected in the Bryansk region, raising concerns that radionuclide contamination from the Chernobyl accident could be resuspended in the atmosphere. We simulate the transport of passive and particulate tracers of biomass burning from this region using the GEOS5 GOCART model driven by assimilated meteorology. Biomass burning emissions are based on MODIS fire detections. We validate the model against aerosol optical depth from MODIS. Using a range of estimates for Cs-137 emissions during wildfires, we estimate the downwind concentration and deposition of Cs-137 based on the emission ratios of Cs-137 to the simulated tracers. We discuss the sensitivity of our results to the location of the fires and the fraction of Cs-137 resuspended.

Negligible influence of spatial autocorrelation in the assessment of fire effects in a mixed conifer forest

USGS Publications Warehouse

van Mantgem, P.J.; Schwilk, D.W.

2009-01-01

Fire is an important feature of many forest ecosystems, although the quantification of its effects is compromised by the large scale at which fire occurs and its inherent unpredictability. A recurring problem is the use of subsamples collected within individual burns, potentially resulting in spatially autocorrelated data. Using subsamples from six different fires (and three unburned control areas) we show little evidence for strong spatial autocorrelation either before or after burning for eight measures of forest conditions (both fuels and vegetation). Additionally, including a term for spatially autocorrelated errors provided little improvement for simple linear models contrasting the effects of early versus late season burning. While the effects of spatial autocorrelation should always be examined, it may not always greatly influence assessments of fire effects. If high patch scale variability is common in Sierra Nevada mixed conifer forests, even following more than a century of fire exclusion, treatments designed to encourage further heterogeneity in forest conditions prior to the reintroduction of fire will likely be unnecessary.

Historic global biomass burning emissions for CMIP6 (BB4CMIP) based on merging satellite observations with proxies and fire models (1750-2015)

NASA Astrophysics Data System (ADS)

van Marle, Margreet J. E.; Kloster, Silvia; Magi, Brian I.; Marlon, Jennifer R.; Daniau, Anne-Laure; Field, Robert D.; Arneth, Almut; Forrest, Matthew; Hantson, Stijn; Kehrwald, Natalie M.; Knorr, Wolfgang; Lasslop, Gitta; Li, Fang; Mangeon, Stéphane; Yue, Chao; Kaiser, Johannes W.; van der Werf, Guido R.

2017-09-01

Fires have influenced atmospheric composition and climate since the rise of vascular plants, and satellite data have shown the overall global extent of fires. Our knowledge of historic fire emissions has progressively improved over the past decades due mostly to the development of new proxies and the improvement of fire models. Currently, there is a suite of proxies including sedimentary charcoal records, measurements of fire-emitted trace gases and black carbon stored in ice and firn, and visibility observations. These proxies provide opportunities to extrapolate emission estimates back in time based on satellite data starting in 1997, but each proxy has strengths and weaknesses regarding, for example, the spatial and temporal extents over which they are representative. We developed a new historic biomass burning emissions dataset starting in 1750 that merges the satellite record with several existing proxies and uses the average of six models from the Fire Model Intercomparison Project (FireMIP) protocol to estimate emissions when the available proxies had limited coverage. According to our approach, global biomass burning emissions were relatively constant, with 10-year averages varying between 1.8 and 2.3 Pg C yr-1. Carbon emissions increased only slightly over the full time period and peaked during the 1990s after which they decreased gradually. There is substantial uncertainty in these estimates, and patterns varied depending on choices regarding data representation, especially on regional scales. The observed pattern in fire carbon emissions is for a large part driven by African fires, which accounted for 58 % of global fire carbon emissions. African fire emissions declined since about 1950 due to conversion of savanna to cropland, and this decrease is partially compensated for by increasing emissions in deforestation zones of South America and Asia. These global fire emission estimates are mostly suited for global analyses and will be used in the Coupled Model Intercomparison Project Phase 6 (CMIP6) simulations.

Modelling Middle Infrared Thermal Imagery from Observed or Simulated Active Fire

NASA Astrophysics Data System (ADS)

Paugam, R.; Gastellu-Etchegorry, J. P.; Mell, W.; Johnston, J.; Filippi, J. B.

2016-12-01

The Fire Radiative Power (FRP) is used in the atmospheric and fire communities to estimate fire emission. For example, the current version of the emission inventory GFAS is using FRP observation from the MODIS sensors to derive daily global distribution of fire emissions. Although the FRP product is widely accepted, most of its theoretical justifications are still based on small scale burns. When up-scaling to large fires effects of view angle, canopy cover, or smoke absorption are still unknown. To cover those questions, we are building a system based on the DART radiative transfer model to simulate the middle infrared radiance emitted by a propagating fire front and propagating in the surrounding scene made of ambient vegetation and plume aerosols. The current version of the system was applied to fire ranging from a 1m2 to 7ha. The 3D fire scene used as input in DART is made of the flame, the vegetation (burnt and unburnt), and the plume. It can be either set up from [i] 3D physical based model scene (ie WFDS, mainly applicable for small scale burn), [ii] coupled 2D fire spread - atmospheric models outputs (eg ForeFire-MesoNH) or [iii] derived from thermal imageries observations (here plume effects are not considered). In the last two cases, as the complexity of physical processes occurring in the flame (in particular soot formation and emission) is not to solved, the flames structures are parameterized with (a) temperature and soot concentration based on empirical derived profiles and (b) 3D triangular shape hull interpolated at the fire front location. Once the 3D fire scene is set up, DART is then used to render thermal imageries in the middle infrared. Using data collected from burns conducted at different scale, the modelled thermal imageries are compared against observations, and effects of view angle are discussed.

Climate vs. carbon dioxide controls on biomass burning: a model analysis of the glacial-interglacial contrast

NASA Astrophysics Data System (ADS)

Calvo, M. Martin; Prentice, I. C.; Harrison, S. P.

2014-02-01

Climate controls fire regimes through its influence on the amount and types of fuel present and their dryness; CO2 availability, in turn, constrains primary production by limiting photosynthetic activity in plants. However, although fuel accumulation depends on biomass production, and hence CO2 availability, the links between atmospheric CO2 and biomass burning are not well known. Here a fire-enabled dynamic global vegetation model (the Land surface Processes and eXchanges model, LPX) is used to attribute glacial-interglacial changes in biomass burning to CO2 increase, which would be expected to increase primary production and therefore fuel loads even in the absence of climate change, vs. climate change effects. Four general circulation models provided Last Glacial Maximum (LGM) climate anomalies - that is, differences from the pre-industrial (PI) control climate - from the Palaeoclimate Modelling Intercomparison Project Phase 2, allowing the construction of four scenarios for LGM climate. Modelled carbon fluxes in biomass burning were corrected for the model's observed biases in contemporary biome-average values. With LGM climate and low CO2 (185 ppm) effects included, the modelled global flux was 70 to 80% lower at the LGM than in PI time. LGM climate with pre-industrial CO2 (280 ppm) however yielded unrealistic results, with global and Northern Hemisphere biomass burning fluxes greater than in the pre-industrial climate. Using the PI CO2 concentration increased the modelled LGM biomass burning fluxes for all climate models and latitudinal bands to between four and ten times their values under LGM CO2 concentration. It is inferred that a substantial part of the increase in biomass burning after the LGM must be attributed to the effect of increasing CO2 concentration on productivity and fuel load. Today, by analogy, both rising CO2 and global warming must be considered as risk factors for increasing biomass burning. Both effects need to be included in models to project future fire risks.

Effects of biotic feedback and harvest management on boreal forest fire activity under climate change.

PubMed

Krawchuk, Meg A; Cumming, Steve G

2011-01-01

Predictions of future fire activity over Canada's boreal forests have primarily been generated from climate data following assumptions that direct effects of weather will stand alone in contributing to changes in burning. However, this assumption needs explicit testing. First, areas recently burned can be less likely to burn again in the near term, and this endogenous regulation suggests the potential for self-limiting, negative biotic feedback to regional climate-driven increases in fire. Second, forest harvest is ongoing, and resulting changes in vegetation structure have been shown to affect fire activity. Consequently, we tested the assumption that fire activity will be driven by changes in fire weather without regulation by biotic feedback or regional harvest-driven changes in vegetation structure in the mixedwood boreal forest of Alberta, Canada, using a simulation experiment that includes the interaction of fire, stand dynamics, climate change, and clear cut harvest management. We found that climate change projected with fire weather indices calculated from the Canadian Regional Climate Model increased fire activity, as expected, and our simulations established evidence that the magnitude of regional increase in fire was sufficient to generate negative feedback to subsequent fire activity. We illustrate a 39% (1.39-fold) increase in fire initiation and 47% (1.47-fold) increase in area burned when climate and stand dynamics were included in simulations, yet 48% (1.48-fold) and 61% (1.61-fold) increases, respectively, when climate was considered alone. Thus, although biotic feedbacks reduced burned area estimates in important ways, they were secondary to the direct effect of climate on fire. We then show that ongoing harvest management in this region changed landscape composition in a way that led to reduced fire activity, even in the context of climate change. Although forest harvesting resulted in decreased regional fire activity when compared to unharvested conditions, forest composition and age structure was shifted substantially, illustrating a trade-off between management goals to minimize fire and conservation goals to emulate natural disturbance.

Measuring short-term post-fire forest recovery across a burn severity gradient in a mixed pine-oak forest using multi-sensor remote sensing techniques

DOE PAGES

Meng, Ran; Wu, Jin; Zhao, Feng; ...

2018-06-01

Understanding post-fire forest recovery is pivotal to the study of forest dynamics and global carbon cycle. Field-based studies indicated a convex response of forest recovery rate to burn severity at the individual tree level, related with fire-induced tree mortality; however, these findings were constrained in spatial/temporal extents, while not detectable by traditional optical remote sensing studies, largely attributing to the contaminated effect from understory recovery. For this work, we examined whether the combined use of multi-sensor remote sensing techniques (i.e., 1m simultaneous airborne imaging spectroscopy and LiDAR and 2m satellite multi-spectral imagery) to separate canopy recovery from understory recovery wouldmore » enable to quantify post-fire forest recovery rate spanning a large gradient in burn severity over large-scales. Our study was conducted in a mixed pine-oak forest in Long Island, NY, three years after a top-killing fire. Our studies remotely detected an initial increase and then decline of forest recovery rate to burn severity across the burned area, with a maximum canopy area-based recovery rate of 10% per year at moderate forest burn severity class. More intriguingly, such remotely detected convex relationships also held at species level, with pine trees being more resilient to high burn severity and having a higher maximum recovery rate (12% per year) than oak trees (4% per year). These results are one of the first quantitative evidences showing the effects of fire adaptive strategies on post-fire forest recovery, derived from relatively large spatial-temporal domains. Our study thus provides the methodological advance to link multi-sensor remote sensing techniques to monitor forest dynamics in a spatially explicit manner over large-scales, with important implications for fire-related forest management, and for constraining/benchmarking fire effect schemes in ecological process models.« less

Measuring short-term post-fire forest recovery across a burn severity gradient in a mixed pine-oak forest using multi-sensor remote sensing techniques

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

Meng, Ran; Wu, Jin; Zhao, Feng

Understanding post-fire forest recovery is pivotal to the study of forest dynamics and global carbon cycle. Field-based studies indicated a convex response of forest recovery rate to burn severity at the individual tree level, related with fire-induced tree mortality; however, these findings were constrained in spatial/temporal extents, while not detectable by traditional optical remote sensing studies, largely attributing to the contaminated effect from understory recovery. For this work, we examined whether the combined use of multi-sensor remote sensing techniques (i.e., 1m simultaneous airborne imaging spectroscopy and LiDAR and 2m satellite multi-spectral imagery) to separate canopy recovery from understory recovery wouldmore » enable to quantify post-fire forest recovery rate spanning a large gradient in burn severity over large-scales. Our study was conducted in a mixed pine-oak forest in Long Island, NY, three years after a top-killing fire. Our studies remotely detected an initial increase and then decline of forest recovery rate to burn severity across the burned area, with a maximum canopy area-based recovery rate of 10% per year at moderate forest burn severity class. More intriguingly, such remotely detected convex relationships also held at species level, with pine trees being more resilient to high burn severity and having a higher maximum recovery rate (12% per year) than oak trees (4% per year). These results are one of the first quantitative evidences showing the effects of fire adaptive strategies on post-fire forest recovery, derived from relatively large spatial-temporal domains. Our study thus provides the methodological advance to link multi-sensor remote sensing techniques to monitor forest dynamics in a spatially explicit manner over large-scales, with important implications for fire-related forest management, and for constraining/benchmarking fire effect schemes in ecological process models.« less

Theoretical evaluation of burns to the human respiratory tract due to inhalation of hot gas in the early stage of fires.

PubMed

Lv, Yong-Gang; Liu, Jing; Zhang, Jun

2006-06-01

A transient two-dimensional mathematical model for heat and water vapor transport across the respiratory tract of human body was established and applied to predict the thermal impact of inhaled hot gas to the nasal tissues during the early stage of fires. Influences of individual's physiological status and environment variables were comprehensively investigated through numerical calculations. Burn evaluation was performed using the classical Henriques model to predict the time for thermal injury to occur. It was shown that decreasing the air velocity and increasing the respiratory rate is helpful to minimize the burn over the respiratory tract. The effect of relative humidity of surrounding dry hot air could be ignored in predicting burns for short duration exposures. Due to evaporation cooling on the mucousal membrane, the burn often occurs at certain positions underneath the skin of the tract near the inlet of the respiratory tract. Most of the tissues near the surface suffer injury immediately after exposure to fire, while in the deeper tissues, serious damage occurs after a relatively longer time period. The method presented in this paper may suggest a valuable approach to theoretically evaluate the injury of hot air to the human respiratory tract under various fire situations.

Multi-scale evaluation of the environmental controls on burn probability in a southern Sierra Nevada landscape

Treesearch

Sean A. Parks; Marc-Andre Parisien; Carol Miller

2011-01-01

We examined the scale-dependent relationship between spatial fire likelihood or burn probability (BP) and some key environmental controls in the southern Sierra Nevada, California, USA. Continuous BP estimates were generated using a fire simulation model. The correspondence between BP (dependent variable) and elevation, ignition density, fuels and aspect was evaluated...

Evaluating the coupled vegetation-fire model, LPJ-GUESS-SPITFIRE, against observed tropical forest biomass

NASA Astrophysics Data System (ADS)

Spessa, Allan; Forrest, Matthew; Werner, Christian; Steinkamp, Joerg; Hickler, Thomas

2013-04-01

Wildfire is a fundamental Earth System process. It is the most important disturbance worldwide in terms of area and variety of biomes affected; a major mechanism by which carbon is transferred from the land to the atmosphere (2-4 Pg per annum, equiv. 20-30% of global fossil fuel emissions over the last decade); and globally a significant source of particulate aerosols and trace greenhouse gases. Fire is also potentially important as a feedback in the climate system. If climate change favours more intense fire regimes, this would result in a net transfer of carbon from ecosystems to the atmosphere, as well as higher emissions, and under certain circumstances, increased troposphere ozone production- all contributing to positive climate-land surface feedbacks. Quantitative analysis of fire-vegetation-climate interactions has been held back until recently by a lack of consistent global data sets on fire, and by the underdeveloped state of dynamic vegetation-fire modelling. Dynamic vegetation-fire modelling is an essential part of our forecasting armory for examining the possible impacts of climate, fire regimes and land-use on ecosystems and emissions from biomass burning beyond the observation period, as part of future climate or paleo-climate studies. LPJ-GUESS is a process-based model of vegetation dynamics designed for regional to global applications. It combines features of the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM) with those of the General Ecosystem Simulator (GUESS) in a single, flexible modelling framework. The models have identical representations of eco-physiological and biogeochemical processes, including the hydrological cycle. However, they differ in the detail with which vegetation dynamics and canopy structure are simulated. Simplified, computationally efficient representations are used in the LPJ-DGVM, while LPJ-GUESS employs a gap-model approach, which better captures ecological succession and hence ecosystem changes due to disturbance such as fire. SPITFIRE (SPread and InTensity of FIRe and Emissions) mechanistically simulates the number of fires, area burnt, fire intensity, crown fires, fire-induced plant mortality, and emissions of carbon, trace gases and aerosols from biomass burning. Originally developed as an embedded model within LPJ-DGVM, SPITFIRE has since been coupled to LPJ-GUESS. However, neither LPJ-DGVM-SPITFIRE nor LPJ-GUESS-SPITFIRE has been fully benchmarked, especially in terms of how well each model simulates vegetation patterns and biomass in areas where fire is known to be important. This information is crucial if we are to have confidence in the models in forecasting fire, emissions from biomass burning and fire-climate impacts on ecosystems. Here we report on the benchmarking of the LPJ-GUESS-SPITFIRE model. We benchmarked LPJ-GUESS-SPITFIRE driven by a combination of daily reanalysis climate data (Sheffield 2012), monthly GFEDv3 burnt area data (1997-2009) (van der Werf et al. 2010) and long-term annual fire statistics (1901 to 2000) (Mouillot and Field 2005) against new Lidar-based biomass data for tropical forests and savannas (Saatchi et al. 2011; Baccini et al., 2012). Our new work has focused on revising the way GUESS simulates tree allometry, light penetration through the tree canopy and sapling recruitment, and how GUESS-SPITFIRE simulates fire-induced mortality, all based on recent literature, as well as a more explicit accounting of land cover change (JRC's GLC 2009). We present how these combined changes result in a much improved simulation of tree carbon across the tropics, including the Americas, Africa, Asia and Australia. Our results are compared with respect to more empirical-based approaches to calculating emissions from biomass burning. We discuss our findings in terms of improved forecasting of fire, emissions from biomass burning and fire-climate impacts on ecosystems.

Determining relative contributions of vegetation and topography to burn severity from LANDSAT imagery.

PubMed

Wu, Zhiwei; He, Hong S; Liang, Yu; Cai, Longyan; Lewis, Bernard J

2013-10-01

Fire is a dominant process in boreal forest landscapes and creates a spatial patch mosaic with different burn severities and age classes. Quantifying effects of vegetation and topography on burn severity provides a scientific basis on which forest fire management plans are developed to reduce catastrophic fires. However, the relative contribution of vegetation and topography to burn severity is highly debated especially under extreme weather conditions. In this study, we hypothesized that relationships of vegetation and topography to burn severity vary with fire size. We examined this hypothesis in a boreal forest landscape of northeastern China by computing the burn severity of 24 fire patches as the difference between the pre- and post-fire Normalized Difference Vegetation Index obtained from two Landsat TM images. The vegetation and topography to burn severity relationships were evaluated at three fire-size levels of small (<100 ha, n = 12), moderate (100-1,000 ha, n = 9), and large (>1,000 ha, n = 3). Our results showed that vegetation and topography to burn severity relationships were fire-size-dependent. The burn severity of small fires was primary controlled by vegetation conditions (e.g., understory cover), and the burn severity of large fires was strongly influenced by topographic conditions (e.g., elevation). For moderate fires, the relationships were complex and indistinguishable. Our results also indicated that the pattern trends of relative importance for both vegetation and topography factors were not dependent on fire size. Our study can help managers to design fire management plans according to vegetation characteristics that are found important in controlling burn severity and prioritize management locations based on the relative importance of vegetation and topography.

Determining Relative Contributions of Vegetation and Topography to Burn Severity from LANDSAT Imagery

NASA Astrophysics Data System (ADS)

Wu, Zhiwei; He, Hong S.; Liang, Yu; Cai, Longyan; Lewis, Bernard J.

2013-10-01

Fire is a dominant process in boreal forest landscapes and creates a spatial patch mosaic with different burn severities and age classes. Quantifying effects of vegetation and topography on burn severity provides a scientific basis on which forest fire management plans are developed to reduce catastrophic fires. However, the relative contribution of vegetation and topography to burn severity is highly debated especially under extreme weather conditions. In this study, we hypothesized that relationships of vegetation and topography to burn severity vary with fire size. We examined this hypothesis in a boreal forest landscape of northeastern China by computing the burn severity of 24 fire patches as the difference between the pre- and post-fire Normalized Difference Vegetation Index obtained from two Landsat TM images. The vegetation and topography to burn severity relationships were evaluated at three fire-size levels of small (<100 ha, n = 12), moderate (100-1,000 ha, n = 9), and large (>1,000 ha, n = 3). Our results showed that vegetation and topography to burn severity relationships were fire-size-dependent. The burn severity of small fires was primary controlled by vegetation conditions (e.g., understory cover), and the burn severity of large fires was strongly influenced by topographic conditions (e.g., elevation). For moderate fires, the relationships were complex and indistinguishable. Our results also indicated that the pattern trends of relative importance for both vegetation and topography factors were not dependent on fire size. Our study can help managers to design fire management plans according to vegetation characteristics that are found important in controlling burn severity and prioritize management locations based on the relative importance of vegetation and topography.

Spatial controls of occurrence and spread of wildfires in the Missouri Ozark Highlands.

PubMed

Yang, Jian; He, Hong S; Shifley, Stephen R

2008-07-01

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 biotic, abiotic, and anthropogenic constraints on the spatial pattern of fire occurrence with that on burn probability (i.e., the probability that fire will spread to a particular location). Spatial point pattern analysis and landscape succession fire model (LANDIS) were used to create maps to show the contrast. We quantified spatial controls on both fire occurrence and fire spread in the Midwest Ozark Highlands region, USA. This area exhibits a typical anthropogenic surface fire regime. We found that (1) human accessibility and land ownership were primary limiting factors in shaping clustered fire origin locations; (2) vegetation and topography had a negligible influence on fire occurrence in this anthropogenic regime; (3) burn probability was higher in grassland and open woodland than in closed-canopy forest, even though fire occurrence density was less in these vegetation types; and (4) biotic and abiotic factors were secondary descriptive ingredients for determining the spatial patterns of burn probability. This study demonstrates how fire occurrence and spread interact with landscape patterns to affect the spatial distribution of wildfire risk. The application of spatial point pattern data analysis would also be valuable to researchers working on landscape forest fire models to integrate historical ignition location patterns in fire simulation.

The impact of antecedent fire area on burned area in southern California coastal ecosystems

USGS Publications Warehouse

Price, Owen F.; Bradstock, Ross A.; Keeley, Jon E.; Syphard, Alexandra D.

2012-01-01

Frequent wildfire disasters in southern California highlight the need for risk reduction strategies for the region, of which fuel reduction via prescribed burning is one option. However, there is no consensus about the effectiveness of prescribed fire in reducing the area of wildfire. Here, we use 29 years of historical fire mapping to quantify the relationship between annual wildfire area and antecedent fire area in predominantly shrub and grassland fuels in seven southern California counties, controlling for annual variation in weather patterns. This method has been used elsewhere to measure leverage: the reduction in wildfire area resulting from one unit of prescribed fire treatment. We found little evidence for a leverage effect (leverage = zero). Specifically our results showed no evidence that wildfire area was negatively influenced by previous fires, and only weak relationships with weather variables rainfall and Santa Ana wind occurrences, which were variables included to control for inter-annual variation. We conclude that this is because only 2% of the vegetation burns each year and so wildfires rarely encounter burned patches and chaparral shrublands can carry a fire within 1 or 2 years after previous fire. Prescribed burning is unlikely to have much influence on fire regimes in this area, though targeted treatment at the urban interface may be effective at providing defensible space for protecting assets. These results fit an emerging global model of fire leverage which position California at the bottom end of a continuum, with tropical savannas at the top (leverage = 1: direct replacement of wildfire by prescribed fire) and Australian eucalypt forests in the middle (leverage ∼ 0.25).

Pattern and process of prescribed fires influence effectiveness at reducing wildfire severity in dry coniferous forests

USGS Publications Warehouse

Arkle, Robert S.; Pilliod, David S.; Welty, Justin L.

2012-01-01

We examined the effects of three early season (spring) prescribed fires on burn severity patterns of summer wildfires that occurred 1–3 years post-treatment in a mixed conifer forest in central Idaho. Wildfire and prescribed fire burn severities were estimated as the difference in normalized burn ratio (dNBR) using Landsat imagery. We used GIS derived vegetation, topography, and treatment variables to generate models predicting the wildfire burn severity of 1286–5500 30-m pixels within and around treated areas. We found that wildfire severity was significantly lower in treated areas than in untreated areas and significantly lower than the potential wildfire severity of the treated areas had treatments not been implemented. At the pixel level, wildfire severity was best predicted by an interaction between prescribed fire severity, topographic moisture, heat load, and pre-fire vegetation volume. Prescribed fire severity and vegetation volume were the most influential predictors. Prescribed fire severity, and its influence on wildfire severity, was highest in relatively warm and dry locations, which were able to burn under spring conditions. In contrast, wildfire severity peaked in cooler, more mesic locations that dried later in the summer and supported greater vegetation volume. We found considerable evidence that prescribed fires have landscape-level influences within treatment boundaries; most notable was an interaction between distance from the prescribed fire perimeter and distance from treated patch edges, which explained up to 66% of the variation in wildfire severity. Early season prescribed fires may not directly target the locations most at risk of high severity wildfire, but proximity of these areas to treated patches and the discontinuity of fuels following treatment may influence wildfire severity and explain how even low severity treatments can be effective management tools in fire-prone landscapes.

The impact of antecedent fire area on burned area in southern California coastal ecosystems.

PubMed

Price, Owen F; Bradstock, Ross A; Keeley, Jon E; Syphard, Alexandra D

2012-12-30

Frequent wildfire disasters in southern California highlight the need for risk reduction strategies for the region, of which fuel reduction via prescribed burning is one option. However, there is no consensus about the effectiveness of prescribed fire in reducing the area of wildfire. Here, we use 29 years of historical fire mapping to quantify the relationship between annual wildfire area and antecedent fire area in predominantly shrub and grassland fuels in seven southern California counties, controlling for annual variation in weather patterns. This method has been used elsewhere to measure leverage: the reduction in wildfire area resulting from one unit of prescribed fire treatment. We found little evidence for a leverage effect (leverage = zero). Specifically our results showed no evidence that wildfire area was negatively influenced by previous fires, and only weak relationships with weather variables rainfall and Santa Ana wind occurrences, which were variables included to control for inter-annual variation. We conclude that this is because only 2% of the vegetation burns each year and so wildfires rarely encounter burned patches and chaparral shrublands can carry a fire within 1 or 2 years after previous fire. Prescribed burning is unlikely to have much influence on fire regimes in this area, though targeted treatment at the urban interface may be effective at providing defensible space for protecting assets. These results fit an emerging global model of fire leverage which position California at the bottom end of a continuum, with tropical savannas at the top (leverage = 1: direct replacement of wildfire by prescribed fire) and Australian eucalypt forests in the middle (leverage ~ 0.25). Copyright © 2012 Elsevier Ltd. All rights reserved.

A foundation for initial attack simulation: the Fried and Fried fire containment model

Treesearch

Jeremy S. Fried; Burton D. Fried

2010-01-01

The Fried and Fried containment algorithm, which models the effect of suppression efforts on fire growth, allows simulation of any mathematically representable fire shape, provides for "head" and "tail" attack tactics as well as parallel attack (building fireline parallel to but at some offset distance from the free-burning fire perimeter, alone and...

Weather Observation Systems and Efficiency of Fighting Forest Fires

NASA Astrophysics Data System (ADS)

Khabarov, N.; Moltchanova, E.; Obersteiner, M.

2007-12-01

Weather observation is an essential component of modern forest fire management systems. Satellite and in-situ based weather observation systems might help to reduce forest loss, human casualties and destruction of economic capital. In this paper, we develop and apply a methodology to assess the benefits of various weather observation systems on reductions of burned area due to early fire detection. In particular, we consider a model where the air patrolling schedule is determined by a fire hazard index. The index is computed from gridded daily weather data for the area covering parts Spain and Portugal. We conduct a number of simulation experiments. First, the resolution of the original data set is artificially reduced. The reduction of the total forest burned area associated with air patrolling based on a finer weather grid indicates the benefit of using higher spatially resolved weather observations. Second, we consider a stochastic model to simulate forest fires and explore the sensitivity of the model with respect to the quality of input data. The analysis of combination of satellite and ground monitoring reveals potential cost saving due to a "system of systems effect" and substantial reduction in burned area. Finally, we estimate the marginal improvement schedule for loss of life and economic capital as a function of the improved fire observing system.

Evaluating and monitoring forest fuel treatments using remote sensing applications in Arizona, U.S.A.

USGS Publications Warehouse

Petrakis, Roy; Villarreal, Miguel; Wu, Zhuoting; Hetzler, Robert; Middleton, Barry R.; Norman, Laura M.

2018-01-01

The practice of fire suppression across the western United States over the past century has led to dense forests, and when coupled with drought has contributed to an increase in large and destructive wildfires. Forest management efforts aimed at reducing flammable fuels through various fuel treatments can help to restore frequent fire regimes and increase forest resilience. Our research examines how different fuel treatments influenced burn severity and post-fire vegetative stand dynamics on the San Carlos Apache Reservation, in east-central Arizona, U.S.A. Our methods included the use of multitemporal remote sensing data and cloud computing to evaluate burn severity and post-fire vegetation conditions as well as statistical analyses. We investigated how forest thinning, commercial harvesting, prescribed burning, and resource benefit burning (managed wildfire) related to satellite measured burn severity (the difference Normalized Burn Ratio – dNBR) following the 2013 Creek Fire and used spectral measures of post-fire stand dynamics to track changes in land surface characteristics (i.e., brightness, greenness and wetness). We found strong negative relationships between dNBR and post-fire greenness and wetness, and a positive non-linear relationship between dNBR and brightness, with greater variability at higher severities. Fire severity and post-fire surface changes also differed by treatment type. Our results showed harvested and thinned sites that were not treated with prescribed fire had the highest severity fire. When harvesting was followed by a prescribed burn, the sites experienced lower burn severity and reduced post-fire changes in vegetation greenness and wetness. Areas that had previously experienced resource benefit burns had the lowest burn severities and the highest post-fire greenness measurements compared to all other treatments, except for where the prescribed burn had occurred. These results suggest that fire treatments may be most effective at reducing the probability of hazardous fire and increasing post-fire recovery. This research demonstrates the utility of remote sensing and spatial data to inform forest management, and how various fuel treatments can influence burn severity and post-fire vegetation response within ponderosa pine forests across the southwestern U.S.

Brazil Fire Characterization and Burn Area Estimation Using the Airborne Infrared Disaster Assessment (AIRDAS) System

NASA Technical Reports Server (NTRS)

Brass, J. A.; Riggan, P. J.; Ambrosia, V. G.; Lockwood, R. N.; Pereira, J. A.; Higgins, R. G.; Peterson, David L. (Technical Monitor)

1995-01-01

Remotely sensed estimations of regional and global emissions from biomass combustion have been used to characterize fire behavior, determine fire intensity, and estimate burn area. Highly temporal, low resolution satellite data have been used to calculate estimates of fire numbers and area burned. These estimates of fire activity and burned area have differed dramatically, resulting in a wide range of predictions on the ecological and environmental impacts of fires. As part of the Brazil/United States Fire Initiative, an aircraft campaign was initiated in 1992 and continued in 1994. This multi-aircraft campaign was designed to assist in the characterization of fire activity, document fire intensity and determine area burned over prescribed, agricultural and wildland fires in the savanna and forests of central Brazil. Using a unique, multispectral scanner (AIRDAS), designed specifically for fire characterization, a variety of fires and burned areas were flown with a high spatial and high thermal resolution scanner. The system was used to measure flame front size, rate of spread, ratio of smoldering to flaming fronts and fire intensity. In addition, long transects were flown to determine the size of burned areas within the cerrado and transitional ecosystems. The authors anticipate that the fire activity and burned area estimates reported here will lead to enhanced information for precise regional trace gas prediction.

Modelling the role of fires in the terrestrial carbon balance by incorporating SPITFIRE into the global vegetation modelORCHIDEE - Part 1: Simulating historical global burned area and fire regimes

Treesearch

C. Yue; P. Ciais; P. Cadule; K. Thonicke; S. Archibald; B. Poulter; W. M. Hao; S. Hantson; F. Mouillot; P. Friedlingstein; F. Maignan; N. Viovy

2014-01-01

Fire is an important global ecological process that influences the distribution of biomes, with consequences for carbon, water, and energy budgets. Therefore it is impossible to appropriately model the history and future of the terrestrial ecosystems and the climate system without including fire. This study incorporates the process-based prognostic fire module SPITFIRE...

Interactive effects of climate, hydrology and fire on nitrogen retention and export in coastal California chaparral

NASA Astrophysics Data System (ADS)

Hanan, E. J.; Schimel, J.; Tague, C.

2012-12-01

Fire is a major restructuring force in Mediterranean-type ecosystems, inducing nutrient redistribution that is frequently invoked as a driver of ecosystem recovery. Fire regimes are expected to change with climate warming and associated droughts. To study watershed responses to high severity landscape fire, we combined ground-based sampling of soil nitrogen dynamics with modeling in two burned, chaparral-dominated watersheds. These two watersheds, Mission Canyon and Rattlesnake Canyon, span the foothills of the Santa Ynez Mountains in Santa Barbara County, California, and large portions of both watersheds burned in November 2008 and/or May 2009. We established fifteen burned and three unburned plots in November 2009 and monitored them on a monthly basis through June 2011 for a variety of ecosystem properties including water content, soil and foliar carbon and nitrogen, soil pH, exchangeable inorganic nitrogen, and microbial biomass. We then used the GIS-based hydro-biogeochemical model, Regional Hydro-Ecologic Simulation System (RHESSys) to to evaluate the effects of fire season, climate and hydrology on biogeochemical fluxes across the fire-scarred watersheds. Fires were imposed at the beginning and end of the growing season under various climates. Soil samples collected prior to the onset of rain were relatively enriched in ammonium, presumably due to ash residue deposition. Storm events then stimulated nitrification and pulses of mineralization. Ephemeral herbs established quickly following the first post-fire rain events, thereby maintaining ecosystem nutrient capital as shrubs gradually returned. Nitrate production was significantly enhanced in burned chaparral perhaps because fires elevated soil pH, which can both raise the solubility of soil organic matter, and stimulate nitrification, or perhaps because fires released nitrifying bacteria from competition with vegetation for ammonium. Overall however, nitrogen retention and export varied among plots, highlighting the complexity of ecosystem response to fire. Modeling results suggest that chaparral nutrients pools recover more slowly when fires occur at the end of the growing season, prior to the hot, dry summer. Thus climate impacts on the timing of fire are likely to alter trajectories of ecosystem recovery.

Large forest fires in Canada, 1959-1997

NASA Astrophysics Data System (ADS)

Stocks, B. J.; Mason, J. A.; Todd, J. B.; Bosch, E. M.; Wotton, B. M.; Amiro, B. D.; Flannigan, M. D.; Hirsch, K. G.; Logan, K. A.; Martell, D. L.; Skinner, W. R.

2002-01-01

A Large Fire Database (LFDB), which includes information on fire location, start date, final size, cause, and suppression action, has been developed for all fires larger than 200 ha in area for Canada for the 1959-1997 period. The LFDB represents only 3.1% of the total number of Canadian fires during this period, the remaining 96.9% of fires being suppressed while <200 ha in size, yet accounts for ˜97% of the total area burned, allowing a spatial and temporal analysis of recent Canadian landscape-scale fire impacts. On average ˜2 million ha burned annually in these large fires, although more than 7 million ha burned in some years. Ecozones in the boreal and taiga regions experienced the greatest areas burned, with an average of 0.7% of the forested land burning annually. Lightning fires predominate in northern Canada, accounting for 80% of the total LFDB area burned. Large fires, although small in number, contribute substantially to area burned, most particularly in the boreal and taiga regions. The Canadian fire season runs from late April through August, with most of the area burned occurring in June and July due primarily to lightning fire activity in northern Canada. Close to 50% of the area burned in Canada is the result of fires that are not actioned due to their remote location, low values-at-risk, and efforts to accommodate the natural role of fire in these ecosystems. The LFDB is updated annually and is being expanded back in time to permit a more thorough analysis of long-term trends in Canadian fire activity.

Large forest fires in Canada, 1959-1997

NASA Astrophysics Data System (ADS)

Stocks, B. J.; Mason, J. A.; Todd, J. B.; Bosch, E. M.; Wotton, B. M.; Amiro, B. D.; Flannigan, M. D.; Hirsch, K. G.; Logan, K. A.; Martell, D. L.; Skinner, W. R.

2003-01-01

A Large Fire Database (LFDB), which includes information on fire location, start date, final size, cause, and suppression action, has been developed for all fires larger than 200 ha in area for Canada for the 1959-1997 period. The LFDB represents only 3.1% of the total number of Canadian fires during this period, the remaining 96.9% of fires being suppressed while <200 ha in size, yet accounts for ~97% of the total area burned, allowing a spatial and temporal analysis of recent Canadian landscape-scale fire impacts. On average ~2 million ha burned annually in these large fires, although more than 7 million ha burned in some years. Ecozones in the boreal and taiga regions experienced the greatest areas burned, with an average of 0.7% of the forested land burning annually. Lightning fires predominate in northern Canada, accounting for 80% of the total LFDB area burned. Large fires, although small in number, contribute substantially to area burned, most particularly in the boreal and taiga regions. The Canadian fire season runs from late April through August, with most of the area burned occurring in June and July due primarily to lightning fire activity in northern Canada. Close to 50% of the area burned in Canada is the result of fires that are not actioned due to their remote location, low values-at-risk, and efforts to accommodate the natural role of fire in these ecosystems. The LFDB is updated annually and is being expanded back in time to permit a more thorough analysis of long-term trends in Canadian fire activity.

The influence of weather and fuel type on the fuel composition of the area burned by forest fires in Ontario, 1996-2006.

PubMed

Podur, Justin J; Martell, David L

2009-07-01

Forest fires are influenced by weather, fuels, and topography, but the relative influence of these factors may vary in different forest types. Compositional analysis can be used to assess the relative importance of fuels and weather in the boreal forest. Do forest or wild land fires burn more flammable fuels preferentially or, because most large fires burn in extreme weather conditions, do fires burn fuels in the proportions they are available despite differences in flammability? In the Canadian boreal forest, aspen (Populus tremuloides) has been found to burn in less than the proportion in which it is available. We used the province of Ontario's Provincial Fuels Database and fire records provided by the Ontario Ministry of Natural Resources to compare the fuel composition of area burned by 594 large (>40 ha) fires that occurred in Ontario's boreal forest region, a study area some 430,000 km2 in size, between 1996 and 2006 with the fuel composition of the neighborhoods around the fires. We found that, over the range of fire weather conditions in which large fires burned and in a study area with 8% aspen, fires burn fuels in the proportions that they are available, results which are consistent with the dominance of weather in controlling large fires.

A new tool for fire managers: An electronic duff moisture meter

Treesearch

Peter R. Robichaud; Jim Bilskie

2004-01-01

Prescribed fires are increasingly being used to reduce hazardous fuels, a major objective of the National Fire Plan. Despite advancing technology and ever-improving models, fire managers still find it challenging to determine the right time for a prescribed burn.

Effects of fire and post-fire salvage logging on avian communities in conifer-dominated forests of the western United States

USGS Publications Warehouse

Kotliar, N.B.; Hejl, S.J.; Hutto, R.L.; Saab, V.; Melcher, Cynthia; McFadzen, M.E.; George, T.L.; Dobkin, D.S.

2002-01-01

Historically, fire was one of the most widespread natural disturbances in the western United States. More recently, however, significant anthropogenic activities, especially fire suppression and silvicultural practices, have altered fire regimes; as a result, landscapes and associated communities have changed as well. Herein, we review current knowledge of how fire and postfire salvaging practices affect avian communities in conifer-dominated forests of the western United States. Specifically, we contrast avian communities in (1) burned vs. unburned forest, and (2) unsalvaged vs. salvage-logged burns. We also examine how variation in burn characteristics (e.g., severity, age, size) and salvage logging can alter avian communities in burns.Of the 41 avian species observed in three or more studies comparing early postfire and adjacent unburned forests, 22% are consistently more abundant in burned forests, 34% are usually more abundant in unburned forests, and 44% are equally abundant in burned and unburned forests or have varied responses. In general, woodpeckers and aerial foragers are more abundant in burned forest, whereas most foliage-gleaning species are more abundant in unburned forests. Bird species that are frequently observed in stand-replacement burns are less common in understory burns; similarly, species commonly observed in unburned forests often decrease in abundance with increasing burn severity. Granivores and species common in open-canopy forests exhibit less consistency among studies. For all species, responses to tire may be influenced by a number of factors including burn severity, fire size and shape, proximity to unburned forests, pre-and post-fire cover types, and time since fire. In addition, postfire management can alter species’ responses to burns. Most cavity-nesting species do not use severely salvaged burns, whereas some cavity-nesters persist in partially salvaged burns. Early post fire specialists, in particular, appear to prefer unsalvaged burns. We discuss several alternatives to severe salvage-logging that will help provide habitat for cavity nesters.We provide an overview of critical research questions and design considerations crucial for evaluating the effects of prescribed fire and other anthropogenic disturbances, such as forest fragmentation. Management of native avifaunas may be most successful if natural disturbance regimes, including fire, are permitted to occur when possible. Natural fires could be augmented with practices, such as prescribed fire (including high-severity fire), that mimic inherent disturbance regimes.

Trends in fire risk and burned area in Brazil in the 20th century

NASA Astrophysics Data System (ADS)

Silva, P.; Bastos, A.; DaCamara, C.; Libonati, R.

2016-12-01

Fire has a significant contribution to the global greenhouse gas emissions and vast ecological and climatic impacts. Worldwide, Brazil is one of the areas most affected by fire, which highly influences the state of the vegetation cover, the ecological diversity of the region and has significant consequences to the global CO2 balance [1]. Hence, with the increasing evidence of human induced climate change, it becomes essential to understand the present and future trends of fire risk in Brazil. Although a large number of fires in Brazil are anthropogenic, it has been shown that the burned area is mainly controlled by meteorological conditions [2], therefore being partially determined by fire risk. In this study we use a fire danger index specifically tailored for the Brazilian climate and biome characteristics, the MFDI developed by INPE, to assess the patterns and trends of fire risk in Brazil. The index relies on values of maximum temperature, accumulated precipitation over different periods, minimum relative humidity and vegetation cover to estimate the likelihood of fire occurrence. We test the sensitivity of the index to different climate reanalyses and evaluate the trends in fire risk in Brazil during the past four decades for different biomes. We further assess the link between the calculated fire risk and observed fire occurrence and burned area. Finally, we compare the results with fire risk simulated by a regional climate model (RCA4 forced by EC-Earth from CORDEX) in order to evaluate its suitability for future projections of fire risk and burned area. [1] Bowman, D. M. et al. Fire in the earth system. Science, v. 324, p. 481-484, 24 apr. 2009. [2] Libonati, R. et al. An Algorithm for Burned Area Detection in the Brazilian Cerrado Using 4 μm MODIS Imagery. Remote Sensing, v. 7, p. 15782-15803, 2015.

Linking Satellite-Derived Fire Counts to Satellite-Derived Weather Data in Fire Prediction Models to Forecast Extreme Fires in Siberia

NASA Astrophysics Data System (ADS)

Westberg, David; Soja, Amber; Stackhouse, Paul, Jr.

2010-05-01

Fire is the dominant disturbance that precipitates ecosystem change in boreal regions, and fire is largely under the control of weather and climate. Boreal systems contain the largest pool of terrestrial carbon, and Russia holds 2/3 of the global boreal forests. Fire frequency, fire severity, area burned and fire season length are predicted to increase in boreal regions under climate change scenarios. Meteorological parameters influence fire danger and fire is a catalyst for ecosystem change. Therefore to predict fire weather and ecosystem change, we must understand the factors that influence fire regimes and at what scale these are viable. Our data consists of NASA Langley Research Center (LaRC)-derived fire weather indices (FWI) and National Climatic Data Center (NCDC) surface station-derived FWI on a domain from 50°N-80°N latitude and 70°E-170°W longitude and the fire season from April through October for the years of 1999, 2002, and 2004. Both of these are calculated using the Canadian Forest Service (CFS) FWI, which is based on local noon surface-level air temperature, relative humidity, wind speed, and daily (noon-noon) rainfall. The large-scale (1°) LaRC product uses NASA Goddard Earth Observing System version 4 (GEOS-4) reanalysis and NASA Global Precipitation Climatology Project (GEOS-4/GPCP) data to calculate FWI. CFS Natural Resources Canada uses Geographic Information Systems (GIS) to interpolate NCDC station data and calculate FWI. We compare the LaRC GEOS- 4/GPCP FWI and CFS NCDC FWI based on their fraction of 1° grid boxes that contain satellite-derived fire counts and area burned to the domain total number of 1° grid boxes with a common FWI category (very low to extreme). These are separated by International Geosphere-Biosphere Programme (IGBP) 1°x1° resolution vegetation types to determine and compare fire regimes in each FWI/ecosystem class and to estimate the fraction of each of the 18 IGBP ecosystems burned, which are dependent on the FWI. On days with fire counts, the domain total of 1°x1° grid boxes with and without daily fire counts and area burned are totaled. The fraction of 1° grid boxes with fire counts and area burned to the total number of 1° grid boxes having common FWI category and vegetation type are accumulated, and a daily mean for the burning season is calculated. The mean fire counts and mean area burned plots appear to be well related. The ultimate goal of this research is to assess the viability of large-scale (1°) data to be used to assess fire weather danger and fire regimes, so these data can be confidently used to predict future fire regimes using large-scale fire weather data. Specifically, we related large-scale fire weather, area burned, and the amount of fire-induced ecosystem change. Both the LaRC and CFS FWI showed gradual linear increase in fraction of grid boxes with fire counts and area burned with increasing FWI category, with an exponential increase in the higher FWI categories in some cases, for the majority of the vegetation types. Our analysis shows a direct correlation between increased fire activity and increased FWI, independent of time or the severity of the fire season. During normal and extreme fire seasons, we noticed the fraction of fire counts and area burned per 1° grid box increased with increasing FWI rating. Given this analysis, we are confident large-scale weather and climate data, in this case from the GEOS-4 reanalysis and the GPCP data sets, can be used to accurately assess future fire potential. This increases confidence in the ability of large-scale IPCC weather and climate scenarios to predict future fire regimes in boreal regions.

Large-Scale Aerosol Modeling and Analysis

DTIC Science & Technology

2010-09-30

Application of Earth Sciences Products” supports improvements in NAAPS physics and model initialization. The implementation of NAAPS, NAVDAS-AOD, FLAMBE ...Forecasting of Biomass-Burning Smoke: Description of and Lessons From the Fire Locating and Modeling of Burning Emissions ( FLAMBE ) Program, IEEE Journal of

Assessment of fire emission inventories during the South American Biomass Burning Analysis (SAMBBA) experiment

NASA Astrophysics Data System (ADS)

Pereira, Gabriel; Siqueira, Ricardo; Rosário, Nilton E.; Longo, Karla L.; Freitas, Saulo R.; Cardozo, Francielle S.; Kaiser, Johannes W.; Wooster, Martin J.

2016-06-01

Fires associated with land use and land cover changes release large amounts of aerosols and trace gases into the atmosphere. Although several inventories of biomass burning emissions cover Brazil, there are still considerable uncertainties and differences among them. While most fire emission inventories utilize the parameters of burned area, vegetation fuel load, emission factors, and other parameters to estimate the biomass burned and its associated emissions, several more recent inventories apply an alternative method based on fire radiative power (FRP) observations to estimate the amount of biomass burned and the corresponding emissions of trace gases and aerosols. The Brazilian Biomass Burning Emission Model (3BEM) and the Fire Inventory from NCAR (FINN) are examples of the first, while the Brazilian Biomass Burning Emission Model with FRP assimilation (3BEM_FRP) and the Global Fire Assimilation System (GFAS) are examples of the latter. These four biomass burning emission inventories were used during the South American Biomass Burning Analysis (SAMBBA) field campaign. This paper analyzes and inter-compared them, focusing on eight regions in Brazil and the time period of 1 September-31 October 2012. Aerosol optical thickness (AOT550 nm) derived from measurements made by the Moderate Resolution Imaging Spectroradiometer (MODIS) operating on board the Terra and Aqua satellites is also applied to assess the inventories' consistency. The daily area-averaged pyrogenic carbon monoxide (CO) emission estimates exhibit significant linear correlations (r, p > 0.05 level, Student t test) between 3BEM and FINN and between 3BEM_ FRP and GFAS, with values of 0.86 and 0.85, respectively. These results indicate that emission estimates in this region derived via similar methods tend to agree with one other. However, they differ more from the estimates derived via the alternative approach. The evaluation of MODIS AOT550 nm indicates that model simulation driven by 3BEM and FINN typically underestimate the smoke particle loading in the eastern region of Amazon forest, while 3BEM_FRP estimations to the area tend to overestimate fire emissions. The daily regional CO emission fluxes from 3BEM and FINN have linear correlation coefficients of 0.75-0.92, with typically 20-30 % higher emission fluxes in FINN. The daily regional CO emission fluxes from 3BEM_FRP and GFAS show linear correlation coefficients between 0.82 and 0.90, with a particularly strong correlation near the arc of deforestation in the Amazon rainforest. In this region, GFAS has a tendency to present higher CO emissions than 3BEM_FRP, while 3BEM_FRP yields more emissions in the area of soybean expansion east of the Amazon forest. Atmospheric aerosol optical thickness is simulated by using the emission inventories with two operational atmospheric chemistry transport models: the IFS from Monitoring Atmospheric Composition and Climate (MACC) and the Coupled Aerosol and Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modelling System (CCATT-BRAMS). Evaluation against MODIS observations shows a good representation of the general patterns of the AOT550 nm time series. However, the aerosol emissions from fires with particularly high biomass consumption still lead to an underestimation of the atmospheric aerosol load in both models.

A Large Underestimate of Formic Acid from Tropical Fires: Constraints from Space-Borne Measurements.

PubMed

Chaliyakunnel, S; Millet, D B; Wells, K C; Cady-Pereira, K E; Shephard, M W

2016-06-07

Formic acid (HCOOH) is one of the most abundant carboxylic acids and a dominant source of atmospheric acidity. Recent work indicates a major gap in the HCOOH budget, with atmospheric concentrations much larger than expected from known sources. Here, we employ recent space-based observations from the Tropospheric Emission Spectrometer with the GEOS-Chem atmospheric model to better quantify the HCOOH source from biomass burning, and assess whether fire emissions can help close the large budget gap for this species. The space-based data reveal a severe model HCOOH underestimate most prominent over tropical burning regions, suggesting a major missing source of organic acids from fires. We develop an approach for inferring the fractional fire contribution to ambient HCOOH and find, based on measurements over Africa, that pyrogenic HCOOH:CO enhancement ratios are much higher than expected from direct emissions alone, revealing substantial secondary organic acid production in fire plumes. Current models strongly underestimate (by 10 ± 5 times) the total primary and secondary HCOOH source from African fires. If a 10-fold bias were to extend to fires in other regions, biomass burning could produce 14 Tg/a of HCOOH in the tropics or 16 Tg/a worldwide. However, even such an increase would only represent 15-20% of the total required HCOOH source, implying the existence of other larger missing sources.

Biomass burning fuel consumption dynamics in the tropics and subtropics assessed from satellite

NASA Astrophysics Data System (ADS)

Andela, Niels; van der Werf, Guido R.; Kaiser, Johannes W.; van Leeuwen, Thijs T.; Wooster, Martin J.; Lehmann, Caroline E. R.

2016-06-01

Landscape fires occur on a large scale in (sub)tropical savannas and grasslands, affecting ecosystem dynamics, regional air quality and concentrations of atmospheric trace gasses. Fuel consumption per unit of area burned is an important but poorly constrained parameter in fire emission modelling. We combined satellite-derived burned area with fire radiative power (FRP) data to derive fuel consumption estimates for land cover types with low tree cover in South America, Sub-Saharan Africa, and Australia. We developed a new approach to estimate fuel consumption, based on FRP data from the polar-orbiting Moderate Resolution Imaging Spectroradiometer (MODIS) and the geostationary Spinning Enhanced Visible and Infrared Imager (SEVIRI) in combination with MODIS burned-area estimates. The fuel consumption estimates based on the geostationary and polar-orbiting instruments showed good agreement in terms of spatial patterns. We used field measurements of fuel consumption to constrain our results, but the large variation in fuel consumption in both space and time complicated this comparison and absolute fuel consumption estimates remained more uncertain. Spatial patterns in fuel consumption could be partly explained by vegetation productivity and fire return periods. In South America, most fires occurred in savannas with relatively long fire return periods, resulting in comparatively high fuel consumption as opposed to the more frequently burning savannas in Sub-Saharan Africa. Strikingly, we found the infrequently burning interior of Australia to have higher fuel consumption than the more productive but frequently burning savannas in northern Australia. Vegetation type also played an important role in explaining the distribution of fuel consumption, by affecting both fuel build-up rates and fire return periods. Hummock grasslands, which were responsible for a large share of Australian biomass burning, showed larger fuel build-up rates than equally productive grasslands in Africa, although this effect might have been partially driven by the presence of grazers in Africa or differences in landscape management. Finally, land management in the form of deforestation and agriculture also considerably affected fuel consumption regionally. We conclude that combining FRP and burned-area estimates, calibrated against field measurements, is a promising approach in deriving quantitative estimates of fuel consumption. Satellite-derived fuel consumption estimates may both challenge our current understanding of spatiotemporal fuel consumption dynamics and serve as reference datasets to improve biogeochemical modelling approaches. Future field studies especially designed to validate satellite-based products, or airborne remote sensing, may further improve confidence in the absolute fuel consumption estimates which are quickly becoming the weakest link in fire emission estimates.

Effects of oblique air flow on burning rates of square ethanol pool fires.

PubMed

Tao, Changfa; He, Yaping; Li, Yuan; Wang, Xishi

2013-09-15

The effects of downward airflow on the burning rate and/or burning intensity of square alcohol pool fires for different airflow speeds and directions have been studied experimentally in an inclined wind tunnel. An interesting flame-wrapping phenomenon, caused by impingement of air flow, was observed. The mass burning intensity was found to increase with the airflow speed and the impinging angle. The fuel pan rim temperatures were also measured to study the effect of wind direction and speed on heat transfer from the flame to the fuel source. A model based on heat transfer analysis was developed to correlate the burning intensity with the pan rim characteristic temperature. A good correlation was established between the model results and the experimental results. Copyright © 2013 Elsevier B.V. All rights reserved.

Fire decreases arthropod abundance but increases diversity: Early and late season prescribed fire effects in a Sierra Nevada mixed-conifer forest

USGS Publications Warehouse

Ferrenberg, Scott; Schwilk, Dylan W.; Knapp, Eric E.; Groth, Eric; Keeley, Jon E.

2006-01-01

Prior to fire suppression in the 20th century, the mixed-conifer forests of the Sierra Nevada, California, U.S.A., historically burned in frequent fires that typically occurred during the late summer and early fall. Fire managers have been attempting to restore natural ecosystem processes through prescription burning, and have often favored burning during the fall in order to mimic historical fire regimes. Increasingly, however, prescription burning is also being done during the late spring and early summer in order to expand the window of opportunity for needed fuel reduction burning. The effect of prescribed fires outside of the historical fire season on forest arthropods is not known. The objective of this study was to compare the short-term effects of prescribed fires ignited in the early and late fire season on forest floor arthropods. Arthropod abundance and diversity were assessed using pitfall trapping in replicated burn units in Sequoia National Park, California. Overall, abundance of arthropods was lower in the burn treatments than in the unburned control. However, diversity tended to be greater in the burn treatments. Fire also altered the relative abundances of arthropod feeding guilds. No significant differences in arthropod community structure were found between early and late season burn treatments. Instead, changes in the arthropod community appeared to be driven largely by changes in fuel loading, vegetation, and habitat heterogeneity, all of which differed more between the burned and unburned treatments than between early and late season burn treatments.

Modeling carbon-nutrient interactions during the early recovery of tundra after fire.

PubMed

Jiang, Yueyang; Rastetter, Edward B; Rocha, Adrian V; Pearce, Andrea R; Kwiatkowski, Bonnie L; Shaver, Gaius R

2015-09-01

Fire frequency has dramatically increased in the tundra of northern Alaska, USA, which has major implications for the carbon budget of the region and the functioning of these ecosystems, which support important wildlife species. We investigated the postfire succession of plant and soil carbon (C), nitrogen (N), and phosphorus (P) fluxes and stocks along a burn severity gradient in the 2007 Anaktuvuk River fire scar in northern Alaska. Modeling results indicated that the early regrowth of postfire tundra vegetation was limited primarily by its canopy photosynthetic potential, rather than nutrient availability, because of the initially low leaf area and relatively high inorganic N and P concentrations in soil. Our simulations indicated that the postfire recovery of tundra vegetation was sustained predominantly by the uptake of residual inorganic N (i.e., in the remaining ash), and the redistribution of N and P from soil organic matter to vegetation. Although residual nutrients in ash were higher in the severe burn than the moderate burn, the moderate burn recovered faster because of the higher remaining biomass and consequent photosynthetic potential. Residual nutrients in ash allowed both burn sites to recover and exceed the unburned site in both aboveground biomass and production five years after the fire. The investigation of interactions among postfire C, N, and P cycles has contributed to a mechanistic understanding of the response of tundra ecosystems to fire disturbance. Our study provided insight on how the trajectory of recovery of tundra from wildfire is regulated during early succession.

Anticipating the severity of the fire season in Northern Portugal using statistical models based on meteorological indices of fire danger

NASA Astrophysics Data System (ADS)

Nunes, Sílvia A.; DaCamara, Carlos C.; Turkman, Kamil F.; Ermida, Sofia L.; Calado, Teresa J.

2017-04-01

Like in other regions of Mediterranean Europe, climate and weather are major drivers of fire activity in Portugal. The aim of the present study is to assess the role played by meteorological factors on inter-annual variability of burned area over a region of Portugal characterized by large fire activity. Monthly cumulated values of burned area in August are obtained from the fire database of ICNF, the Portuguese authority for forests. The role of meteorological factors is characterized by means of Daily Severity Rating, DSR, an index of meteorological fire danger, which is derived from meteorological fields as obtained from ECMWF Interim Reanalysis. The study area is characterized by the predominance of forest, with high percentages of maritime pine and eucalyptus, two species with high flammability in summer. The time series of recorded burned area in August during 1980-2011 is highly correlated (correlation coefficient of 0.93) with the one for whole Portugal. First, a normal distribution model is fitted to the 32-year sample of decimal logarithms of monthly burned area. The model is improved by introducing two covariates:(1) the top-down meteorological factor (DSRtd) which consists of daily cumulated values of DSR since April 1 to July 31 and may be viewed as the cumulated stress on vegetation due to meteorological conditions during the pre-fire season; (2) the bottom-up factor (DSRbu) which consists of the square root of the mean of the squared daily deviations (restricted to days with positive departures of DSR from the corresponding long term mean) and may be viewed as the contribution of days characterized by extreme weather conditions favoring the onset and spreading of wildfires. Three different statistical models are then developed: the "climate anomaly" model, using DSRtd as covariate, the "weather anomaly", using DSRbu as covariate, and the "combined" model using both variables as covariates. These models are used to define background fire danger, fire weather danger and combined fire danger, respectively quantifying the contribution of DSRtd, DSRbu and both covariates to increasing or decreasing the probability of having extremely high/low values of burned area in August. Using the information obtained by the "combined" model it is possible to calculate the minimum/ maximum value of DSRbu for a given year to be modelled as severe/weak. The probability is then made using a normal distribution of the data series of DSRbu, if the probability is below 20% than the year will be considered as not belonging to that classification. This classification is able to correctly identify 34 out of the 36 years studied. This results can be of extreme use to forest managers and firefighters when deciding which the best fire preventing measures are and where to allocate the resources.

Perspectives on Fire Research Collaboration in Siberia: What Have We Learned; Why Does It Matter; and Where Do We Go from Here?

NASA Astrophysics Data System (ADS)

Conard, S. G.

2010-12-01

My first experience of the vast taiga forests of Russia, and my first chance to meet and work with Russian fire researchers, was at a 1993 conference and field experiment planned jointly by Johann G. Goldammer from Germany and Valentin V. Furyaev from Russia. This meeting was the beginning of a long and fruitful collaboration among US, Canadian, and Russian fire scientists. We all became increasingly aware of the global signifiance of the circumpolar boreal zone, and of the need for better information on the extent and effects of boreal fires. Wildfires are the dominant disturbance regime in the Russian boreal zone, burning 10 to 20 million hectares per year. These fires are a significant source of CO2 and other greenhouse gases and aerosols. Our research team published some of the first remote-sensing based estimates of the extent of fire in Russia and of the potential variability in emissions that could result from different burning conditions. Through a series of 20 prescribed burns we were able to mimic a wide range of burning conditions and obtain information on the impacts on soils, vegetation, and fuel consumption. Based on these experimental fires, we have modeled the effects of weather and fuels on fuel consumption and other factors, and related fire characteristics to emissions, carbon stocks, and soil and vegetation processes. For the past 10 years, we have focused on the ecosystem effects of fires of varying severity in the Scots pine and mixed larch forests of central Siberia, on improved remote-sensing based estimates of burned area and fire effects, and on relating fire weather indices to fire potential and fuel consumption. Logging is an increasingly important disturbance in Russia’s forests, and logged sites, with their high fuel loads seem particularly susceptible to fire. We are currently studying interactions between logging and fire, with an emphasis on the differences in fuel consumption, emissions, and carbon stocks when fires burn in logged and unlogged areas. Fire activity and emissions are projected to increase substantially in the boreal zone as climate warms. We are currently working to develop a 30-yr fire record for Siberia based on satellite data. We will integrate these data with historic fire weather, emissions, and vegetation data to estimate fuel consumption and emissions from fires in Siberia from 1980 to 2010. We will reconstruct past fire regimes using dendrochronology data for selected sub-regions. The relationships derived through this work will provide a basis for projecting the future effects of changing climate on fire patterns, emissions and carbon cycle in Siberia. This project will provide critical information for input to global change models and for analysis of the regional and global impacts of changing fire regimes in the boreal zone.

Mercury emissions from biomass burning in China.

PubMed

Huang, Xin; Li, Mengmeng; Friedli, Hans R; Song, Yu; Chang, Di; Zhu, Lei

2011-11-01

Biomass burning covers open fires (forest and grassland fires, crop residue burning in fields, etc.) and biofuel combustion (crop residues and wood, etc., used as fuel). As a large agricultural country, China may produce large quantities of mercury emissions from biomass burning. A new mercury emission inventory in China is needed because previous studies reflected outdated biomass burning with coarse resolution. Moreover, these studies often adopted the emission factors (mass of emitted species per mass of biomass burned) measured in North America. In this study, the mercury emissions from biomass burning in China (excluding small islands in the South China Sea) were estimated, using recently measured mercury concentrations in various biomes in China as emission factors. Emissions from crop residues and fuelwood were estimated based on annual reports distributed by provincial government. Emissions from forest and grassland fires were calculated by combining moderate resolution imaging spectroradiometer (MODIS) burned area product with combustion efficiency (ratio of fuel consumption to total available fuels) considering fuel moisture. The average annual emission from biomass burning was 27 (range from 15.1 to 39.9) Mg/year. This inventory has high spatial resolution (1 km) and covers a long period (2000-2007), making it useful for air quality modeling.

X-Ray Fluorescence to Estimate the Maximum Temperature Reached at Soil Surface during Experimental Slash-and-Burn Fires.

PubMed

Melquiades, Fábio L; Thomaz, Edivaldo L

2016-05-01

An important aspect for the evaluation of fire effects in slash-and-burn agricultural system, as well as in wildfire, is the soil burn severity. The objective of this study is to estimate the maximum temperature reached in real soil burn events using energy dispersive X-ray fluorescence (EDXRF) as an analytical tool, combined with partial least square (PLS) regression. Muffle-heated soil samples were used for PLS regression model calibration and two real slash-and-burn soils were tested as external samples in the model. It was possible to associate EDXRF spectra alterations to the maximum temperature reached in the heat affected soils with about 17% relative standard deviation. The results are promising since the analysis is fast, nondestructive, and conducted after the burn event, although local calibration for each type of burned soil is necessary. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

The use of geographic information for fire management planning in Yosemite National Park

USGS Publications Warehouse

Van Wagtendonk, Jan W.; van Wagtendonk, Kent A.; Meyer, Joseph B.; Paintner, Kara J.

2002-01-01

Fire has played a critical role in the ecosystems of Yosemite National park for millennia. Before the advent of Euro-Americans, lightning fires and fires set by Native Americans burned freely across the landscape. These fires burned periodically, with the interval between fires dependent on the availability of ignition sources, adequate fuels, and weather conducive to burning. As a result, different vegetation types burned at different intervals.

Simulating modern-day cropland and pasture burning in an Earth system model

NASA Astrophysics Data System (ADS)

Rabin, Sam; Malyshev, Sergey; Shevliakova, Elena; Magi, Brian; Pacala, Steve

2015-04-01

Throughout the Holocene, humans have extended our influence across a larger and larger fraction of ecosystems, even creating some new ones in the process. Herds of livestock grazing either native vegetation (rangeland) or specially planted species (pasture) have modified huge areas of land. We have even developed new plant species and cultivated them as crops. The extent of our ecosystem modification intensified dramatically with the advent of industrialized agriculture, to the point where cropland and pasture (which will henceforth encompass rangeland as well) now cover over a third of the Earth's land area. One way we have altered the terrestrial biosphere is by intentionally and unintentionally altering fire's frequency, intensity, and seasonal timing. This is especially true for agricultural ecosystems. Because their maintenance and use require a level of human control, cropland and pasture often experience fire regimes substantially different from those of the ecosystems they replaced or what would occur in the absence of active fire management. For example, farmers might burn to prepare land for planting or to dispose of crop residues, and pastoralists often use fire to prevent encroachment of unpalatable woody plants. Due to the vast global extent of agriculture, and considering the myriad ways fire affects the Earth system, it is critical that we understand (a) the ways people manage fire on cropland and pasture and (b) the effects of this management on the Earth system. Earth system models are an ideal tool for examining this kind of question. By simulating the processes within and interactions among the atmosphere, oceans, land, and terrestrial ecosystems, Earth system models allow phenomena such as fire to be examined in their global context. However, while the past fifteen years have seen great progress in the simulation of vegetation fire within Earth system models, the direct human influence via cropland and pasture management burning has been mostly ignored. Instead, indirect functions are usually used to incorporate human influence based on population density and economic factors. This paper describes a global fire model that incorporates knowledge from new estimates of cropland and pasture burning to explicitly simulate fire on those lands across the world. After briefly describing some of the agricultural fire patterns observed in Eurasia, we detail the structure of the model and context in which it was developed. We then use the model to investigate the contribution of cropland and pasture fire to emissions of greenhouse gases and aerosols, as well as net carbon cycling across the globe.

Alternative pathways to landscape transformation: Invasive grasses, burn severity and fire frequency in arid ecosystems

USGS Publications Warehouse

Klinger, Robert C.; Brooks, Matthew L.

2017-01-01

Arid ecosystems are often vulnerable to transformation to invasive-dominated states following fire, but data on persistence of these states are sparse. The grass/fire cycle is a feedback process between invasive annual grasses and fire frequency that often leads to the formation of alternative vegetation states dominated by the invasive grasses. However, other components of fire regimes, such as burn severity, also have the potential to produce long-term vegetation transformations. Our goal was to evaluate the influence of both fire frequency and burn severity on the transformation of woody-dominated communities to communities dominated by invasive grasses in major elevation zones of the Mojave Desert of western North America.We used a chronosequence design to collect data on herbaceous and woody cover at 229 unburned reference plots and 578 plots that burned between 1972 and 2010. We stratified the plots by elevation zone (low, mid, high), fire frequency (1–3 times) and years post-fire (YPF; 1–5, 6–10, 11–20 and 21–40 YPF). Burn severity for each plot was estimated by the difference normalized burn ratio.We identified two broad post-fire successional pathways. One was an outcome of fire frequency, resulting in a strong potential transformation via the grass/fire cycle. The second pathway was driven by burn severity, the critical aspect being that long-term transformation of a community could occur from just one fire in areas that burned at high or sometimes moderate severity. Dominance by invasive grasses was most likely to occur in low-and high-elevation communities; cover of native herbaceous species was often greater than that of invasive grasses in the mid-elevation zone.Synthesis. Invasive grasses can dominate a site that burned only one time in many decades at high severity, or a site that burned at low severity but multiple times in the same time period. However, high burn severity may predispose areas to more frequent fire because they have relatively high cover of invasive annual grass, suggesting burn severity and fire frequency have both independent and synergistic effects. Resilience in vegetation structure following fire in many arid communities may be limited to a narrow window of low burn severity in areas that have not burned in many decades.

Grand challenges in developing a predictive understanding of global fire dynamics

NASA Astrophysics Data System (ADS)

Randerson, J. T.; Chen, Y.; Wiggins, E. B.; Andela, N.; Morton, D. C.; Veraverbeke, S.; van der Werf, G.

2017-12-01

High quality satellite observations of burned area and fire thermal anomalies over the past two decades have transformed our understanding of climate, ecosystem, and human controls on the spatial and temporal distribution of landscape fires. The satellite observations provide evidence for a rapid and widespread loss of fire from grassland and savanna ecosystems worldwide. Continued expansion of industrial agriculture suggests that observed declines in global burned area are likely to continue in future decades, with profound consequences for ecosystem function and the habitat of many endangered species. Satellite time series also highlight the importance of El Niño-Southern Oscillation and other climate modes as drivers of interannual variability. In many regions, lead times between climate indices and fire activity are considerable, enabling the development of early warning prediction systems for fire season severity. With the recent availability of high-resolution observations from Suomi NPP, Landsat 8, and Sentinel 2, the field of global fire ecology is poised to make even more significant breakthroughs over the next decade. With these new observations, it may be possible to reduce uncertainties in the spatial pattern of burned area by several fold. It is difficult to overstate the importance of these new data constraints for improving our understanding of fire impacts on human health and radiative forcing of climate change. A key research challenge in this context is to understand how the loss of global burned area will affect magnitude of the terrestrial carbon sink and trends in atmospheric composition. Advances in prognostic fire modeling will require new approaches linking agriculture with landscape fire dynamics. A critical need in this context is the development of predictive models of road networks and other drivers of land fragmentation, and a closer integration of fragmentation information with algorithms predicting fire spread. Concurrently, a better representation of the influence of livestock on fuels and fire management is essential for modeling long-term trends. In northern ecosystems, climate-driven changes in lightning ignition may accelerate the northward migration of boreal forests into arctic tundra, increasing the vulnerability of permafrost carbon.

Spectral Mixture Analysis to map burned areas in Brazil's deforestation arc from 1992 to 2011

NASA Astrophysics Data System (ADS)

Antunes Daldegan, G.; Ribeiro, F.; Roberts, D. A.

2017-12-01

The two most extensive biomes in South America, the Amazon and the Cerrado, are subject to several fire events every dry season. Both are known for their ecological and environmental importance. However, due to the intensive human occupation over the last four decades, they have been facing high deforestation rates. The Cerrado biome is adapted to fire and is considered a fire-dependent landscape. In contrast, the Amazon as a tropical moist broadleaf forest does not display similar characteristics and is classified as a fire-sensitive landscape. Nonetheless, studies have shown that forest areas that have already been burned become more prone to experience recurrent burns. Remote sensing has been extensively used by a large number of researchers studying fire occurrence at a global scale, as well as in both landscapes aforementioned. Digital image processing aiming to map fire activity has been applied to a number of imagery from sensors of various spatial, temporal, and spectral resolutions. More specifically, several studies have used Landsat data to map fire scars in the Amazon forest and in the Cerrado. An advantage of using Landsat data is the potential to map fire scars at a finer spatial resolution, when compared to products derived from imagery of sensors featuring better temporal resolution but coarser spatial resolution, such as MODIS (Moderate Resolution Imaging Spectrometer) and GOES (Geostationary Operational Environmental Satellite). This study aimed to map burned areas present in the Amazon-Cerrado transition zone by applying Spectral Mixture Analysis on Landsat imagery for a period of 20 years (1992-2011). The study area is a subset of this ecotone, centered at the State of Mato Grosso. By taking advantage of the Landsat 5TM and Landsat 7ETM+ imagery collections available in Google Earth Engine platform and applying Spectral Mixture Analysis (SMA) techniques over them permitted to model fire scar fractions and delimitate burned areas. Overlaying yearly burned areas allowed to identify areas with high fire recurrence.

Burned area detection based on Landsat time series in savannas of southern Burkina Faso

NASA Astrophysics Data System (ADS)

Liu, Jinxiu; Heiskanen, Janne; Maeda, Eduardo Eiji; Pellikka, Petri K. E.

2018-02-01

West African savannas are subject to regular fires, which have impacts on vegetation structure, biodiversity and carbon balance. An efficient and accurate mapping of burned area associated with seasonal fires can greatly benefit decision making in land management. Since coarse resolution burned area products cannot meet the accuracy needed for fire management and climate modelling at local scales, the medium resolution Landsat data is a promising alternative for local scale studies. In this study, we developed an algorithm for continuous monitoring of annual burned areas using Landsat time series. The algorithm is based on burned pixel detection using harmonic model fitting with Landsat time series and breakpoint identification in the time series data. This approach was tested in a savanna area in southern Burkina Faso using 281 images acquired between October 2000 and April 2016. An overall accuracy of 79.2% was obtained with balanced omission and commission errors. This represents a significant improvement in comparison with MODIS burned area product (67.6%), which had more omission errors than commission errors, indicating underestimation of the total burned area. By observing the spatial distribution of burned areas, we found that the Landsat based method misclassified cropland and cloud shadows as burned areas due to the similar spectral response, and MODIS burned area product omitted small and fragmented burned areas. The proposed algorithm is flexible and robust against decreased data availability caused by clouds and Landsat 7 missing lines, therefore having a high potential for being applied in other landscapes in future studies.

Tree injury and mortality in fires: developing process-based models

Treesearch

Bret W. Butler; Matthew B. Dickinson

2010-01-01

Wildland fire managers are often required to predict tree injury and mortality when planning a prescribed burn or when considering wildfire management options; and, currently, statistical models based on post-fire observations are the only tools available for this purpose. Implicit in the derivation of statistical models is the assumption that they are strictly...

Biomass burning emissions of reactive gases estimated from satellite data analysis and ecosystem modeling for the Brazilian Amazon region

NASA Astrophysics Data System (ADS)

Potter, Christopher; Brooks-Genovese, Vanessa; Klooster, Steven; Torregrosa, Alicia

2002-10-01

To produce a new daily record of trace gas emissions from biomass burning events for the Brazilian Legal Amazon, we have combined satellite advanced very high resolution radiometer (AVHRR) data on fire counts together for the first time with vegetation greenness imagery as inputs to an ecosystem biomass model at 8 km spatial resolution. This analysis goes beyond previous estimates for reactive gas emissions from Amazon fires, owing to a more detailed geographic distribution estimate of vegetation biomass, coupled with daily fire activity for the region (original 1 km resolution), and inclusion of fire effects in extensive areas of the Legal Amazon (defined as the Brazilian states of Acre, Amapá, Amazonas, Maranhao, Mato Grosso, Pará, Rondônia, Roraima, and Tocantins) covered by open woodland, secondary forests, savanna, and pasture vegetation. Results from our emissions model indicate that annual emissions from Amazon deforestation and biomass burning in the early 1990s total to 102 Tg yr-1 carbon monoxide (CO) and 3.5 Tg yr-1 nitrogen oxides (NOx). Peak daily burning emissions, which occurred in early September 1992, were estimated at slightly more than 3 Tg d-1for CO and 0.1 Tg d-1for NOx flux to the atmosphere. Other burning source fluxes of gases with relatively high emission factors are reported, including methane (CH4), nonmethane hydrocarbons (NMHC), and sulfur dioxide (SO2), in addition to total particulate matter (TPM). We estimate the Brazilian Amazon region to be a source of between one fifth and one third for each of these global emission fluxes to the atmosphere. The regional distribution of burning emissions appears to be highest in the Brazilian states of Maranhao and Tocantins, mainly from burning outside of moist forest areas, and in Pará and Mato Grosso, where we identify important contributions from primary forest cutting and burning. These new daily emission estimates of reactive gases from biomass burning fluxes are designed to be used as detailed spatial and temporal inputs to computer models and data analysis of tropospheric chemistry over the tropical region.

The Wildland Fire Emission Inventory: Western United States emission estimates and an evaluation of uncertainty

Treesearch

S. P. Urbanski; W. M. Hao; B. Nordgren

2011-01-01

Biomass burning emission inventories serve as critical input for atmospheric chemical transport models that are used to understand the role of biomass fires in the chemical composition of the atmosphere, air quality, and the climate system. Significant progress has been achieved in the development of regional and global biomass burning emission inventories over the...

Woodland salamander responses to a shelterwood harvest-prescribed burn silvicultural treatment within Appalachian mixed-oak forests

USGS Publications Warehouse

Ford, W. Mark; Mahoney, Kathleen R.; Russell, Kevin R.; Rodrigue, Jane L.; Riddle, Jason D.; Schuler, Thomas M.; Adams, Mary Beth

2015-01-01

Forest management practices that mimic natural canopy disturbances, including prescribed fire and timber harvests, may reduce competition and facilitate establishment of favorable vegetative species within various ecosystems. Fire suppression in the central Appalachian region for almost a century has contributed to a transition from oak-dominated to more mesophytic, fire-intolerant forest communities. Prescribed fire coupled with timber removal is currently implemented to aid in oak regeneration and establishment but responses of woodland salamanders to this complex silvicultural system is poorly documented. The purpose of our research was to determine how woodland salamanders respond to shelterwood harvests following successive burns in a central Appalachian mixed-oak forest. Woodland salamanders were surveyed using coverboard arrays in May, July, and August–September 2011 and 2012. Surveys were conducted within fenced shelterwood-burn (prescribed fires, shelterwood harvest, and fencing to prevent white-tailed deer [Odocoileus virginianus] herbivory), shelterwood-burn (prescribed fires and shelterwood harvest), and control plots. Relative abundance was modeled in relation to habitat variables measured within treatments for mountain dusky salamanders (Desmognathus ochrophaeus), slimy salamanders (Plethodon glutinosus), and eastern red-backed salamanders (Plethodon cinereus). Mountain dusky salamander relative abundance was positively associated with canopy cover and there were significantly more individuals within controls than either shelterwood-burn or fenced shelterwood-burn treatments. Conversely, habitat variables associated with slimy salamanders and eastern red-backed salamanders did not differ among treatments. Salamander age-class structure within controls did not differ from shelterwood-burn or fenced shelterwood-burn treatments for any species. Overall, the woodland salamander assemblage remained relatively intact throughout the shelterwoodburn silvicultural treatment compared to previous research within the same study area that examined pre-harvest fire effects. However, because of the multi-faceted complexities of this specific silvicultural system, continued research is warranted that evaluates long-term, additive impacts on woodland salamanders within managed central Appalachian deciduous forests.

Simulating the impacts of fire: A computer program

NASA Astrophysics Data System (ADS)

Ffolliott, Peter F.; Guertin, D. Phillip; Rasmussen, William D.

1988-11-01

Recurrent fire has played a dominant role in the ecology of southwestern ponderosa pine forests. To assess the benefits or losses of fire in these forests, a computer simulation model, called BURN, considers vegetation (mortality, regeneration, and production of herbaceous vegetation), wildlife (populations and habitats), and hydrology (streamflow and water quality). In the formulation of the model, graphical representations (time-trend response curves) of increases or losses (compared to an unburned control) after the occurrence of fire are converted to fixedterm annual ratios, and then annuities for the simulation components. Annuity values higher than 1.0 indicate benefits, while annuity values lower than 1.0 indicate losses. Studies in southwestern ponderosa pine forests utilized in the development of BURN are described briefly.

Allocating resources to large wildland fires: a model with stochastic production rates

Treesearch

Romain Mees; David Strauss

1992-01-01

Wildland fires that grow out of the initial attack phase are responsible for most of the damage and burned area. We model the allocation of fire suppression resources (ground crews, engines, bulldozers, and airdrops) to these large fires. The fireline at a given future time is partitioned into homogeneous segments on the basis of fuel type, available resources, risk,...

Evaluating post-wildfire hydrologic recovery using ParFlow in southern California

NASA Astrophysics Data System (ADS)

Lopez, S. R.; Kinoshita, A. M.; Atchley, A. L.

2016-12-01

Wildfires are naturally occurring hazards that can have catastrophic impacts. They can alter the natural processes within a watershed, such as surface runoff and subsurface water storage. Generally, post-fire hydrologic models are either one-dimensional, empirically-based models, or two-dimensional, conceptually-based models with lumped parameter distributions. These models are useful in providing runoff measurements at the watershed outlet; however, do not provide distributed hydrologic simulation at each point within the watershed. This research demonstrates how ParFlow, a three-dimensional, distributed hydrologic model can simulate post-fire hydrologic processes by representing soil burn severity (via hydrophobicity) and vegetation recovery as they vary both spatially and temporally. Using this approach, we are able to evaluate the change in post-fire water components (surface flow, lateral flow, baseflow, and evapotranspiration). This model is initially developed for a hillslope in Devil Canyon, burned in 2003 by the Old Fire in southern California (USA). The domain uses a 2m-cell size resolution over a 25 m by 25 m lateral extent. The subsurface reaches 2 m and is assigned a variable cell thickness, allowing an explicit consideration of the soil burn severity throughout the stages of recovery and vegetation regrowth. Vegetation regrowth is incorporated represented by satellite-based Enhanced Vegetation Index (EVI) products. The pre- and post-fire surface runoff, subsurface storage, and surface storage interactions are evaluated and will be used as a basis for developing a watershed-scale model. Long-term continuous simulations will advance our understanding of post-fire hydrological partitioning between water balance components and the spatial variability of watershed processes, providing improved guidance for post-fire watershed management.

Characterising Brazilian biomass burning emissions using WRF-Chem with MOSAIC sectional aerosol

NASA Astrophysics Data System (ADS)

Archer-Nicholls, S.; Lowe, D.; Darbyshire, E.; Morgan, W. T.; Bela, M. M.; Pereira, G.; Trembath, J.; Kaiser, J. W.; Longo, K. M.; Freitas, S. R.; Coe, H.; McFiggans, G.

2014-09-01

The South American Biomass Burning Analysis (SAMBBA) field campaign took detailed in-situ flight measurements of aerosol during the 2012 dry season to characterise biomass burning aerosol and improve understanding of its impacts on weather and climate. Developments have been made to the Weather research and Forecast model with chemistry (WRF-Chem) model to improve the representation of biomass burning aerosol in the region by coupling a sectional aerosol scheme to the plume rise parameterisation. Brazilian Biomass Burning Emissions Model (3BEM) fire emissions are used, prepared using PREP-CHEM-SRC, and mapped to CBM-Z and MOSAIC species. Model results have been evaluated against remote sensing products, AERONET sites, and four case studies of flight measurements from the SAMBBA campaign. WRF-Chem predicted layers of elevated aerosol loadings (5-20 μg sm-3) of particulate organic matter at high altitude (6-8 km) over tropical forest regions, while flight measurements showed a sharp decrease above 2-4 km altitude. This difference was attributed to the plume-rise parameterisation overestimating injection height. The 3BEM emissions product was modified using estimates of active fire size and burned area for the 2012 fire season, which reduced the fire size. The enhancement factor for fire emissions was increased from 1.3 to 5 to retain reasonable aerosol optical depths (AOD). The smaller fire size lowered the injection height of the emissions, but WRF-Chem still showed elevated aerosol loadings between 4-5 km altitude. Over eastern Cerrado (savannah-like) regions, both modelled and measured aerosol loadings decreased above approximately 4 km altitude. Compared with MODIS satellite data and AERONET sites, WRF-Chem represented AOD magnitude well (between 0.3-1.5) over western tropical forest fire regions in the first half of the campaign, but tended to over-predict them in the second half, when precipitation was more significant. Over eastern Cerrado regions, WRF-Chem tended to under-predict AOD. Modeled aerosol loadings in the east were higher in the modified emission scenario. The primary organic matter to black carbon ratio was typically between 8-10 in WRF-Chem. This was lower than western flights measurements (interquartile range of 11.6-15.7 in B734, 14.7-24.0 in B739), but similar to the eastern flight B742 (8.1-10.4). However, single scattering albedo was close to measured over the western flights (0.87-0.89 in model; 0.88-0.91 in flight B734, and 0.86-0.95 in flight B739 measurements) but too high over the eastern flight B742 (0.86-0.87 in model, 0.81-0.84 in measurements). This suggests that improvements are needed to both modeled aerosol composition and optical properties calculations in WRF-Chem.

Techniques for Estimating Emissions Factors from Forest Burning: ARCTAS and SEAC4RS Airborne Measurements Indicate which Fires Produce Ozone

NASA Technical Reports Server (NTRS)

Chatfield, Robert B.; Andreae, Meinrat O.

2016-01-01

Previous studies of emission factors from biomass burning are prone to large errors since they ignore the interplay of mixing and varying pre-fire background CO2 levels. Such complications severely affected our studies of 446 forest fire plume samples measured in the Western US by the science teams of NASA's SEAC4RS and ARCTAS airborne missions. Consequently we propose a Mixed Effects Regression Emission Technique (MERET) to check techniques like the Normalized Emission Ratio Method (NERM), where use of sequential observations cannot disentangle emissions and mixing. We also evaluate a simpler "consensus" technique. All techniques relate emissions to fuel burned using C(burn) = delta C(tot) added to the fire plume, where C(tot) approximately equals (CO2 = CO). Mixed-effects regression can estimate pre-fire background values of C(tot) (indexed by observation j) simultaneously with emissions factors indexed by individual species i, delta, epsilon lambda tau alpha-x(sub I)/C(sub burn))I,j. MERET and "consensus" require more than emissions indicators. Our studies excluded samples where exogenous CO or CH4 might have been fed into a fire plume, mimicking emission. We sought to let the data on 13 gases and particulate properties suggest clusters of variables and plume types, using non-negative matrix factorization (NMF). While samples were mixtures, the NMF unmixing suggested purer burn types. Particulate properties (b scant, b abs, SSA, AAE) and gas-phase emissions were interrelated. Finally, we sought a simple categorization useful for modeling ozone production in plumes. Two kinds of fires produced high ozone: those with large fuel nitrogen as evidenced by remnant CH3CN in the plumes, and also those from very intense large burns. Fire types with optimal ratios of delta-NOy/delta- HCHO associate with the highest additional ozone per unit Cburn, Perhaps these plumes exhibit limited NOx binding to reactive organics. Perhaps these plumes exhibit limited NOx binding to reactive organics

Techniques for Estimating Emissions Factors from Forest Burning: ARCTAS and SEAC4RS Airborne Measurements Indicate Which Fires Produce Ozone

NASA Technical Reports Server (NTRS)

Chatfield, Robert B.; Andreae, Meinrat O.

2015-01-01

Previous studies of emission factors from biomass burning are prone to large errors since they ignore the interplay of mixing and varying pre-fire background CO2 levels. Such complications severely affected our studies of 446 forest fire plume samples measured in the Western US by the science teams of NASA's SEAC4RS and ARCTAS airborne missions. Consequently we propose a Mixed Effects Regression Emission Technique (MERET) to check techniques like the Normalized Emission Ratio Method (NERM), where use of sequential observations cannot disentangle emissions and mixing. We also evaluate a simpler "consensus" technique. All techniques relate emissions to fuel burned using C(sub burn) = delta C(sub tot) added to the fire plume, where C(sub tot) approximately equals (CO2 + CO). Mixed-effects regression can estimate pre-fire background values of Ctot (indexed by observation j) simultaneously with emissions factors indexed by individual species i, delta epsilon lambda tau alpha-x(sub i)/(C(sub burn))i,j., MERET and "consensus" require more than two emissions indicators. Our studies excluded samples where exogenous CO or CH4 might have been fed into a fire plume, mimicking emission. We sought to let the data on 13 gases and particulate properties suggest clusters of variables and plume types, using non-negative matrix factorization (NMF). While samples were mixtures, the NMF unmixing suggested purer burn types. Particulate properties (bscat, babs, SSA, AAE) and gas-phase emissions were interrelated. Finally, we sought a simple categorization useful for modeling ozone production in plumes. Two kinds of fires produced high ozone: those with large fuel nitrogen as evidenced by remnant CH3CN in the plumes, and also those from very intense large burns. Fire types with optimal ratios of delta-NOy/delta- HCHO associate with the highest additional ozone per unit Cburn, Perhaps these plumes exhibit limited NOx binding to reactive organics. Perhaps these plumes exhibit limited NOx binding to reactive organics.

Fire spread in chaparral – a comparison of laboratory data and model predictions in burning live fuels

Treesearch

David R. Weise; Eunmo Koo; Xiangyang Zhou; Shankar Mahalingam; Frédéric Morandini; Jacques-Henri Balbi

2016-01-01

Fire behaviour data from 240 laboratory fires in high-density live chaparral fuel beds were compared with model predictions. Logistic regression was used to develop a model to predict fire spread success in the fuel beds and linear regression was used to predict rate of spread. Predictions from the Rothermel equation and three proposed changes as well as two physically...

The influence of solid rocket motor retro-burns on the space debris environment

NASA Astrophysics Data System (ADS)

Stabroth, Sebastian; Homeister, Maren; Oswald, Michael; Wiedemann, Carsten; Klinkrad, Heiner; Vörsmann, Peter

The ESA space debris population model MASTER (Meteoroid and Space Debris Terrestrial Environment Reference) considers firings of solid rocket motors (SRM) as a debris source with the associated generation of slag and dust particles. The resulting slag and dust population is a major contribution to the sub-millimetre size debris environment in Earth orbit. The current model version, MASTER-2005, is based on the simulation of 1076 orbital SRM firings which contributed to the long-term debris environment. A comparison of the modelled flux with impact data from returned surfaces shows that the shape and quantity of the modelled SRM dust distribution matches that of recent Hubble Space Telescope (HST) solar array measurements very well. However, the absolute flux level for dust is under-predicted for some of the analysed Long Duration Exposure Facility (LDEF) surfaces. This points into the direction of some past SRM firings not included in the current event database. The most suitable candidates for these firings are the large number of SRM retro-burns of return capsules. Objects released by those firings have highly eccentric orbits with perigees in the lower regions of the atmosphere. Thus, they produce no long-term effect on the debris environment. However, a large number of those firings during the on-orbit time frame of LDEF might lead to an increase of the dust population for some of the LDEF surfaces. In this paper, the influence of SRM retro-burns on the short- and long-term debris environment is analysed. The existing firing database is updated with gathered information of some 800 Russian retro-firings. Each firing is simulated with the MASTER population generation module. The resulting population is compared against the existing background population of SRM slag and dust particles in terms of spatial density and flux predictions.

Fire alters patterns of genetic diversity among 3 lizard species in Florida Scrub habitat.

PubMed

Schrey, Aaron W; Ashton, Kyle G; Heath, Stacy; McCoy, Earl D; Mushinsky, Henry R

2011-01-01

The Florida Sand Skink (Plestiodon reynoldsi), the Florida Scrub Lizard (Sceloporus woodi), and the Six-lined Racerunner (Aspidoscelis sexlineata) occur in the threatened and fire-maintained Florida scrub habitat. Fire may have different consequences to local genetic diversity of these species because they each have different microhabitat preference. We collected tissue samples of each species from 3 sites with different time-since-fire: Florida Sand Skink n = 73, Florida Scrub Lizard n = 70, and Six-lined Racerunner n = 66. We compared the effect of fire on genetic diversity at microsatellite loci for each species. We screened 8 loci for the Florida Sand Skink, 6 loci for the Florida Scrub Lizard, and 6 loci for the Six-lined Racerunner. We also tested 2 potential driving mechanisms for the observed change in genetic diversity, a metapopulation source/sink model and a local demographic model. Genetic diversity varied with fire history, and significant genetic differentiation occurred among sites. The Florida Scrub Lizard had highest genetic variation at more recently burned sites, whereas the Florida Sand Skink and the Six-lined Racerunner had highest genetic variation at less recently burned sites. Habitat preferences of the Florida Sand Skink and the Florida Scrub Lizard may explain their discordant results, and the Six-lined Racerunner may have a more complicated genetic response to fire or is acted on at a different geographic scale than we have investigated. Our results indicate that these species may respond to fire in a more complicated manner than predicted by our metapopulation model or local demographic model. Our results show that the population-level responses in genetic diversity to fire are species-specific mandating conservation management of habitat diversity through a mosaic of burn frequencies.

Fire environment effects on particulate matter emission factors in southeastern U.S. pine-grasslands

NASA Astrophysics Data System (ADS)

Robertson, Kevin M.; Hsieh, Yuch P.; Bugna, Glynnis C.

2014-12-01

Particulate matter (PM) emission factors (EFPM), which predict particulate emissions per biomass consumed, have a strong influence on event-based and regional PM emission estimates and inventories. PM < 2.5 μm aerodynamic diameter (PM2.5), regulated for its impacts to human health and visibility, is of special concern. Although wildland fires vary widely in their fuel conditions, meteorology, and fire behavior which might influence combustion reactions, the EFPM2.5 component of emission estimates is typically a constant for the region or general fuel type being assessed. The goal of this study was to use structural equation modeling (SEM) to identify and measure effects of fire environment variables on EFPM2.5 in U.S. pine-grasslands, which contribute disproportionately to total U.S. PM2.5 emissions. A hypothetical model was developed from past literature and tested using 41 prescribed burns in northern Florida and southern Georgia, USA with varying years since previous fire, season of burn, and fire direction of spread. Measurements focused on EFPM2.5 from flaming combustion, although a subset of data considered MCE and smoldering combustion. The final SEM after adjustment showed EFPM2.5 to be higher in burns conducted at higher ambient temperatures, corresponding to later dates during the period from winter to summer and increases in live herbaceous vegetation and ambient humidity, but not total fine fuel moisture content. Percentage of fine fuel composed of pine needles had the strongest positive effect on EFPM2.5, suggesting that pine timber stand volume may significantly influence PM2.5 emissions. Also, percentage of fine fuel composed of grass showed a negative effect on EFPM2.5, consistent with past studies. Results of the study suggest that timber thinning and frequent prescribed fire minimize EFPM2.5 and total PM2.5 emissions on a per burn basis, and that further development of PM emission models should consider adjusting EFPM2.5 as a function of common land use variables, including pine timber stocking, surface vegetation composition, fire frequency, and season of burn.

Wildfire exposure and fuel management on western US national forests.

PubMed

Ager, Alan A; Day, Michelle A; McHugh, Charles W; Short, Karen; Gilbertson-Day, Julie; Finney, Mark A; Calkin, David E

2014-12-01

Substantial investments in fuel management activities on national forests in the western US are part of a national strategy to reduce human and ecological losses from catastrophic wildfire and create fire resilient landscapes. Prioritizing these investments within and among national forests remains a challenge, partly because a comprehensive assessment that establishes the current wildfire risk and exposure does not exist, making it difficult to identify national priorities and target specific areas for fuel management. To gain a broader understanding of wildfire exposure in the national forest system, we analyzed an array of simulated and empirical data on wildfire activity and fuel treatment investments on the 82 western US national forests. We first summarized recent fire data to examine variation among the Forests in ignition frequency and burned area in relation to investments in fuel reduction treatments. We then used simulation modeling to analyze fine-scale spatial variation in burn probability and intensity. We also estimated the probability of a mega-fire event on each of the Forests, and the transmission of fires ignited on national forests to the surrounding urban interface. The analysis showed a good correspondence between recent area burned and predictions from the simulation models. The modeling also illustrated the magnitude of the variation in both burn probability and intensity among and within Forests. Simulated burn probabilities in most instances were lower than historical, reflecting fire exclusion on many national forests. Simulated wildfire transmission from national forests to the urban interface was highly variable among the Forests. We discuss how the results of the study can be used to prioritize investments in hazardous fuel reduction within a comprehensive multi-scale risk management framework. Published by Elsevier Ltd.

Comparison of biomass burning inventories processed by GEOS-Chem and ACCESS2.0 with total column and satellite data in Australia.

NASA Astrophysics Data System (ADS)

Desservettaz, M.; Fisher, J. A.; Jones, N. B.; Bukosa, B.; Greenslade, J.; Luhar, A.; Woodhouse, M.; Griffith, D. W. T.; Velazco, V. A.

2016-12-01

Australia contributes approximately 6% of global biomass burning CO2 emissions, mostly from savanna type fires. This estimate comes from biomass burning inventories that use emission factors derived from field campaigns performed outside Australia. The relevance of these emission factors to the Australian environment has not previously been evaluated and therefore needs to be tested. Here we compare predictions from the chemical transport model GEOS-Chem and the global chemistry-climate model ACCESS-UKCA run using different biomass burning inventories to total column measurements of CO, C2H6 and HCHO, in order to identify the most representative inventory for Australian fire emissions. The measurements come from the Network for Detection of Atmospheric Composition Change (NDACC) and Total Carbon Column Observing Network (TCCON) solar remote sensing Fourier transform spectrometers and satellite measurements from IASI and OMI over Australia. We evaluate three inventories: the Global Fire Emission Database version 4 - GFED4 (Giglio et al. 2013), the Fire Inventory from NCAR - FINN (Wiedinmyer et al. 2011), the Quick Fire Emission Database - QFED from NASA and the MACCity emission inventory (from the MACC/CityZEN EU projects; Angiola et al. 2010). From this evaluation we aim to give recommendations for the most appropriate inventory to use for different Australian environments. We also plan to examine any significant concentration variations arising from the differences between the two model setups.

Using the Fire Weather Index (FWI) to improve the estimation of fire emissions from fire radiative power (FRP) observations

NASA Astrophysics Data System (ADS)

Di Giuseppe, Francesca; Rémy, Samuel; Pappenberger, Florian; Wetterhall, Fredrik

2018-04-01

The atmospheric composition analysis and forecast for the European Copernicus Atmosphere Monitoring Services (CAMS) relies on biomass-burning fire emission estimates from the Global Fire Assimilation System (GFAS). The GFAS is a global system and converts fire radiative power (FRP) observations from MODIS satellites into smoke constituents. Missing observations are filled in using persistence, whereby observed FRP values from the previous day are progressed in time until a new observation is recorded. One of the consequences of this assumption is an increase of fire duration, which in turn translates into an increase of emissions estimated from fires compared to what is available from observations. In this study persistence is replaced by modelled predictions using the Canadian Fire Weather Index (FWI), which describes how atmospheric conditions affect the vegetation moisture content and ultimately fire duration. The skill in predicting emissions from biomass burning is improved with the new technique, which indicates that using an FWI-based model to infer emissions from FRP is better than persistence when observations are not available.

Repeated wildfires alter forest recovery of mixed-conifer ecosystems.

PubMed

Stevens-Rumann, Camille; Morgan, Penelope

2016-09-01

Most models project warmer and drier climates that will contribute to larger and more frequent wildfires. However, it remains unknown how repeated wildfires alter post-fire successional patterns and forest structure. Here, we test the hypothesis that the number of wildfires, as well as the order and severity of wildfire events interact to alter forest structure and vegetation recovery and implications for vegetation management. In 2014, we examined forest structure, composition, and tree regeneration in stands that burned 1-18 yr before a subsequent 2007 wildfire. Three important findings emerged: (1) Repeatedly burned forests had 15% less woody surface fuels and 31% lower tree seedling densities compared with forests that only experienced one recent wildfire. These repeatedly burned areas are recovering differently than sites burned once, which may lead to alternative ecosystem structure. (2) Order of burn severity (high followed by low severity compared with low followed by high severity) did influence forest characteristics. When low burn severity followed high, forests had 60% lower canopy closure and total basal area with 92% fewer tree seedlings than when high burn severity followed low. (3) Time between fires had no effect on most variables measured following the second fire except large woody fuels, canopy closure and tree seedling density. We conclude that repeatedly burned areas meet many vegetation management objectives of reduced fuel loads and moderate tree seedling densities. These differences in forest structure, composition, and tree regeneration have implications not only for the trajectories of these forests, but may reduce fire intensity and burn severity of subsequent wildfires and may be used in conjunction with future fire suppression tactics. © 2016 by the Ecological Society of America.

Resilience of Mediterranean terrestrial ecosystems and fire severity in semiarid areas: Responses of Aleppo pine forests in the short, mid and long term.

PubMed

González-De Vega, S; De Las Heras, J; Moya, D

2016-12-15

In recent decades, the fire regime of the Mediterranean Basin has been disturbed by various factors: climate change; forest management policies; land cover; changed landscape. Size and severity have notably increased, which in turn have increased large fires events with >500ha burned (high severity). In spite of Mediterranean ecosystems' high resilience to fire, these changes have implied more vulnerability and reduced natural recovery with irreparable long-term negative effects. Knowledge of the response of ecosystems to increasing severity, mainly in semiarid areas, is still lacking, which is needed to rehabilitate and restore burned areas. Our approach assessed the resilience concept by focusing on the recovery of ecosystem functions and services, measured as changes in the composition and diversity of plant community vegetation and structure. This will be validated in the long term as a model of ecosystem response. Also, depending on the pre-fire characteristics of vegetation, fire severity and the post-fire management, this approach will lead to tools that can be applied to implement post-fire restoration efforts in order to help decision making in planning activities. Regarding Mediterranean ecosystems' ability to recover after wildfires, this study concludes that pre-fire communities are resilient in these fire-prone areas, but the window for natural recovery in semiarid areas of Aleppo pine forest in SE Iberian Peninsula varied from 3 to 15 post-fire years. Fire severity was also key for effects on the ecosystem: the vegetation types of areas burned with low and medium severity recovered naturally, while those areas with a high-severity burn induced shrublands. We concluded that very strong regeneration activity exists in the short term, and that the negative effects of medium- and high-severity fire are evidenced in the mid and long term, which affect natural recovery. Adaptive forest management to rehabilitate and restore burned Mediterranean ecosystems should be implemented. Copyright © 2016 Elsevier B.V. All rights reserved.

Analysis of particulate emissions from tropical biomass burning using a global aerosol model and long-term surface observations

NASA Astrophysics Data System (ADS)

Reddington, Carly L.; Spracklen, Dominick V.; Artaxo, Paulo; Ridley, David A.; Rizzo, Luciana V.; Arana, Andrea

2016-09-01

We use the GLOMAP global aerosol model evaluated against observations of surface particulate matter (PM2.5) and aerosol optical depth (AOD) to better understand the impacts of biomass burning on tropical aerosol over the period 2003 to 2011. Previous studies report a large underestimation of AOD over regions impacted by tropical biomass burning, scaling particulate emissions from fire by up to a factor of 6 to enable the models to simulate observed AOD. To explore the uncertainty in emissions we use three satellite-derived fire emission datasets (GFED3, GFAS1 and FINN1). In these datasets the tropics account for 66-84 % of global particulate emissions from fire. With all emission datasets GLOMAP underestimates dry season PM2.5 concentrations in regions of high fire activity in South America and underestimates AOD over South America, Africa and Southeast Asia. When we assume an upper estimate of aerosol hygroscopicity, underestimation of AOD over tropical regions impacted by biomass burning is reduced relative to previous studies. Where coincident observations of surface PM2.5 and AOD are available we find a greater model underestimation of AOD than PM2.5, even when we assume an upper estimate of aerosol hygroscopicity. Increasing particulate emissions to improve simulation of AOD can therefore lead to overestimation of surface PM2.5 concentrations. We find that scaling FINN1 emissions by a factor of 1.5 prevents underestimation of AOD and surface PM2.5 in most tropical locations except Africa. GFAS1 requires emission scaling factor of 3.4 in most locations with the exception of equatorial Asia where a scaling factor of 1.5 is adequate. Scaling GFED3 emissions by a factor of 1.5 is sufficient in active deforestation regions of South America and equatorial Asia, but a larger scaling factor is required elsewhere. The model with GFED3 emissions poorly simulates observed seasonal variability in surface PM2.5 and AOD in regions where small fires dominate, providing independent evidence that GFED3 underestimates particulate emissions from small fires. Seasonal variability in both PM2.5 and AOD is better simulated by the model using FINN1 emissions. Detailed observations of aerosol properties over biomass burning regions are required to better constrain particulate emissions from fires.

Fire hazard after prescribed burning in a gorse shrubland: implications for fuel management.

PubMed

Marino, Eva; Guijarro, Mercedes; Hernando, Carmen; Madrigal, Javier; Díez, Carmen

2011-03-01

Prescribed burning is commonly used to prevent accumulation of biomass in fire-prone shrubland in NW Spain. However, there is a lack of knowledge about the efficacy of the technique in reducing fire hazard in these ecosystems. Fire hazard in burned shrubland areas will depend on the initial capacity of woody vegetation to recover and on the fine ground fuels existing after fire. To explore the effect that time since burning has on fire hazard, experimental tests were performed with two fuel complexes (fine ground fuels and regenerated shrubs) resulting from previous prescribed burnings conducted in a gorse shrubland (Ulex europaeus L.) one, three and five years earlier. A point-ignition source was used in burning experiments to assess ignition and initial propagation success separately for each fuel complex. The effect of wind speed was also studied for shrub fuels, and several flammability parameters were measured. Results showed that both ignition and initial propagation success of fine ground fuels mainly depended on fuel depth and were independent of time since burning, although flammability parameters indicated higher fire hazard three years after burning. In contrast, time since burning increased ignition and initial propagation success of regenerated shrub fuels, as well as the flammability parameters assessed, but wind speed had no significant effect. The combination of results of fire hazard for fine ground fuels and regenerated shrubs according to the variation in relative coverage of each fuel type after prescribed burning enabled an assessment of integrated fire hazard in treated areas. The present results suggest that prescribed burning is a very effective technique to reduce fire hazard in the study area, but that fire hazard will be significantly increased by the third year after burning. These results are valuable for fire prevention and fuel management planning in gorse shrubland areas. Copyright © 2010 Elsevier Ltd. All rights reserved.

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.

Ponderosa pine snag densities following multiple fires in the Gila Wilderness, New Mexico

USGS Publications Warehouse

Holden, Z.A.; Morgan, P.; Rollins, M.G.; Wright, R.G.

2006-01-01

Fires create and consume snags (standing dead trees), an important structural and ecological component of ponderosa pine forests. The effects of repeated fires on snag densities in ponderosa pine forests of the southwestern USA have not been studied. Line intercept sampling was used to estimate snag densities in areas of the Gila Wilderness that had burned one to three times under Wildland Fire Use for Resource Benefit (WFU), a fire management policy implemented since 1974 aimed at restoring natural fire regimes. Twenty randomly located transects were measured in areas burned since 1946; six in once-burned areas, six in twice-burned areas and eight in thrice-burned areas. The mean density ?? standard errors of large (>47.5 cm dbh) snags for areas that burned once, twice and thrice was 7.0 ?? 2.7, 4.4 ?? 1.1 and 4.1 ?? 1.3 snags/ha, respectively. Differences in snag densities between once- and multiple-burned areas were significant (F-test; p < 0.05). There was no significant difference in density of large snags between twice- and thrice-burned areas. Proportions of type 1 snags (recently created) were higher in once- and twice-burned areas than in areas that burned three times, likely reflecting high tree mortality and snag recruitment resulting from an initial entry fire. Type 3 snags (charred by previous fire) were more abundant in areas that burned multiple times. The lack of differences in snag densities between areas that burned two and three times suggests that repeated fires leave many snags standing. The increasing proportion of type 3 snags with repeated fires supports this conclusion. ?? 2005 Elsevier B.V. All rights reserved.

Theory-Based Cartographic Risk Model Development and Application for Home Fire Safety.

PubMed

Furmanek, Stephen; Lehna, Carlee; Hanchette, Carol

There is a gap in the use of predictive risk models to identify areas at risk for home fires and burn injury. The purpose of this study was to describe the creation, validation, and application of such a model using a sample from an intervention study with parents of newborns in Jefferson County, KY, as an example. Performed was a literature search to identify risk factors for home fires and burn injury in the target population. Obtained from the American Community Survey at the census tract level and synthesized to create a predictive cartographic risk model was risk factor data. Model validation was performed through correlation, regression, and Moran's I with fire incidence data from open records. Independent samples t-tests were used to examine the model in relation to geocoded participant addresses. Participant risk level for fire rate was determined and proximity to fire station service areas and hospitals. The model showed high and severe risk clustering in the northwest section of the county. Strongly correlated with fire rate was modeled risk; the best predictive model for fire risk contained home value (low), race (black), and non high school graduates. Applying the model to the intervention sample, the majority of participants were at lower risk and mostly within service areas closest to a fire department and hospital. Cartographic risk models were useful in identifying areas at risk and analyzing participant risk level. The methods outlined in this study are generalizable to other public health issues.

Differences in human versus lightning fires between urban and rural areas of the boreal forest in interior Alaska

USGS Publications Warehouse

Calef, Monika; Varvak, Anna; McGuire, A. David

2017-01-01

In western North America, the carbon-rich boreal forest is experiencing warmer temperatures, drier conditions and larger and more frequent wildfires. However, the fire regime is also affected by direct human activities through suppression, ignition, and land use changes. Models are important predictive tools for understanding future conditions but they are based on regional generalizations of wildfire behavior and weather that do not adequately account for the complexity of human–fire interactions. To achieve a better understanding of the intensity of human influence on fires in this sparsely populated area and to quantify differences between human and lightning fires, we analyzed fires by both ignition types in regard to human proximity in urban (the Fairbanks subregion) and rural areas of interior Alaska using spatial (Geographic Information Systems) and quantitative analysis methods. We found substantial differences in drivers of wildfire: while increases in fire ignitions and area burned were caused by lightning in rural interior Alaska, in the Fairbanks subregion these increases were due to human fires, especially in the wildland urban interface. Lightning fires are starting earlier and fires are burning longer, which is much more pronounced in the Fairbanks subregion than in rural areas. Human fires differed from lightning fires in several ways: they started closer to settlements and highways, burned for a shorter duration, were concentrated in the Fairbanks subregion, and often occurred outside the brief seasonal window for lightning fires. This study provides important insights that improve our understanding of the direct human influence on recently observed changes in wildfire regime with implications for both fire modeling and fire management.

Effects of fire on spotted owl site occupancy in a late-successional forest

USGS Publications Warehouse

Roberts, Susan L.; van Wagtendonk, Jan W.; Miles, A. Keith; Kelt, Douglas A.

2011-01-01

The spotted owl (Strix occidentalis) is a late-successional forest dependent species that is sensitive to forest management practices throughout its range. An increase in the frequency and spatial extent of standreplacing fires in western North America has prompted concern for the persistence of spotted owls and other sensitive late-successional forest associated species. However, there is sparse information on the effects of fire on spotted owls to guide conservation policies. In 2004-2005, we surveyed for California spotted owls during the breeding season at 32 random sites (16 burned, 16 unburned) throughout late-successional montane forest in Yosemite National Park, California. Our burned areas burned at all severities, but predominately involved low to moderate fire severity. Based on an information theoretic approach, spotted owl detection and occupancy rates were similar between burned and unburned sites. Nest and roost site occupancy was best explained by a model that combined total tree basal area (positive effect) with cover by coarse woody debris (negative effect). The density estimates of California spotted owl pairs were similar in burned and unburned forests, and the overall mean density estimate for Yosemite was higher than previously reported for montane forests. Our results indicate that low to moderate severity fires, historically common within montane forests of the Sierra Nevada, California, maintain habitat characteristics essential for spotted owl site occupancy. These results suggest that managed fires that emulate the historic fire regime of these forests may maintain spotted owl habitat and protect this species from the effects of future catastrophic fires.

Effects of past burning frequency on plant species structure and composition in dry dipterocarp forest

NASA Astrophysics Data System (ADS)

Wanthongchai, Dr.; Bauhus, Prof.; Goldammer, Prof.

2009-04-01

Anthropogenic burning in dry dipterocarp forests (DDF) has become a common phenomenon throughout Thailand. It is feared that too frequent fires may affect vegetation structure and composition and thus impact on ecosystem productivity. The aim of this study was to quantify the effects of prescribed fires on sites with different past burning regimes on vegetation structure and composition in the Huay Kha Khaeng Wildlife Sanctuary (HKK), Thailand. Fire frequency was determined from satellite images and ranged from frequent, infrequent, rare and unburned with fire occurrences of 7, 2, 1 and 0 out of the past 10 years, respectively. The pre-burn fuel loads, the overstorey and understorey vegetation structure and composition were determined to investigate the effects of the contrasting past burning regimes. The burning experiment was carried out, applying a three-strip head-fire burning technique. The vegetation structure and composition were sampled again one year after the fire to assess the fire impacts. Aboveground fine fuel loads increased with the length of fire-free interval. The woody plant structures of the frequently burned stand differed from those of the other less frequently burned stands. The species composition of the overstorey on the frequently burned site, in particular that of small sized trees (4.5-10 cm dbh), also differed significantly from that of the other sites. Whilst the ground vegetation including shrubs and herbs did not differ between the past burning regimes, frequent burning obviously promoted the proliferation of graminoid vegetation. There was no clear evidence showing that the prescribed fires affected the mortality of trees (dbh> 4.5 cm) on the sites of the different past burning regimes. The effects of prescribed burning on the understorey vegetation structures varied between the past burning regimes and the understorey vegetation type. Therefore, it is recommended that the DDF at HKK should be subjected to a prescribed fire frequency not shorter than every 6-7 years, or 1-2 fires per decade, to maintain ecosystem structure and function. Variation in time and space in this way, the biodiversity of the landscape may be maintained for the long-term. Keywords: Prescribed burning, burning history, burning frequency, plant species, vegetation structure, dry dipterocarp forest, Huay Kha Khaeng wildlife Sanctuary

Evolution of human-driven fire regimes in Africa

PubMed Central

Archibald, Sally; Staver, A. Carla; Levin, Simon A.

2012-01-01

Human ability to manipulate fire and the landscape has increased over evolutionary time, but the impact of this on fire regimes and consequences for biodiversity and biogeochemistry are hotly debated. Reconstructing historical changes in human-derived fire regimes empirically is challenging, but information is available on the timing of key human innovations and on current human impacts on fire; here we incorporate this knowledge into a spatially explicit fire propagation model. We explore how changes in population density, the ability to create fire, and the expansion of agropastoralism altered the extent and seasonal distribution of fire as modern humans arose and spread through Africa. Much emphasis has been placed on the positive effect of population density on ignition frequency, but our model suggests this is less important than changes in fire spread and connectivity that would have occurred as humans learned to light fires in the dry season and to transform the landscape through grazing and cultivation. Different landscapes show different limitations; we show that substantial human impacts on burned area would only have started ∼4,000 B.P. in open landscapes, whereas they could have altered fire regimes in closed/dissected landscapes by ∼40,000 B.P. Dry season fires have been the norm for the past 200–300 ky across all landscapes. The annual area burned in Africa probably peaked between 4 and 40 kya. These results agree with recent paleocarbon studies that suggest that the biomass burned today is less than in the recent past in subtropical countries. PMID:22184249

Emergency Assessment of Debris-Flow Hazards from Basins Burned by the Piru, Simi, and Verdale Fires of 2003, Southern California

USGS Publications Warehouse

Cannon, Susan H.; Gartner, Joseph E.; Rupert, Michael G.; Michael, John A.

2003-01-01

These maps present preliminary assessments of the probability of debris-flow activity and estimates of peak discharges that can potentially be generated by debris-flows issuing from basins burned by the Piru, Simi and Verdale Fires of October 2003 in southern California in response to the 25-year, 10-year, and 2-year 1-hour rain storms. The probability maps are based on the application of a logistic multiple regression model that describes the percent chance of debris-flow production from an individual basin as a function of burned extent, soil properties, basin gradients and storm rainfall. The peak discharge maps are based on application of a multiple-regression model that can be used to estimate debris-flow peak discharge at a basin outlet as a function of basin gradient, burn extent, and storm rainfall. Probabilities of debris-flow occurrence for the Piru Fire range between 2 and 94% and estimates of debris flow peak discharges range between 1,200 and 6,640 ft3/s (34 to 188 m3/s). Basins burned by the Simi Fire show probabilities for debris-flow occurrence between 1 and 98%, and peak discharge estimates between 1,130 and 6,180 ft3/s (32 and 175 m3/s). The probabilities for debris-flow activity calculated for the Verdale Fire range from negligible values to 13%. Peak discharges were not estimated for this fire because of these low probabilities. These maps are intended to identify those basins that are most prone to the largest debris-flow events and provide information for the preliminary design of mitigation measures and for the planning of evacuation timing and routes.

Burns and Fire Safety

MedlinePlus

Number of Deaths Death Rate Burns and Fire Safety Fact Sheet (2015) Fatalities • 334 children ages 19 and under died from fires or burns ... burns were ages 4 and under. 1 The death rate for children this age (0.73 per 100, ...

Climatic and socio-economic fire drivers in the Mediterranean basin at a century scale: Analysis and modelling based on historical fire statistics and dynamic global vegetation models (DGVMs)

NASA Astrophysics Data System (ADS)

Mouillot, F.; Koutsias, N.; Conedera, M.; Pezzatti, B.; Madoui, A.; Belhadj Kheder, C.

2017-12-01

Wildfire is the main disturbance affecting Mediterranean ecosystems, with implications on biogeochemical cycles, biosphere/atmosphere interactions, air quality, biodiversity, and socio-ecosystems sustainability. The fire/climate relationship is time-scale dependent and may additionally vary according to concurrent changes climatic, environmental (e.g. land use), and fire management processes (e.g. fire prevention and control strategies). To date, however, most studies focus on a decadal scale only, being fire statistics ore remote sensing data usually available for a few decades only. Long-term fire data may allow for a better caption of the slow-varying human and climate constrains and for testing the consistency of the fire/climate relationship on the mid-time to better apprehend global change effects on fire risks. Dynamic Global Vegetation Models (DGVMs) associated with process-based fire models have been recently developed to capture both the direct role of climate on fire hazard and the indirect role of changes in vegetation and human population, to simulate biosphere/atmosphere interactions including fire emissions. Their ability to accurately reproduce observed fire patterns is still under investigation regarding seasonality, extreme events or temporal trend to identify potential misrepresentations of processes. We used a unique long-term fire reconstruction (from 1880 to 2016) of yearly burned area along a North/South and East/West environmental gradient across the Mediterranean Basin (southern Switzerland, Greece, Algeria, Tunisia) to capture the climatic and socio economic drivers of extreme fire years by linking yearly burned area with selected climate indices derived from historical climate databases and socio-economic variables. We additionally compared the actual historical reconstructed fire history with the yearly burned area simulated by a panel of DGVMS (FIREMIP initiative) driven by daily CRU climate data at 0.5° resolution across the Mediterranean basin. We will present and discuss the key processes driving interannual fire hazard along the 20th century, and analysed how DGVMs capture this interannual variability.

Linking Wildfire and Climate as Drivers of Plant Species and Community-level Change

NASA Astrophysics Data System (ADS)

Newingham, B. A.; Hudak, A. T.; Bright, B. C.

2015-12-01

Plant species distributions and community shifts after fire are affected by burn severity, elevation, aspect, and climate. However, little empirical data exists on long-term (decadal) recovery after fire across these interacting factors, limiting understanding of fire regime characteristics and climate in post-fire community trajectories. We examined plant species and community responses a decade after fire across five fires in ponderosa pine, dry mixed coniferous, and moist mixed coniferous forests across the western USA. Using field data, we determined changes in plant communities one and ten years post-fire across gradients of burn severity, elevation, and aspect. Existing published work has shown that plant species distributions can be accurately predicted from physiologically relevant climate variables using non-parametric Random Forests models; such models have also been linked to projected climate profiles in 2030, 2060, and 2090 generated from three commonly used general circulation models (GCMs). We explore the possibility that fire and climate are coupled drivers affecting plant species distributions. Climate change may not manifest as a slow shift in plant species distributions, but as sudden, localized events tied to changing fire and other disturbance regimes.

Wildfire Suppression Costs for Canada under a Changing Climate

PubMed Central

Stocks, Brian J.; Gauthier, Sylvie

2016-01-01

Climate-influenced changes in fire regimes in northern temperate and boreal regions will have both ecological and economic ramifications. We examine possible future wildfire area burned and suppression costs using a recently compiled historical (i.e., 1980–2009) fire management cost database for Canada and several Intergovernmental Panel on Climate Change (IPCC) climate projections. Area burned was modelled as a function of a climate moisture index (CMI), and fire suppression costs then estimated as a function of area burned. Future estimates of area burned were generated from projections of the CMI under two emissions pathways for four General Circulation Models (GCMs); these estimates were constrained to ecologically reasonable values by incorporating a minimum fire return interval of 20 years. Total average annual national fire management costs are projected to increase to just under $1 billion (a 60% real increase from the 1980–2009 period) under the low greenhouse gas emissions pathway and $1.4 billion (119% real increase from the base period) under the high emissions pathway by the end of the century. For many provinces, annual costs that are currently considered extreme (i.e., occur once every ten years) are projected to become commonplace (i.e., occur once every two years or more often) as the century progresses. It is highly likely that evaluations of current wildland fire management paradigms will be necessary to avoid drastic and untenable cost increases as the century progresses. PMID:27513660

Fire frequency drives decadal changes in soil carbon and nitrogen and ecosystem productivity

NASA Astrophysics Data System (ADS)

Pellegrini, Adam F. A.; Ahlström, Anders; Hobbie, Sarah E.; Reich, Peter B.; Nieradzik, Lars P.; Staver, A. Carla; Scharenbroch, Bryant C.; Jumpponen, Ari; Anderegg, William R. L.; Randerson, James T.; Jackson, Robert B.

2018-01-01

Fire frequency is changing globally and is projected to affect the global carbon cycle and climate. However, uncertainty about how ecosystems respond to decadal changes in fire frequency makes it difficult to predict the effects of altered fire regimes on the carbon cycle; for instance, we do not fully understand the long-term effects of fire on soil carbon and nutrient storage, or whether fire-driven nutrient losses limit plant productivity. Here we analyse data from 48 sites in savanna grasslands, broadleaf forests and needleleaf forests spanning up to 65 years, during which time the frequency of fires was altered at each site. We find that frequently burned plots experienced a decline in surface soil carbon and nitrogen that was non-saturating through time, having 36 per cent (±13 per cent) less carbon and 38 per cent (±16 per cent) less nitrogen after 64 years than plots that were protected from fire. Fire-driven carbon and nitrogen losses were substantial in savanna grasslands and broadleaf forests, but not in temperate and boreal needleleaf forests. We also observe comparable soil carbon and nitrogen losses in an independent field dataset and in dynamic model simulations of global vegetation. The model study predicts that the long-term losses of soil nitrogen that result from more frequent burning may in turn decrease the carbon that is sequestered by net primary productivity by about 20 per cent of the total carbon that is emitted from burning biomass over the same period. Furthermore, we estimate that the effects of changes in fire frequency on ecosystem carbon storage may be 30 per cent too low if they do not include multidecadal changes in soil carbon, especially in drier savanna grasslands. Future changes in fire frequency may shift ecosystem carbon storage by changing soil carbon pools and nitrogen limitations on plant growth, altering the carbon sink capacity of frequently burning savanna grasslands and broadleaf forests.

Fire frequency drives decadal changes in soil carbon and nitrogen and ecosystem productivity.

PubMed

Pellegrini, Adam F A; Ahlström, Anders; Hobbie, Sarah E; Reich, Peter B; Nieradzik, Lars P; Staver, A Carla; Scharenbroch, Bryant C; Jumpponen, Ari; Anderegg, William R L; Randerson, James T; Jackson, Robert B

2018-01-11

Fire frequency is changing globally and is projected to affect the global carbon cycle and climate. However, uncertainty about how ecosystems respond to decadal changes in fire frequency makes it difficult to predict the effects of altered fire regimes on the carbon cycle; for instance, we do not fully understand the long-term effects of fire on soil carbon and nutrient storage, or whether fire-driven nutrient losses limit plant productivity. Here we analyse data from 48 sites in savanna grasslands, broadleaf forests and needleleaf forests spanning up to 65 years, during which time the frequency of fires was altered at each site. We find that frequently burned plots experienced a decline in surface soil carbon and nitrogen that was non-saturating through time, having 36 per cent (±13 per cent) less carbon and 38 per cent (±16 per cent) less nitrogen after 64 years than plots that were protected from fire. Fire-driven carbon and nitrogen losses were substantial in savanna grasslands and broadleaf forests, but not in temperate and boreal needleleaf forests. We also observe comparable soil carbon and nitrogen losses in an independent field dataset and in dynamic model simulations of global vegetation. The model study predicts that the long-term losses of soil nitrogen that result from more frequent burning may in turn decrease the carbon that is sequestered by net primary productivity by about 20 per cent of the total carbon that is emitted from burning biomass over the same period. Furthermore, we estimate that the effects of changes in fire frequency on ecosystem carbon storage may be 30 per cent too low if they do not include multidecadal changes in soil carbon, especially in drier savanna grasslands. Future changes in fire frequency may shift ecosystem carbon storage by changing soil carbon pools and nitrogen limitations on plant growth, altering the carbon sink capacity of frequently burning savanna grasslands and broadleaf forests.

Seasonal and interannual variations in CO and BC emissions from open biomass burning in Southern Africa during 1998-2005

NASA Astrophysics Data System (ADS)

Ito, Akinori; Ito, Akihiko; Akimoto, Hajime

2007-06-01

We estimate the emissions of carbon monoxide (CO) and black carbon (BC) from open vegetation fires in the Southern Hemisphere Africa from 1998 to 2005 using satellite information in conjunction with a biogeochemical model. Monthly burned areas at a 0.5-degree resolution are estimated from the Visible InfraRed Scanner (VIRS) fire count product and the MODerate resolution Imaging Spectroradiometer (MODIS) burned area data set associated with the MODIS tree cover imagery in grasslands and woodlands. The monthly fuel load distributions are derived from a 0.5-degree terrestrial carbon cycle model in conjunction with satellite data. The monthly maps of combustion factors and emission factors are estimated using empirical models that predict the effects of fuel conditions on these factors in grasslands and woodlands. Our annually averaged effective CO and BC emissions per area burned are 27 g CO m-2 and 0.17 g BC m-2 which are consistent with the products of fuel consumption and emission factors typically measured in southern Africa. The CO and BC emissions from open vegetation burning in southern Africa range from 45 Tg CO yr-1 and 0.26 Tg BC yr-1 for 2002 to 75 Tg CO yr-1 and 0.42 Tg BC yr-1 for 1998. The monthly averaged burned areas from VIRS fire counts peak earlier than modeled CO emissions. This characteristic delay between burned areas and emissions is mainly explained by significant changes in combustion factors for woodlands in our model. Consequently, the peaks in CO and BC emissions from our bottom-up approach are identical to those from previous top-down estimates using the Measurement Of the Pollution In The Troposphere (MOPITT) and the Total Ozone Mapping Spectrometer (TOMS) Aerosol Index (AI) data.

State of Fire Behavior Models and their Application to Ecosystem and Smoke Management Issues: Special Session Summary Report

DTIC Science & Technology

2013-10-24

advance fire science: (1) fire behavior, (2) ecological effects of fire, (3) carbon accounting , (4) emissions characterization, and (5) fire plume...relates to smoke management. 3) Carbon accounting in forest management and prescribed fire programs (including tradeoffs such as prescribed burning...carbon accounting , 4) emissions characterization and 5) fire plume dispersion. 1) Fire behavior. Better characterization of wildland fire behavior is

Assessing accuracy of a probabilistic model for very large fire in the Rocky Mountains: A High Park Fire case study

NASA Astrophysics Data System (ADS)

Stavros, E.; Abatzoglou, J. T.; Larkin, N.; McKenzie, D.; Steel, A.

2012-12-01

Across the western United States, the largest wildfires account for a major proportion of the area burned and substantially affect mountain forests and their associated ecosystem services, among which is pristine air quality. These fires commandeer national attention and significant fire suppression resources. Despite efforts to understand the influence of fuel loading, climate, and weather on annual area burned, few studies have focused on understanding what abiotic factors enable and drive the very largest wildfires. We investigated the correlation between both antecedent climate and in-situ biophysical variables and very large (>20,000 ha) fires in the western United States from 1984 to 2009. We built logistic regression models, at the spatial scale of the national Geographic Area Coordination Centers (GACCs), to estimate the probability that a given day is conducive to a very large wildfire. Models vary in accuracy and in which variables are the best predictors. In a case study of the conditions of the High Park Fire, neighboring Fort Collins, Colorado, occurring in early summer 2012, we evaluate the predictive accuracy of the Rocky Mountain model.

Planning and evaluating prescribed fires--a standard procedure

Treesearch

William C. Fischer

1978-01-01

Provides a standard format and checklist to guide the land manager through the important steps for prescribed burning. Describes the kind of information needed to prepare fire prescriptions and burning plans. Identifies the elements of a fire prescription, a burning plan, and a prescribed fire evaluation. A plan written for an actual prescribed burning is included as...

Climate versus carbon dioxide controls on biomass burning: a model analysis of the glacial-interglacial contrast

NASA Astrophysics Data System (ADS)

Calvo, M. Martin; Prentice, I. C.; Harrison, S. P.

2014-11-01

Climate controls fire regimes through its influence on the amount and types of fuel present and their dryness. CO2 concentration constrains primary production by limiting photosynthetic activity in plants. However, although fuel accumulation depends on biomass production, and hence on CO2 concentration, the quantitative relationship between atmospheric CO2 concentration and biomass burning is not well understood. Here a fire-enabled dynamic global vegetation model (the Land surface Processes and eXchanges model, LPX) is used to attribute glacial-interglacial changes in biomass burning to an increase in CO2, which would be expected to increase primary production and therefore fuel loads even in the absence of climate change, vs. climate change effects. Four general circulation models provided last glacial maximum (LGM) climate anomalies - that is, differences from the pre-industrial (PI) control climate - from the Palaeoclimate Modelling Intercomparison Project Phase~2, allowing the construction of four scenarios for LGM climate. Modelled carbon fluxes from biomass burning were corrected for the model's observed prediction biases in contemporary regional average values for biomes. With LGM climate and low CO2 (185 ppm) effects included, the modelled global flux at the LGM was in the range of 1.0-1.4 Pg C year-1, about a third less than that modelled for PI time. LGM climate with pre-industrial CO2 (280 ppm) yielded unrealistic results, with global biomass burning fluxes similar to or even greater than in the pre-industrial climate. It is inferred that a substantial part of the increase in biomass burning after the LGM must be attributed to the effect of increasing CO2 concentration on primary production and fuel load. Today, by analogy, both rising CO2 and global warming must be considered as risk factors for increasing biomass burning. Both effects need to be included in models to project future fire risks.

Analysis of Alaskan burn severity patterns using remotely sensed data

USGS Publications Warehouse

Duffy, P.A.; Epting, J.; Graham, J.M.; Rupp, T.S.; McGuire, A.D.

2007-01-01

Wildland fire is the dominant large-scale disturbance mechanism in the Alaskan boreal forest, and it strongly influences forest structure and function. In this research, patterns of burn severity in the Alaskan boreal forest are characterised using 24 fires. First, the relationship between burn severity and area burned is quantified using a linear regression. Second, the spatial correlation of burn severity as a function of topography is modelled using a variogram analysis. Finally, the relationship between vegetation type and spatial patterns of burn severity is quantified using linear models where variograms account for spatial correlation. These results show that: 1) average burn severity increases with the natural logarithm of the area of the wildfire, 2) burn severity is more variable in topographically complex landscapes than in flat landscapes, and 3) there is a significant relationship between burn severity and vegetation type in flat landscapes but not in topographically complex landscapes. These results strengthen the argument that differential flammability of vegetation exists in some boreal landscapes of Alaska. Additionally, these results suggest that through feedbacks between vegetation and burn severity, the distribution of forest vegetation through time is likely more stable in flat terrain than it is in areas with more complex topography. ?? IAWF 2007.

Emergency assessments of postfire debris-flow hazards for the 2009 La Brea, Jesusita, Guiberson, Morris, Sheep, Oak Glen, Pendleton, and Cottonwood fires in southern California

USGS Publications Warehouse

Cannon, Susan H.; Gartner, Joseph E.; Rupert, Michael G.; Michael, John A.

2010-01-01

This report presents an emergency assessment of potential debris-flow hazards from basins burned by the 2009 La Brea and Jesusita fires in Santa Barbara County, the Guiberson fire in Ventura County, the Morris fire in Los Angeles County, the Sheep, Oak Glen, and Pendleton fires in San Bernardino County, and the Cottonwood fire in Riverside County, southern California. Statistical-empirical models developed to analyze postfire debris flows are used to estimate the probability and volume of debris-flows produced from drainage basins within each of the burned areas. Debris-flow probabilities and volumes are estimated as functions of different measures of basin burned extent, gradient, and material properties in response to both a 3-hour-duration, 2-year-recurrence thunderstorm and to a widespread, 12-hour-duration, 2-year-recurrence winter storm. This assessment provides critical information for issuing warnings, locating and designing mitigation measures, and planning evacuation timing and routes within the first two winters following the fire.

An Objective Summary of US Army Electro-Optical Modeling and Field Testing in an Obscuring Environment.

DTIC Science & Technology

1981-10-01

NUMBER 7. AUTHOR( e ) 8. CONTRACT OR GRANT NUMBER(&) Robert A. Sutherland Donald W. Hoock Rirhard R r.nM NA 9. PERFORMING ORGANIZATION NAME AND ADDRESS...smoke produced by a burning tank (BURN), another treats fires in general (FIRE), four are inventory smoke munitions expenditure models ( STILES , SEMM... E . Cramer (HEC) Company under contract to ASL and Tforms the basic transport and diffusion routine for the larger system called Experimental Prototype

Fire history of the Peron Peninsula, Shark Bay, Western Australia based on remote sensing, dendrochronology, and anecdotal evidence

NASA Astrophysics Data System (ADS)

Beller, Benjamin J.

Remote sensing data, dendrochronology, Geographical Information Systems (GIS), and anecdotal information were used to describe the fire regime of the 180,000 ha Peron Peninsula of Western Australia. Fire scars present in 1944 aerial photos were still visible in 2009, both in imagery and on the ground. Tree-ring dates from specimens sampled within these burned areas indicated the occurrence of at least three separate fires before 1944. The oldest fire occurred ca. 1911 and burned at least 5,880 ha. Subsequent fires ca. 1922 and 1936 burned across 8,240 ha and 9,400 ha respectively. The fire dates determined from tree-ring counts were consistent with precipitation data which showed conditions particularly favorable for fire before or during the estimated year of each fire. Plant communities most often burned before 1944 were the Acacia ramulosa var. linophylla Scrub and the Acacia - Lamarchea hakefolia Thicket with, respectively, 73% and 75% of these plant community types at the study area found to have been burned at some time. Remote sensing imagery from 1944-2009 identified only 300 additional hectares burned, a 25 ha fire in 1991 in the combined Acacia ramulosa var. linophylla Scrub and A.ligulata and A. rostellifora Thicket, ten prescribed burns in 1995 totaling 274 ha in various habitats, and two late 1990's scars from prescribed burns designed to create fire buffers, one 4.6 km and the other 7.4 km long. Combined data for all years assessed showed 59,000 ha (66%) of the total study area to have been burned or reburned since ca. 1911, most prior to 1944, with a total of nearly 24,000 ha (27%) of the study area unburned for more than 110 years. Birridas, which cannot burn, accounted for the remaining 6,000 ha (7%) of the study area. These results show fire occurred more frequently 100 years ago (fires every 10-15 years) than at present (> 65 years between fires) suggesting that more frequent prescribed burning than occurs at present on the Peron Peninsula would be most consistent with the pre-European fire regimes of the region and the ecosystems they maintained.

Effects of wet- and dry-season fires on Jacquemontia curtisii, a South Florida pine forest endemic

USGS Publications Warehouse

Spier, L.P.; Snyder, J.R.

1998-01-01

South Florida pine forests have a diverse endemic flora that has evolved under the influence of recurrent fire. We studied the response of Jacquemontia curtisii Peter ex Hallier f. (pineland clustervine), a perennial herbaceous member of that flora, to experimental fires during wet and dry seasons. In each of three populations, three treatments were applied: wet-season (June) prescribed fire, dry-season (January) prescribed fire, and an unburned control. Flowering, fruiting, and seedling establishment were followed for up to one year. Mortality of adult plants was twice as great after wet-season burns than after dry-season burns even though fire temperatures were higher in the dry-season burns. Within a season of burning, mortality was greater for the more severely burned plants or the smaller plants. Wet-season burns produced over three times more flowers than not burning, in spite of mortality of more than half the plants. Burning stimulated germination from the soil seed bank. Dry-season burns resulted in five times more seedlings than wet-season burns and more of these seedlings were alive one year after the burn. It is likely that the long-term viability of Jacquemontia curtisii populations is favored by diversity in fire season and severity.

Importance of fuel treatment for limiting moderate-to-high intensity fire: Findings from comparative fire modeling

Treesearch

Geoffrey J. Cary; Ian D. Davies; Ross A. Bradstock; Robert E. Keane; Mike D. Flannigan

2017-01-01

Context: Wildland fire intensity influences natural communities, soil properties, erosion, and sequestered carbon. Measuring effectiveness of fuel treatment for reducing area of higher intensity unplanned fire is argued to be more meaningful than determining effect on total unplanned area burned. Objectives...

Biomass burning aerosols and the low-visibility events in Southeast Asia

DOE PAGES

Lee, Hsiang-He; Bar-Or, Rotem Z.; Wang, Chien

2017-01-23

Fires including peatland burning in Southeast Asia have become a major concern to the general public as well as governments in the region. This is because aerosols emitted from such fires can cause persistent haze events under certain weather conditions in downwind locations, degrading visibility and causing human health issues. In order to improve our understanding of the spatiotemporal coverage and influence of biomass burning aerosols in Southeast Asia, we have used surface visibility and particulate matter concentration observations, supplemented by decade-long (2003 to 2014) simulations using the Weather Research and Forecasting (WRF) model with a fire aerosol module, driven bymore » high-resolution biomass burning emission inventories. We find that in the past decade, fire aerosols are responsible for nearly all events with very low visibility (< 7 km). Fire aerosols alone are also responsible for a substantial fraction of low-visibility events (visibility  < 10 km) in the major metropolitan areas of Southeast Asia: up to 39 % in Bangkok, 36 % in Kuala Lumpur, and 34 % in Singapore. Biomass burning in mainland Southeast Asia accounts for the largest contribution to total fire-produced PM 2.5 in Bangkok (99 %), while biomass burning in Sumatra is a major contributor to fire-produced PM 2.5 in Kuala Lumpur (50 %) and Singapore (41 %). To examine the general situation across the region, we have further defined and derived a new integrated metric for 50 cities of the Association of Southeast Asian Nations (ASEAN): the haze exposure day (HED), which measures the annual exposure days of these cities to low visibility (< 10 km) caused by particulate matter pollution. It is shown that HEDs have increased steadily in the past decade across cities with both high and low populations. Fire events alone are found to be responsible for up to about half of the total HEDs. Our results suggest that in order to improve the overall air quality in Southeast Asia, mitigation policies targeting both biomass burning and fossil fuel burning sources need to be implemented.« less

Biomass burning aerosols and the low-visibility events in Southeast Asia

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

Lee, Hsiang-He; Bar-Or, Rotem Z.; Wang, Chien

Fires including peatland burning in Southeast Asia have become a major concern to the general public as well as governments in the region. This is because aerosols emitted from such fires can cause persistent haze events under certain weather conditions in downwind locations, degrading visibility and causing human health issues. In order to improve our understanding of the spatiotemporal coverage and influence of biomass burning aerosols in Southeast Asia, we have used surface visibility and particulate matter concentration observations, supplemented by decade-long (2003 to 2014) simulations using the Weather Research and Forecasting (WRF) model with a fire aerosol module, driven bymore » high-resolution biomass burning emission inventories. We find that in the past decade, fire aerosols are responsible for nearly all events with very low visibility (< 7 km). Fire aerosols alone are also responsible for a substantial fraction of low-visibility events (visibility  < 10 km) in the major metropolitan areas of Southeast Asia: up to 39 % in Bangkok, 36 % in Kuala Lumpur, and 34 % in Singapore. Biomass burning in mainland Southeast Asia accounts for the largest contribution to total fire-produced PM 2.5 in Bangkok (99 %), while biomass burning in Sumatra is a major contributor to fire-produced PM 2.5 in Kuala Lumpur (50 %) and Singapore (41 %). To examine the general situation across the region, we have further defined and derived a new integrated metric for 50 cities of the Association of Southeast Asian Nations (ASEAN): the haze exposure day (HED), which measures the annual exposure days of these cities to low visibility (< 10 km) caused by particulate matter pollution. It is shown that HEDs have increased steadily in the past decade across cities with both high and low populations. Fire events alone are found to be responsible for up to about half of the total HEDs. Our results suggest that in order to improve the overall air quality in Southeast Asia, mitigation policies targeting both biomass burning and fossil fuel burning sources need to be implemented.« less

Sensitivity of the Plume Rise Model in the estimation of biomass burning plume injection heights in South America

NASA Astrophysics Data System (ADS)

Ferrada, Gonzalo A.; Freitas, Saulo; Pereira, Gabriel; Paugam, Ronan

2017-04-01

This study had the aim to evaluate the new developments on the Plume Rise Model (PRM), embedded into the Brazilian developments on the Regional Atmospheric Modelling System (BRAMS). PRM computes the biomass burning plume injection heights and returns that information to the host model. Then, the atmospheric model releases all the fire emissions at this height. New developments are based on the initialization data used by the PRM, using fire size and fire radiative power (FRP) from remote sensing. The main difference between the two new versions is the conversion parameter (β) used to convert from FRP to the plume convective flux. In addition, a new scheme to generate daily fire emission fluxes is offered using the fire radiative energy (computed from remote sensing) in the Brazilian Biomass Burning Emission Model (3BEM-FRE). Model results using the three versions of the PRM are compared with observed airborne CO and O3 data from the SAMBBA campaign, which took place in southern Amazonia and Cerrado (savanna-like) regions in September 2012. Results show that improvements in both 3BEM-FRE and PRM models, had a better performance in the vertical and horizontal reproduction of CO and O3 than the original versions of them, especially in the middle and upper troposphere. Nevertheless, with some difficulty to reproduce the emissions by the end of the campaign, probably due to the cumulus parameterization used, which overestimated the precipitation in the region of study. Also, developments made in the 3BEM model show better agreement with the observed remote sensing data of daily fire emissions than the original version of it in the Amazon region, but with some difficulty in the Cerrado.

Comparison Between Surf and Multi-Shock Forest Fire High Explosive Burn Models

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

Greenfield, Nicholas Alexander

PAGOSA1 has several different burn models used to model high explosive detonation. Two of these, Multi-Shock Forest Fire and Surf, are capable of modeling shock initiation. Accurately calculating shock initiation of a high explosive is important because it is a mechanism for detonation in many accident scenarios (i.e. fragment impact). Comparing the models to pop-plot data give confidence that the models are accurately calculating detonation or lack thereof. To compare the performance of these models, pop-plots2 were created from simulations where one two cm block of PBX 9502 collides with another block of PBX 9502.

Analyzing post-fire topography at the hillslope-channel interface with terrestrial LiDAR: contrasting geomorphic responses from the 2012 Waldo Canyon Fire of Colorado and the 2013 Springs Fire of California

NASA Astrophysics Data System (ADS)

Storesund, R.; Chin, A.; Florsheim, J. L.; O'Hirok, L.; Williams, K.; Austin, K. E.

2014-12-01

Mountains areas are increasingly susceptible to wildfires because of warming climates. Although knowledge of the hydro-geomorphological impacts of wildfire has advanced in recent years, much is still unknown regarding how environmental fluxes move through burned watersheds. Because of the loss of vegetation and hydrophobic soils, flash floods often accompany elevated runoff events from burned watersheds, making direct process measurements challenging. Direct measurements are also only partly successful at capturing the spatial variations of post-fire effects. Coupled with short temporal windows for observing such responses, opportunities are often missed for collecting data needed for developing predictive models. Terrestrial LiDAR scanning (TLS) of burned areas allows detailed documentation of the post-fire topography to cm-level accuracy, providing pictures of geomorphic responses not previously possible. This paper reports a comparative study of hillslope-channel interactions, using repeat TLS, in two contrasting environments. Burned by the 2012 Waldo Canyon Fire and 2013 Springs Fire, in Colorado and California respectively, the study sites share many similarities including steep erosive slopes, small drainage areas, and step-pool channel morphologies. TLS provided a tool to test the central hypothesis that, dry ravel, distinct in the California Mediterranean environment, would prompt a greater sedimentological response from the Springs Fire compared to the Waldo Canyon Fire. At selected sites in each area, TLS documented baseline conditions immediately following the fire. Repeat scanning after major storms allowed detection of changes in the landscape. Results show a tendency for sedimentation in river channels in the study sites interacting with dry ravel on hillslopes, whereas erosion dominated the response from the Waldo Canyon Fire with an absence of dry ravel. These data provide clues to developing generalizations for post-fire effects at regional scales, which could assist with managing hazards from wildfires. TLS provides a promising tool to expand the range of studies concerning environmental responses through burned landscapes.

Effects of salvage logging and pile-and-burn on fuel loading, potential fire behaviour, fuel consumption and emissions

Treesearch

Morris C. Johnson; Jessica E. Halofsky; David L. Peterson

2013-01-01

We used a combination of field measurements and simulation modelling to quantify the effects of salvage logging, and a combination of salvage logging and pile-and-burn fuel surface fuel treatment (treatment combination), on fuel loadings, fire behaviour, fuel consumption and pollutant emissions at three points in time: post-windstorm (before salvage logging), post-...

Modeling very large-fire occurrences over the continental United States from weather and climate forcing

Treesearch

R Barbero; J T Abatzoglou; E A Steel

2014-01-01

Very large-fires (VLFs) have widespread impacts on ecosystems, air quality, fire suppression resources, and in many regions account for a majority of total area burned. Empirical generalized linear models of the largest fires (>5000 ha) across the contiguous United States (US) were developed at ¡­60 km spatial and weekly temporal resolutions using solely atmospheric...

EcoSmart Fire as structure ignition model in wildland urban interface: predictions and validations

Treesearch

Mark A. Dietenberger; Charles R. Boardman

2016-01-01

EcoSmartFire is a Windows program that models heat damage and piloted ignition of structures from radiant exposure to discrete landscaped tree fires. It calculates the radiant heat transfer from cylindrical shaped fires to the walls and roof of the structure while accounting for radiation shadowing, attenuation, and ground reflections. Tests of litter burn, a 0.6 m...

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...

Sensitivity analysis of a FMC model for improving forecasting forest fires: Comparison with real fires in Spain

NASA Astrophysics Data System (ADS)

San Jose, Roberto; Perez, Juan Luis; Gonzalez-Barras, Rosa M.; Pecci, Julia; Palacios, Marino

2014-05-01

Forest fires continue to be a very dangerous and extreme violent episode jeopardizing the human lives and owns. Spain is plagued by forest and brush fires every summer, when extremely dry weather sets in along with high temperatures. The use of fire behavior models requires the availability of high resolution environmental and fuel data; in absence of realistic data, errors on the simulated fire spread con be compounded to produce o decrease of the spatial and temporal accuracy of predicted data. In this work we have carried out a sensitivity analysis of different components of the fire model and particularly the fuel moisture content (FMC) such as microphysics and solar radiation model. Three different real fire models have been used: Murcia (September, 7, 2010 19h09 and 9 hours duration), Gabiel (March, 7, 2007, 22h15 and 38 hours duration) and Culla (Marzo, 7, 2007, 23h36 and 37 hours duration). We use the 100 m European Corine Land Cover map. We use the WRF-Fire model developed by NCAR (USA). The WRF mode is run using the GFS global data and over the Iberian Peninsula with 15 km spatial resolution. We apply the nesting approach over the fires areas (located in the South East of the Iberian Peninsula) with 3 km, 1 km and 200 m spatial resolution. The Fire module included into WRF is run with 20 m spatial resolution and the landuse is interpolated from the Corine 100 m land use map. The results show that the Thompson et al. microphysics scheme and the RRTM solar radiation scheme are those with the best combination using a specific counting score to classify the goodness of the results compare with the real burned area. Those pixels not burned by the simulations but burned by the observational data sets are penalized double compare with the vice versa process. The NDVI obtained by satellite on the day of starting the fire is included in the simulations and a substantial improving in the final score is obtained.

Fire management strategies to maintain species population processes in a fragmented landscape of fire-interval extremes.

PubMed

Tulloch, Ayesha I T; Pichancourt, Jean-Baptiste; Gosper, Carl R; Sanders, Angela; Chadès, Iadine

2016-10-01

Changed fire regimes have led to declines of fire-regime-adapted species and loss of biodiversity globally. Fire affects population processes of growth, reproduction, and dispersal in different ways, but there is little guidance about the best fire regime(s) to maintain species population processes in fire-prone ecosystems. We use a process-based approach to determine the best range of fire intervals for keystone plant species in a highly modified Mediterranean ecosystem in southwestern Australia where current fire regimes vary. In highly fragmented areas, fires are few due to limited ignitions and active suppression of wildfire on private land, while in highly connected protected areas fires are frequent and extensive. Using matrix population models, we predict population growth of seven Banksia species under different environmental conditions and patch connectivity, and evaluate the sensitivity of species survival to different fire management strategies and burning intervals. We discover that contrasting, complementary patterns of species life-histories with time since fire result in no single best fire regime. All strategies result in the local patch extinction of at least one species. A small number of burning strategies secure complementary species sets depending on connectivity and post-fire growing conditions. A strategy of no fire always leads to fewer species persisting than prescribed fire or random wildfire, while too-frequent or too-rare burning regimes lead to the possible local extinction of all species. In low landscape connectivity, we find a smaller range of suitable fire intervals, and strategies of prescribed or random burning result in a lower number of species with positive growth rates after 100 years on average compared with burning high connectivity patches. Prescribed fire may reduce or increase extinction risk when applied in combination with wildfire depending on patch connectivity. Poor growing conditions result in a significantly reduced number of species exhibiting positive growth rates after 100 years of management. By exploring the consequences of managing fire, we are able to identify which species are likely to disappear under a given fire regime. Identifying the appropriate complementarity of fire intervals, and their species-specific as well as community-level consequences, is crucial to reduce local extinctions of species in fragmented fire-prone landscapes. © 2016 by the Ecological Society of America.

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.

Tree mortality from fire and bark beetles following early and late season prescribed fires in a Sierra Nevada mixed-conifer forest

USGS Publications Warehouse

Schwilk, Dylan W.; Knapp, Eric E.; Ferrenberg, Scott; Keeley, Jon E.; Caprio, Anthony C.

2006-01-01

Over the last century, fire exclusion in the forests of the Sierra Nevada has allowed surface fuels to accumulate and has led to increased tree density. Stand composition has also been altered as shade tolerant tree species crowd out shade intolerant species. To restore forest structure and reduce the risk of large, intense fires, managers have increasingly used prescription burning. Most fires prior to EuroAmerican settlement occurred during the late summer and early fall and most prescribed burning has taken place during the latter part of this period. Poor air quality and lack of suitable burn windows during the fall, however, have resulted in a need to conduct more prescription burning earlier in the season. Previous reports have suggested that burning during the time when trees are actively growing may increase mortality rates due to fine root damage and/or bark beetle activity. This study examines the effects of fire on tree mortality and bark beetle attacks under prescription burning during early and late season. Replicated early season burn, late season burn and unburned control plots were established in an old-growth mixed conifer forest in the Sierra Nevada that had not experienced a fire in over 120 years. Although prescribed burns resulted in significant mortality of particularly the smallest tree size classes, no difference between early and late season burns was detected. Direct mortality due to fire was associated with fire intensity. Secondary mortality due to bark beetles was not significantly correlated with fire intensity. The probability of bark beetle attack on pines did not differ between early and late season burns, while the probability of bark beetle attack on firs was greater following early season burns. Overall tree mortality appeared to be primarily the result of fire intensity rather than tree phenology at the time of the burns. Early season burns are generally conducted under higher fuel moisture conditions, leading to less fuel consumption and potentially less injury to trees. This reduction in fire severity may compensate for relatively modest increases in bark beetle attack probabilities on some tree species, ultimately resulting in a forest structure that differs little between early and late season prescribed burning treatments.

Climate, lightning ignitions, and fire severity in Yosemite National Park, California, USA

USGS Publications Warehouse

Lutz, J.A.; van Wagtendonk, J.W.; Thode, A.E.; Miller, J.D.; Franklin, J.F.

2009-01-01

Continental-scale studies of western North America have attributed recent increases in annual area burned and fire size to a warming climate, but these studies have focussed on large fires and have left the issues of fire severity and ignition frequency unaddressed. Lightning ignitions, any of which could burn a large area given appropriate conditions for fire spread, could be the first indication of more frequent fire. We examined the relationship between snowpack and the ignition and size of fires that occurred in Yosemite National Park, California (area 3027 km2), between 1984 and 2005. During this period, 1870 fires burned 77 718 ha. Decreased spring snowpack exponentially increased the number of lightning-ignited fires. Snowpack mediated lightning-ignited fires by decreasing the proportion of lightning strikes that caused lightning-ignited fires and through fewer lightning strikes in years with deep snowpack. We also quantified fire severity for the 103 fires >40 ha with satellite fire-severity indices using 23 years of Landsat Thematic Mapper data. The proportion of the landscape that burned at higher severities and the complexity of higher-severity burn patches increased with the log10 of annual area burned. Using one snowpack forecast, we project that the number of lightning-ignited fires will increase 19.1% by 2020 to 2049 and the annual area burned at high severity will increase 21.9%. Climate-induced decreases in snowpack and the concomitant increase in fire severity suggest that existing assumptions may be understated-fires may become more frequent and more severe. ?? IAWF 2009.

The Influence of Solid Rocket Motor Retro-Burns on the Space Debris Environment

NASA Astrophysics Data System (ADS)

Stabroth, S.; Homeister, M.; Oswald, M.; Wiedemann, C.; Klinkrad, H.; Vörsmann, P.

The ESA space debris population model MASTER Meteoroid and Space Debris Terrestrial Environment Reference considers firings of solid rocket motors SRM as a debris source with the associated generation of slag and dust particles The resulting slag and dust population is a major contribution to the sub-millimetre size debris environment in Earth orbit The current model version MASTER-2005 is based on the simulation of 1 076 orbital SRM firings which contributed to the long-term debris environment A comparison of the modelled flux with impact data from returned surfaces shows that the shape and quantity of the modelled SRM dust distribution matches that of recent Hubble Space Telescope HST solar array measurements very well However the absolute flux level for dust is under-predicted for some of the analysed Long Duration Exposure Facility LDEF surfaces This points into the direction of some past SRM firings not included in the current event database The most suitable candidates for these firings are the large number of SRM retro-burns of return capsules Objects released by those firings have highly eccentric orbits with perigees in the lower regions of the atmosphere Thus they produce no long-term effect on the debris environment However a large number of those firings during the on-orbit time frame of LDEF might lead to an increase of the dust population for some of the LDEF surfaces In this paper the influence of SRM retro-burns on the short- and long-term debris environment is analysed The existing firing database is updated with gathered

Risk of hospitalization for fire-related burns during extreme cold weather.

PubMed

Ayoub, Aimina; Kosatsky, Tom; Smargiassi, Audrey; Bilodeau-Bertrand, Marianne; Auger, Nathalie

2017-10-01

Environmental factors are important predictors of fires, but no study has examined the association between outdoor temperature and fire-related burn injuries. We sought to investigate the relationship between extremely cold outdoor temperatures and the risk of hospitalization for fire-related burns. We carried out a time-stratified case-crossover study of 2470 patients hospitalized for fire-related burn injuries during cold months between 1989 and 2014 in Quebec, Canada. The main exposure was the minimum outdoor temperature on the day of and the day before the burn. We computed odds ratios (OR) and 95% confidence intervals (CI) to evaluate the relationship between minimum temperature and fire-related burns, and assessed how associations varied across sex and age. Exposure to extreme cold temperature was associated with a significantly higher risk of hospitalization for fire-related burns. Compared with 0°C, exposure to a minimum temperature of -30°C was associated with an OR of 1.51 (95% CI 1.22-1.87) for hospitalization for fire-related burns. The associations were somewhat stronger for women, youth, and the elderly. Compared with 0°C, a minimum temperature of -30°C was associated with an OR for fire-related burn hospitalization of 1.65 for women (95% CI 1.13-2.40), 1.60 for age < 25 years (95% CI 1.02-2.52), and 1.73 for age ≥ 65 years (95% CI 1.08-2.77). Extremely cold outdoor temperature is a risk factor for fire-related burns. Measures to prevent fires should be implemented prior to the winter season, and enhanced during extreme cold. Copyright © 2017 Elsevier Inc. All rights reserved.

High severity experimental burns in Siberian larch forests increase permafrost thaw and larch tree regeneration

NASA Astrophysics Data System (ADS)

Alexander, H. D.; Davydov, S.; Zimov, N.; Mack, M. C.

2013-12-01

Global change models predict increased fire activity in boreal forests as climate warms and dries. We hypothesized that fire-driven decreases in soil organic layer (SOL) depth will (1) increase permafrost thaw by reducing the insulating capacity of the SOL and (2) improve seedbed conditions for tree regeneration. Over time, these changes will lead to altered patterns of above- and belowground carbon (C) accumulation. To test these hypotheses, we conducted plot-level experimental burns in July 2012 in a low-density, mature larch stand near the Northeast Science Station in Cherskii, Siberia. Dried fuels of naturally occurring vegetation were added to plots to achieve four burn severity treatments based on residual SOL depths: control, low (> 8 cm), moderate (5-8 cm), and high severity (2-5 cm). Pre-fire and during two growing seasons post-fire, we measured thaw depth, soil moisture, and soil temperature to determine severity effects on permafrost thaw. We also sowed larch seeds in fall 2012 and quantified germination rates the following growing season. By 1 wk post-fire, thaw depth was 15-25 cm deeper in plots burned at high severity (55 cm) compared to other treatments (30-40 cm). These differences in thaw depth with burn severity were maintained during the subsequent growing season and were associated with increased soil temperature and moisture. Larch regeneration was 10x higher on severely burned plots than those unburned. Our findings highlight the potential for increased fire severity to degrade permafrost and alter successional dynamics and patterns of C accumulation.

Responsible for Fire Safety. Seventh Grade. Fire Safety for Texans: Fire and Burn Prevention Curriculum Guide.

ERIC Educational Resources Information Center

Texas State Commission on Fire Protection, Austin.

This booklet comprises the seventh grade component of a series of curriculum guides on fire and burn prevention. Designed to meet the age-specific needs of seventh grade students, its objectives include: (1) practicing responsible decision-making regarding fire and burn hazards, including peer pressure related to fire risks; and (2) practicing…

Mapping day-of-burning with coarse-resolution satellite fire-detection data

Treesearch

Sean A. Parks

2014-01-01

Evaluating the influence of observed daily weather on observed fire-related effects (e.g. smoke production, carbon emissions and burn severity) often involves knowing exactly what day any given area has burned. As such, several studies have used fire progression maps ­ in which the perimeter of an actively burning fire is mapped at a fairly high temporal resolution -...

High-resolution observations of combustion in heterogeneous surface fuels

Treesearch

E. Louise Loudermilk; Gary L. Achtemeier; Joseph J. O' Brien; J. Kevin Hiers; Benjamin S. Hornsby

2014-01-01

In ecosystems with frequent surface fires, fire and fuel heterogeneity at relevant scales have been largely ignored. This could be because complete burns give an impression of homogeneity, or due to the difficulty in capturing fine-scale variation in fuel characteristics and fire behaviour. Fire movement between patches of fuel can have implications for modelling fire...

Carbon and Aerosol Emissions from Biomass Fires in Mexico

NASA Astrophysics Data System (ADS)

Hao, W. M.; Flores Garnica, G.; Baker, S. P.; Urbanski, S. P.

2009-12-01

Biomass burning is an important source of many atmospheric greenhouse gases and photochemically reactive trace gases. There are limited data available on the spatial and temporal extent of biomass fires and associated trace gas and aerosol emissions in Mexico. Biomass burning is a unique source of these gases and aerosols, in comparison to industrial and biogenic sources, because the locations of fires vary considerably both daily and seasonally and depend on human activities and meteorological conditions. In Mexico, the fire season starts in January and about two-thirds of the fires occur in April and May. The amount of trace gases and aerosols emitted by fires spatially and temporally is a major uncertainty in quantifying the impact of fire emissions on regional atmospheric chemical composition. To quantify emissions, it is necessary to know the type of vegetation, the burned area, the amount of biomass burned, and the emission factor of each compound for each ecosystem. In this study biomass burning experiments were conducted in Mexico to measure trace gas emissions from 24 experimental fires and wildfires in semiarid, temperate, and tropical ecosystems from 2005 to 2007. A range of representative vegetation types were selected for ground-based experimental burns to characterize fire emissions from representative Mexico fuels. A third of the country was surveyed each year, beginning in the north. The fire experiments in the first year were conducted in Chihuahua, Nuevo Leon, and Tamaulipas states in pine forest, oak forest, grass, and chaparral. The second-year fire experiments were conducted on pine forest, oak forest, shrub, agricultural, grass, and herbaceous fuels in Jalisco, Puebla, and Oaxaca states in central Mexico. The third-year experiments were conducted in pine-oak forests of Chiapas, coastal grass, and low subtropical forest on the Yucatan peninsula. FASS (Fire Atmosphere Sampling System) towers were deployed for the experimental fires. Each FASS system contains 4 electro-polished stainless steel canisters to sample trace gas emissions, with a corresponding set of Teflon filters in the sampling ports to collect PM2.5 particulates. In addition, biomass burning was sampled by aircraft with canisters and real-time instruments as part of the MILAGRO field campaign. We present the emission factors of CO2, CO, CH4, C2-C4 compounds, and PM2.5 for prescribed fires of the major vegetation types in Mexico, as well as for regional wildfires in southern and central Mexico. We will also present a high-resolution vegetation map in Mexico based on the Landsat satellites and the fuel consumption models for various components and sizes of fuels.

A comparison of effects from prescribed fires and wildfires managed for resource objectives in Sequoia and Kings Canyon National Parks

USGS Publications Warehouse

Nesmith, C.B.; Caprio, Anthony C.; Pfaff, Anne H.; McGinnis, Thomas W.; Keeley, Jon E.

2011-01-01

Current goals for prescription burning are focused on measures of fuel consumption and changes in forest density. These benchmarks, however, do not address the extent to which prescription burning meets perceived ecosystem needs of heterogeneity in burning, both for overstory trees and understory herbs and shrubs. There are still questions about how closely prescribed fires mimic these patterns compared to natural wildfires. This study compared burn patterns of prescribed fires and managed unplanned wildfires to understand how the differing burning regimes affect ecosystem properties. Measures of forest structure and fire severity were sampled in three recent prescribed fires and three wildfires managed for resource objectives in Sequoia and Kings Canyon National Parks. Fine scale patterns of fire severity and heterogeneity were compared between fire types using ground-based measures of fire effects on fuels and overstory and understory vegetation. Prescribed fires and wildfires managed for resource objectives displayed similar patterns of overstory and understory fire severity, heterogeneity, and seedling and sapling survival. Variation among plots within the same fire was always greater than between fire types. Prescribed fires can provide burned landscapes that approximate natural fires in many ways. It is recognized that constraints placed on when wildfires managed for resource objectives are allowed to burn freely may bias the range of conditions that might have been experienced under more natural conditions. Therefore they may not exactly mimic natural wildfires. Overall, the similarity in fire effects that we observed between prescribed fires and managed wildfires indicate that despite the restrictions that are often placed on prescribed fires, they appear to be creating post-fire conditions that approximate natural fires when assessed on a fine spatial scale.

Quantifying Fire Impact on Alaskan Tundra from Satellite Observations and Field Measurements

NASA Astrophysics Data System (ADS)

Loboda, T. V.; Chen, D.; He, J.; Jenkins, L. K.

2017-12-01

Wildfire is a major disturbance agent in Alaskan tundra. The frequency and extent of fire events obtained from paleo, management, and satellite records may yet underestimate the scope of tundra fire impact. Field measurements, collected within the NASA's ABoVE campaign, revealed unexpectedly shallow organic soils ( 15 cm) across all sampled sites of the Noatak valley with no significant difference between recently burned and unburned sites. In typical small and medium-sized tundra burns vegetation recovers rapidly and scars are not discernable in 30 m optical satellite imagery by the end of the first post-fire season. However, field observations indicate that vegetation and subsurface characteristics within fire scars of different ages vary across the landscape. In this study we develop linkages between fire-induced changes to tundra and satellite-based observations from optical, thermal, and microwave imagers to enable extrapolation of in-situ observations to cover the full extent of Alaskan tundra. Our results show that recent ( 30 years) fire history can be reconstructed from optical observations (R2 0.65, p<0.001) within a specific narrow temporal window or thermal signatures (R2 0.54, p < 0.001), in both cases controlled for slope and southern exposure. Using microwave SAR imagery fire history can be determined for 4 years post fire primarily due to increased soil moisture at burned sites. Field measurements suggest that the relatively quick SAR signal dissipation results from more even distribution of surface moisture through the soil column with increases in Active Layer Thickness (ALT). Similar to previous long-term field studies we find an increase in shrub fraction and shrub height within burns over time at the landscape scale; however, the strength and significance of the relationship between shrub fraction and time since fire is governed by burn severity with more severe burns predictably (p < 0.01) resulting in higher post-fire shrub cover. Although reasonably well-correlated to each other when adjusted for topography (R2 0.35, p < 0.001), neither ALT nor soil temperature can be directly linked to optical or thermal brightness observations with acceptable statistical significance, necessitating a more complex modeling environment for wall-to-wall mapping of subsurface parameters.

Barren-ground caribou (Rangifer tarandus groenlandicus) behaviour after recent fire events; integrating caribou telemetry data with Landsat fire detection techniques.

PubMed

Rickbeil, Gregory J M; Hermosilla, Txomin; Coops, Nicholas C; White, Joanne C; Wulder, Michael A

2017-03-01

Fire regimes are changing throughout the North American boreal forest in complex ways. Fire is also a major factor governing access to high-quality forage such as terricholous lichens for barren-ground caribou (Rangifer tarandus groenlandicus). Additionally, fire alters forest structure which can affect barren-ground caribou's ability to navigate in a landscape. Here, we characterize how the size and severity of fires are changing across five barren-ground caribou herd ranges in the Northwest Territories and Nunavut, Canada. Additionally, we demonstrate how time since fire, fire severity, and season result in complex changes in caribou behavioural metrics estimated using telemetry data. Fire disturbances were identified using novel gap-free Landsat surface reflectance composites from 1985 to 2011 across all herd ranges. Burn severity was estimated using the differenced normalized burn ratio. Annual area burned and burn severity were assessed through time for each herd and related to two behavioural metrics: velocity and relative turning angle. Neither annual area burned nor burn severity displayed any temporal trend within the study period. However, certain herds, such as the Ahiak/Beverly, have more exposure to fire than other herds (i.e. Cape Bathurst had a maximum forested area burned of less than 4 km 2 ). Time since fire and burn severity both significantly affected velocity and relative turning angles. During fall, winter, and spring, fire virtually eliminated foraging-focused behaviour for all 26 years of analysis while more severe fires resulted in a marked increase in movement-focused behaviour compared to unburnt patches. Between seasons, caribou used burned areas as early as 1-year postfire, demonstrating complex, nonlinear reactions to time since fire, fire severity, and season. In all cases, increases in movement-focused behaviour were detected postfire. We conclude that changes in caribou behaviour immediately postfire are primarily driven by changes in forest structure rather than changes in terricholous lichen availability. © 2016 John Wiley & Sons Ltd.

Application of wildfire simulation methods to assess wildfire exposure in a Mediterranean fire-prone area (Sardinia, Italy)

NASA Astrophysics Data System (ADS)

Salis, M.; Ager, A.; Arca, B.; Finney, M.; Bacciu, V. M.; Spano, D.; Duce, P.

2012-12-01

Spatial and temporal patterns of fire spread and behavior are dependent on interactions among climate, topography, vegetation and fire suppression efforts (Pyne et al. 1996; Viegas 2006; Falk et al. 2007). Humans also play a key role in determining frequency and spatial distribution of ignitions (Bar Massada et al, 2011), and thus influence fire regimes as well. The growing incidence of catastrophic wildfires has led to substantial losses for important ecological and human values within many areas of the Mediterranean basin (Moreno et al. 1998; Mouillot et al. 2005; Viegas et al. 2006a; Riaño et al. 2007). The growing fire risk issue has led to many new programs and policies of fuel management and risk mitigation by environmental and fire agencies. However, risk-based methodologies to help identify areas characterized by high potential losses and prioritize fuel management have been lacking for the region. Formal risk assessment requires the joint consideration of likelihood, intensity, and susceptibility, the product of which estimates the chance of a specific loss (Brillinger 2003; Society of Risk Analysis, 2006). Quantifying fire risk therefore requires estimates of a) the probability of a specific location burning at a specific intensity and location, and b) the resulting change in financial or ecological value (Finney 2005; Scott 2006). When large fires are the primary cause of damage, the application of this risk formulation requires modeling fire spread to capture landscape properties that affect burn probability. Recently, the incorporation of large fire spread into risk assessment systems has become feasible with the development of high performance fire simulation systems (Finney et al. 2011) that permit the simulation of hundreds of thousands of fires to generate fine scale maps of burn probability, flame length, and fire size, while considering the combined effects of weather, fuels, and topography (Finney 2002; Andrews et al. 2007; Ager and Finney 2009; Finney et al. 2009; Salis et al. 2012 accepted). In this work, we employed wildfire simulation methods to quantify wildfire exposure to human and ecological values for the island of Sardinia, Italy. The work was focused on the risk and exposure posed by large fires (e.g. 100 - 10,000 ha), and considers historical weather, ignition patterns and fuels. We simulated 100,000 fires using burn periods that replicated the historical size distribution on the Island, and an ignition probability grid derived from historic ignition data. We then examine spatial variation in three exposure components (burn probability, flame length, fire size) among important human and ecological values. The results allowed us to contract exposure among and within the various features examined, and highlighted the importance of human factors in shaping wildfire exposure in Sardinia. The work represents the first application of burn probability modeling in the Mediterranean region, and sets the stage for expanded work in the region to quantify risk from large fires

Impacts of global warming on boreal larch forest in East Siberia: simulations with a coupled carbon cycle and fire regime model

NASA Astrophysics Data System (ADS)

Ito, A.

2005-12-01

Boreal forest is one of the focal areas in the study of global warming and carbon cycle. In this study, a coupled carbon cycle and fire regime model was developed and applied to a larch forest in East Siberia, near Yakutsk. Fire regime is simulated with a cellular automaton (20 km x 20 km), in which fire ignition, propagation, and extinction are parameterized in a stochastic manner, including the effects of fuel accumulation and weather condition. For each grid, carbon cycle is simulated with a 10-box scheme, in which net biome production by photosynthesis, respiration, decomposition, and biomass burning are calculated explicitly. Model parameters were calibrated with field data of biomass, litter stock, and fire statistics; the carbon cycle scheme was examined with flux measurement data. As a result, the model successfully captured average carbon stocks, productivity, fire frequency, and biomass burning. To assess the effects of global warming, a series of simulations were performed using climatic projections based on the IPCC-SRES emission scenarios from 1990 to 2100. The range of uncertainty among the different climate models and emission scenarios was assessed by using multi-model projection data by CCCma, CCSR/NIES, GFDL, and HCCPR corresponding to the SRES A2 and B2 scenarios. The model simulations showed that global warming in the 21st century would considerably enhance the fire regime (e.g., cumulative burnt area increased by 80 to 120 percent), leading to larger carbon emission by biomass burning. The effect was so strong that growth enhancement by elevated atmospheric CO2 concentration and elongated growing period was cancelled out at landscape scale. In many cases, the larch forest was estimated to act as net carbon sources of 2 to 5 kg C m_|2 by the end of the 21st century, underscoring the importance of forest fire monitoring and management in this region.

Modeling prescribed fire impacts on local to regional air quality and potential climate effects

EPA Science Inventory

Biomass burning, including wildfires and prescribed burns, are of increasing concern due to the potential impacts on ambient air quality. The direct and indirect radiative forcings associated the particulate matter from biomass burning are also raising questions regarding the pot...

The production of black carbon during managed burning of UK peatlands: could managed burning of peatlands lead to enhanced carbon storage?

NASA Astrophysics Data System (ADS)

Clay, G.; Worrall, F.

2008-12-01

Peatlands are the UK's largest single terrestrial carbon store with carbon stored in UK peatlands than in forests of Britain and France combined. Unlike most northern peatlands in the peat soils of the UK are heavily managed for recreation and agriculture and due to their proximity to major centres of population are under more anthropogenic pressure than most peatlands. A typical management strategy on UK upland peats is the use of managed fire to restrict vegetation. Fires are used upon a 10-25 year rotation and are described as "cool" as they are designed to remove the crown of the vegetation without scorching the litter layer or the underlying soil. In this case the fire destroys primary productivity and limits litter production but produces char. Char is a low volume, highly refractory, high carbon content product while litter is a high volume, decomposable, lower carbon content product. Therefore, the question is if there are fire conditions under which the production of char causes more carbon to be stored in the peat than would have been stored if no fire management had been employed. This study combines field studies of recent managed burns and wildfires along with detailed vegetation studies from a long term monitoring site in order to assess litter, biomass and black carbon production. In the laboratory experimental burns were undertaken in order to assess the amount and controls upon char production and the carbon content of that char. Results of field and laboratory observations are used to model carbon accumulation under a series of fire management scenarios and the modelling shows that cools burns at long rotations could lead to higher carbon storage than if no fire had occurred, further in several cases more carbon accumulation occurred even if less depth of peat was generated.

A Lifetime for Fire Safety. Health (High School). Fire Safety for Texans: Fire and Burn Prevention Curriculum Guide.

ERIC Educational Resources Information Center

Texas State Commission on Fire Protection, Austin.

This booklet comprises the high school health component of a series of curriculum guides on fire and burn prevention. It is designed to meet the age-specific needs of ninth and tenth grade students. Objectives include: (1) reviewing comprehensive fire and burn prevention techniques and emergency actions; (2) developing an awareness of fire safety…

Modeling and risk assessment for soil temperatures beneath prescribed forest fires

Treesearch

Haiganoush K. Preisler; Sally M. Haase; Stephen S. Sackett

2000-01-01

Prescribed fire is a management tool used by wildland resource management organizations in many ecosystems to reduce hazardous fuels and to achieve a host of other objectives. To study the effects of fire in naturally accumulating fuel conditions, the ambient soil temperature is monitored beneath prescribed burns. In this study we developed a stochastic model for...

Modeling potential structure ignitions from flame radiation exposure with implications for wildland/urban interface fire management

Treesearch

Jack D. Cohen; Bret W. Butler

1998-01-01

Residential losses associated with wildland fires have become a serious international fire protection problem. The radiant heat flux from burning vegetation adjacent to a structure is a principal ignition factor. A thermal radiation and ignition model estimated structure ignition potential using designated flame characteristics (inferred from various types and...

Satellite Contributions to the Quantitative Characterization of Biomass Burning for Climate Modeling

NASA Technical Reports Server (NTRS)

Ichoku, Charles; Kahn, Ralph; Chin, Mian

2012-01-01

Characterization of biomass burning from space has been the subject of an extensive body of literature published over the last few decades. Given the importance of this topic, we review how satellite observations contribute toward improving the representation of biomass burning quantitatively in climate and air-quality modeling and assessment. Satellite observations related to biomass burning may be classified into five broad categories: (i) active fire location and energy release, (ii) burned areas and burn severity, (iii) smoke plume physical disposition, (iv) aerosol distribution and particle properties, and (v) trace gas concentrations. Each of these categories involves multiple parameters used in characterizing specific aspects of the biomass-burning phenomenon. Some of the parameters are merely qualitative, whereas others are quantitative, although all are essential for improving the scientific understanding of the overall distribution (both spatial and temporal) and impacts of biomass burning. Some of the qualitative satellite datasets, such as fire locations, aerosol index, and gas estimates have fairly long-term records. They date back as far as the 1970s, following the launches of the DMSP, Landsat, NOAA, and Nimbus series of earth observation satellites. Although there were additional satellite launches in the 1980s and 1990s, space-based retrieval of quantitative biomass burning data products began in earnest following the launch of Terra in December 1999. Starting in 2000, fire radiative power, aerosol optical thickness and particle properties over land, smoke plume injection height and profile, and essential trace gas concentrations at improved resolutions became available. The 2000s also saw a large list of other new satellite launches, including Aqua, Aura, Envisat, Parasol, and CALIPSO, carrying a host of sophisticated instruments providing high quality measurements of parameters related to biomass burning and other phenomena. These improved data products have enabled significant progress in the study of biomass burning from space. However, appreciable uncertainty remains in many of the measurements that still needs to be addressed. Nevertheless, climate and other atmospheric models are

Recent changes in the fire regime across the North American boreal region-Spatial and temporal patterns of burning across Canada and Alaska

NASA Astrophysics Data System (ADS)

Kasischke, Eric S.; Turetsky, Merritt R.

2006-05-01

We used historic records from 1959-99 to explore fire regime characteristics at ecozone scales across the entire North American boreal region (NABR). Shifts in the NABR fire regime between the 1960s/70s and the 1980s/90s were characterized by a doubling of annual burned area and more than a doubling of the frequency of larger fire years because of more large fire events (>1,000 km2). The proportion of total burned area from human-ignited fires decreased over this same time period, while the proportion of burning during the early and late- growing-seasons increased. Trends in increased burned area were consistent across the NABR ecozones, though the western ecozones experienced greater increases in larger fire years compared to the eastern ecozones. Seasonal patterns of burning differed among ecozones. Along with the climate warming, changes in the fire regime characteristics may be an important driver of future ecosystem processes in the NABR.

Vegetation shifts observed in arctic tundra 17 years after fire

USGS Publications Warehouse

Barrett, Kirsten; Rocha, Adrian V.; van de Weg, Martine Janet; Shaver, Gaius

2012-01-01

With anticipated climate change, tundra fires are expected to occur more frequently in the future, but data on the long-term effects of fire on tundra vegetation composition are scarce. This study addresses changes in vegetation structure that have persisted for 17 years after a tundra fire on the North Slope of Alaska. Fire-related shifts in vegetation composition were assessed from remote-sensing imagery and ground observations of the burn scar and an adjacent control site. Early-season remotely sensed imagery from the burn scar exhibits a low vegetation index compared with the control site, whereas the late-season signal is slightly higher. The range and maximum vegetation index are greater in the burn scar, although the mean annual values do not differ among the sites. Ground observations revealed a greater abundance of moss in the unburned site, which may account for the high early growing season normalized difference vegetation index (NDVI) anomaly relative to the burn. The abundance of graminoid species and an absence of Betula nana in the post-fire tundra sites may also be responsible for the spectral differences observed in the remotely sensed imagery. The partial replacement of tundra by graminoid-dominated ecosystems has been predicted by the ALFRESCO model of disturbance, climate and vegetation succession.

Improving satellite-based post-fire evapotranspiration estimates in semi-arid regions

NASA Astrophysics Data System (ADS)

Poon, P.; Kinoshita, A. M.

2017-12-01

Climate change and anthropogenic factors contribute to the increased frequency, duration, and size of wildfires, which can alter ecosystem and hydrological processes. The loss of vegetation canopy and ground cover reduces interception and alters evapotranspiration (ET) dynamics in riparian areas, which can impact rainfall-runoff partitioning. Previous research evaluated the spatial and temporal trends of ET based on burn severity and observed an annual decrease of 120 mm on average for three years after fire. Building upon these results, this research focuses on the Coyote Fire in San Diego, California (USA), which burned a total of 76 km2 in 2003 to calibrate and improve satellite-based ET estimates in semi-arid regions affected by wildfire. The current work utilizes satellite-based products and techniques such as the Google Earth Engine Application programming interface (API). Various ET models (ie. Operational Simplified Surface Energy Balance Model (SSEBop)) are compared to the latent heat flux from two AmeriFlux eddy covariance towers, Sky Oaks Young (US-SO3), and Old Stand (US-SO2), from 2000 - 2015. The Old Stand tower has a low burn severity and the Young Stand tower has a moderate to high burn severity. Both towers are used to validate spatial ET estimates. Furthermore, variables and indices, such as Enhanced Vegetation Index (EVI), Normalized Difference Moisture Index (NDMI), and the Normalized Burn Ratio (NBR) are utilized to evaluate satellite-based ET through a multivariate statistical analysis at both sites. This point-scale study will able to improve ET estimates in spatially diverse regions. Results from this research will contribute to the development of a post-wildfire ET model for semi-arid regions. Accurate estimates of post-fire ET will provide a better representation of vegetation and hydrologic recovery, which can be used to improve hydrologic models and predictions.

Modeling Smoke Plume-Rise and Dispersion from Southern United States Prescribed Burns with Daysmoke

Treesearch

G L Achtemeier; S L Goodrick; Y Liu; F Garcia-Menendez; Y Hu; M. Odman

2011-01-01

We present Daysmoke, an empirical-statistical plume rise and dispersion model for simulating smoke from prescribed burns. Prescribed fires are characterized by complex plume structure including multiple-core updrafts which makes modeling with simple plume models difficult. Daysmoke accounts for plume structure in a three-dimensional veering/sheering atmospheric...

Using Logistic Regression To Predict the Probability of Debris Flows Occurring in Areas Recently Burned By Wildland Fires

USGS Publications Warehouse

Rupert, Michael G.; Cannon, Susan H.; Gartner, Joseph E.

2003-01-01

Logistic regression was used to predict the probability of debris flows occurring in areas recently burned by wildland fires. Multiple logistic regression is conceptually similar to multiple linear regression because statistical relations between one dependent variable and several independent variables are evaluated. In logistic regression, however, the dependent variable is transformed to a binary variable (debris flow did or did not occur), and the actual probability of the debris flow occurring is statistically modeled. Data from 399 basins located within 15 wildland fires that burned during 2000-2002 in Colorado, Idaho, Montana, and New Mexico were evaluated. More than 35 independent variables describing the burn severity, geology, land surface gradient, rainfall, and soil properties were evaluated. The models were developed as follows: (1) Basins that did and did not produce debris flows were delineated from National Elevation Data using a Geographic Information System (GIS). (2) Data describing the burn severity, geology, land surface gradient, rainfall, and soil properties were determined for each basin. These data were then downloaded to a statistics software package for analysis using logistic regression. (3) Relations between the occurrence/non-occurrence of debris flows and burn severity, geology, land surface gradient, rainfall, and soil properties were evaluated and several preliminary multivariate logistic regression models were constructed. All possible combinations of independent variables were evaluated to determine which combination produced the most effective model. The multivariate model that best predicted the occurrence of debris flows was selected. (4) The multivariate logistic regression model was entered into a GIS, and a map showing the probability of debris flows was constructed. The most effective model incorporates the percentage of each basin with slope greater than 30 percent, percentage of land burned at medium and high burn severity in each basin, particle size sorting, average storm intensity (millimeters per hour), soil organic matter content, soil permeability, and soil drainage. The results of this study demonstrate that logistic regression is a valuable tool for predicting the probability of debris flows occurring in recently-burned landscapes.

The Perfect Fire? Aging Stands in the Alaskan Boreal Forest Encounter Global Warming

NASA Astrophysics Data System (ADS)

Mann, D.; Rupp, S.; Duffy, P.

2008-12-01

The ecological responses of the boreal forest to climate change have global significance because of the large amount of carbon stored in its soils and biomass. Fire, mostly ignited by lightning, is the keystone disturbance agent in this forest. It triggers cycles of forest succession in its wake, and burning is the main avenue for carbon release back to the atmosphere. We studied the interactions between climate, fires, forest succession, and the age distributions of forest stands in a 60-million hectare region of Interior Alaska over the past 150 years. First we developed a statistical model relating climate to area burned over the period of record (1950-2005). Next we combined this model with climate reconstructions to extend the estimates of area burned back to A.D. 1860. We checked the resultant fire history against stand-age data from 5000 living trees sampled in the study region. Then we fed the history of area burned into a computer model that simulates forest succession on real landscapes. Results show striking changes in the means and variances of stand ages over the last 150 years in response to interactions between climate change and the successional dynamics of the boreal forest. Average stand age increased steadily between 1880 and 1940 and has fluctuated at high levels since then, indicating a historically unusual abundance of flammable stands. This accumulation of old stands has created the potential for unusually large fires. Some support for this conclusion comes from the unprecedented large sizes of the areas burned in 2004 and 2005. Further support comes when we add to the analysis the forecasts made by global climate models for Alaska over the next twenty years. Bracketing estimates for climate warming and precipitation change suggest that warmer, drier summers combined with aging forest stands will cause a series of unusually large fires, the like of which have not occurred in the region for >150 years. We infer that the enhanced burning of the Alaska boreal forest over the next 20 years will increase the release of trace gases from this region. We speculate that the forest will be transformed from being conifer dominated to one dominated by deciduous tree species, which could have sweeping effects on the region's other biota, its hydrology, and the role of the boreal forest in the global carbon cycle.

Fire Safe Together. Kindergarten. Fire Safety for Texans: Fire and Burn Prevention Curriculum Guide.

ERIC Educational Resources Information Center

Texas State Commission on Fire Protection, Austin.

This booklet comprises the kindergarten component of a series of curriculum guides on fire and burn prevention. Designed to meet the age-specific needs of kindergarten students, its objectives include developing basic awareness of fire and burn dangers, developing simple actions to reduce injury, and encouraging parent involvement. Texas essential…

Total peroxy nitrates and ozone production : analysis of forest fire plumes during BORTAS campaign

NASA Astrophysics Data System (ADS)

Busilacchio, Marcella; Di Carlo, Piero; Aruffo, Eleonora; Biancofiore, Fabio; Giammaria, Franco; Bauguitte, Stephane; Lee, James; Moller, Sarah; Lewis, Ally; Parrington, Mark; Palmer, Paul; Dari Salisburgo, Cesare

2014-05-01

The goal of this work is to investigate the connection between PNS and ozone within plumes emitted from boreal forest fires and the possible perturbation to oxidant chemistry in the troposphere. During the Aircraft campaign in Canada called BORTAS (summer 2011 ) were carried out several profiles from ground up to 10 km with the BAe-146 aircraft to observe the atmospheric composition inside and outside fire plumes. The BORTAS flights have been selected based on the preliminary studies of 'Plume identification', selecting those effected by Boreal forest fire emissions (CO > 200 ppbv). The FLAMBE fire counts were used concertedly with back trajectory calculations generated by the HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to locate the sources of Boreal biomass burning.Profiles measured on board the BAe-146 aircraft are used to calculate the productions of PNs and O3 within the biomass burning plume. By selecting the flights that intercept the biomass burning plume, we evaluate the ratio between the ozone production and the PNs production within the plume. Analyzing this ratio it is possible to determine whether O3 production or PNs production is the dominant process in the biomass burning boreal plume detected during BORTAS campaign.

The role of fire on soil mounds and surface roughness in the Mojave Desert

USGS Publications Warehouse

Soulard, Christopher E.; Esque, Todd C.; Bedford, David R.; Bond, Sandra

2013-01-01

A fundamental question in arid land management centers on understanding the long-term effects of fire on desert ecosystems. To assess the effects of fire on surface topography, soil roughness, and vegetation, we used terrestrial (ground-based) LiDAR to quantify the differences between burned and unburned surfaces by creating a series of high-resolution vegetation structure and bare-earth surface models for six sample plots in the Grand Canyon-Parashant National Monument, Arizona. We find that 11 years following prescribed burns, mound volumes, plant heights, and soil-surface roughness were significantly lower on burned relative to unburned plots. Results also suggest a linkage between vegetation and soil mounds, either through accretion or erosion mechanisms such as wind and/or water erosion. The biogeomorphic implications of fire-induced changes are significant. Reduced plant cover and altered soil surfaces from fire likely influence seed residence times, inhibit seed germination and plant establishment, and affect other ecohydrological processes.

Detection, Emission Estimation and Risk Prediction of Forest Fires in China Using Satellite Sensors and Simulation Models in the Past Three Decades—An Overview

PubMed Central

Zhang, Jia-Hua; Yao, Feng-Mei; Liu, Cheng; Yang, Li-Min; Boken, Vijendra K.

2011-01-01

Forest fires have major impact on ecosystems and greatly impact the amount of greenhouse gases and aerosols in the atmosphere. This paper presents an overview in the forest fire detection, emission estimation, and fire risk prediction in China using satellite imagery, climate data, and various simulation models over the past three decades. Since the 1980s, remotely-sensed data acquired by many satellites, such as NOAA/AVHRR, FY-series, MODIS, CBERS, and ENVISAT, have been widely utilized for detecting forest fire hot spots and burned areas in China. Some developed algorithms have been utilized for detecting the forest fire hot spots at a sub-pixel level. With respect to modeling the forest burning emission, a remote sensing data-driven Net Primary productivity (NPP) estimation model was developed for estimating forest biomass and fuel. In order to improve the forest fire risk modeling in China, real-time meteorological data, such as surface temperature, relative humidity, wind speed and direction, have been used as the model input for improving prediction of forest fire occurrence and its behavior. Shortwave infrared (SWIR) and near infrared (NIR) channels of satellite sensors have been employed for detecting live fuel moisture content (FMC), and the Normalized Difference Water Index (NDWI) was used for evaluating the forest vegetation condition and its moisture status. PMID:21909297

Detection, emission estimation and risk prediction of forest fires in China using satellite sensors and simulation models in the past three decades--an overview.

PubMed

Zhang, Jia-Hua; Yao, Feng-Mei; Liu, Cheng; Yang, Li-Min; Boken, Vijendra K

2011-08-01

Forest fires have major impact on ecosystems and greatly impact the amount of greenhouse gases and aerosols in the atmosphere. This paper presents an overview in the forest fire detection, emission estimation, and fire risk prediction in China using satellite imagery, climate data, and various simulation models over the past three decades. Since the 1980s, remotely-sensed data acquired by many satellites, such as NOAA/AVHRR, FY-series, MODIS, CBERS, and ENVISAT, have been widely utilized for detecting forest fire hot spots and burned areas in China. Some developed algorithms have been utilized for detecting the forest fire hot spots at a sub-pixel level. With respect to modeling the forest burning emission, a remote sensing data-driven Net Primary productivity (NPP) estimation model was developed for estimating forest biomass and fuel. In order to improve the forest fire risk modeling in China, real-time meteorological data, such as surface temperature, relative humidity, wind speed and direction, have been used as the model input for improving prediction of forest fire occurrence and its behavior. Shortwave infrared (SWIR) and near infrared (NIR) channels of satellite sensors have been employed for detecting live fuel moisture content (FMC), and the Normalized Difference Water Index (NDWI) was used for evaluating the forest vegetation condition and its moisture status.

Fire regime in Mediterranean ecosystem

NASA Astrophysics Data System (ADS)

Biondi, Guido; Casula, Paolo; D'Andrea, Mirko; Fiorucci, Paolo

2010-05-01

The analysis of burnt areas time series in Mediterranean regions suggests that ecosystems characterising this area consist primarily of species highly vulnerable to the fire but highly resilient, as characterized by a significant regenerative capacity after the fire spreading. In a few years the area burnt may once again be covered by the same vegetation present before the fire. Similarly, Mediterranean conifer forests, which often refers to plantations made in order to reforest the areas most severely degraded with high erosion risk, regenerate from seed after the fire resulting in high resilience to the fire as well. Only rarely, and usually with negligible damages, fire affects the areas covered by climax species in relation with altitude and soil types (i.e, quercus, fagus, abies). On the basis of these results, this paper shows how the simple Drossel-Schwabl forest fire model is able to reproduce the forest fire regime in terms of number of fires and burned area, describing whit good accuracy the actual fire perimeters. The original Drossel-Schwabl model has been slightly modified in this work by introducing two parameters (probability of propagation and regrowth) specific for each different class of vegetation cover. Using model selection methods based on AIC, the model with the optimal number of classes with different fire behaviour was selected. Two different case studies are presented in this work: Regione Liguria and Regione Sardegna (Italy). Both regions are situated in the center of the Mediterranean and are characterized by a high number of fires and burned area. However, the two regions have very different fire regimes. Sardinia is affected by the fire phenomenon only in summer whilst Liguria is affected by fires also in winter, with higher number of fires and larger burned area. In addition, the two region are very different in vegetation cover. The presence of Mediterranean conifers, (Pinus Pinaster, Pinus Nigra, Pinus halepensis) is quite spread in Liguria and is limited in Sardinia. What is common in the two regions is the widespread presence of shrub species frequently spread by fire. The analysis in the two regions thus allows in a rather limited area to study almost all the species that characterize the Mediterranean region. This work shows that the fire regime in Mediterranean area is strongly related with vegetation patterns, is almost totally independent by the cause of ignition, and only partially dependent by fire extinguishing actions.

Charring temperatures are driven by the fuel types burned in a peatland wildfire

PubMed Central

Hudspith, Victoria A.; Belcher, Claire M.; Yearsley, Jonathan M.

2014-01-01

Peatlands represent a globally important carbon store; however, the human exploitation of this ecosystem is increasing both the frequency and severity of fires on drained peatlands. Yet, the interactions between the hydrological conditions (ecotopes), the fuel types being burned, the burn severity, and the charring temperatures (pyrolysis intensity) remain poorly understood. Here we present a post-burn assessment of a fire on a lowland raised bog in Co. Offaly, Ireland (All Saints Bog). Three burn severities were identified in the field (light, moderate, and deeply burned), and surface charcoals were taken from 17 sites across all burn severities. Charcoals were classified into two fuel type categories (either ground or aboveground fuel) and the reflectance of each charcoal particle was measured under oil using reflectance microscopy. Charcoal reflectance shows a positive relationship with charring temperature and as such can be used as a temperature proxy to reconstruct minimum charring temperatures after a fire event. Resulting median reflectance values for ground fuels are 1.09 ± 0.32%Romedian, corresponding to estimated minimum charring temperatures of 447°C ± 49°C. In contrast, the median charring temperatures of aboveground fuels were found to be considerably higher, 646°C ± 73°C (3.58 ± 0.77%Romedian). A mixed-effects modeling approach was used to demonstrate that the interaction effects of burn severity, as well as ecotope classes, on the charcoal reflectance is small compared to the main effect of fuel type. Our findings reveal that the different fuel types on raised bogs are capable of charring at different temperatures within the same fire, and that the pyrolysis intensity of the fire on All Saints Bog was primarily driven by the fuel types burning, with only a weak association to the burn severity or ecotope classes. PMID:25566288

Home Fires Involving Grills

MedlinePlus

... the home and from other things that can burn. f fEleven percent of home grill structure fires ... 200 or 49%) of the injuries were thermal burns, including burns both from fire and from contact ...

Assessing wildland fire risk transmission to communities in northern Spain

Treesearch

Fermín J. Alcasena; Michele Salis; Alan A. Ager; Rafael Castell; Cristina Vega-García

2017-01-01

We assessed potential economic losses and transmission to residential houses from wildland fires in a rural area of central Navarra (Spain). Expected losses were quantified at the individual structure level (n = 306) in 14 rural communities by combining fire model predictions of burn probability and fire intensity with susceptibility functions derived from expert...

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.

Lizard activity and abundance greater in burned habitat of a xeric montane forest

USGS Publications Warehouse

Fouts, Kevin L.; Moore, Clinton; Johnson, Kristine D.; Maerz, John C.

2017-01-01

Restoring the natural or historical state of ecosystems is a common objective among resource managers, but determining whether desired system responses to management actions are occurring is often protracted and challenging. For wildlife, the integration of mechanistic habitat modeling with population monitoring may provide expedited measures of management effectiveness and improve understanding of how management actions succeed or fail to recover populations. Southern Appalachia is a region of high biodiversity that has undergone dramatic change as a result of human activities such as historic logging, exotic invasions, and alteration of disturbance regimes—including reduction in application of fire. Contemporary efforts to restore fire-maintained ecosystems within southern Appalachian forests require tools to assess the effects of fire management practices on individual animal fitness and relate them to corresponding influences on species abundance. Using automated sensing equipment, we investigated the effects of burned forests on reptile habitat suitability within the western portion of Great Smoky Mountains National Park, Tennessee. Specifically, we used microclimate measurements to model northern fence lizard Sceloporus undulatus hyacinthinus diurnal activity budgets in unburned and variable burn age (3–27-y) forest stands. We estimated northern fence lizard occurrence and abundance along transects through burned and unburned forests. Burned forest stands had microclimates that resulted in longer modeled daily activity periods under most conditions during summer. S. undulatus abundance was 4.75 times greater on burned stands compared to paired unburned stands, although the relationship between burn age and abundance was not well determined. Results suggest the more open habitat structure of burned areas within these xeric pine–oak forests may benefit S. undulatus.

Fuels planning: science synthesis and integration; environmental consequences fact sheet 02: First Order Fire Effects Model (FOFEM)

Treesearch

Steve Sutherland

2004-01-01

FOFEM 5.2 is a simple, yet versatile computer program that predicts first order fire effects using text and graphic outputs. It can be used in a variety of situations including: determining acceptable upper and lower fuel moistures for conducting prescribed burns, determining the number of acres that may be burned on a given day without exceeding particulate emission...

1984–2010 trends in fire burn severity and area for the conterminous US

USGS Publications Warehouse

Picotte, Joshua J.; Peterson, Birgit E.; Meier, Gretchen; Howard, Stephen M.

2016-01-01

Burn severity products created by the Monitoring Trends in Burn Severity (MTBS) project were used to analyse historical trends in burn severity. Using a severity metric calculated by modelling the cumulative distribution of differenced Normalized Burn Ratio (dNBR) and Relativized dNBR (RdNBR) data, we examined burn area and burn severity of 4893 historical fires (1984–2010) distributed across the conterminous US (CONUS) and mapped by MTBS. Yearly mean burn severity values (weighted by area), maximum burn severity metric values, mean area of burn, maximum burn area and total burn area were evaluated within 27 US National Vegetation Classification macrogroups. Time series assessments of burned area and severity were performed using Mann–Kendall tests. Burned area and severity varied by vegetation classification, but most vegetation groups showed no detectable change during the 1984–2010 period. Of the 27 analysed vegetation groups, trend analysis revealed burned area increased in eight, and burn severity has increased in seven. This study suggests that burned area and severity, as measured by the severity metric based on dNBR or RdNBR, have not changed substantially for most vegetation groups evaluated within CONUS.

Landscape Patterns of Burn Severity in the Soberanes Fire of 2016

NASA Technical Reports Server (NTRS)

Potter, Christopher

2016-01-01

The Soberanes Fire started on July 22, 2016 in Monterey County on the California Central Coast from an illegal campfire. This fire burned for 10 weeks at a record cost of more than $208 million for protection and control. A progressive analysis of the normalized burn ratio from the Landsat satellite showed that the final high burn severity (HBS) area for the Soberanes Fire comprised 22 percent of the total area burned, whereas final moderate burn severity (MBS) area comprised about 10 percent of the total area burned of approximately 53,470 ha (132,130 acres). The resulting landscape pattern of burn severity classes from the 2016 Soberanes Fire revealed that the majority of HBS area was located in the elevation zone between 500 and 1000 m, in the slope zone between 15 percent and 30 percent, or on south-facing aspects.

Modeling post-wildfire hydrological processes with ParFlow

NASA Astrophysics Data System (ADS)

Escobar, I. S.; Lopez, S. R.; Kinoshita, A. M.

2017-12-01

Wildfires alter the natural processes within a watershed, such as surface runoff, evapotranspiration rates, and subsurface water storage. Post-fire hydrologic models are typically one-dimensional, empirically-based models or two-dimensional, conceptually-based models with lumped parameter distributions. These models are useful for modeling and predictions at the watershed outlet; however, do not provide detailed, distributed hydrologic processes at the point scale within the watershed. This research uses ParFlow, a three-dimensional, distributed hydrologic model to simulate post-fire hydrologic processes by representing the spatial and temporal variability of soil burn severity (via hydrophobicity) and vegetation recovery. Using this approach, we are able to evaluate the change in post-fire water components (surface flow, lateral flow, baseflow, and evapotranspiration). This work builds upon previous field and remote sensing analysis conducted for the 2003 Old Fire Burn in Devil Canyon, located in southern California (USA). This model is initially developed for a hillslope defined by a 500 m by 1000 m lateral extent. The subsurface reaches 12.4 m and is assigned a variable cell thickness to explicitly consider soil burn severity throughout the stages of recovery and vegetation regrowth. We consider four slope and eight hydrophobic layer configurations. Evapotranspiration is used as a proxy for vegetation regrowth and is represented by the satellite-based Simplified Surface Energy Balance (SSEBOP) product. The pre- and post-fire surface runoff, subsurface storage, and surface storage interactions are evaluated at the point scale. Results will be used as a basis for developing and fine-tuning a watershed-scale model. Long-term simulations will advance our understanding of post-fire hydrological partitioning between water balance components and the spatial variability of watershed processes, providing improved guidance for post-fire watershed management. In reference to the presenter, Isabel Escobar: Research is funded by the NASA-DIRECT STEM Program. Travel expenses for this presentation is funded by CSU-LSAMP. CSU-LSAMP is supported by the National Science Foundation under Grant # HRD-1302873 and the CSU Office of Chancellor.

Carbon loss and greenhouse gas emission from extreme fire events occurred in Sardinia, Italy

NASA Astrophysics Data System (ADS)

Bacciu, V. M.; Salis, M.; Pellizzaro, G.; Arca, B.; Duce, P.; Spano, D.

2011-12-01

It is widely recognized that biomass burning is a significant driver of CO2 cycling and a source of greenhouse gases, aerosol particles, and other chemically reactive atmospheric gases. The large amounts of carbon that fires release into the atmosphere could approach levels of anthropogenic carbon emissions, especially in years of extreme fire activity. CO2 emissions from 2007 forest fires in Greece were in the range of 4.5 Mt, representing about the 4% of the total annual CO2 emissions of that country (http://effis.jrc.it/). Barbosa et al. (2006) reported a similar percentage of fire emissions to total emissions of CO2 in Portugal during the extreme fire seasons of 2003 and 2005. Currently, inventory methods for biomass burning emission use the equation first proposed by Seiler and Crutzen (1980), taking into account the area burned, the amount of biomass burned, and the emission factors associated with each specific chemical species. However, several errors and uncertainties can affect the emission assessment, due to the estimate consistency of the various parameters involved in the equation, including flaming and smoldering combustion periods, appropriate fuel load evaluations and gaseous emission factors for different fuel fractions and fire types. In this context, model approaching can contribute to better appraise fuel consumption and the resultant emissions. In addition, more comprehensive and accurate data inputs would be of valuable help for predicting and quantifying the source and the composition of fire emissions. The purpose of this work is to explore the impacts of extreme fire events occurred in Sardinia Island (Italy) using an integrated approach combining modelling fire emissions, field observations and remotely-sensed data. In order to achieve realistic fire emission estimates, we used the FOFEM model, due to the necessity to use a consistent modeling methodology across source categories, the input required, and its ability to estimate flaming and smoldering emissions. FOFEM input fuel load data were surveyed to represent those combusted, and fuel availability was obtained from supervised classification of remotely-sensed images. Data relative to fire perimeters, fire weather data, and fire behaviour were gathered by the Sardinian Forestry Corps (CFVA). Consumptions and emissions for each fuel types were estimated through FOFEM. Finally, all the data were assembled into a Geographical Information System (GIS) to facilitate manipulation and display of the data. The results showed the crucial role of appropriate fuel, fire, and weather data and maps to attain reasonable simulations of fuel consumption and smoke emissions. Carbon emission estimates are sensitive to pre-fire fuel loads, so the method used to establish initial fuel conditions is crucial. The FOFEM outputs and the derived smoke emission maps are useful for several applications including emissions inventories, air quality management plans, and emission source models coupled with dispersion models and decision support systems.

Refined Use of Satellite Aerosol Optical Depth Snapshots to Constrain Biomass Burning Emissions in the GOCART Model

NASA Astrophysics Data System (ADS)

Petrenko, Mariya; Kahn, Ralph; Chin, Mian; Limbacher, James

2017-10-01

Simulations of biomass burning (BB) emissions in global chemistry and aerosol transport models depend on external inventories, which provide location and strength for BB aerosol sources. Our previous work shows that to first order, satellite snapshots of aerosol optical depth (AOD) near the emitted smoke plume can be used to constrain model-simulated AOD, and effectively, the smoke source strength. We now refine the satellite-snapshot method and investigate where applying simple multiplicative emission adjustment factors alone to the widely used Global Fire Emission Database version 3 emission inventory can achieve regional-scale consistency between Moderate Resolution Imaging Spectroradiometer (MODIS) AOD snapshots and the Goddard Chemistry Aerosol Radiation and Transport model. The model and satellite AOD are compared globally, over a set of BB cases observed by the MODIS instrument during the 2004, and 2006-2008 biomass burning seasons. Regional discrepancies between the model and satellite are diverse around the globe yet quite consistent within most ecosystems. We refine our approach to address physically based limitations of our earlier work (1) by expanding the number of fire cases from 124 to almost 900, (2) by using scaled reanalysis-model simulations to fill missing AOD retrievals in the MODIS observations, (3) by distinguishing the BB components of the total aerosol load from background aerosol in the near-source regions, and (4) by including emissions from fires too small to be identified explicitly in the satellite observations. The small-fire emission adjustment shows the complimentary nature of correcting for source strength and adding geographically distinct missing sources. Our analysis indicates that the method works best for fire cases where the BB fraction of total AOD is high, primarily evergreen or deciduous forests. In heavily polluted or agricultural burning regions, where smoke and background AOD values tend to be comparable, this approach encounters large uncertainties, and in some regions, other model- or measurement-related factors might contribute significantly to model-satellite discrepancies. This work sets the stage for a larger study within the Aerosol Comparison between Observations and Models (AeroCOM) multimodel biomass burning experiment. By comparing multiple model results using the refined technique presented here, we aim to separate BB inventory from model-specific contributions to the remaining discrepancies.

A multi-sensor burned area algorithm for crop residue burning in northwestern India: validation and sources of error

NASA Astrophysics Data System (ADS)

Liu, T.; Marlier, M. E.; Karambelas, A. N.; Jain, M.; DeFries, R. S.

2017-12-01

A leading source of outdoor emissions in northwestern India comes from crop residue burning after the annual monsoon (kharif) and winter (rabi) crop harvests. Agricultural burned area, from which agricultural fire emissions are often derived, can be poorly quantified due to the mismatch between moderate-resolution satellite sensors and the relatively small size and short burn period of the fires. Many previous studies use the Global Fire Emissions Database (GFED), which is based on the Moderate Resolution Imaging Spectroradiometer (MODIS) burned area product MCD64A1, as an outdoor fires emissions dataset. Correction factors with MODIS active fire detections have previously attempted to account for small fires. We present a new burned area classification algorithm that leverages more frequent MODIS observations (500 m x 500 m) with higher spatial resolution Landsat (30 m x 30 m) observations. Our approach is based on two-tailed Normalized Burn Ratio (NBR) thresholds, abbreviated as ModL2T NBR, and results in an estimated 104 ± 55% higher burned area than GFEDv4.1s (version 4, MCD64A1 + small fires correction) in northwestern India during the 2003-2014 winter (October to November) burning seasons. Regional transport of winter fire emissions affect approximately 63 million people downwind. The general increase in burned area (+37% from 2003-2007 to 2008-2014) over the study period also correlates with increased mechanization (+58% in combine harvester usage from 2001-2002 to 2011-2012). Further, we find strong correlation between ModL2T NBR-derived burned area and results of an independent survey (r = 0.68) and previous studies (r = 0.92). Sources of error arise from small median landholding sizes (1-3 ha), heterogeneous spatial distribution of two dominant burning practices (partial and whole field), coarse spatio-temporal satellite resolution, cloud and haze cover, and limited Landsat scene availability. The burned area estimates of this study can be used to build a new agricultural fire emissions inventory to re-evaluate the contributions of winter agricultural fires to rural and urban air quality degradation.

Temporal effects of prescribed burning on terpene production in Mediterranean pines.

PubMed

Valor, Teresa; Ormeño, Elena; Casals, Pere

2017-12-01

Prescribed burning is used to reduce fuel hazard but underburning can damage standing trees. The effect of burning on needle terpene storage, a proxy for secondary metabolism, in fire-damaged pines is poorly understood despite the protection terpenes confer against biotic and abiotic stressors. We investigated variation in needle terpene storage after burning in three Mediterranean pine species featuring different adaptations to fire regimes. In two pure-stands of Pinus halepensis Mill. and two mixed-stands of Pinus sylvestris L. and Pinus nigra ssp. salzmanni (Dunal) Franco, we compared 24 h and 1 year post-burning concentrations with pre-burning concentrations in 20 trees per species, and evaluated the relative contribution of tree fire severity and physiological condition (δ13C and N concentration) on temporal terpene dynamics (for mono- sesqui- and diterpenes). Twenty-four hours post-burning, monoterpene concentrations were slightly higher in P. halepensis than at pre-burning, while values were similar in P. sylvestris. Differently, in the more fire-resistant P. nigra monoterpene concentrations were lower at 24 h, compared with pre-burning. One year post-burning, concentrations were always lower compared with pre- or 24 h post-burning, regardless of the terpene group. Mono- and sesquiterpene variations were negatively related to pre-burning δ13C, while diterpene variations were associated with fire-induced changes in needle δ13C and N concentration. At both post-burning times, mono- and diterpene concentrations increased significantly with crown scorch volume in all species. Differences in post-burning terpene contents as a function of the pine species' sensitivity to fire suggest that terpenic metabolites could have adaptive importance in fire-prone ecosystems in terms of flammability or defence against biotic agents post-burning. One year post-burning, our results suggest that in a context of fire-induced resource availability, pines likely prioritize primary rather than secondary metabolism. Overall, this study contributes to the assessment of the direct and indirect effects of fire on pine terpene storage, providing valuable information about their vulnerability to biotic and abiotic stressors throughout time. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Trends and causes of severity, size, and number of fires in northwestern California, USA.

PubMed

Miller, J D; Skinner, C N; Safford, H D; Knapp, E E; Ramirez, C M

2012-01-01

Research in the last several years has indicated that fire size and frequency are on the rise in western U.S. forests. Although fire size and frequency are important, they do not necessarily scale with ecosystem effects of fire, as different ecosystems have different ecological and evolutionary relationships with fire. Our study assessed trends and patterns in fire size and frequency from 1910 to 2008 (all fires > 40 ha), and the percentage of high-severity in fires from 1987 to 2008 (all fires > 400 ha) on the four national forests of northwestern California. During 1910-2008, mean and maximum fire size and total annual area burned increased, but we found no temporal trend in the percentage of high-severity fire during 1987-2008. The time series of severity data was strongly influenced by four years with region-wide lightning events that burned huge areas at primarily low-moderate severity. Regional fire rotation reached a high of 974 years in 1984 and fell to 95 years by 2008. The percentage of high-severity fire in conifer-dominated forests was generally higher in areas dominated by smaller-diameter trees than in areas with larger-diameter trees. For Douglas-fir forests, the percentage of high-severity fire did not differ significantly between areas that re-burned and areas that only burned once (10% vs. 9%) when re-burned within 30 years. Percentage of high-severity fire decreased to 5% when intervals between first and second fires were > 30 years. In contrast, in both mixed-conifer and fir/high-elevation conifer forests, the percentage of high-severity fire was less when re-burned within 30 years compared to first-time burned (12% vs. 16% for mixed conifer; 11% vs. 19% for fir/high-elevation conifer). Additionally, the percentage of high-severity fire did not differ whether the re-burn interval was less than or greater than 30 years. Years with larger fires and greatest area burned were produced by region-wide lightning events, and characterized by less winter and spring precipitation than years dominated by smaller human-ignited fires. Overall percentage of high-severity fire was generally less in years characterized by these region-wide lightning events. Our results suggest that, under certain conditions, wildfires could be more extensively used to achieve ecological and management objectives in northwestern California.

Postwildfire debris flows hazard assessment for the area burned by the 2011 Track Fire, northeastern New Mexico and southeastern Colorado

USGS Publications Warehouse

Tillery, Anne C.; Darr, Michael J.; Cannon, Susan H.; Michael, John A.

2011-01-01

In June 2011, the Track Fire burned 113 square kilometers in Colfax County, northeastern New Mexico, and Las Animas County, southeastern Colorado, including the upper watersheds of Chicorica and Raton Creeks. The burned landscape is now at risk of damage from postwildfire erosion, such as that caused by debris flows and flash floods. This report presents a preliminary hazard assessment of the debris-flow potential from basins burned by the Track Fire. A pair of empirical hazard-assessment models developed using data from recently burned basins throughout the intermountain western United States were used to estimate the probability of debris-flow occurrence and volume of debris flows at the outlets of selected drainage basins within the burned area. The models incorporate measures of burn severity, topography, soils, and storm rainfall to estimate the probability and volume of post-fire debris flows following the fire. In response to a design storm of 38 millimeters of rain in 30 minutes (10-year recurrence-interval), the probability of debris flow estimated for basins burned by the Track fire ranged between 2 and 97 percent, with probabilities greater than 80 percent identified for the majority of the tributary basins to Raton Creek in Railroad Canyon; six basins that flow into Lake Maloya, including the Segerstrom Creek and Swachheim Creek basins; two tributary basins to Sugarite Canyon, and an unnamed basin on the eastern flank of the burned area. Estimated debris-flow volumes ranged from 30 cubic meters to greater than 100,000 cubic meters. The largest volumes (greater than 100,000 cubic meters) were estimated for Segerstrom Creek and Swachheim Creek basins, which drain into Lake Maloya. The Combined Relative Debris-Flow Hazard Ranking identifies the Segerstrom Creek and Swachheim Creek basins as having the highest probability of producing the largest debris flows. This finding indicates the greatest post-fire debris-flow impacts may be expected to Lake Maloya. In addition, Interstate Highway 25, Raton Creek and the rail line in Railroad Canyon, County road A-27, and State Highway 526 in Sugarite Canyon may also be affected where they cross drainages downstream from recently burned basins. Although this assessment indicates that a rather large debris flow (approximately 42,000 cubic meters) may be generated from the basin above the City of Raton (basin 9) in response to the design storm, the probability of such an event is relatively low (approximately 10 percent). Additional assessment is necessary to determine if the estimated volume of material is sufficient to travel into the City of Raton. In addition, even small debris flows may affect structures at or downstream from basin outlets and increase the threat of flooding downstream by damaging or blocking flood mitigation structures. The maps presented here may be used to prioritize areas where erosion mitigation or other protective measures may be necessary within a 2- to 3-year window of vulnerability following the Track Fire.

Could managed burning of peatlands lead to enhanced carbon storage?

NASA Astrophysics Data System (ADS)

Worrall, F.; Clay, G. D.

2009-04-01

Peatlands are the UK's largest single terrestrial carbon store with carbon stored in UK peatlands than in forests of Britain and France combined. Unlike most northern peatlands in the peat soils of the UK are heavily managed for recreation and agriculture and due to their proximity to major centres of population are under more anthropogenic pressure than most peatlands. A typical management strategy on UK upland peats is the use of managed fire to restrict vegetation. Fires are used upon a 10-25 year rotation and are described as "cool" as they are designed to remove the crown of the vegetation without scorching the litter layer or the underlying soil. In this case the fire destroys primary productivity and limits litter production but produces char. Char is a low volume, highly refractory, high carbon content product while litter is a high volume, decomposable, lower carbon content product. Therefore, the question is if there are fire conditions under which the production of char causes more carbon to be stored in the peat than would have been stored if no fire management had been employed. This study combines field studies of recent managed burns and wildfires along with detailed vegetation studies from a long term monitoring site in order to assess litter, biomass and black carbon production. In the laboratory experimental burns were undertaken in order to assess the amount and controls upon char production and the carbon content of that char. Results of field and laboratory observations are used to model carbon accumulation under a series of fire management scenarios and the modelling shows that cools burns at long rotations could lead to higher carbon storage than if no fire had occurred, further in several cases more carbon accumulation occurred even if less depth of peat was generated.

Fuel reduction and coarse woody debris dynamics with early season and late season prescribed fire in a Sierra Nevada mixed conifer forest

USGS Publications Warehouse

Knapp, E.E.; Keeley, J.E.; Ballenger, E.A.; Brennan, T.J.

2005-01-01

Fire exclusion has led to an unnatural accumulation and greater spatial continuity of organic material on the ground in many forests. This material serves both as potential fuel for forest fires and habitat for a large array of forest species. Managers must balance fuel reduction to reduce wildfire hazard with fuel retention targets to maintain other forest functions. This study reports fuel consumption and changes to coarse woody debris attributes with prescribed burns ignited under different fuel moisture conditions. Replicated early season burn, late season burn, and unburned control plots were established in old-growth mixed conifer forest in Sequoia National Park that had not experienced fire for more than 120 years. Early season burns were ignited during June 2002 when fuels were relatively moist, and late season burns were ignited during September/October 2001 when fuels were dry. Fuel loading and coarse woody debris abundance, cover, volume, and mass were evaluated prior to and after the burns. While both types of burns reduced fuel loading, early season burns consumed significantly less of the total dead and down organic matter than late season burns (67% versus 88%). This difference in fuel consumption between burning treatments was significant for most all woody fuel components evaluated, plus the litter and duff layers. Many logs were not entirely consumed - therefore the number of logs was not significantly changed by fire - but burning did reduce log length, cover, volume, and mass. Log cover, volume, and mass were reduced to a lesser extent by early season burns than late season burns, as a result of higher wood moisture levels. Early season burns also spread over less of the ground surface within the burn perimeter (73%) than late season burns (88%), and were significantly patchier. Organic material remaining after a fire can dam sediments and reduce erosion, while unburned patches may help mitigate the impact of fire on fire-sensitive species by creating refugia from which these species can recolonize burned areas. Early season burns may be an effective means of moderating potential ecosystem damage when treating heavy and/or continuous fuels resulting from long periods of fire exclusion, if burning during this season is not detrimental to other forest functions. ?? 2005 Elsevier B.V. All rights reserved.

Characterising Brazilian biomass burning emissions using WRF-Chem with MOSAIC sectional aerosol

NASA Astrophysics Data System (ADS)

Archer-Nicholls, S.; Lowe, D.; Darbyshire, E.; Morgan, W. T.; Bela, M. M.; Pereira, G.; Trembath, J.; Kaiser, J. W.; Longo, K. M.; Freitas, S. R.; Coe, H.; McFiggans, G.

2015-03-01

The South American Biomass Burning Analysis (SAMBBA) field campaign took detailed in situ flight measurements of aerosol during the 2012 dry season to characterise biomass burning aerosol and improve understanding of its impacts on weather and climate. Developments have been made to the Weather Research and Forecast model with chemistry (WRF-Chem) model to improve the representation of biomass burning aerosol in the region, by coupling a sectional aerosol scheme to the plume-rise parameterisation. Brazilian Biomass Burning Emissions Model (3BEM) fire emissions are used, prepared using PREP-CHEM-SRC, and mapped to CBM-Z and MOSAIC species. Model results have been evaluated against remote sensing products, AERONET sites, and four case studies of flight measurements from the SAMBBA campaign. WRF-Chem predicted layers of elevated aerosol loadings (5-20 μg sm-3) of particulate organic matter at high altitude (6-8 km) over tropical forest regions, while flight measurements showed a sharp decrease above 2-4 km altitude. This difference was attributed to the plume-rise parameterisation overestimating injection height. The 3BEM emissions product was modified using estimates of active fire size and burned area for the 2012 fire season, which reduced the fire size. The enhancement factor for fire emissions was increased from 1.3 to 5 to retain reasonable aerosol optical depths (AODs). The smaller fire size lowered the injection height of the emissions, but WRF-Chem still showed elevated aerosol loadings between 4-5 km altitude. Over eastern cerrado (savannah-like) regions, both modelled and measured aerosol loadings decreased above approximately 4 km altitude. Compared with MODIS satellite data and AERONET sites, WRF-Chem represented AOD magnitude well (between 0.3-1.5) over western tropical forest fire regions in the first half of the campaign, but tended to over-predict them in the second half, when precipitation was more significant. Over eastern cerrado regions, WRF-Chem tended to under-predict AODs. Modelled aerosol loadings in the east were higher in the modified emission scenario. The primary organic matter to black carbon ratio was typically between 8-10 in WRF-Chem. This was lower than the western flight measurements (interquartile range of 11.6-15.7 in B734, 14.7-24.0 in B739), but similar to the eastern flight B742 (8.1-10.4). However, single scattering albedo was close to measured over the western flights (0.87-0.89 in model; 0.86-0.91 in flight B734, and 0.81-0.95 in flight B739 measurements) but too high over the eastern flight B742 (0.86-0.87 in model, 0.79-0.82 in measurements). This suggests that improvements are needed to both modelled aerosol composition and optical properties calculations in WRF-Chem.

Modeling post-fire woody carbon dynamics with data from remeasured inventory plots

Treesearch

Bianca N.I. Eskelson; Jeremy Fried; Vicente Monleon

2015-01-01

In California, the Forest Inventory and Analysis (FIA) plots within large fires were visited one year after the fire occurred resulting in a time series of measurements before and after fire. During this additional plot visit, the standard inventory measurements were augmented for these burned plots to assess fire effects. One example of the additional measurements is...

Resistance of the boreal forest to high burn rates.

PubMed

Héon, Jessie; Arseneault, Dominique; Parisien, Marc-André

2014-09-23

Boreal ecosystems and their large carbon stocks are strongly shaped by extensive wildfires. Coupling climate projections with records of area burned during the last 3 decades across the North American boreal zone suggests that area burned will increase by 30-500% by the end of the 21st century, with a cascading effect on ecosystem dynamics and on the boreal carbon balance. Fire size and the frequency of large-fire years are both expected to increase. However, how fire size and time since previous fire will influence future burn rates is poorly understood, mostly because of incomplete records of past fire overlaps. Here, we reconstruct the length of overlapping fires along a 190-km-long transect during the last 200 y in one of the most fire-prone boreal regions of North America to document how fire size and time since previous fire will influence future fire recurrence. We provide direct field evidence that extreme burn rates can be sustained by a few occasional droughts triggering immense fires. However, we also show that the most fire-prone areas of the North American boreal forest are resistant to high burn rates because of overabundant young forest stands, thereby creating a fuel-mediated negative feedback on fire activity. These findings will help refine projections of fire effect on boreal ecosystems and their large carbon stocks.

Resistance of the boreal forest to high burn rates

PubMed Central

Héon, Jessie; Arseneault, Dominique; Parisien, Marc-André

2014-01-01

Boreal ecosystems and their large carbon stocks are strongly shaped by extensive wildfires. Coupling climate projections with records of area burned during the last 3 decades across the North American boreal zone suggests that area burned will increase by 30–500% by the end of the 21st century, with a cascading effect on ecosystem dynamics and on the boreal carbon balance. Fire size and the frequency of large-fire years are both expected to increase. However, how fire size and time since previous fire will influence future burn rates is poorly understood, mostly because of incomplete records of past fire overlaps. Here, we reconstruct the length of overlapping fires along a 190-km-long transect during the last 200 y in one of the most fire-prone boreal regions of North America to document how fire size and time since previous fire will influence future fire recurrence. We provide direct field evidence that extreme burn rates can be sustained by a few occasional droughts triggering immense fires. However, we also show that the most fire-prone areas of the North American boreal forest are resistant to high burn rates because of overabundant young forest stands, thereby creating a fuel-mediated negative feedback on fire activity. These findings will help refine projections of fire effect on boreal ecosystems and their large carbon stocks. PMID:25201981

Fire, Climate, and Human Activity: A Combustive Combination

NASA Astrophysics Data System (ADS)

Kehrwald, N. M.; Battistel, D.; Argiriadis, E.; Barbante, C.; Barber, L. B.; Fortner, S. K.; Jasmann, J.; Kirchgeorg, T.; Zennaro, P.

2017-12-01

Ice and lake core records demonstrate that fires caused by human activity can dominate regional biomass burning records in the Common Era. These major increases in fires are often associated with extensive land use change such as an expansion in agriculture. Regions with few humans, relatively stable human populations and/or unvarying land use often have fire histories that are dominated by climate parameters such as temperature and precipitation. Here, we examine biomass burning recorded in ice cores from northern Greenland (NEEM, (77°27'N; 51°3.6'W), Alaska (Juneau Icefield, 58° 35' N; 134° 29'W) and East Antarctica (EPICA DOME C; 75°06'S; 123°21'E), along with New Zealand lake cores to investigate interactions between climate, fire and human activity. Biomarkers such as levoglucosan, and its isomers mannosan and galactosan, can only be produced by cellulose combustion and therefore are specific indicators of past fire activity archived in ice and lake cores. These fire histories add another factor to climate proxies from the same core, and provide a comparison to regional fire syntheses from charcoal records and climate models. For example, fire data from the JSBACH-Spitfire model for the past 2000 years demonstrates that a climate-only scenario would not increase biomass burning in high northern latitudes for the past 2000 years, while NEEM ice core and regional pollen records demonstrate both increased fire activity and land use change that may be ascribed to human activity. Additional biomarkers such as fecal sterols in lake sediments can determine when people were in an area, and can help establish if an increased human presence in an area corresponds with intensified fire activity. This combination of specific biomarkers, other proxy data, and model output can help determine the relative impact of humans versus climate factors on regional fire activity.

Does fire severity influence shrub resprouting after spring prescribed burning?

NASA Astrophysics Data System (ADS)

Fernández, Cristina; Vega, José A.; Fonturbel, Teresa

2013-04-01

Prescribed burning is commonly used to reduce the risk of severe wildfire. However, further information about the associated environmental effects is required to help forest managers select the most appropriate treatment. To address this question, we evaluated if fire severity during spring prescribed burning significantly affects the resprouting ability of two common shrub species in shrubland under a Mediterranean climate in NW Spain. Fire behaviour and temperatures were recorded in tagged individuals of Erica australis and Pterospartum tridentatum during prescribed burning. The number and length of resprouted shoots were measured three times (6, 12 and 18 months) after the prescribed burning. The influence of a series of fire severity indicators on some plant resprouting vigour parameters was tested by canonical correlation analysis. Six months and one year after prescribed burning, soil burn severity (measured by the absolute reduction in depth of the organic soil layer, maximum temperatures in the organic soil layer and the mineral soil surface during burning and the post-fire depth of the organic soil layer) reduced the resprouting vigour of E. australis and P. tridentatum. In contrast, direct measurements of fire effects on plants (minimum branch diameter, duration of temperatures above 300 °C in the shrub crown and fireline intensity) did not affect the post-fire plant vigour. Soil burn severity during spring prescribed burning significantly affected the short-term resprouting vigour in a mixed heathland in Galicia. The lack of effects eighteen months after prescribed burning indicates the high resilience of these species and illustrates the need to conciliate fire prevention and conservation goals.

Positively Fire Safe. Third Grade. Fire Safety for Texans: Fire and Burn Prevention Curriculum Guide.

ERIC Educational Resources Information Center

Texas State Commission on Fire Protection, Austin.

This booklet comprises the third grade component of a series of curriculum guides on fire and burn prevention. Designed to meet the age-specific needs of third grade students, its objectives include: (1) acquiring basic knowledge of hazards and safe storage of flammable liquids; and (2) developing positive actions to prevent fires and burns or to…

Fire Safety: Any Time, Any Place. First Grade. Fire Safety for Texans: Fire and Burn Prevention Curriculum Guide.

ERIC Educational Resources Information Center

Texas State Commission on Fire Protection, Austin.

This booklet comprises the first grade component of a series of curriculum guides on fire and burn prevention. Designed to meet the age-specific needs of first grade students, its objectives include acquiring basic knowledge of fire and burn hazards, developing a basic understanding of simple injury reduction, and encouraging parent involvement.…

Recent acceleration of biomass burning and carbon losses in Alaskan forests and peatlands

USGS Publications Warehouse

Turetsky, M.R.; Kane, E.S.; Harden, J.W.; Ottmar, R.D.; Manies, K.L.; Hoy, E.; Kasischke, E.S.

2011-01-01

Climate change has increased the area affected by forest fires each year in boreal North America. Increases in burned area and fire frequency are expected to stimulate boreal carbon losses. However, the impact of wildfires on carbon emissions is also affected by the severity of burning. How climate change influences the severity of biomass burning has proved difficult to assess. Here, we examined the depth of ground-layer combustion in 178 sites dominated by black spruce in Alaska, using data collected from 31 fire events between 1983 and 2005. We show that the depth of burning increased as the fire season progressed when the annual area burned was small. However, deep burning occurred throughout the fire season when the annual area burned was large. Depth of burning increased late in the fire season in upland forests, but not in peatland and permafrost sites. Simulations of wildfire-induced carbon losses from Alaskan black spruce stands over the past 60 years suggest that ground-layer combustion has accelerated regional carbon losses over the past decade, owing to increases in burn area and late-season burning. As a result, soils in these black spruce stands have become a net source of carbon to the atmosphere, with carbon emissions far exceeding decadal uptake.

Healthcare costs of burn patients from homes without fire sprinklers

PubMed Central

Banfield, Joanne; Rehou, Sarah; Gomez, Manuel; Redelmeier, Donald A.; Jeschke, Marc G.

2014-01-01

The treatment of burn injuries requires high-cost services for healthcare and society. Automatic fire sprinklers are a preventive measure that can decrease fire injuries, deaths, property damage and environmental toxins. This study’s aim was to conduct a cost-analysis of patients with burn or inhalation injuries due to residential fires, and to compare this to the cost of implementing residential automatic fire sprinklers. We conducted a cohort analysis of adult burn patients admitted to our provincial burn center (1995–2012). Patient demographics and injury characteristics were collected from medical records, and clinical and coroner databases. Resource costs included average cost per day at our intensive care and rehabilitation program, transportation, and property loss. During the study period there were 1,557 residential fire-related deaths province-wide and 1,139 patients were admitted to our provincial burn center due to a flame injury occurring at home. At our burn center, the average cost was CAN$84,678 per patient with a total cost of CAN$96,448,194. All resources totaled CAN$3,605,775,200. This study shows the considerable healthcare costs of burn patients from homes without fire sprinklers. PMID:25412056

Understanding the transmission of wildfire risk on a fire prone landscape - A Case study from Central Oregon

NASA Astrophysics Data System (ADS)

Ager, Alan; Barros, Ana; Day, Michelle; Preisler, Haiganoush; Evers, Cody

2015-04-01

We develop the idea of risk transmission from large wildfires and apply network analyses to understand its importance within the 3.2 million ha Fire-People-Forest study area in central Oregon, US. Historic wildfires within the study and elsewhere in the western US frequently burn over long distances (e.g., 20-50 km) through highly fragmented landscapes with respect to ownership, fuels, management intensity, population density, and ecological conditions. The collective arrangement of fuel loadings in concert with weather and suppression efforts ultimately determines containment and the resulting fire perimeter. While spatial interactions among land parcels in terms of fire spread and intensity have been frequently noted by fire managers, quantifying risk and exposure transmission is not well understood. In this paper we used simulation modeling to quantify wildfire transmission and built a transmission network among and within land owners and communities within the study area. The results suggested that 84% of the predicted area burned within the 25 communities in the study area was from simulated fires that ignited on federal lands. The wildland urban interface surrounding the communities was predicted to burn at a rate of 2 % per year, with 57% of the area burned from fires ignited on federal lands. The node degree for communities indicated that simulated fires originated on about 6 different landowners. Network analyses in general revealed independent variation in transmitted fire among landowners in terms of both node degree (diversity of landowners exchanging fire) and transmitted fire, indicating that both the spatial grain of land ownership and wildfire topology contribute to transmission among land parcels. We discuss how network analyses of wildfire transmission can inform fire management goals for creating fire adapted communities, conserving biodiversity, and resolving competing demands for fire-prone ecosystem services. We also discuss how biophysical fire networks can potentially be coupled with social fire networks to improve wildfire mitigation planning.

Object-based Forest Fire Analysis for Pedrógão Grande Fire Using Landsat 8 OLI and Sentinel-2A Imagery

NASA Astrophysics Data System (ADS)

Tonbul, H.; Kavzoglu, T.

2017-12-01

Forest fires are among the most important natural disasters with the damage to the natural habitat and human-life. Mapping damaged forest fires is crucial for assessing ecological effects caused by fire, monitoring land cover changes and modeling atmospheric and climatic effects of fire. In this context, satellite data provides a great advantage to users by providing a rapid process of detecting burning areas and determining the severity of fire damage. Especially, Mediterranean ecosystems countries sets the suitable conditions for the forest fires. In this study, the determination of burnt areas of forest fire in Pedrógão Grande region of Portugal occurred in June 2017 was carried out using Landsat 8 OLI and Sentinel-2A satellite images. The Pedrógão Grande fire was one of the largest fires in Portugal, more than 60 people was killed and thousands of hectares were ravaged. In this study, four pairs of pre-fire and post-fire top of atmosphere (TOA) and atmospherically corrected images were utilized. The red and near infrared (NIR) spectral bands of pre-fire and post-fire images were stacked and multiresolution segmentation algorithm was applied. In the segmentation processes, the image objects were generated with estimated optimum homogeneity criteria. Using eCognition software, rule sets have been created to distinguish unburned areas from burned areas. In constructing the rule sets, NDVI threshold values were determined pre- and post-fire and areas where vegetation loss was detected using the NDVI difference image. The results showed that both satellite images yielded successful results for burned area discrimination with a very high degree of consistency in terms of spatial overlap and total burned area (over 93%). Object based image analysis (OBIA) was found highly effective in delineation of burnt areas.

Rapid recovery of gross ecosystem production and ecosystem-level respiration in a semiarid sagebrush shrubland following prescribed fire.

NASA Astrophysics Data System (ADS)

Fellows, A.; Flerchinger, G. N.

2016-12-01

The impact of fire remains a key uncertainty in our understanding of the spatio-temporal dynamics of carbon cycling on Western US rangelands. We, therefore, tracked the recovery of carbon fluxes and vegetative carbon stocks following prescribed fire in a sagebrush shrubland located in the Western US Great Basin. We quantified the change in plant function type, Leaf Area Index (LAI), aboveground carbon stocks, Gross Ecosystem Production (GEP), and Ecosystem-level Respiration (Reco) for 2 years before and 5 years following a prescribed fire that burned in 2007. Recruitment of burned sagebrush shrubland by fast growing grasses and forbs drove a rapid recovery of LAI, GEP, and Reco following fire; LAI, GEP, and Reco recovered within 1-3 years. These findings are consistent with previous measurement and modeling work by Flerchinger that demonstrated rooting depths, soil moisture withdrawal, and evapotranspiration also recovered within a few years of this fire. Live aboveground biomass reached 15% of pre-fire aboveground biomass after 5 years. The rapid recovery of LAI, rooting depth, GEP and Reco may partially reflect conducive environmental conditions at this site and at the time of the fire. In particular, the site was wet for a sagebrush shrubland; annual precipitation averaged 545 mm during the study and large-deep snow drifts formed upslope of the site. Post-fire weather was particularly wet, with the second, third and fourth years following fire receiving 587, 614, and 745 mm of water. Grazing was excluded from the burned area, which limited herbivory and may have facilitated vegetation establishment and growth. Lastly, the fire burned in September after many grasses and herbaceous plants had already senesced.

Mapping Fire Severity Using Imaging Spectroscopy and Kernel Based Image Analysis

NASA Astrophysics Data System (ADS)

Prasad, S.; Cui, M.; Zhang, Y.; Veraverbeke, S.

2014-12-01

Improved spatial representation of within-burn heterogeneity after wildfires is paramount to effective land management decisions and more accurate fire emissions estimates. In this work, we demonstrate feasibility and efficacy of airborne imaging spectroscopy (hyperspectral imagery) for quantifying wildfire burn severity, using kernel based image analysis techniques. Two different airborne hyperspectral datasets, acquired over the 2011 Canyon and 2013 Rim fire in California using the Airborne Visible InfraRed Imaging Spectrometer (AVIRIS) sensor, were used in this study. The Rim Fire, covering parts of the Yosemite National Park started on August 17, 2013, and was the third largest fire in California's history. Canyon Fire occurred in the Tehachapi mountains, and started on September 4, 2011. In addition to post-fire data for both fires, half of the Rim fire was also covered with pre-fire images. Fire severity was measured in the field using Geo Composite Burn Index (GeoCBI). The field data was utilized to train and validate our models, wherein the trained models, in conjunction with imaging spectroscopy data were used for GeoCBI estimation wide geographical regions. This work presents an approach for using remotely sensed imagery combined with GeoCBI field data to map fire scars based on a non-linear (kernel based) epsilon-Support Vector Regression (e-SVR), which was used to learn the relationship between spectra and GeoCBI in a kernel-induced feature space. Classification of healthy vegetation versus fire-affected areas based on morphological multi-attribute profiles was also studied. The availability of pre- and post-fire imaging spectroscopy data over the Rim Fire provided a unique opportunity to evaluate the performance of bi-temporal imaging spectroscopy for assessing post-fire effects. This type of data is currently constrained because of limited airborne acquisitions before a fire, but will become widespread with future spaceborne sensors such as those on the planned NASA HyspIRI mission.

Aerosol Microphysics and Radiation Integration

DTIC Science & Technology

2003-09-30

656-4769 email: reidj@nrlmry.navy.mil Award Number: N0001403WX20570 http://www.nrlmry.navy.mil/aerosol/ http://www.nrlmry.navy.mil/ flambe ...Fire Locating and Modeling of Burning Emissions ( FLAMBE ) project, which also provides NAAPS with a real-time biomass burning source function. In...Locating and Modeling of Burning Emissions ( FLAMBE ) project are currently being utilized by internet community, Air quality/human health research

The impact of diverse types of biomass burning in a tropical country

Treesearch

R. J. Yokelson; I. R. Burling; Shawn Urbanski; T. J. Christian; E. L. Atlas; C. Wiedinmyer; S. K. Akagi; G. Engling

2010-01-01

We couple laboratory work, airborne and ground-based field measurements, remote sensing of fires, and modeling to assess the impact of diverse types of biomass burning (BB) in Mexico as a model tropical country. About 70-80% of open BB occurs in the tropics along with large amounts of biofuel use and garbage burning (GB); both in rural and urban areas. During the...

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.

Use of ordinary kriging to interpolate observations of fire radiative heat flux sampled with airborne imagery

NASA Astrophysics Data System (ADS)

Klauberg Silva, C.; Hudak, A. T.; Bright, B. C.; Dickinson, M. B.; Kremens, R.; Paugam, R.; Mell, W.

2016-12-01

Biomass burning has impacts on air pollution at local to regional scales and contributes to greenhouse gases and affects carbon balance at the global scale. Therefore, is important to accurately estimate and manage carbon pools (fuels) and fluxes (gases and particulate emissions having public health implications) associated with wildland fires. Fire radiative energy (FRE) has been shown to be linearly correlated with biomass burned in small-scale experimental fires but not at the landscape level. Characterization of FRE density (FRED) flux in J m-2 from a landscape-level fire presents an undersampling problem. Specifically, airborne acquisitions of long-wave infrared radiation (LWIR) from a nadir-viewing LWIR camera mounted on board fixed-wing aircraft provide only samples of FRED from a landscape-level fire, because of the time required to turn the plane around between passes, and a fire extent that is broader than the camera field of view. This undersampling in time and space produces apparent firelines in an image of observed FRED, capturing the fire spread only whenever and wherever the scene happened to be imaged. We applied ordinary kriging to images of observed FRED from five prescribed burns collected in forested and non-forested management units burned at Eglin Air Force Base in Florida USA in 2011 and 2012. The three objectives were to: 1. more realistically map FRED, 2. more accurately estimate total FRED as predicted from fuel consumption measurements, and 3. compare the sampled and kriged FRED maps to modeled estimates of fire rate of spread (ROS). Observed FRED was integrated from LWIR images calibrated to units of fire radiative flux density (FRFD) in W m-2. Iterating the kriging analysis 2-10 times (depending on the burn unit) led to more accurate FRED estimates, both in map form and in terms of total FRED, as corroborated by independent estimates of fuel consumption and ROS.

Burn severity of areas reburned by wildfires in the Gila National Forest, New Mexico, USA

Treesearch

Zachary A. Holden; Penelope Morgan; Andrew T. Hudak

2010-01-01

We describe satellite-inferred burn severity patterns of areas that were burned and then reburned by wildland fire from 1984 to 2004 within the Gila Aldo Leopold Wilderness Complex, New Mexico, USA. Thirteen fires have burned 27 000 hectares across multiple vegetation types at intervals between fires ranging from 3 yr to 14 yr. Burn severity of reburned areas showed...

Satellite data driven modeling system for predicting air quality and visibility during wildfire and prescribed burn events

NASA Astrophysics Data System (ADS)

Nair, U. S.; Keiser, K.; Wu, Y.; Maskey, M.; Berendes, D.; Glass, P.; Dhakal, A.; Christopher, S. A.

2012-12-01

The Alabama Forestry Commission (AFC) is responsible for wildfire control and also prescribed burn management in the state of Alabama. Visibility and air quality degradation resulting from smoke are two pieces of information that are crucial for this activity. Currently the tools available to AFC are the dispersion index available from the National Weather Service and also surface smoke concentrations. The former provides broad guidance for prescribed burning activities but does not provide specific information regarding smoke transport, areas affected and quantification of air quality and visibility degradation. While the NOAA operational air quality guidance includes surface smoke concentrations from existing fire events, it does not account for contributions from background aerosols, which are important for the southeastern region including Alabama. Also lacking is the quantification of visibility. The University of Alabama in Huntsville has developed a state-of-the-art integrated modeling system to address these concerns. This system based on the Community Air Quality Modeling System (CMAQ) that ingests satellite derived smoke emissions and also assimilates NASA MODIS derived aerosol optical thickness. In addition, this operational modeling system also simulates the impact of potential prescribed burn events based on location information derived from the AFC prescribed burn permit database. A lagrangian model is used to simulate smoke plumes for the prescribed burns requests. The combined air quality and visibility degradation resulting from these smoke plumes and background aerosols is computed and the information is made available through a web based decision support system utilizing open source GIS components. This system provides information regarding intersections between highways and other critical facilities such as old age homes, hospitals and schools. The system also includes satellite detected fire locations and other satellite derived datasets relevant for fire and smoke management.

Land cover, more than monthly fire weather, drives fire-size distribution in Southern Québec forests: Implications for fire risk management.

PubMed

Marchal, Jean; Cumming, Steve G; McIntire, Eliot J B

2017-01-01

Fire activity in North American forests is expected to increase substantially with climate change. This would represent a growing risk to human settlements and industrial infrastructure proximal to forests, and to the forest products industry. We modelled fire size distributions in southern Québec as functions of fire weather and land cover, thus explicitly integrating some of the biotic interactions and feedbacks in a forest-wildfire system. We found that, contrary to expectations, land-cover and not fire weather was the primary driver of fire size in our study region. Fires were highly selective on fuel-type under a wide range of fire weather conditions: specifically, deciduous forest, lakes and to a lesser extent recently burned areas decreased the expected fire size in their vicinity compared to conifer forest. This has large implications for fire risk management in that fuels management could reduce fire risk over the long term. Our results imply, for example, that if 30% of a conifer-dominated landscape were converted to hardwoods, the probability of a given fire, occurring in that landscape under mean fire weather conditions, exceeding 100,000 ha would be reduced by a factor of 21. A similarly marked but slightly smaller effect size would be expected under extreme fire weather conditions. We attribute the decrease in expected fire size that occurs in recently burned areas to fuel availability limitations on fires spread. Because regenerating burned conifer stands often pass through a deciduous stage, this would also act as a negative biotic feedback whereby the occurrence of fires limits the size of nearby future for some period of time. Our parameter estimates imply that changes in vegetation flammability or fuel availability after fires would tend to counteract shifts in the fire size distribution favoring larger fires that are expected under climate warming. Ecological forecasts from models neglecting these feedbacks may markedly overestimate the consequences of climate warming on fire activity, and could be misleading. Assessments of vulnerability to climate change, and subsequent adaptation strategies, are directly dependent on integrated ecological forecasts. Thus, we stress the need to explicitly incorporate land-cover's direct effects and feedbacks in simulation models of coupled climate-fire-fuels systems.

Hydrogeological controls on post-fire moss recovery in peatlands

NASA Astrophysics Data System (ADS)

Lukenbach, M. C.; Devito, K. J.; Kettridge, N.; Petrone, R. M.; Waddington, J. M.

2015-11-01

Wildfire is the largest disturbance affecting boreal peatlands, however, little is known about the controls on post-fire peatland vegetation recovery. While small-scale variation in burn severity can reduce post-fire moss water availability, high water table (WT) positions following wildfire are also critical to enable the re-establishment of keystone peatland mosses (i.e. Sphagnum). Thus, post-fire moss water availability is also likely a function of landscape-scale controls on peatland WT dynamics, specifically, connectivity to groundwater flow systems (i.e. hydrogeological setting). For this reason, we assessed the interacting controls of hydrogeological setting and burn severity on post-fire moss water availability in three burned, Sphagnum-dominated peatlands in Alberta's Boreal Plains. At all sites, variation in burn severity resulted in a dichotomy between post-fire surface covers that: (1) exhibited low water availability, regardless of WT position, and had minimal (<5%) moss re-establishment (i.e. lightly burned feather mosses and severely burned Sphagnum fuscum) or (2) exhibited high water availability, depending on WT position, and had substantial (>50%) moss re-establishment (i.e. lightly burned S. fuscum and where depth of burn was >0.05 m). Notably, hydrogeological setting influenced the spatial coverage of these post-fire surface covers by influencing pre-fire WTs and stand characteristics (e.g., shading). Because feather moss cover is controlled by tree shading, lightly burned feather mosses were ubiquitous (>25%) in drier peatlands (deeper pre-fire WTs) that were densely treed and had little connection to large groundwater flow systems. Moreover, hydrogeological setting also controlled post-fire WT positions, thereby affecting moss re-establishment in post-fire surface covers that were dependent on WT position (e.g., lightly burned S. fuscum). Accordingly, higher recolonization rates were observed in a peatland located in a groundwater flow through system that had a shallow post-fire WT. Therefore, we argue that hydrogeological setting influences post-fire recovery in two ways: (1) by influencing vegetation structure prior to wildfire, thereby controlling the coverage of post-fire surface covers and (2) by influencing post-fire WT positions. These results suggest that post-fire moss recovery in peatlands isolated from groundwater flow systems may be particularly susceptible to droughts and future climate change.

"Fire Moss" Cover and Function in Severely Burned Forests of the Western United States

NASA Astrophysics Data System (ADS)

Grover, H.; Doherty, K.; Sieg, C.; Robichaud, P. R.; Fulé, P. Z.; Bowker, M.

2017-12-01

With wildfires increasing in severity and extent throughout the Western United States, land managers need new tools to stabilize recently burned ecosystems. "Fire moss" consists of three species, Ceratodon purpureus, Funaria hygrometrica, and Bryum argentum. These mosses colonize burned landscapes quickly, aggregate soils, have extremely high water holding capacity, and can be grown rapidly ex-situ. In this talk, I will focus on our efforts to understand how Fire Moss naturally interacts with severely burned landscapes. We examined 14 fires in Arizona, New Mexico, Washington, and Idaho selecting a range of times since fire, and stratified plots within each wildfire by winter insolation and elevation. At 75+ plots we measured understory plant cover, ground cover, Fire Moss cover, and Fire Moss reproductive effort. On plots in the Southwest, we measured a suite of soil characteristics on moss covered and adjacent bare soil including aggregate stability, shear strength, compressional strength, and infiltration rates. Moss cover ranged from 0-75% with a mean of 16% across all plots and was inversely related to insolation (R2 = .32, p = <.01), directly related to elevation (R2 = .13, p = .02), and not related to slope (R2 = .02, p =.41). Moss covered areas had twice as much shear strength and compressional strength, and three times higher aggregate stability and infiltration rates as adjacent bare ground. These results will allow us to model locations where Fire Moss will naturally increase postfire hillslope soil stability, locations for targeting moss restoration efforts, and suggest that Fire Moss could be a valuable tool to mitigate post wildfire erosion.

First-order fire effects on herbs and Shrubs: present knowledge and process modeling needs

Treesearch

Kirsten Stephan; Melanie Miller; Matthew B. Dickinson

2010-01-01

Herbaceous plants and shrubs have received little attention in terms of fire effects modeling despite their critical role in ecosystem integrity and resilience after wildfires and prescribed burns. In this paper, we summarize current knowledge of direct effects of fire on herb and shrub (including cacti) vegetative tissues and seed banks, propose key components for...

Advancing investigation and physical modeling of first-order fire effects on soils

Treesearch

William J. Massman; John M. Frank; Sacha J. Mooney

2010-01-01

Heating soil during intense wildland fires or slash-pile burns can alter the soil irreversibly, resulting in many significant long-term biological, chemical, physical, and hydrological effects. To better understand these long-term effects, it is necessary to improve modeling capability and prediction of the more immediate, or first-order, effects that fire can have on...

The influence of burn severity on post-fire vegetation recovery and albedo change during early succession in North American boreal forests

NASA Astrophysics Data System (ADS)

Jin, Y.; Randerson, J. T.; Goetz, S. J.; Beck, P. S.; Loranty, M. M.; Goulden, M.

2011-12-01

Severity of burning can influence multiple aspects of forest composition, carbon cycling, and climate forcing. We quantified how burn severity affected vegetation recovery and albedo change during early succession in Canadian boreal regions by combining satellite observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Canadian Large Fire Data Base (LFDB). We used the difference Normalized Burn Ratio (dNBR) and changes in spring albedo derived from MODIS 500m albedo product as measures of burn severity. We found that the most severe burns had the greatest reduction in summer EVI in first year after fire, indicating greater loss of vegetation cover immediately following fire. By 5-7 years after fire, summer EVI for all severity classes had recovered to within 90-110% of pre-fire levels. Burn severity had a positive effect on the increase of post-fire spring albedo during the first 7 years after fire, and a shift from low to moderate or moderate to severe fires led to amplification of the post-fire albedo increase by approximately 30%. Fire-induced increases in both spring and summer albedo became progressively larger with stand age from years 1-7, with the trend in spring albedo likely driven by continued losses of needles and branches from trees killed by the fire (and concurrent losses of black carbon coatings on remaining debris), and the summer trend associated with increases in leaf area of short-stature herbs and shrubs. Our results suggest that increases in burn severity and carbon losses observed in some areas of boreal forests (e.g., Turetsky et al., 2011) may be at least partly offset by increases in negative forcing associated with changes in surface albedo.

Developing ecological criteria for prescribed fire in South Florida pine rockland ecosystems

USGS Publications Warehouse

Snyder, James R.; Ross, Michael S.; Koptur, Suzanne; Sah, Jay P.

2005-01-01

The pine rocklands of South Florida, characterized by a rich herbaceous flora with many narrowly endemic taxa beneath an overstory of south Florida slash pine (Pinus elliottii var. densa), are found in three areas: the Miami Rock Ridge of southeastern peninsular Florida, the Lower Florida Keys, and slightly elevated portions of the southern Big Cypress National Preserve. Fire is an important element in these ecosystems, since in its absence the pine canopy is likely to be replaced by dense hardwoods, resulting in loss of the characteristic pineland herb flora. Prescribed fire has been used in Florida Keys pine forests since the creation of the National Key Deer Refuge (NKDR), with the primary aim of reducing fuels. Because fire can also be an effective tool in shaping ecological communities, we conducted a 4-year research study which explored a range of fire management options in NKDR. The intent of the study was to provide the Fish and Wildlife Service and other land managers with information regarding when and where to burn in order to perpetuate these unique forests. In 1998 we initiated a burning experiment in a randomized complete block design. Three treatments were to be carried out in a single well-defined block in each of two characteristic understory types during each year from 1998 through 2000. One understory type was characterized by a relatively sparse shrub layer and a well-developed herb layer ('open'), and the second had a dense shrub layer and poorly developed herb layer ('shrubby'). The three burn treatments were: (a) summer burn, (b) winter burn, and (c) no burn, or control. Three 1- ha plots were established in each block, and randomly assigned to the three treatments. Though the first year experimental burns were carried out without incident, constraints posed by external factors, including nationwide and statewide prohibitions on prescribed burning due to wildfires in other regions, delayed the experimental burns and precluded collection of postburn data on one third of the burns. Ultimately we burned only eleven plots, three in winter and eight in summer, over a four-year period from 1998 to 2001. Vegetation was sampled in a stratified, nested design within 18 plots. Trees were sampled in a 1.0-ha plot, shrubs in twenty 50-m2 circular (radius 4 m) subplots within the tree plot, and the herb layer in four circular 1-m2 quadrats (radius 0.57 m) within each subplot. The amount of fuel in the shrub layer was estimated by applying regression models to plant dimensional data, and ground layer fuel was estimated by a harvest method. The effects of Key deer herbivory on regeneration of the understory pine rockland plant community after fire was studied by monitoring inside and outside exclosures established within two of the six blocks. Pine trees constituted more than half (53.3%) of the biomass, but understory fine fuels comprised a surprisingly high proportion of total aboveground biomass. In the three blocks in which paired summer and winter burns were successfully conducted, the summer burns were more intense than the winter burns as judged by our indicators of fire intensity. Because of the differences in fire intensity between seasons, it was not possible to say whether observed differences in vegetation response between summer and winter burns were due to season or to fire intensity. The mortality of South Florida slash pine trees was greater after the summer burn than the winter burn in each block, but other vegetation responses were rarely as consistent. For instance, Metopium showed less recovery after summer burns in two blocks and after the winter burn in the third block. Moreover, there were instances in which alternative growth stages of the same species responded differently. Adult palms succumbed more frequently to summer than winter burns, and mortality of Coccothrinax exceeded that of Thrinax. In contrast, small palms recovered more readily after summer burns than winter burns. High in

Caliver: An R package for CALIbration and VERification of forest fire gridded model outputs.

PubMed

Vitolo, Claudia; Di Giuseppe, Francesca; D'Andrea, Mirko

2018-01-01

The name caliver stands for CALIbration and VERification of forest fire gridded model outputs. This is a package developed for the R programming language and available under an APACHE-2 license from a public repository. In this paper we describe the functionalities of the package and give examples using publicly available datasets. Fire danger model outputs are taken from the modeling components of the European Forest Fire Information System (EFFIS) and observed burned areas from the Global Fire Emission Database (GFED). Complete documentation, including a vignette, is also available within the package.

Caliver: An R package for CALIbration and VERification of forest fire gridded model outputs

PubMed Central

Di Giuseppe, Francesca; D’Andrea, Mirko

2018-01-01

The name caliver stands for CALIbration and VERification of forest fire gridded model outputs. This is a package developed for the R programming language and available under an APACHE-2 license from a public repository. In this paper we describe the functionalities of the package and give examples using publicly available datasets. Fire danger model outputs are taken from the modeling components of the European Forest Fire Information System (EFFIS) and observed burned areas from the Global Fire Emission Database (GFED). Complete documentation, including a vignette, is also available within the package. PMID:29293536

Remote sensing sensitivity to fire severity and fire recovery

USGS Publications Warehouse

Key, C.H.

2005-01-01

The paper examines fundamental ways that geospatial data on fire severity and recovery are influenced by conditions of the remote sensing. Remote sensing sensitivities are spatial, temporal and radiometric in origin. Those discussed include spatial resolution, the sampling time of year, and time since fire. For standard reference, sensitivities are demonstrated with examples drawn from an archive of burn assessments based on one radiometric index, the differenced Normalized Burn Ratio. Resolution determines the aggregation of fire effects within a pixel (alpha variation), hence defining the detected ecological response, and controlling the ability to determine patchiness and spatial distribution of responses throughout a burn (beta variation). As resolution decreases, alpha variation increases, extracting beta variation from the complexity of the whole burn. Seasonal timing impacts the radiometric quality of data in terms of transmittance, sun angle, and potential for enhanced contrast between responses within burns. Remote sensing sensitivity can degrade during many fire seasons when snow, incomplete burning, hazy conditions, low sun angles, or extended drought are common. Time since fire (lag timing) most notably shapes severity detection through the first-order fire effects evident in survivorship and delayed mortality that emerge by the growth period after fire. The former effects appear overly severe at first, but diminish, as burned vegetation remains viable. Conversely, the latter signals vegetation that appears healthy at first, but is damaged by heat to the extent that it soon dies. Both responses can lead to either over- or under-estimating severity, respectively, depending on fire behavior and pre-fire composition unique to each burned area. Based on implications of such sensitivities, three sampling intervals for short-term burn severity are identified; rapid, initial, and extended assessment, sampled within ca. two weeks, two months, and depending on the ecotype, from three months to one year after fire, respectively. Jointly, remote sensing conditions and the way burns are studied yield different tendencies for data quality and information content that impact the objectives and hypotheses that can be studied. Such considerations can be commonly overlooked, but need to be incorporated especially in comparative studies, and to build long-term reference databases on fire severity and recovery.

Land cover, more than monthly fire weather, drives fire-size distribution in Southern Québec forests: Implications for fire risk management

PubMed Central

Marchal, Jean; Cumming, Steve G.; McIntire, Eliot J. B.

2017-01-01

Fire activity in North American forests is expected to increase substantially with climate change. This would represent a growing risk to human settlements and industrial infrastructure proximal to forests, and to the forest products industry. We modelled fire size distributions in southern Québec as functions of fire weather and land cover, thus explicitly integrating some of the biotic interactions and feedbacks in a forest-wildfire system. We found that, contrary to expectations, land-cover and not fire weather was the primary driver of fire size in our study region. Fires were highly selective on fuel-type under a wide range of fire weather conditions: specifically, deciduous forest, lakes and to a lesser extent recently burned areas decreased the expected fire size in their vicinity compared to conifer forest. This has large implications for fire risk management in that fuels management could reduce fire risk over the long term. Our results imply, for example, that if 30% of a conifer-dominated landscape were converted to hardwoods, the probability of a given fire, occurring in that landscape under mean fire weather conditions, exceeding 100,000 ha would be reduced by a factor of 21. A similarly marked but slightly smaller effect size would be expected under extreme fire weather conditions. We attribute the decrease in expected fire size that occurs in recently burned areas to fuel availability limitations on fires spread. Because regenerating burned conifer stands often pass through a deciduous stage, this would also act as a negative biotic feedback whereby the occurrence of fires limits the size of nearby future for some period of time. Our parameter estimates imply that changes in vegetation flammability or fuel availability after fires would tend to counteract shifts in the fire size distribution favoring larger fires that are expected under climate warming. Ecological forecasts from models neglecting these feedbacks may markedly overestimate the consequences of climate warming on fire activity, and could be misleading. Assessments of vulnerability to climate change, and subsequent adaptation strategies, are directly dependent on integrated ecological forecasts. Thus, we stress the need to explicitly incorporate land-cover’s direct effects and feedbacks in simulation models of coupled climate–fire–fuels systems. PMID:28609467

Impact of prescribed fire and other factors on cheatgrass persistence in a Sierra Nevada ponderosa pine forest

USGS Publications Warehouse

Keeley, J.E.; McGinnis, T.W.

2007-01-01

Following the reintroduction of fire Bromus tectorum has invaded the low elevation ponderosa pine forests in parts of Kings Canyon National Park, California. We used prescribed burns, other field manipulations, germination studies, and structural equation modelling, to investigate how fire and other factors affect the persistence of cheatgrass in these forests. Our studies show that altering burning season to coincide with seed maturation is not likely to control cheatgrass because sparse fuel loads generate low fire intensity. Increasing time between prescribed fires may inhibit cheatgrass by increasing surface fuels (both herbaceous and litter), which directly inhibit cheatgrass establishment, and by creating higher intensity fires capable of killing a much greater fraction of the seed bank. Using structural equation modelling, postfire cheatgrass dominance was shown to be most strongly controlled by the prefire cheatgrass seedbank; other factors include soil moisture, fire intensity, soil N, and duration of direct sunlight. Current fire management goals in western conifer forests are focused on restoring historical fire regimes; however, these frequent fire regimes may enhance alien plant invasion in some forest types. Where feasible, fire managers should consider the option of an appropriate compromise between reducing serious fire hazards and exacerbating alien plant invasions. ?? IAWF 2007.

The Bee Fire: a case study validation of BEHAVE in chaparral fuels

Treesearch

David Weise; A. Gelobter; J. Regelbrugge; J. Millar

2002-01-01

The Bee Fire burned 9,620 acres of grass and chaparral in the San Bernardino National Forest in southern California from June 29 to July 2, 1996. Rate of spread data were determined from successive fire perimeters and compared with rate of spread predicted by the Rothermel rate of spread model using fuel model 4 (heavy brush) and a custom fuel model for chamise...

Drought, multi-seasonal climate, and wildfire in northern New Mexico

USGS Publications Warehouse

Margolis, Ellis; Woodhouse, Connie A.; Swetnam, Thomas W.

2017-01-01

Wildfire is increasingly a concern in the USA, where 10 million acres burned in 2015. Climate is a primary driver of wildfire, and understanding fire-climate relationships is crucial for informing fire management and modeling the effects of climate change on fire. In the southwestern USA, fire-climate relationships have been informed by tree-ring data that extend centuries prior to the onset of fire exclusion in the late 1800s. Variability in cool-season precipitation has been linked to fire occurrence, but the effects of the summer North American monsoon on fire are less understood, as are the effects of climate on fire seasonality. We use a new set of reconstructions for cool-season (October–April) and monsoon-season (July–August) moisture conditions along with a large new fire scar dataset to examine relationships between multi-seasonal climate variability, fire extent, and fire seasonality in the Jemez Mountains, New Mexico (1599–1899 CE). Results suggest that large fires burning in all seasons are strongly influenced by the current year cool-season moisture, but fires burning mid-summer to fall are also influenced by monsoon moisture. Wet conditions several years prior to the fire year during the cool season, and to a lesser extent during the monsoon season, are also important for spring through late-summer fires. Persistent cool-season drought longer than 3 years may inhibit fires due to the lack of moisture to replenish surface fuels. This suggests that fuels may become increasingly limiting for fire occurrence in semi-arid regions that are projected to become drier with climate change.

Mapping burned areas and burn severity patterns across the Mediterranean region

NASA Astrophysics Data System (ADS)

Kalogeropoulos, Christos; Amatulli, Giuseppe; Kempeneers, Pieter; Sedano, Fernando; San Miguel-Ayanz, Jesus; Camia, Andrea

2010-05-01

The Mediterranean region is highly susceptible to wildfires. On average, about 60,000 fires take place in this region every year, burning on average half a million hectares of forests and natural vegetation. Wildfires cause environmental degradation and affect the lives of thousands of people in the region. In order to minimize the consequences of these catastrophic events, fire managers and national authorities need to have in their disposal accurate and updated spatial information concerning the size of the burned area as well as the burn severity patterns. Mapping burned areas and burn severity patterns is necessary to effectively support the decision-making process in what concerns strategic (long-term) planning with the definition of post-fire actions at European and national scales. Although a comprehensive archive of burnt areas exists at the European Forest Fire Information System, the analysis of the severity of the areas affected by forest fires in the region is not yet available. Fire severity is influenced by many variables, including fuel type, topography and meteorological conditions before and during the fire. The analysis of fire severity is essential to determine the socio-economic impact of forest fires, to assess fire impacts, and to determine the need of post-fire rehabilitation measures. Moreover, fire severity is linked to forest fire emissions and determines the rate of recovery of the vegetation after the fire. Satellite imagery can give important insights about the conditions of the live fuel moisture content and can be used to assess changes on vegetation structure and vitality after forest fires. Fire events occurred in Greece, Portugal and Spain during the fire season of 2009 were recorded and analyzed in a GIS environment. The Normalized Difference Vegetation Index (NDVI), the Enhanced Vegetation Index (EVI) and the Normalized Burn Ratio (NBR) were calculated from 8-days composites MODIS/TERRA imagery from March to October 2009. In addition, subtracting a post-fire from a pre-fire image derived index produces a measure of absolute change of the vegetation condition, like the differenced Normalized Burn Ratio index (dNBR). The aim of this study was the assessment of fire severity across diverse ecological and environmental conditions in the Mediterranean region. The specific objectives were: • The analysis of the correlation between the fire severity and local site conditions, including topography, fuel type, land use, land cover. • The analysis of the correlation between fire severity and fire danger conditions during the fire, as estimated by the European Forest Fire Information System. • Assessing the performance of several vegetation indices derived from MODIS imagery in estimating fire severity. • Assessing the permanence of the burnt signal for large fires as an estimate of fire severity.

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...

Flame characteristics for fires in southern fuels

Treesearch

Ralph M. Nelson

1980-01-01

A flame model and analytical method are used to derive forest fire flame characteristics. Approximate solutions are used to express flame lengths, angles, heights, and tip velocities of headfires and calm-air fires in terms of fire intensity. Equations are compared with data from low-intensity controlled burns in southern fuels and with data from the literature.

Behaviour and effects of prescribed fire in masticated fuelbeds

Treesearch

Eric Knapp; J. Morgan Varner; Matt Busse; Carl Skinner; Carol Shestak

2011-01-01

Mechanical mastication converts shrub and small tree fuels into surface fuels, and this method is being widely used as a treatment to reduce fire hazard. The compactness of these fuelbeds is thought to moderate fire behaviour, but whether standard fuel models can accurately predict fire behaviour and effects is poorly understood. Prescribed burns were conducted in...

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...

Ensemble projections of wildfire activity and carbonaceous aerosol concentrations over the western United States in the mid-21st century

PubMed Central

Yue, Xu; Mickley, Loretta J.; Logan, Jennifer A.; Kaplan, Jed O.

2013-01-01

We estimate future wildfire activity over the western United States during the mid-21st century (2046–2065), based on results from 15 climate models following the A1B scenario. We develop fire prediction models by regressing meteorological variables from the current and previous years together with fire indexes onto observed regional area burned. The regressions explain 0.25–0.60 of the variance in observed annual area burned during 1980–2004, depending on the ecoregion. We also parameterize daily area burned with temperature, precipitation, and relative humidity. This approach explains ~0.5 of the variance in observed area burned over forest ecoregions but shows no predictive capability in the semi-arid regions of Nevada and California. By applying the meteorological fields from 15 climate models to our fire prediction models, we quantify the robustness of our wildfire projections at mid-century. We calculate increases of 24–124% in area burned using regressions and 63–169% with the parameterization. Our projections are most robust in the southwestern desert, where all GCMs predict significant (p<0.05) meteorological changes. For forested ecoregions, more GCMs predict significant increases in future area burned with the parameterization than with the regressions, because the latter approach is sensitive to hydrological variables that show large inter-model variability in the climate projections. The parameterization predicts that the fire season lengthens by 23 days in the warmer and drier climate at mid-century. Using a chemical transport model, we find that wildfire emissions will increase summertime surface organic carbon aerosol over the western United States by 46–70% and black carbon by 20–27% at midcentury, relative to the present day. The pollution is most enhanced during extreme episodes: above the 84th percentile of concentrations, OC increases by ~90% and BC by ~50%, while visibility decreases from 130 km to 100 km in 32 Federal Class 1 areas in Rocky Mountains Forest. PMID:24015109

Long-term impacts of prescribed burns on soil thermal conductivity and soil heating at a Colorado Rocky Mountain site: a data/model fusion study

Treesearch

W. J. Massman; J. M. Frank; N. B. Reisch

2008-01-01

Heating any soil during a sufficiently intense wild fire or prescribed burn can alter that soil irreversibly, resulting in many significant, and well studied, long-term biological, chemical, and hydrological effects. On the other hand, much less is known about how fire affects the thermal properties and the long-term thermal regime of soils. Such knowledge is important...

Reliability of biomass burning estimates from savanna fires: Biomass burning in northern Australia during the 1999 Biomass Burning and Lightning Experiment B field campaign

NASA Astrophysics Data System (ADS)

Russell-Smith, Jeremy; Edwards, Andrew C.; Cook, Garry D.

2003-02-01

This paper estimates the two-daily extent of savanna burning and consumption of fine (grass and litter) fuels from an extensive 230,000 km2 region of northern Australia during August-September 1999 encompassing the Australian continental component of the Biomass Burning and Lightning Experiment B (BIBLE B) campaign [, 2002]. The extent of burning for the study region was derived from fire scar mapping of imagery from the advanced very high resolution radiometer (AVHRR) on board the National Oceanic and Atmospheric Administration (NOAA) satellite. The mapping was calibrated and verified with reference to one Landsat scene and associated aerial transect validation data. Fine fuel loads were estimated using published fuel accumulation relationships for major regional fuel types. It is estimated that more than 43,000 km2 was burnt during the 25 day study period, with about 19 Mt of fine (grass and litter) fuels. This paper examines assumptions and errors associated with these estimates. It is estimated from uncalibrated fire mapping derived from AVHRR imagery that 417,500 km2 of the northern Australian savanna was burnt in 1999, of which 136,405 km2, or 30%, occurred in the Northern Territory study region. Using generalized fuel accumulation equations, such biomass burning consumed an estimated 212.3 Mt of fine fuels, but no data are available for consumption of coarse fuels. This figure exceeds a recent estimate, based on fine fuels only, for the combined Australian savanna and temperate grassland biomass burning over the period 1990-1999 but is lower than past estimates derived from classification approaches. We conclude that (1) fire maps derived from coarse-resolution optical imagery can be applied relatively reliably to estimate the extent of savanna fires, generally with 70-80% confidence using the approach adopted here, over the major burning period in northern Australia and (2) substantial further field assessment and associated modeling of fuel accumulation, especially of coarse fuels, is required.

Emergency assessment of postwildfire debris-flow hazards for the 2011 Motor Fire, Sierra and Stanislaus National Forests, California

USGS Publications Warehouse

Cannon, Susan H.; Michael, John A.

2011-01-01

This report presents an emergency assessment of potential debris-flow hazards from basins burned by the 2011 Motor fire in the Sierra and Stanislaus National Forests, Calif. Statistical-empirical models are used to estimate the probability and volume of debris flows that may be produced from burned drainage basins as a function of different measures of basin burned extent, gradient, and soil physical properties, and in response to a 30-minute-duration, 10-year-recurrence rainstorm. Debris-flow probability and volume estimates are then combined to form a relative hazard ranking for each basin. This assessment provides critical information for issuing warnings, locating and designing mitigation measures, and planning evacuation timing and routes within the first two years following the fire.

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.

Factors influencing occupancy of nest cavities in recently burned forests

USGS Publications Warehouse

Saab, V.A.; Dudley, J.; Thompson, W.L.

2004-01-01

Recently burned forests in western North America provide nesting habitat for many species of cavity-nesting birds. However, little is understood about the time frame and the variables affecting occupancy of postfire habitats by these birds. We studied factors influencing the occupancy and reuse of nest cavities from 1-7 years after fire in two burned sites of western Idaho during 1994-1999. Tree cavities were used for nesting by 12 species of cavity nesters that were classified by the original occupant (strong excavator, weak excavator, or nonexcavator) of 385 nest cavities. We used logistic regression to model cavity occupancy by strong excavators (n = 575 trials) and weak excavators (n = 206 trials). Year after fire had the greatest influence on occupancy of nest cavities for both groups, while site of the burn was secondarily important in predicting occupancy by strong excavators and less important for weak excavators. Predicted probability of cavity occupancy was highest during the early years (1-4) after fire, declined over time (5-7 years after fire), and varied by site, with a faster decline in the smaller burned site with a greater mosaic of unburned forest. Closer proximity and greater interspersion of unburned forest (15% unburned) may have allowed a quicker recolonization by nest predators into the smaller burn compared to the larger burn with few patches of unburned forest (4% unburned). In combination with time and space effects, the predicted probability of cavity occupancy was positively affected by tree and nest heights for strong and weak excavators, respectively.

Prediction and Mitigation of the Effects of Catastrophic Fire on Water Supplies: Science for Risk Reduction and Planning for Future Scenarios

NASA Astrophysics Data System (ADS)

Martin, D. A.; Tindall, J.

2008-12-01

Precipitation falling on forests and grasslands provides much of the water to communities across the United States. The U.S. Forest Service estimates that over 3,400 communities are served by water draining land under its jurisdiction alone. Much of this land is subject to wildland fires, which have been increasing in size and severity in the western United States in response to climatic forcing and increased ignitions from human sources. Runoff from burned landscapes can present a significant risk to municipal and agricultural water supplies from ash, sediment, contaminants from burned structures, and fire-fighting chemicals. Several municipalities, including Denver, Colorado, have experienced both short-term and long-term degradation of their water supplies in the aftermath of fires in watersheds upstream from drinking water reservoirs. Scientific efforts to predict and mitigate the effects of catastrophic fire on water supplies have focused on three areas. The first consists of data collection and carefully designed experiments to understand the change of the hydrologic behavior of burned watersheds in response to rain with different intensities, durations, and trajectories as the watersheds recover. Results from these studies are used to validate models that predict watershed response under different initial conditions constrained by remotely-sensed burn severity, topography, rainfall-intensity recurrence probabilities and other factors. These predictions are the basis for rehabilitation measures applied to the landscape to minimize post-fire runoff and erosion. Efforts are under way to incorporate the chemical effects of ash and fire-fighting compounds in decision-support tools. A second area of scientific focus is the characterization of the chemical and physical properties of ash from wildland fire, including ash from structures consumed by fire. The ash chemistry is correlated to remotely- sensed data, type of vegetation that burned, and the underlying geology. Ash affects the hydraulic properties and behavior of soils in burned watersheds while it still mantles the hillslopes, but it is easily delivered to water bodies by rain and wind as a flush of material that affects water chemistry and properties like turbidity and temperature. A third thrust is to identify watersheds that are critical to the function of municipal water supplies and infrastructure to determine their vulnerability to fire and post-fire effects. This information can be used to prioritize areas for fuel treatments or land management practices to minimize the probability of high severity fire and hence the effects of post-fire runoff. Scientific studies are providing crucial information about such topics as changes in soil erodibility, infiltration and runoff after fire, and the effects of vegetation recovery. Even in watersheds where land management actions are limited by topography or land use designation, such as wilderness areas, knowledge of the potential response of burned areas allows water providers to develop rapid-response and long-term plans based on scientific data and tools. Some climate change models are predicting hotter, drier temperatures in certain areas of the United States and a higher probability of larger, more severe wildfires. These predictions have a direct bearing on the potential risk of impairment of water supplies by post-fire runoff and erosion. In an era when water availability and quality are of utmost importance, careful scientific studies focused on the effects of wildland fire on water supplies will continue to inform public policy and decision making on topics of vulnerability and risk reduction.

Satellite versus ground-based estimates of burned area: A comparison between MODIS based burned area and fire agency reports over North America in 2007

Treesearch

Stephane Mangeon; Robert Field; Michael Fromm; Charles McHugh; Apostolos Voulgarakis

2015-01-01

North American wildfire management teams routinely assess burned area on site during firefighting campaigns; meanwhile, satellite observations provide systematic and global burned-area data. Here we compare satellite and ground-based daily burned area for wildfire events for selected large fires across North America in 2007 on daily timescales. In a sample of 26 fires...

Synergistic interactions between leaf beetle herbivory and fire enhance tamarisk (Tamarix spp.) mortality

USGS Publications Warehouse

Drus, Gail M.; Dudley, Tom L.; Antonio, Carla M.; Even, Thomas J.; Brooks, Matt L.; Matchett, J.R.

2014-01-01

The combined effects of herbivory and fire on plant mortality were investigated using prescribed burns of tamarisk (Tamarix ramosissima Lebed) exposed to herbivory by the saltcedar leaf beetle (Chrysomelidae: Diorhabda carinulata Desbrocher). Tamarix stands in the Humboldt Sink (NV, USA) were divided into three treatments: summer burn (August 2006), fall burn (October 2006) and control (unburned), and litter depth was manipulated to vary fire intensity within burn seasons. A gradient of existing herbivory impact was described with three plant condition metrics prior to fire: reduced proportions of green canopy, percent root crown starch sampled at the height of the growing season (August 2006), and percent root crown starch measured during dormancy (December 2006). August root crown starch concentration and proportion green canopy were strongly correlated, although the proportion green canopy predicted mortality better than August root crown starch. December root crown starch concentration was more depleted in unburned trees and in trees burned during the summer than in fall burn trees. Mortality in summer burned trees was higher than fall burned trees due to higher fire intensity, but December root crown starch available for resprouting in the spring was also lower in summer burned trees. The greatest mortality was observed in trees with the lowest December root crown starch concentration which were exposed to high fire intensity. Disproportionate changes in the slope and curvature of prediction traces as fire intensity and December starch reach reciprocal maximum and minimum levels indicate that beetle herbivory and fire intensity are synergistic.

Modeling crop residue burning experiments and assessing the fire impacts on air quality

EPA Science Inventory

Prescribed burning is a common land management practice that results in ambient emissions of a variety of primary and secondary pollutants with negative health impacts. The community Multiscale Air Quality (CMAQ) model is used to conduct 2 km grid resolution simulations of prescr...

Decreases in Soil Moisture and Organic Matter Quality Suppress Microbial Decomposition Following a Boreal Forest Fire

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

Holden, Sandra R.; Berhe, Asmeret A.; Treseder, Kathleen K.

Climate warming is projected to increase the frequency and severity of wildfires in boreal forests, and increased wildfire activity may alter the large soil carbon (C) stocks in boreal forests. Changes in boreal soil C stocks that result from increased wildfire activity will be regulated in part by the response of microbial decomposition to fire, but post-fire changes in microbial decomposition are poorly understood. Here, we investigate the response of microbial decomposition to a boreal forest fire in interior Alaska and test the mechanisms that control post-fire changes in microbial decomposition. We used a reciprocal transplant between a recently burnedmore » boreal forest stand and a late successional boreal forest stand to test how post-fire changes in abiotic conditions, soil organic matter (SOM) composition, and soil microbial communities influence microbial decomposition. We found that SOM decomposing at the burned site lost 30.9% less mass over two years than SOM decomposing at the unburned site, indicating that post-fire changes in abiotic conditions suppress microbial decomposition. Our results suggest that moisture availability is one abiotic factor that constrains microbial decomposition in recently burned forests. In addition, we observed that burned SOM decomposed more slowly than unburned SOM, but the exact nature of SOM changes in the recently burned stand are unclear. Finally, we found no evidence that post-fire changes in soil microbial community composition significantly affect decomposition. Taken together, our study has demonstrated that boreal forest fires can suppress microbial decomposition due to post-fire changes in abiotic factors and the composition of SOM. Models that predict the consequences of increased wildfires for C storage in boreal forests may increase their predictive power by incorporating the observed negative response of microbial decomposition to boreal wildfires.« less

Bugaboo Fire Rages in Georgia and Florida

NASA Technical Reports Server (NTRS)

2007-01-01

Subtropical Storm Andrea apparently did little to quench numerous large wildfires burning in the U.S. Southeast in early May 2007. On May 11, 2007, when the Moderate Resolution Imaging Spectroradiometer Terra satellite captured this image, the remnants of the storm had dwindled to a small ball of clouds in the Atlantic Ocean, and huge plumes of smoke snaked across Georgia, Florida, and the Gulf of Mexico. Areas where MODIS detected actively burning fires are outlined in red. A huge fire is burning in and near the Okefenokee Swamp, which straddles the state line between Georgia and Florida. For logistical purposes, fire officials are calling the part of the fire in Florida the Florida Bugaboo Fire and the part in Georgia the Bugaboo Scrub Fire. The distinction is simply administrative, however; in reality, it is single, continuous swath of burning timber, swamp land, grass, and scrubland. The blaze was more than 133,000 thousand acres as of May 11, and it appeared to be spreading on virtually all perimeters at the time of the image, with active fire locations detected in a circle that surrounds an already burned (or partially burned) area. According to reports form the Southern Area Coordination Center, the fire grew by at least 20,000 acres on May 10. Numerous communities were threatened and hundreds of people were evacuated, while parts of Interstate 10 were closed to all but emergency vehicles. To the northeast of the Bugaboo Fire, other large wildfires were burning in Georgia as well. The Floyds Prairie Fire, to the immediate north, was threatening endangered species and their habitat, while farther north the 116,000-plus-acre Sweat Farm Road/Big Turnaround Complex Fire was still burning in the area south of the city of Waycross, nearly a month after the fires first started in mid-April. Southern Georgia and Florida are in the grip of moderate to extreme drought. The state line area where the Bugaboo Fire is burning is one of the areas in extreme drought. The extremely dry fuels, including easily flammable pine forests and plantations, and the rugged, isolated stretches of terrain, make fire officials think that these fires will continue to burn for a long time. Although extreme fire behavior may decline, smoldering and creeping fire will probably continue until heavy rain - possibly a hurricane - drenches the area. The large image provided above has a spatial resolution (level of detail) of 250 meters per pixel. The MODIS Rapid Response Team provides the image in additional resolutions. The group also provides twice-daily subset images of the United States in a variety of resolutions and formats, including and infrared-enhanced version that emphasizes the burn scars.

Controls on variations in MODIS fire radiative power in Alaskan boreal forests: implications for fire severity conditions

USGS Publications Warehouse

Barrett, Kirsten; Kasischke, Eric S.

2013-01-01

Fire activity in the Alaskan boreal forest, though episodic at annual and intra-annual time scales, has experienced an increase over the last several decades. Increases in burned area and fire severity are not only releasing more carbon to the atmosphere, but likely shifting vegetation composition in the region towards greater deciduous dominance and a reduction in coniferous stands. While some recent studies have addressed qualitative differences between large and small fire years in the Alaskan boreal forest, the ecological effects of a greater proportion of burning occurring during large fire years and during late season fires have not yet been examined. Some characteristics of wildfires that can be detected remotely are related to fire severity and can provide new information on spatial and temporal patterns of burning. This analysis focused on boreal wildfire intensity (fire radiative power, or FRP) contained in the Moderate Resolution Imaging Spectroradiometer (MODIS) daily active fire product from 2003 to 2010. We found that differences in FRP resulted from seasonality and intra-annual variability in fire activity levels, vegetation composition, latitudinal variation, and fire spread behavior. Our studies determined two general categories of active fire detections: new detections associated with the spread of the fire front and residual pixels in areas that had already experienced front burning. Residual pixels had a lower average FRP than front pixels, but represented a high percentage of all pixels during periods of high fire activity (large fire years, late season burning, and seasonal periods of high fire activity). As a result, the FRP from periods of high fire activity was less intense than those from periods of low fire activity. Differences related to latitude were greater than expected, with higher latitudes burning later in the season and at a higher intensity than lower latitudes. Differences in vegetation type indicate that coniferous vegetation is the most fire prone, but deciduous vegetation is not particularly fire resistant, as the proportion of active fire detections in deciduous stands is roughly the same as the fraction of deciduous vegetation in the region. Qualitative differences between periods of high and low fire activity are likely to reflect important differences in fire severity. Large fire years are likely to be more severe, characterized by more late season fires and a greater proportion of residual burning. Given the potential for severe fires to effect changes in vegetation cover, the shift toward a greater proportion of area burning during large fire years may influence vegetation patterns in the region over the medium to long term.

Assessing the spatial representability of charcoal and PAH-based paleofire records with integrated GIS, modelling, and empirical approaches

NASA Astrophysics Data System (ADS)

Vachula, R. S.; Huang, Y.; Russell, J. M.

2017-12-01

Lake sediment-based fire reconstructions offer paleoenvironmental context in which to assess modern fires and predict future burning. However, despite the ubiquity, many uncertainties remain regarding the taphonomy of paleofire proxies and the spatial scales for which they record variations in fire history. Here we present down-core proxy analyses of polycyclic aromatic hydrocarbons (PAHs) and three size-fractions of charcoal (63-150, >150 and >250 μm) from Swamp Lake, California, an annually laminated lacustrine archive. Using a statewide historical GIS dataset of area burned, we assess the spatial scales for which these proxies are reliable recorders of fire history. We find that the coherence of observed and proxy-recorded fire history inherently depends upon spatial scale. Contrary to conventional thinking that charcoal mainly records local fires, our results indicate that macroscopic charcoal (>150 μm) may record spatially broader (<25 km) changes in fire history, and as such, the coarsest charcoal particles (>250 μm) may be a more conservative proxy for local burning. We find that sub-macroscopic charcoal particles (63-150 μm) reliably record regional (up to 150 km) changes in fire history. These results indicate that charcoal-based fire reconstructions may represent spatially broader fire history than previously thought, which has major implications for our understanding of spatiotemporal paleofire variations. Our analyses of PAHs show that dispersal mobility is heterogeneous between compounds, but that PAH fluxes are reliable proxies of fire history within 25-50 km, which suggests PAHs may be a better spatially constrained paleofire proxy than sedimentary charcoal. Further, using a linear discriminant analysis model informed by modern emissions analyses, we show that PAH assemblages preserved in lake sediments can differentiate vegetation type burned, and are thus promising paleoecological biomarkers warranting further research and implementation. In sum, our analyses offer new insight into the spatial dimensions of paleofire proxies and constitute a methodology that can be applied to other locations and proxies to better inform site-specific reconstructions.

Influences on Prescribed Burning Activity and Costs in the National Forest System

Treesearch

David A. Cleaves; Jorge Martinez; Terry K. Haines

2000-01-01

The results of a survey concerning National Forest System prescribed burning activity and costs from 1985 to 1995 are examined. Ninety-five of one hundred and fourteen national forests responded. Acreage burned and costs for conducting burns are reported for four types of prescribed fires slash reduction; management-ignited fires; prescribed natural fires; and brush,...

Consequences of fire on aquatic nitrate and phosphate dynamics in Yellowstone National Park

Treesearch

James A. Brass; Vincent G. Ambrosia; Philip J. Riggan; Paul D. Sebesta

1996-01-01

Airborne remotely sensed data were collected and analyzed during and following the 1988 Greater Yellowstone Ecosystem (GYE) fires in order to characterize the fire front movements, burn intensities and various vegetative components of selected watersheds. Remotely sensed data were used to categorize the burn intensities as: severely burned, moderately burned, mixed...

16 CFR 1145.3 - Extremely flammable contact adhesives; risk of burns from explosive vapor ignition and flashback...

Code of Federal Regulations, 2014 CFR

2014-01-01

... of burns from explosive vapor ignition and flashback fire. 1145.3 Section 1145.3 Commercial Practices...; risk of burns from explosive vapor ignition and flashback fire. (a) The Commission finds that it is in the public interest to regulate the risk of burns from explosive vapor ignition and flashback fire...

16 CFR 1145.3 - Extremely flammable contact adhesives; risk of burns from explosive vapor ignition and flashback...

Code of Federal Regulations, 2011 CFR

2011-01-01

... of burns from explosive vapor ignition and flashback fire. 1145.3 Section 1145.3 Commercial Practices...; risk of burns from explosive vapor ignition and flashback fire. (a) The Commission finds that it is in the public interest to regulate the risk of burns from explosive vapor ignition and flashback fire...

16 CFR 1145.3 - Extremely flammable contact adhesives; risk of burns from explosive vapor ignition and flashback...

Code of Federal Regulations, 2012 CFR

2012-01-01

... of burns from explosive vapor ignition and flashback fire. 1145.3 Section 1145.3 Commercial Practices...; risk of burns from explosive vapor ignition and flashback fire. (a) The Commission finds that it is in the public interest to regulate the risk of burns from explosive vapor ignition and flashback fire...

16 CFR 1145.3 - Extremely flammable contact adhesives; risk of burns from explosive vapor ignition and flashback...

Code of Federal Regulations, 2010 CFR

2010-01-01

... of burns from explosive vapor ignition and flashback fire. 1145.3 Section 1145.3 Commercial Practices...; risk of burns from explosive vapor ignition and flashback fire. (a) The Commission finds that it is in the public interest to regulate the risk of burns from explosive vapor ignition and flashback fire...

In Situ Burning of Oil Spills

PubMed Central

Evans, David D.; Mulholland, George W.; Baum, Howard R.; Walton, William D.; McGrattan, Kevin B.

2001-01-01

For more than a decade NIST conducted research to understand, measure and predict the important features of burning oil on water. Results of that research have been included in nationally recognized guidelines for approval of intentional burning. NIST measurements and predictions have played a major role in establishing in situ burning as a primary oil spill response method. Data are given for pool fire burning rates, smoke yield, smoke particulate size distribution, smoke aging, and polycyclic aromatic hydrocarbon content of the smoke for crude and fuel oil fires with effective diameters up to 17.2 m. New user-friendly software, ALOFT, was developed to quantify the large-scale features and trajectory of wind blown smoke plumes in the atmosphere and estimate the ground level smoke particulate concentrations. Predictions using the model were tested successfully against data from large-scale tests. ALOFT software is being used by oil spill response teams to help assess the potential impact of intentional burning. PMID:27500022

Black Carbon in the Arctic: Assessment of and efforts to reduce black carbon emissions from wildfires and agricultural burning in Russia

NASA Astrophysics Data System (ADS)

Kinder, B.; Hao, W. M.; Larkin, N. K.; McCarty, G.; O'neal, K. J.; Gonzalez, O.; Luxenberg, J.; Rosenblum, M.; Petkov, A.

2011-12-01

Black carbon and other short-lived climate forcers exert a warming effect on the climate but remain in the atmosphere for short time periods when compared to carbon dioxide. Black carbon is a significant contributor to increasing temperatures in the Arctic region, which has warmed at twice the global rate over the past 100 years. Black carbon warms the Arctic by absorbing incoming solar radiation while in the atmosphere and, when deposited onto Arctic ice, leading to increased atmospheric temperatures and snow and ice melt. Black carbon remains in the atmosphere for a short time period ranging from days to weeks; therefore, local atmospheric conditions at the time of burning determine the amount of black carbon transport to the Arctic. Most black carbon transport and deposition in the Arctic results from the occurrence of wildfires, prescribed forest fires, and agricultural burning at latitudes greater than 40 degrees north latitude. Wildfire affects some 10-15 million hectares of forest, forest steppe, and grasslands in Russia each year. In addition to wildfire, there is widespread cropland burning in Russia occurring in the fall following harvest and in the spring prior to tilling. Agricultural burning is common practice for crop residue removal as well as suppression of weeds, insects and residue-borne diseases. The goal of the United States Department of Agriculture (USDA) Black Carbon Initiative is to assess black carbon emissions from agricultural burning and wildfires in Russia and explore practical options and opportunities for reducing emissions from these two sources. The emissions assessment combines satellite-derived burned area measurements of forest and agricultural fires, burn severity information, ancillary geospatial data, vegetation and land cover maps, fuels data, fire emissions data, fire/weather relationship information, and smoke transport models to estimate black carbon transport and deposition in the Arctic. The assessment addresses necessary improvements to fire and burned area detection algorithms to improve agricultural burned area mapping accuracy. Efforts to explore practical options for reducing black carbon emissions from wildfires and agricultural burning in Russia have been focused on designing community-based fire prevention and education programs in Siberia and the Russia Far East, two regions prone to frequent human-caused fires. The initiative also seeks to identify practical alternatives to reduce black carbon emissions from agricultural burning and to help promote these alternatives through outreach to farmers and other agricultural organizations. This submission will explore the initial findings and results of the emissions assessment and discuss the progress and challenges associated with implementation of local-level fire prevention and mitigation efforts in Russia. The results of this initiative will help inform future policy and management tools to address black carbon emissions from wildfires and agricultural burning in Russia and perhaps additional interested countries.

Grassland Smoke Emission Measurement Supporting Multi-Modeling Framework Simulation of Rangeland Burning Practices for the Kansas Flint Hills Fire Experiment

EPA Science Inventory

Historically, frequent wildfires were essential for the maintenance of native prairie fire adapted ecosystems. Today prescribed fires are used to control invasive woody species and potentially improve forage production in these same prairie ecosystems for the beef-cattle industry...

Postwildfire preliminary debris flow hazard assessment for the area burned by the 2011 Las Conchas Fire in north-central New Mexico

USGS Publications Warehouse

Tillery, Anne C.; Darr, Michael J.; Cannon, Susan H.; Michael, John A.

2011-01-01

The Las Conchas Fire during the summer of 2011 was the largest in recorded history for the state of New Mexico, burning 634 square kilometers in the Jemez Mountains of north-central New Mexico. The burned landscape is now at risk of damage from postwildfire erosion, such as that caused by debris flows and flash floods. This report presents a preliminary hazard assessment of the debris-flow potential from 321 basins burned by the Las Conchas Fire. A pair of empirical hazard-assessment models developed using data from recently burned basins throughout the intermountain western United States was used to estimate the probability of debris-flow occurrence and volume of debris flows at the outlets of selected drainage basins within the burned area. The models incorporate measures of burn severity, topography, soils, and storm rainfall to estimate the probability and volume of debris flows following the fire. In response to a design storm of 28.0 millimeters of rain in 30 minutes (10-year recurrence interval), the probabilities of debris flows estimated for basins burned by the Las Conchas Fire were greater than 80 percent for two-thirds (67 percent) of the modeled basins. Basins with a high (greater than 80 percent) probability of debris-flow occurrence were concentrated in tributaries to Santa Clara and Rio del Oso Canyons in the northeastern part of the burned area; some steep areas in the Valles Caldera National Preserve, Los Alamos, and Guaje Canyons in the east-central part of the burned area; tributaries to Peralta, Colle, Bland, and Cochiti canyons in the southwestern part of the burned area; and tributaries to Frijoles, Alamo, and Capulin Canyons in the southeastern part of the burned area (within Bandelier National Monument). Estimated debris-flow volumes ranged from 400 cubic meters to greater than 72,000 cubic meters. The largest volumes (greater than 40,000 cubic meters) were estimated for basins in Santa Clara, Los Alamos, and Water Canyons, and for two basins at the northeast edge of the burned area tributary to Rio del Oso and Vallecitos Creek. The Combined Relative Debris-Flow Hazard Rankings identify the areas of highest probability of the largest debris flows. Basins with high Combined Relative Debris-Flow Hazard Rankings include upper Santa Clara Canyon in the northern section of the burn scar, and portions of Peralta, Colle, Bland, Cochiti, Capulin, Alamo, and Frijoles Canyons in the southern section of the burn scar. Three basins with high Combined Relative Debris-Flow Hazard Rankings also occur in areas upstream from the city of Los Alamos—the city is home to and surrounded by numerous technical sites for the Los Alamos National Laboratory. Potential debris flows in the burned area could affect the water supply for Santa Clara Pueblo and several recreational lakes, as well as recreational and archeological resources in Bandelier National Monument. Debris flows could damage bridges and culverts along State Highway 501 and other roadways. Additional assessment is necessary to determine if the estimated volume of material is sufficient to travel into areas downstream from the modeled basins along the valley floors, where they could affect human life, property, agriculture, and infrastructure in those areas. Additionally, further investigation is needed to assess the potential for debris flows to affect structures at or downstream from basin outlets and to increase the threat of flooding downstream by damaging or blocking flood mitigation structures. The maps presented here may be used to prioritize areas where erosion mitigation or other protective measures may be necessary within a 2- to 3-year window of vulnerability following the Las Conchas Fire.

Characterization of biomass burning aerosols produced in the laboratory with a light-scattering aerosol mass spectrometer

NASA Astrophysics Data System (ADS)

Middlebrook, A. M.; Adler, G. A.; Coggon, M.; De Gouw, J. A.; Franchin, A.; Gilman, J.; Koss, A.; Krechmer, J. E.; Lamb, K.; Manfred, K.; Roberts, J. M.; Schwarz, J. P.; Sekimoto, K.; Selimovic, V.; Stockwell, C.; Wagner, N.; Warneke, C.; Washenfelder, R. A.; Womack, C.; Yokelson, R. J.; Yuan, B.

2017-12-01

During the 2016 NOAA FIREX project at the Missoula Fire Sciences Laboratory, small fires of known fuel type and properties were ignited to characterize their direct emissions with a large variety of new sampling methods. Two types of experiments were employed: sampling smoke directly from the exhaust stack throughout the lifecycle of the fires (stack burns) or sampling when the exhaust vent was closed to fill the room with smoke (room burns). For both types of burns, photo-oxidation chambers were at times used to mimic aging in the atmosphere. During all these experiments, we measured the non-refractory components of the smoke particles using an Aerodyne compact time-of-flight aerosol mass spectrometer (AMS) with a light scattering module and diluted the sample line as little as possible (usually by a factor of 10) without overwhelming our instrument. For the stack burns, our AMS was placed near the top of the exhaust stack to capture the composition and size distribution during the rapidly changing stages of the fires. We found that the chemical composition of the aerosols varied with fuel type and combustion conditions on time scales of a few minutes as the fuels went through different stages of heating and combustion. For the room burns, we obtained additional measurements with the light-scattering module aimed at understanding how well smoke particles are measured with the AMS, along with characterization of their physical properties. We will present a summary of our results, with connections to their relevance for constraining model treatments of fire emissions on the atmosphere.

Fire decreases arthropod abundance but increases diversity: early and late season prescribed fire effects in a Sierra Nevada mixed-conifer forest

Treesearch

Scott M. Ferrenberg; Dylan W. Schwilk; Eric E. Knapp; Eric Groth; Jon E. Keeley

2006-01-01

Prior to fire suppression in the 20th century, the mixed-conifer forests of the Sierra Nevada, California, U.S.A., historically burned in frequent fires that typically occurred during the late summer and early fall. Fire managers have been attempting to restore natural ecosystem processes through prescription burning, and have often favored burning during the fall in...

Evaluation of the composite burn index for assessing fire severity in Alaskan black spruce forests

Treesearch

Eric S. Kasischke; Merritt R. Turetsky; Roger D. Ottmar; Nancy H.F. French; Elizabeth E. Hoy; Evan S. Kane

2008-01-01

We evaluated the utility of the composite burn index (CBI) for estimating fire severity in Alaskan black spruce forests by comparing data from 81 plots located in 2004 and 2005 fire events. We collected data to estimate the CBI and quantify crown damage, percentage of trees standing after the fire, depth of the organic layer remaining after the fire, depth of burning...

Experimental Constraints on Iron Mobilization into Biomass Burning Aerosols

NASA Astrophysics Data System (ADS)

Sherry, A. M.; Romaniello, S. J.; Herckes, P.; Anbar, A. D.

2017-12-01

Atmospheric deposition of iron (Fe) can limit marine primary productivity and, therefore, carbon dioxide uptake. Recent modeling studies suggest that biomass burning aerosols may contribute a significant amount of soluble Fe to the surface ocean. To address this hypothesis, we collected foliage samples from species representative of several biomes impacted by severe fire events. Existing studies of burn-induced trace element mobilization have often collected both entrained soil particles along with material from burning biomass, making it difficult to determine the actual source of aerosolized trace metals. In order to better constrain the importance of biomass vs. entrained soil as a source of trace metals in burn aerosols, we conducted burn experiments using soil-free foliage representative of a variety of fire-impacted ecosystems. The resulting burn aerosols were collected in two stages (PM > 2.5 μm and PM < 2.5 μm) on cellulose filters using a high-volume air sampler equipped an all-Teflon impactor. Unburned foliage and burn aerosols were analyzed for Fe and other trace metals using inductively coupled plasma mass spectrometry (ICP-MS). Our results show that 0.06-0.86 % of Fe in plant biomass is likely mobilized as atmospheric aerosols during biomass burning events, depending on the type of foliage. We used these results and estimates of annual global wildfire area to estimate the impact of biomass burning aerosols on total atmospheric Fe flux to the ocean. We estimate that biomass-derived Fe likely contributes 3% of the total soluble Fe flux from aerosols. Prior studies, which implicitly included both biomass and soil-derived Fe, concluded that biomass burning contributed as much as 7% of the total marine soluble Fe flux from aerosols. Together, these studies suggest that biomass and fire-entrained soil probably contribute equally to the total fire-derived Fe aerosol flux. Further study of solubility differences between plant- and soil-derived Fe is needed to improve estimates of the soluble Fe contribution from biomass burning to the marine soluble Fe flux.

Convergence of bark investment according to fire and climate structures ecosystem vulnerability to future change.

PubMed

Pellegrini, Adam F A; Anderegg, William R L; Paine, C E Timothy; Hoffmann, William A; Kartzinel, Tyler; Rabin, Sam S; Sheil, Douglas; Franco, Augusto C; Pacala, Stephen W

2017-03-01

Fire regimes in savannas and forests are changing over much of the world. Anticipating the impact of these changes requires understanding how plants are adapted to fire. In this study, we test whether fire imposes a broad selective force on a key fire-tolerance trait, bark thickness, across 572 tree species distributed worldwide. We show that investment in thick bark is a pervasive adaptation in frequently burned areas across savannas and forests in both temperate and tropical regions where surface fires occur. Geographic variability in bark thickness is largely explained by annual burned area and precipitation seasonality. Combining environmental and species distribution data allowed us to assess vulnerability to future climate and fire conditions: tropical rainforests are especially vulnerable, whereas seasonal forests and savannas are more robust. The strong link between fire and bark thickness provides an avenue for assessing the vulnerability of tree communities to fire and demands inclusion in global models. © 2017 John Wiley & Sons Ltd/CNRS.

Soil geochemistry controls fire severity: A soil approach to improved understanding of forest fire consequences in southwest Montana.

NASA Astrophysics Data System (ADS)

Callahan, R.; Hartshorn, T.

2014-12-01

Fire severity can be defined using satellite imagery to ratio mid (~2.2 um) to near (~0.8 um) infrared reflectance values. We examined how lithology and topography affected burn severity, and how post-fire soils data could be used to ground-truth burn severity at two sites in southwestern Montana. A burned area reflectance classification (BARC), lithology, and terrain attributes were used to predict burn severity for the Millie Fire, which was triggered two years ago by lightning and burned ~4,000 ha. Burn severity showed a strong dependence on lithology: the ratio of areas with high burn severity vs. low or moderate burn severities was 2.9 for gneiss (vs. 0.3 for volcanics). The high-severity burn area for the gneiss was larger than the volcanics, despite the latter lithology covering ~270% greater area (~2,600 ha). Aspect and elevation also influenced burn severity with lower severity at higher elevations (2,600-3,000 m) and higher severity at lower elevations (1,800-2,400 m). Southern and western aspects burned more severely than northern and eastern aspects. To clarify whether post-fire soil geochemical changes might predict ground-based estimates of fire severity, a lab experiment was carried out . We expected residual enrichment of trace metal concentrations, as soil organic matter (SOM) was combusted, which we quantified as loss on ignition (LOI). To test this approach, burned and unburned soils were sampled from the ~6000 ha Beartrap 2 fire, which also burned two years. We simulated differing fire severities on unburned soil using a muffle furnace factorially (duration [5, 15, 30, 45, or 60 minutes] x temperature [50, 100, 200, 300, 400, or 500ºC]). Consistent with expectations, unburned samples had a lower mean (±1SD) concentrations for 23 of 30 elements than field-burned samples. For example, barium concentrations ([Ba]) in unburned samples were (708±37μg/g), 16% lower than field-burned [Ba] (841±7 μg/g). Simulated burning yielded smaller [Ba] (732±9 μg/g). Of the 30 trace metals examined, barium explained the greatest fraction of variance in post-burn LOI (R2 =0.79); gallium explained slightly less variance (R2=0.67). Our results document the promise of post-burn soil geochemistry to indicate soil burn severity, which could complement vegetation-based and remotely sensed indices.

Is proportion burned severely related to daily area burned?

Treesearch

Donovan S. Birch; Penelope Morgan; Crystal A. Kolden; Andrew T. Hudak; Alistair M. S. Smith

2014-01-01

The ecological effects of forest fires burning with high severity are long-lived and have the greatest impact on vegetation successional trajectories, as compared to low-to-moderate severity fires. The primary drivers of high severity fire are unclear, but it has been hypothesized that wind-driven, large fire-growth days play a significant role, particularly on large...

Monitoring a boreal wildfire using multi-temporal Radarsat-1 intensity and coherence images

USGS Publications Warehouse

Rykhus, Russell P.; Lu, Zhong

2011-01-01

Twenty-five C-band Radarsat-1 synthetic aperture radar (SAR) images acquired from the summer of 2002 to the summer of 2005 are used to map a 2003 boreal wildfire (B346) in the Yukon Flats National Wildlife Refuge, Alaska under conditions of near-persistent cloud cover. Our analysis is primarily based on the 15 SAR scenes acquired during arctic growing seasons. The Radarsat-1 intensity data are used to map the onset and progression of the fire, and interferometric coherence images are used to qualify burn severity and monitor post-fire recovery. We base our analysis of the fire on three test sites, two from within the fire and one unburned site. The B346 fire increased backscattered intensity values for the two burn study sites by approximately 5–6 dB and substantially reduced coherence from background levels of approximately 0.8 in unburned background forested areas to approximately 0.2 in the burned area. Using ancillary vegetation information from the National Land Cover Database (NLCD) and information on burn severity from Normalized Burn Ratio (NBR) data, we conclude that burn site 2 was more severely burned than burn site 1 and that C-band interferometric coherence data are useful for mapping landscape changes due to fire. Differences in burn severity and topography are determined to be the likely reasons for the observed differences in post-fire intensity and coherence trends between burn sites.

Impacts of Wildfires on Long-term Land Surface Phenology

NASA Astrophysics Data System (ADS)

Wang, J.; Zhang, X.

2016-12-01

Land surface phenology (LSP) detected from satellite data characterizes seasonal dynamics of vegetation communities within a moderate or coarse resolution pixel. Its long-term variation has been widely used to indicate the biological responses to climate changes. However, few studies have focused on the influence of land disturbance on LSP variations. The wildfire is one of the most important drivers of land disturbances across the world, which shows an increasing trend during past decades. To explore the wildfire impacts on LSP, we analyzed post-fire and pre-fire LSP in two forest fire events that are Hayman Fire occurred in 2002 and Mason Fire occurred in 2005 in Colorado. Specifically, we first generated a two band enhanced vegetation index (EVI2) from MODIS daily surface reflectance product (MOD09GQ) at a spatial resolution of 250 m from 2001-2014. The time series of daily EVI2 was then used to detect the start of growing season (SOS) by applying the LSP detection algorithm based on a hybrid piecewise logistic model (HPLM-LSPD). The SOS was further separated for four levels of burn severity obtained from Monitoring Trends in Burn Severity (MTBS) maps for each fire event. The long-term SOS in the burn scars was finally deviated from surrounding areas based on land cover types. Results show that forests were mainly converted to shrubs in both fire events with some grasslands in Hayman. On average, SOS in Hayman burn scar area was advanced 11 days relative to surrounding region while it was delayed 9 days in Mason fire. The deviation also varied with the burn severity spatially. Moreover, the long-term SOS trend in the local area from 2001-2014 was significantly different with and without considerations of the fire influences. This study demonstrates that the long-term LSP SOS trend is significantly influenced by land disturbances in a local and regional scales.

A project for monitoring trends in burn severity

USGS Publications Warehouse

Eidenshink, Jeffery C.; Schwind, Brian; Brewer, Ken; Zhu, Zhu-Liang; Quayle, Brad; Howard, Stephen M.

2007-01-01

Jeff Eidenshink, Brian Schwind, Ken Brewer, Zhi-Liang Zhu, Brad Quayle, and Elected officials and leaders of environmental agencies need information about the effects of large wildfires in order to set policy and make management decisions. Recently, the Wildland Fire Leadership Council (WFLC), which implements and coordinates the National Fire Plan (NFP) and Federal Wildland Fire Management Policies (National Fire Plan 2004), adopted a strategy to monitor the effectiveness of the National Fire Plan and the Healthy Forests Restoration Act (HFRA). One component of this strategy is to assess the environmental impacts of large wildland fires and identify the trends of burn severity on all lands across the United States. To that end, WFLC has sponsored a six-year project, Monitoring Trends in Burn Severity (MTBS), which requires the U.S. Department of Agriculture Forest Service (USDA-FS) and the U.S. Geological Survey (USGS) to map and assess the burn severity for all large current and historical fires. Using Landsat data and the differenced Normalized Burn Ratio (dNBR) algorithm, the USGS Center for Earth Resources Observation and Science (EROS) and USDA-FS Remote Sensing Applications Center will map burn severity of all fires since 1984 greater than 202 ha (500ac) in the east, and 404 ha (1,000 ac) in the west. The number of historical fires from this period combined with current fires occurring during the course of the project will exceed 9,000. The MTBS project will generate burn severity data, maps, and reports, which will be available for use at local, state, and national levels to evaluate trends in burn severity and help develop and assess the effectiveness of land management decisions. Additionally, the information developed will provide a baseline from which to monitor the recovery and health of fire-affected landscapes over time. Spatial and tabular data quantifying burn severity will augment existing information used to estimate risk associated with a range of current and future resource threats. The annual report of 2004 fires has been completed. All data and results will be distributed to the public on a Web site. A Project for Monitoring Trends in Burn Severity

Fire management of California shrubland landscapes

USGS Publications Warehouse

Keeley, Jon E.

2002-01-01

Fire management of California shrublands has been heavily influenced by policies designed for coniferous forests, however, fire suppression has not effectively excluded fire from chaparral and coastal sage scrub landscapes and catastrophic wildfires are not the result of unnatural fuel accumulation. There is no evidence that prescribed burning in these shrublands provides any resource benefit and in some areas may negatively impact shrublands by increasing fire frequency. Therefore, fire hazard reduction is the primary justification for prescription burning, but it is doubtful that rotational burning to create landscape age mosaics is a cost effective method of controlling catastrophic wildfires. There are problems with prescription burning in this crown-fire ecosystem that are not shared by forests with a natural surface-fire regime. Prescription weather conditions preclude burning at rotation intervals sufficient to effect the control of fires ignited under severe weather conditions. Fire management should focus on strategic placement of prescription burns to both insure the most efficient fire hazard reduction and to minimize the amount of landscape exposed to unnaturally high fire frequency. A major contributor to increased fire suppression costs and increased loss of property and lives is the continued urban sprawl into wildlands naturally subjected to high intensity crown fires. Differences in shrubland fire history suggest there may be a need for different fire management tactics between central coastal and southern California. Much less is known about shrubland fire history in the Sierra Nevada foothills and interior North Coast Ranges, and thus it would be prudent to not transfer these ideas too broadly across the range of chaparral until we have a clearer understanding of the extent of regional variation in shrubland fire regimes.

Fire management of California shrubland landscapes.

PubMed

Keeley, Jon E

2002-03-01

Fire management of California shrublands has been heavily influenced by policies designed for coniferous forests, however, fire suppression has not effectively excluded fire from chaparral and coastal sage scrub landscapes and catastrophic wildfires are not the result of unnatural fuel accumulation. There is no evidence that prescribed burning in these shrublands provides any resource benefit and in some areas may negatively impact shrublands by increasing fire frequency. Therefore, fire hazard reduction is the primary justification for prescription burning, but it is doubtful that rotational burning to create landscape age mosaics is a cost effective method of controlling catastrophic wildfires. There are problems with prescription burning in this crown-fire ecosystem that are not shared by forests with a natural surface-fire regime. Prescription weather conditions preclude burning at rotation intervals sufficient to effect the control of fires ignited under severe weather conditions. Fire management should focus on strategic placement of prescription burns to both insure the most efficient fire hazard reduction and to minimize the amount of landscape exposed to unnaturally high fire frequency. A major contributor to increased fire suppression costs and increased loss of property and lives is the continued urban sprawl into wildlands naturally subjected to high intensity crown fires. Differences in shrubland fire history suggest there may be a need for different fire management tactics between central coastal and southern California. Much less is known about shrubland fire history in the Sierra Nevada foothills and interior North Coast Ranges, and thus it would be prudent to not transfer these ideas too broadly across the range of chaparral until we have a clearer understanding of the extent of regional variation in shrubland fire regimes.

Seasonal impact of regional outdoor biomass burning on air pollution in three Indian cities: Delhi, Bengaluru, and Pune

NASA Astrophysics Data System (ADS)

Liu, Tianjia; Marlier, Miriam E.; DeFries, Ruth S.; Westervelt, Daniel M.; Xia, Karen R.; Fiore, Arlene M.; Mickley, Loretta J.; Cusworth, Daniel H.; Milly, George

2018-01-01

Air pollution in many of India's cities exceeds national and international standards, and effective pollution control strategies require knowledge of the sources that contribute to air pollution and their spatiotemporal variability. In this study, we examine the influence of a single pollution source, outdoor biomass burning, on particulate matter (PM) concentrations, surface visibility, and aerosol optical depth (AOD) from 2007 to 2013 in three of the most populous Indian cities. We define the upwind regions, or ;airsheds,; for the cities by using atmospheric back trajectories from the HYSPLIT model. Using satellite fire radiative power (FRP) observations as a measure of fire activity, we target pre-monsoon and post-monsoon fires upwind of the Delhi National Capital Region and pre-monsoon fires surrounding Bengaluru and Pune. We find varying contributions of outdoor fires to different air quality metrics. For the post-monsoon burning season, we find that a subset of local meteorological variables (air temperature, humidity, sea level pressure, wind speed and direction) and FRP as the only pollution source explained 39% of variance in Delhi station PM10 anomalies, 77% in visibility, and 30% in satellite AOD; additionally, per unit increase in FRP within the daily airshed (1000 MW), PM10 increases by 16.34 μg m-3, visibility decreases by 0.155 km, and satellite AOD increases by 0.07. In contrast, for the pre-monsoon burning season, we find less significant contributions from FRP to air quality in all three cities. Further, we attribute 99% of FRP from post-monsoon outdoor fires within Delhi's average airshed to agricultural burning. Our work suggests that although outdoor fires are not the dominant air pollution source in India throughout the year, post-monsoon fires contribute substantially to regional air pollution and high levels of population exposure around Delhi. During 3-day blocks of extreme PM2.5 in the 2013 post-monsoon burning season, which coincided with statistically significant high fire activity, concentrations in Delhi averaged 304 μg m-3, or more than 1000% above the 24-h PM2.5 guideline (25 μg m-3) of the World Health Organization. These results suggest that providing viable alternatives to agricultural residue burning could help improve post-monsoon air quality for a growing population of 63 million (39% in urban areas) within Delhi's airshed.

Seasonal Impact of Regional Outdoor Biomass Burning on Air Pollution in Three Indian Cities: Delhi, Bengaluru, and Pune

NASA Technical Reports Server (NTRS)

Liu, Tianjia; Marlier, Miriam E.; DeFries, Ruth S.; Westervelt, Daniel M.; Xia, Karen R.; Fiore, Arlene M.; Mickley, Loretta J.; Cusworth, Daniel H.; Milly, George

2017-01-01

Air pollution in many of India's cities exceeds national and international standards, and effective pollution control strategies require knowledge of the sources that contribute to air pollution and their spatiotemporal variability. In this study, we examine the influence of a single pollution source, outdoor biomass burning, on particulate matter (PM) concentrations, surface visibility, and aerosol optical depth (AOD) from 2007 to 2013 in three of the most populous Indian cities. We define the upwind regions, or "airsheds," for the cities by using atmospheric back trajectories from the HYSPLIT model. Using satellite fire radiative power (FRP) observations as a measure of fire activity, we target pre-monsoon and post-monsoon fires upwind of the Delhi National Capital Region and pre-monsoon fires surrounding Bengaluru and Pune. We find varying contributions of outdoor fires to different air quality metrics. For the post-monsoon burning season, we find that a subset of local meteorological variables (air temperature, humidity, sea level pressure, wind speed and direction) and FRP as the only pollution source explained 39% of variance in Delhi station PM(sub 10) anomalies, 77% in visibility, and 30% in satellite AOD; additionally, per unit increase in FRP within the daily airshed (1000 MW), PM(sub 10) increases by 16.34 micrograms per cubic meter, visibility decreases by 0.097 km, and satellite AOD increases by 0.07. In contrast, for the pre-monsoon burning season, we find less significant contributions from FRP to air quality in all three cities. Further, we attribute 99% of FRP from post-monsoon outdoor fires within Delhi's average airshed to agricultural burning. Our work suggests that although outdoor fires are not the dominant air pollution source in India throughout the year, post-monsoon fires contribute substantially to regional air pollution and high levels of population exposure around Delhi. During 3-day blocks of extreme PM(sub 2.5) in the 2013 post-monsoon burning season, which coincided with statistically significant high fire activity, concentrations in Delhi averaged 304 micrograms per cubic meter, or more than 1000% above the 24-h PM(sub 2.5) guideline (25 micrograms per cubic meter) of the World Health Organization. These results suggest that providing viable alternatives to agricultural residue burning could help improve post-monsoon air quality for a growing population of 63 million (39% in urban areas) within Delhi's airshed.

The estimation of territiry predeposition to wildfires

NASA Astrophysics Data System (ADS)

Panchenko, Ekaterina; Dukarev, Anatoly

2010-05-01

Wildfires have significant environmental effects. The indirect damages because of fires are an emission of various combustion products such as aerosols, greenhouse gases and carcinogen. Analysis of smoke emission show that from 1 ha burning area emitted aerosols from 0.2 to 1 ton. The aim of our research is to estimate biomass burning emission: Biomass Burning Emission=BA x FL x CE x EF, where BA is Burned Area (ha); FL is forest litter cover (cm); CE is Combustion Efficiency (0-1), depends on a class of fire danger; EF is Emission Factor (kg emitted / kg dry-mass burnt). Consequently for estimation of biomass burning emission it is necessary to analyze of territory predisposition to wildfires and give characteristic of combustion material types for detection fire hazard, for prognosis fire origin and extension. Prognosis of occurrence of wildfires and definition of emissions is possible by means of data of depth forest litter, types of vegetation and type of landscapes including concrete weather conditions (seasons, length of arid period, current temperature, wind speed and its direction). The investigated object is the territory Tomskii district near to the city of Tomsk (56° 31 N-85°08 E) - with the population more than 500 thousand people. The conducted analysis of investigated territory and the calculation will be basic prognostic model for researching wildfires.

Fire dynamics during the 20th century simulated by the Community Land Model

NASA Astrophysics Data System (ADS)

Kloster, S.; Mahowald, N. M.; Randerson, J. T.; Thornton, P. E.; Hoffman, F. M.; Levis, S.; Lawrence, P. J.; Feddema, J. J.; Oleson, K. W.; Lawrence, D. M.

2010-01-01

Fire is an integral Earth System process that interacts with climate in multiple ways. Here we assessed the parametrization of fires in the Community Land Model (CLM-CN) and improved the ability of the model to reproduce contemporary global patterns of burned areas and fire emissions. In addition to wildfires we extended CLM-CN to account for fires related to deforestation. We compared contemporary fire carbon emissions predicted by the model to satellite based estimates in terms of magnitude, spatial extent as well as interannual and seasonal variability. Longterm trends during the 20th century were compared with historical estimates. Overall we found the best agreement between simulation and observations for the fire parametrization based on the work by Arora and Boer (2005). We obtain substantial improvement when we explicitly considered human caused ignition and fire suppression as a function of population density. Simulated fire carbon emissions ranged between 2.0 and 2.4 Pg C/year for the period 1997-2004. Regionally the simulations had a low bias over Africa and a high bias over South America when compared to satellite based products. The net terrestrial carbon source due to land use change for the 1990s was 1.2 Pg C/year with 11% stemming from deforestation fires. During 2000-2004 this flux decreased to 0.85 Pg C/year with a similar relative contribution from deforestation fires. Between 1900 and 1960 we simulated a slight downward trend in global fire emissions, which is explained by reduced fuels as a consequence of wood harvesting and partly by increasing fire suppression. The model predicted an upward trend in the last three decades of the 20th century caused by climate variations and large burning events associated with ENSO induced drought conditions.

Fire dynamics during the 20th century simulated by the Community Land Model

NASA Astrophysics Data System (ADS)

Kloster, S.; Mahowald, N. M.; Randerson, J. T.; Thornton, P. E.; Hoffman, F. M.; Levis, S.; Lawrence, P. J.; Feddema, J. J.; Oleson, K. W.; Lawrence, D. M.

2010-06-01

Fire is an integral Earth System process that interacts with climate in multiple ways. Here we assessed the parametrization of fires in the Community Land Model (CLM-CN) and improved the ability of the model to reproduce contemporary global patterns of burned areas and fire emissions. In addition to wildfires we extended CLM-CN to account for fires related to deforestation. We compared contemporary fire carbon emissions predicted by the model to satellite-based estimates in terms of magnitude and spatial extent as well as interannual and seasonal variability. Long-term trends during the 20th century were compared with historical estimates. Overall we found the best agreement between simulation and observations for the fire parametrization based on the work by Arora and Boer (2005). We obtained substantial improvement when we explicitly considered human caused ignition and fire suppression as a function of population density. Simulated fire carbon emissions ranged between 2.0 and 2.4 Pg C/year for the period 1997-2004. Regionally the simulations had a low bias over Africa and a high bias over South America when compared to satellite-based products. The net terrestrial carbon source due to land use change for the 1990s was 1.2 Pg C/year with 11% stemming from deforestation fires. During 2000-2004 this flux decreased to 0.85 Pg C/year with a similar relative contribution from deforestation fires. Between 1900 and 1960 we predicted a slight downward trend in global fire emissions caused by reduced fuels as a consequence of wood harvesting and also by increases in fire suppression. The model predicted an upward trend during the last three decades of the 20th century as a result of climate variations and large burning events associated with ENSO-induced drought conditions.

Ground Penetrating Radar, a Method for Exploration and Monitoring of Coal Fires in China

NASA Astrophysics Data System (ADS)

Gundelach, Volker

2010-05-01

Due to the climate change it is a global task to fight against gas emission of coal fires. In China exists many burning coal seams which should be extinguished. A Chinese-German initiative tries to find new technologies and solutions to control these fires. Most of the fires are close to the surface in arid areas. In that case GPR is a possible geophysical method to get detailed information about the structure of the soil. Mining activities and the burning coal are leaving voids which collapse or still exist as dangerous areas. With GPR it is possible to detect voids and clefts. Crevices are potential paths for oxygen transport from the surface to the fire. The knowledge of these structures would help to extinguish the fire. The heat of the burning coal changes the permittivity and the conductivity of the rock. This affects the radar signal and makes it possible to separate burning zones from intact zones. Monitoring of the burning zones helps to find optimal solutions for fire extinguishing strategies. Several field campaigns were made in China. One campaign was in the province Xinjiang with a 50 MHz system from Mala on a steep dipping coal seam. Other campaigns were in the Inner Mongolia with 40 MHz to 200 MHz antennae from GSSI on shallow dipping coal seams. The experiences from these measurements will be shown. The surveys were collected in rough terrain. The data from the unshielded antennae contained a lot of effects coming through the air. The limits of detecting crevices with GPR will be demonstrated. Some parts of the measurements over burning coal were influenced by strong anomalies of the magnetization. Modeling of the radar signal helps at the interpretation. Parts of the interpretation from the surveys can be validated by the outcrop of the investigated structures. A spatial visualization of the results is the basis for discussions.

Forest edge burning in the Brazilian Amazon promoted by escaping fires from managed pastures

NASA Astrophysics Data System (ADS)

Cano-Crespo, Ana; Oliveira, Paulo J. C.; Boit, Alice; Cardoso, Manoel; Thonicke, Kirsten

2015-10-01

Understanding to what extent different land uses influence fire occurrence in the Amazonian forest is particularly relevant for its conservation. We evaluate the relationship between forest fires and different anthropogenic activities linked to a variety of land uses in the Brazilian states of Mato Grosso, Pará, and Rondônia. We combine the new high-resolution (30 m) TerraClass land use database with Moderate Resolution Imaging Spectroradiometer burned area data for 2008 and the extreme dry year of 2010. Excluding the non-forest class, most of the burned area was found in pastures, primary and secondary forests, and agricultural lands across all three states, while only around 1% of the total was located in deforested areas. The trend in burned area did not follow the declining deforestation rates from 2001 to 2010, and the spatial overlap between deforested and burned areas was only 8% on average. This supports the claim of deforestation being disconnected from burning since 2005. Forest degradation showed an even lower correlation with burned area. We found that fires used in managing pastoral and agricultural lands that escape into the neighboring forests largely contribute to forest fires. Such escaping fires are responsible for up to 52% of the burned forest edges adjacent to burned pastures and up to 22% of the burned forest edges adjacent to burned agricultural fields, respectively. Our findings call for the development of control and monitoring plans to prevent fires from escaping from managed lands into forests to support effective land use and ecosystem management.

The Impact of Increasing Fire Frequency on Forest Transformations in the Zabaikal Region, Southern Siberia

NASA Astrophysics Data System (ADS)

Conard, S. G.; Kukavskaya, E. A.; Buryak, L. V.; Shvetsov, E.; Kalenskaya, O. P.; Zhila, S.

2017-12-01

The Zabaikal region of southern Siberia is characterized by some of the highest fire activity in Russia. There has been a significant increase of fire frequency and burned area in the region over the last two decades due to a combination of high anthropogenic pressure, decreased funding to the forestry sector, and increased fire danger, which was associated with higher frequency and intensity of extreme weather events. Central and southern parts of the Zabaikal region where population density is higher and road network is relatively more developed are the most disturbed by fires. Larch stands cover the largest proportion of fire-disturbed lands in the region, while the less common pine and birch stands are characterized by higher fire frequency. About 13% (3.9 M ha) of the total forest area in the Zabaikal region was burned more than once in the 20 years from 1996 to 2015, with many sites burned multiple times. Repeat disturbances led to inadequate tree regeneration on all but the moistest sites. Pine stands on dry soils, which are common in the forest-steppe zone, were the most vulnerable. After repeat burns and over large burned sites we observed transformation of the forests to steppe ecosystems. The most likely causes of insufficient forest regeneration are soil overheating, dominance of tall grasses, and lack of nearby seed sources. Extensive tree plantations have potential to mitigate negative fire impacts; however, due to high fire hazard in the recent decade about half of the plantation area has been burned. Changes in the SWVI index were used to assess postfire reforestation based on a combination of satellite and field data. In the southwestern part of the Zabaikal region, we estimated that reforestation had been hampered over 11% of the forest land area. Regional climate models project increasing temperatures and decreasing precipitation across Siberia by the end of the 21st century, with changes in the Zabaikal region projected to be more than twice the average rate in Siberia. This would likely lead to higher fire activity in the region. Implementation of sustainable forest management strategies has the potential to mitigate effects of changing climate and fire regimes on forest ecosystems in the Zabaikal region. This research was supported by the RFBR grant (# 15-04-06567) and the NASA LCLUC Program.

Mapping burn severity, pine beetle infestation, and their interaction at the High Park Fire

NASA Astrophysics Data System (ADS)

Stone, Brandon

North America's western forests are experiencing wildfire and mountain pine beetle (MPB) disturbances that are unprecedented in the historic record, but it remains unclear whether and how MPB infestation influences post-infestation fire behavior. The 2012 High Park Fire burned in an area that's estimated to have begun a MPB outbreak cycle within five years before the wildfire, resulting in a landscape in which disturbance interactions can be studied. A first step in studying these interactions is mapping regions of beetle infestation and post-fire disturbance. We implemented an approach for mapping beetle infestation and burn severity using as source data three 5 m resolution RapidEye satellite images (two pre-fire, one post-fire). A two-tiered methodology was developed to overcome the spatial limitations of many classification approaches through explicit analyses at both pixel and plot level. Major land cover classes were photo-interpreted at the plot-level and their spectral signature used to classify 5 m images. A new image was generated at 25 m resolution by tabulating the fraction of coincident 5 m pixels in each cover class. The original photo interpretation was then used to train a second classification using as its source image the new 25 m image. Maps were validated using k-fold analysis of the original photo interpretation, field data collected immediately post-fire, and publicly available classifications. To investigate the influence of pre-fire beetle infestation on burn severity within the High Park Fire, we fit a log-linear model of conditional independence to our thematic maps after controlling for forest cover class and slope aspect. Our analysis revealed a high co-occurrence of severe burning and beetle infestation within high elevation lodgepole pine stands, but did not find statistically significant evidence that infected stands were more likely to burn severely than similar uninfected stands. Through an inspection of the year-to-year changes in the class fraction signatures of pixels classified as MPB infestation, we were able to observe increases in infection extent and intensity in the year before the fire. The resulting maps will help to increase our understanding of the process that contributed to the High Park Fire, and we believe that the novel classification approach will allow for improved characterization of forest disturbances.

Impact of anomalous forest fire on aerosol radiative forcing and snow cover over Himalayan region

NASA Astrophysics Data System (ADS)

Bali, Kunal; Mishra, Amit Kumar; Singh, Sachchidanand

2017-02-01

Forest fires are very common in tropical region during February-May months and are known to have significant impact on ecosystem dynamics. Moreover, aerosols emitted from these burning activities significantly modulate the Earth's radiation budget. In present study, we investigated the anomalous forest fire events and their impact on atmospheric radiation budget and glaciated snow cover over the Himalayan region. We used multiple dataset derived from satellites [Moderate Resolution Spectroradiometer (MODIS) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO)] and reanalysis models [Global Fire Assimilation System (GFAS), Second Modern-Era Retrospective analysis for Research and Application (MERRA-2) and ERA-interim] to evaluate the effect of biomass burning aerosols on radiation budget. April 2016 is associated with anomalous fire activities over lower Himalayan region in the last fourteen years (2003-2016). The model estimated organic carbon (OC) and black carbon (BC) emission reaches up to ∼3 × 104 and ∼2 × 103 μg/m2/day, respectively during the biomass burning period of April 2016. The meteorological data analysis accompanied with CALIOP aerosol vertical profile shows that these carbonaceous aerosols could reach up to ∼5-7 km altitude and could be transported towards glaciated region of upper Himalayas. The large amount of BC/OC from biomass burning significantly modulates the atmospheric radiation budget. The estimated columnar heating rate shows that these carbonaceous aerosols could heat up the atmosphere by ∼0.04-0.06 K/day in April-2016 with respect to non-burning period (2015). The glaciated snow cover fractions are found to be decreasing by ∼5-20% in 2016 as compared to long term mean (2003-2016). The combined analyses of various climatic factors, fires and associated BC emissions show that the observed snow cover decrease could be results of increased surface/atmospheric temperature due to combined effect of large scale climatic changes and BC absorption. Our results suggest that biomass burning can have significant effects on the Himalayan region, particularly in view of its importance in hydrological cycle and ecosystem.

Wildfire risk in the wildland-urban interface: A simulation study in northwestern Wisconsin

USGS Publications Warehouse

Massada, Avi Bar; Radeloff, Volker C.; Stewart, Susan I.; Hawbaker, Todd J.

2009-01-01

The rapid growth of housing in and near the wildland–urban interface (WUI) increases wildfirerisk to lives and structures. To reduce fire risk, it is necessary to identify WUI housing areas that are more susceptible to wildfire. This is challenging, because wildfire patterns depend on fire behavior and spread, which in turn depend on ignition locations, weather conditions, the spatial arrangement of fuels, and topography. The goal of our study was to assess wildfirerisk to a 60,000 ha WUI area in northwesternWisconsin while accounting for all of these factors. We conducted 6000 simulations with two dynamic fire models: Fire Area Simulator (FARSITE) and Minimum Travel Time (MTT) in order to map the spatial pattern of burn probabilities. Simulations were run under normal and extreme weather conditions to assess the effect of weather on fire spread, burn probability, and risk to structures. The resulting burn probability maps were intersected with maps of structure locations and land cover types. The simulations revealed clear hotspots of wildfire activity and a large range of wildfirerisk to structures in the study area. As expected, the extreme weather conditions yielded higher burn probabilities over the entire landscape, as well as to different land cover classes and individual structures. Moreover, the spatial pattern of risk was significantly different between extreme and normal weather conditions. The results highlight the fact that extreme weather conditions not only produce higher fire risk than normal weather conditions, but also change the fine-scale locations of high risk areas in the landscape, which is of great importance for fire management in WUI areas. In addition, the choice of weather data may limit the potential for comparisons of risk maps for different areas and for extrapolating risk maps to future scenarios where weather conditions are unknown. Our approach to modeling wildfirerisk to structures can aid fire risk reduction management activities by identifying areas with elevated wildfirerisk and those most vulnerable under extreme weather conditions.

CALIOP-based Biomass Burning Smoke Plume Injection Height

NASA Astrophysics Data System (ADS)

Soja, A. J.; Choi, H. D.; Fairlie, T. D.; Pouliot, G.; Baker, K. R.; Winker, D. M.; Trepte, C. R.; Szykman, J.

2017-12-01

Carbon and aerosols are cycled between terrestrial and atmosphere environments during fire events, and these emissions have strong feedbacks to near-field weather, air quality, and longer-term climate systems. Fire severity and burned area are under the control of weather and climate, and fire emissions have the potential to alter numerous land and atmospheric processes that, in turn, feedback to and interact with climate systems (e.g., changes in patterns of precipitation, black/brown carbon deposition on ice/snow, alteration in landscape and atmospheric/cloud albedo). If plume injection height is incorrectly estimated, then the transport and deposition of those emissions will also be incorrect. The heights to which smoke is injected governs short- or long-range transport, which influences surface pollution, cloud interaction (altered albedo), and modifies patterns of precipitation (cloud condensation nuclei). We are working with the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) science team and other stakeholder agencies, primarily the Environmental Protection Agency and regional partners, to generate a biomass burning (BB) plume injection height database using multiple platforms, sensors and models (CALIOP, MODIS, NOAA HMS, Langley Trajectory Model). These data have the capacity to provide enhanced smoke plume injection height parameterization in regional, national and international scientific and air quality models. Statistics that link fire behavior and weather to plume rise are crucial for verifying and enhancing plume rise parameterization in local-, regional- and global-scale models used for air quality, chemical transport and climate. Specifically, we will present: (1) a methodology that links BB injection height and CALIOP air parcels to specific fires; (2) the daily evolution of smoke plumes for specific fires; (3) plumes transport and deposited on the Greenland Ice Sheet; and (4) compare CALIOP-derived smoke plume injection to CMAQ modeled smoke plume injection. These results have the potential to provide value to national and international modeling communities (scientific and air quality) and to public land, fire, and air quality management and regulations communities.

Large, high-intensity fire events in southern California shrublands: debunking the fine-grain age patch model.

PubMed

Keeley, Jon E; Zedler, Paul H

2009-01-01

We evaluate the fine-grain age patch model of fire regimes in southern California shrublands. Proponents contend that the historical condition was characterized by frequent small to moderate size, slow-moving smoldering fires, and that this regime has been disrupted by fire suppression activities that have caused unnatural fuel accumulation and anomalously large and catastrophic wildfires. A review of more than 100 19th-century newspaper reports reveals that large, high-intensity wildfires predate modern fire suppression policy, and extensive newspaper coverage plus first-hand accounts support the conclusion that the 1889 Santiago Canyon Fire was the largest fire in California history. Proponents of the fine-grain age patch model contend that even the very earliest 20th-century fires were the result of fire suppression disrupting natural fuel structure. We tested that hypothesis and found that, within the fire perimeters of two of the largest early fire events in 1919 and 1932, prior fire suppression activities were insufficient to have altered the natural fuel structure. Over the last 130 years there has been no significant change in the incidence of large fires greater than 10,000 ha, consistent with the conclusion that fire suppression activities are not the cause of these fire events. Eight megafires (> or = 50,000 ha) are recorded for the region, and half have occurred in the last five years. These burned through a mosaic of age classes, which raises doubts that accumulation of old age classes explains these events. Extreme drought is a plausible explanation for this recent rash of such events, and it is hypothesized that these are due to droughts that led to increased dead fine fuels that promoted the incidence of firebrands and spot fires. A major shortcoming of the fine-grain age patch model is that it requires age-dependent flammability of shrubland fuels, but seral stage chaparral is dominated by short-lived species that create a dense surface layer of fine fuels. Results from the Behave Plus fire model with a custom fuel module for young chaparral shows that there is sufficient dead fuel to spread fire even under relatively little winds. Empirical studies of fuel ages burned in recent fires illustrate that young fuels often comprise a major portion of burned vegetation, and there is no difference between evergreen chaparral and semi-deciduous sage scrub. It has also been argued that the present-day fire size distribution in northern Baja California is a model of the historical patterns that were present on southern California landscapes. Applying this model with historical fire frequencies shows that the Baja model is inadequate to maintain these fire-prone ecosystems and further demonstrates that fire managers in southern California are not likely to learn much from studying modern Baja California fire regimes. Further supporting this conclusion are theoretical cellular automata models of fire spread, which show that, even in systems with age dependent flammability, landscapes evolve toward a complex age mosaic with a plausible age structure only when there is a severe stopping rule that constrains fire size, and only if ignitions are saturating.

Large, high-intensity fire events in Southern California shrublands: Debunking the fine-grain age patch model

USGS Publications Warehouse

Keeley, J.E.; Zedler, P.H.

2009-01-01

We evaluate the fine-grain age patch model of fire regimes in southern California shrublands. Proponents contend that the historical condition was characterized by frequent small to moderate size, slow-moving smoldering fires, and that this regime has been disrupted by fire suppression activities that have caused unnatural fuel accumulation and anomalously large and catastrophic wildfires. A review of more than 100 19th-century newspaper reports reveals that large, high-intensity wildfires predate modern fire suppression policy, and extensive newspaper coverage plus first-hand accounts support the conclusion that the 1889 Santiago Canyon Fire was the largest fire in California history. Proponents of the fine-grain age patch model contend that even the very earliest 20th-century fires were the result of fire suppression disrupting natural fuel structure. We tested that hypothesis and found that, within the fire perimeters of two of the largest early fire events in 1919 and 1932, prior fire suppression activities were insufficient to have altered the natural fuel structure. Over the last 130 years there has been no significant change in the incidence of large fires greater than 10000 ha, consistent with the conclusion that fire suppression activities are not the cause of these fire events. Eight megafires (???50 000 ha) are recorded for the region, and half have occurred in the last five years. These burned through a mosaic of age classes, which raises doubts that accumulation of old age classes explains these events. Extreme drought is a plausible explanation for this recent rash of such events, and it is hypothesized that these are due to droughts that led to increased dead fine fuels that promoted the incidence of firebrands and spot fires. A major shortcoming of the fine-grain age patch model is that it requires age-dependent flammability of shrubland fuels, but seral stage chaparral is dominated by short-lived species that create a dense surface layer of fine fuels. Results from the Behave Plus fire model with a custom fuel module for young chaparral shows that there is sufficient dead fuel to spread fire even under relatively little winds. Empirical studies of fuel ages burned in recent fires illustrate that young fuels often comprise a major portion of burned vegetation, and there is no difference between evergreen chaparral and semi-deciduous sage scrub. It has also been argued that the present-day fire size distribution in northern Baja California is a model of the historical patterns that were present on southern California landscapes. Applying this model with historical fire frequencies shows that the Baja model is inadequate to maintain these fire-prone ecosystems and further demonstrates that fire managers in southern California are not likely to learn much from studying modern Baja California fire regimes. Further supporting this conclusion are theoretical cellular automata models of fire spread, which show that, even in systems with age dependent flammability, landscapes evolve toward a complex age mosaic with a plausible age structure only when there is a severe stopping rule that constrains fire size, and only if ignitions are saturating. ?? 2009 by the Ecological Society of America.

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.

Effect of Tundra Fires on Stream Chemistry in Alaska's Yukon-Kuskokwim Delta

NASA Astrophysics Data System (ADS)

Jimmie, J. A.; Mann, P. J.; Schade, J. D.; Natali, S.; Fiske, G.; Holmes, R. M.

2017-12-01

Surface air temperatures in the Arctic have been increasing at approximately twice the global average, contributing to myriad changes including shifting vegetation, thawing permafrost, and altered surface and groundwater hydrology. Wildfire frequency and intensity has also been increasing, and in summer 2015, more area burned in the Yukon-Kuskowkwim Delta than in the previous 64 years combined. We investigated the impact of tundra fire on stream water chemistry, and by extension, on the movement of nutrients and organic matter between terrestrial and aquatic ecosystems. Using a high-resolution Digital Elevation Model, we characterized the contributing sub-watershed area at each of our stream water sampling locations and calculated the percent of each sub-watershed that was burned in summer 2015. We found that nitrate, ammonium, and phosphate concentrations increased with burn area in a watershed, indicating that terrestrial inputs of these constituents to aquatic systems increased following fire. Patterns were less striking for dissolved organic carbon and dissolved organic nitrogen, but there was a positive relationship between burn area and the concentration of these constituents as well. These results highlight the significant impact of tundra fires on terrestrial-aquatic linkages in the Arctic, and suggest that these impacts may increase in the future if fire in Arctic and boreal regions continues to become more common.

Seasonal Fluctuation in Moisture Content of Pine Foliage

Treesearch

Von J. Johnson

1966-01-01

Green or living fuels, particularly pine crowns, are commonly consumed by forest fires burning hot, windy weather. In some cases the pine crown fire has been known to burn ahead of surface-burning fire for some distance before dropping to the ground.

Effectiveness of protected areas in mitigating fire within their boundaries: case study of Chiapas, Mexico.

PubMed

Román-Cuesta, María Rosa; Martínez-Vilalta, Jordi

2006-08-01

Since the severe 1982-1983 El Niño drought, recurrent burning has been reported inside tropical protected areas (TPAs). Despite the key role of fire in habitat degradation, little is known about the effectiveness of TPAs in mitigating fire incidence and burned areas. We used a GPS fire database (1995-2005) (n=3590 forest fires) obtained from the National Forest Commission to compare fire incidence (number of fires) and burned areas inside TPAs and their surrounding adjacent buffer areas in Southern Mexico (Chiapas). Burned areas inside parks ranged from 2% (Palenque) to 45% (Lagunas de Montebello) of a park's area, and the amount burned was influenced by two severe El Niño events (1998 and 2003). These two years together resulted in 67% and 46% of the total area burned in TPAs and buffers, respectively during the period under analysis. Larger burned areas in TPAs than in their buffers were exclusively related to the extent of natural habitats (flammable area excluding agrarian and pasture lands). Higher fuel loads together with access and extinction difficulties were likely behind this trend. A higher incidence of fire in TPAs than in their buffers was exclusively related to anthropogenic factors such as higher road densities and agrarian extensions. Our results suggest that TPAs are failing to mitigate fire impacts, with both fire incidence and total burned areas being significantly higher in the reserves than in adjacent buffer areas. Management plans should consider those factors that facilitate fires in TPAs: anthropogenic origin of fires, sensitivity of TPAs to El Niñio-droughts, large fuel loads and fuel continuity inside parks, and limited financial resources. Consideration of these factors favors lines of action such as alternatives to the use of fire (e.g., mucuna-maize system), climatic prediction to follow the evolution of El Niño, fuel management strategies that favor extinction practices, and the strengthening of local communities and ecotourism.

Fire severity and tree regeneration following bark beetle outbreaks: the role of outbreak stage and burning conditions.

PubMed

Harvey, Brian J; Donato, Daniel C; Romme, William H; Turner, Monica G

The degree to which recent bark beetle (Dendroctonus ponderosae) outbreaks may influence fire severity and postfire tree regeneration is of heightened interest to resource managers throughout western North America, but empirical data on actual fire effects are lacking. Outcomes may depend on burning conditions (i.e., weather during fire), outbreak severity, or intervals between outbreaks and subsequent fire. We studied recent fires that burned through green-attack/red-stage (outbreaks <3 years before fire) and gray-stage (outbreaks 3–15 years before fire) subalpine forests dominated by lodgepole pine (Pinus contorta var. latifolia) in Greater Yellowstone, Wyoming, USA, to determine if fire severity was linked to prefire beetle outbreak severity and whether these two disturbances produced compound ecological effects on postfire tree regeneration. With field data from 143 postfire plots that burned under different conditions, we assessed canopy and surface fire severity, and postfire tree seedling density against prefire outbreak severity. In the green-attack/red stage, several canopy fire-severity measures increased with prefire outbreak severity under moderate burning conditions. Under extreme conditions, few fire-severity measures were related to prefire outbreak severity, and effect sizes were of marginal biological significance. The percentage of tree stems and basal area killed by fire increased with more green-attack vs. red-stage trees (i.e., the earliest stages of outbreak). In the gray stage, by contrast, most fire-severity measures declined with increasing outbreak severity under moderate conditions, and fire severity was unrelated to outbreak severity under extreme burning conditions. Postfire lodgepole pine seedling regeneration was unrelated to prefire outbreak severity in either post-outbreak stage, but increased with prefire serotiny. Results suggest bark beetle outbreaks can affect fire severity in subalpine forests under moderate burning conditions, but have little effect on fire severity under extreme burning conditions when most large wildfires occur in this system. Thus, beetle outbreak severity was moderately linked to fire severity, but the strength and direction of the linkage depended on both endogenous (outbreak stage) and exogenous (fire weather) factors. Closely timed beetle outbreak and fire did not impart compound effects on tree regeneration, suggesting the presence of a canopy seedbank may enhance resilience to their combined effects.

Estimates of global biomass burning emissions for reactive greenhouse gases (CO, NMHCs, and NOx) and CO2

NASA Astrophysics Data System (ADS)

Jain, Atul K.; Tao, Zhining; Yang, Xiaojuan; Gillespie, Conor

2006-03-01

Open fire biomass burning and domestic biofuel burning (e.g., cooking, heating, and charcoal making) algorithms have been incorporated into a terrestrial ecosystem model to estimate CO2 and key reactive GHGs (CO, NOx, and NMHCs) emissions for the year 2000. The emissions are calculated over the globe at a 0.5° × 0.5° spatial resolution using tree density imagery, and two separate sets of data each for global area burned and land clearing for croplands, along with biofuel consumption rate data. The estimated global and annual total dry matter (DM) burned due to open fire biomass burning ranges between 5221 and 7346 Tg DM/yr, whereas the resultant emissions ranges are 6564-9093 Tg CO2/yr, 438-568 Tg CO/yr, 11-16 Tg NOx/yr (as NO), and 29-40 Tg NMHCs/yr. The results indicate that land use changes for cropland is one of the major sources of biomass burning, which amounts to 25-27% (CO2), 25 -28% (CO), 20-23% (NO), and 28-30% (NMHCs) of the total open fire biomass burning emissions of these gases. Estimated DM burned associated with domestic biofuel burning is 3,114 Tg DM/yr, and resultant emissions are 4825 Tg CO2/yr, 243 Tg CO/yr, 3 Tg NOx/yr, and 23 Tg NMHCs/yr. Total emissions from biomass burning are highest in tropical regions (Asia, America, and Africa), where we identify important contributions from primary forest cutting for croplands and domestic biofuel burning.

Vegetation, topography and daily weather influenced burn severity in central Idaho and western Montana forests

Treesearch

Donovan S. Birch; Penelope Morgan; Crystal A. Kolden; John T. Abatzoglou; Gregory K. Dillon; Andrew T. Hudak; Alistair M. S. Smith

2015-01-01

Burn severity as inferred from satellite-derived differenced Normalized Burn Ratio (dNBR) is useful for evaluating fire impacts on ecosystems but the environmental controls on burn severity across large forest fires are both poorly understood and likely to be different than those influencing fire extent. We related dNBR to environmental variables including vegetation,...

16 CFR § 1145.3 - Extremely flammable contact adhesives; risk of burns from explosive vapor ignition and flashback...

Code of Federal Regulations, 2013 CFR

2013-01-01

... of burns from explosive vapor ignition and flashback fire. § 1145.3 Section § 1145.3 Commercial...; risk of burns from explosive vapor ignition and flashback fire. (a) The Commission finds that it is in the public interest to regulate the risk of burns from explosive vapor ignition and flashback fire...

Application of wildfire spread and behavior models to assess fire probability and severity in the Mediterranean region

NASA Astrophysics Data System (ADS)

Salis, Michele; Arca, Bachisio; Bacciu, Valentina; Spano, Donatella; Duce, Pierpaolo; Santoni, Paul; Ager, Alan; Finney, Mark

2010-05-01

Characterizing the spatial pattern of large fire occurrence and severity is an important feature of the fire management planning in the Mediterranean region. The spatial characterization of fire probabilities, fire behavior distributions and value changes are key components for quantitative risk assessment and for prioritizing fire suppression resources, fuel treatments and law enforcement. Because of the growing wildfire severity and frequency in recent years (e.g.: Portugal, 2003 and 2005; Italy and Greece, 2007 and 2009), there is an increasing demand for models and tools that can aid in wildfire prediction and prevention. Newer wildfire simulation systems offer promise in this regard, and allow for fine scale modeling of wildfire severity and probability. Several new applications has resulted from the development of a minimum travel time (MTT) fire spread algorithm (Finney, 2002), that models the fire growth searching for the minimum time for fire to travel among nodes in a 2D network. The MTT approach makes computationally feasible to simulate thousands of fires and generate burn probability and fire severity maps over large areas. The MTT algorithm is imbedded in a number of research and fire modeling applications. High performance computers are typically used for MTT simulations, although the algorithm is also implemented in the FlamMap program (www.fire.org). In this work, we described the application of the MTT algorithm to estimate spatial patterns of burn probability and to analyze wildfire severity in three fire prone areas of the Mediterranean Basin, specifically Sardinia (Italy), Sicily (Italy) and Corsica (France) islands. We assembled fuels and topographic data for the simulations in 500 x 500 m grids for the study areas. The simulations were run using 100,000 ignitions under weather conditions that replicated severe and moderate weather conditions (97th and 70th percentile, July and August weather, 1995-2007). We used both random ignition locations and ignition probability grids (1000 x 1000 m) built from historical fire data (1995-2007). The simulation outputs were then examined to understand relationships between burn probability and specific vegetation types and ignition sources. Wildfire threats to specific values of human interest were quantified to map landscape patterns of wildfire risk. The simulation outputs also allowed us to differentiate between areas of the landscape that were progenitors of fires versus "victims" of large fires. The results provided spatially explicit data on wildfire likelihood and intensity that can be used in a variety of strategic and tactical planning forums to mitigate wildfire threats to human and other values in the Mediterranean Basin.

Effect of a controlled burn on the thermophysical properties of a dry soil using a new model of soil heat flow and a new high temperature heat flux sensor

Treesearch

W. J. Massman; J. M. Frank

2004-01-01

Some fires can be beneficial to soils but, if a fire is sufficiently intense, soil can be irreversible altered. We measured soil temperatures and heat fluxes at several soil depths before, during, and after a controlled surface burn at Manitou Experimental Forest (southern Colorado, USA) to evaluate its effects on the soil's thermophysical properties (thermal...

Desertification and other ecological impacts produced by the historic Rodeo-Chediski Wildfire of 2000, Arizona, USA

NASA Astrophysics Data System (ADS)

Neary, D.; Ffolliott, P.; Stropki, C.

2009-04-01

The Rodeo-Chediski Wildfire - the largest in Arizona's history - damaged or destroyed ecosystem resources and disrupted ecosystem functioning in a largely mosaic pattern throughout the ponderosa pine (Pinus ponderosa) forests exposed to the burn. Impacts of this wildfire on tree overstories were studied on two watersheds in the area burned; one watershed burned by a high severity (stand-replacing) fire, while the other watershed burned by a low severity (stand-modifying) fire. The Rodeo-Chediski wildfire damaged or destroyed ecosystem resources and disrupted the ecological functioning on much of the 189,015 ha impacted by the burning. Intermingling chaparral shrub communities and pinyon-juniper woodlands at lower elevations and ponderosa pine forests at high elevations were located within the burned area. The wildfire was caused by two human ignitions that merged into one inferno. The Rodeo Fire was started by an arsonist on June 18, 2002, while the Chediski Fire was ignited as a signal fire by a stranded motorist on June 20th. The two fires merged on June 26, 2002, to become the Rodeo-Chediski Wildfire. The combined wildfires were contained on July 7th at a suppression (firefighting) cost of about €37.9 million (USA 50 million). However, the estimated costs associated with property losses; losses of ecosystem, anthropological, and cultural resources; and post-fire rehabilitation efforts increased the costs of the wildfire to over €114 million (USA 150 million). About one-half of the total area that was burned by the Rodeo-Chediski Wildfire experienced a high-severity fire, other areas burned at a low- to medium-severity fire, and still other areas were largely unburned according to a Burned Area Emergency Rehabilitation (BAER) report and fire severity map prepared shortly after containment of the wildfire. A mosaic of areas burned at varying fire severities within intermingling unburned areas resulted. Post-fire rehabilitation efforts, including establishment of water bars, wattles, k-rails, and aerial seeding and mulching of herbaceous plants to mitigate that anticipated accelerated post-fire soil erosion, began immediately after the fire was extinguished and it was declared safe for people to enter the burned area and initiate rehabilitation. An assessment of the impacts of the Rodeo-Chediski wildfire on soil erosion was carried out on two watersheds situated at the headwaters of the Little Colorado River. One of the watersheds experienced a high severity burn and the other a low-to-medium severity burn. Estimates of soil erosion on a watershed-basis and relative to physiographic characteristics on the two watersheds following the (a) high-intensity summer monsoonal rains and (2) low-intensity winter precipitation and spring snowmelt-runoff events are presented and compared with estimates of soil erosion following other wildfires in the region. Monitoring of soil erosion and other hydrologic and ecological parameters is continuing to obtain a longer, more comprehensive picture of the impacts of this catastrophic wildfire event. The Rodeo-Chediski Wildfire altered the species composition and impacted the production of herbaceous plants on the burned watersheds studied. Effects of the post-fire vegetation changes reduced the capabilities of watersheds to support livestock and some of the other larger herbivores in the region. When these watersheds will return to pre-fire conditions is largely unknown. Not only must the forage resources be restored but the magnitude of post-fire soil erosion and accompanying nutrient losses must be mitigated. Post-fire rehabilitation efforts including the seeding of herbaceous species and installation of controls to reduce soil erosion and sedimentation processes have helped to accelerate this recovery to some extent. A much longer time will obviously be required for severely burned areas to recover than those areas burned by at a low severity. Portions of the latter have already returned to pre-fire conditions.

Implications of burned area approaches in emission inventories for modeling wildland fire pollution in the contiguous U.S.

EPA Science Inventory

Wildland fires are a major source of fine particulate matter (PM2.5), one of the most harmful ambient pollutants for human health globally. Within the U.S., wildland fires can account for more than 30% of total annual PM2.5 emissions. In order to represent the influence of fire e...

Implications of burned area approaches in emission inventories for modeling wildland fire pollution in the contiguous U.S

EPA Science Inventory

Wildland fires are a major source of fine particulate matter (PM2.5), one of the most harmful ambient pollutants for human health globally. Within the U.S., wildland fires can account for more than 30% of total annual PM2.5 emissions. In order to represent the influence of fire e...

A simulation of probabilistic wildfire risk components for the continental United States

Treesearch

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

2011-01-01

This simulation research was conducted in order to develop a large-fire risk assessment system for the contiguous land area of the United States. The modeling system was applied to each of 134 Fire Planning Units (FPUs) to estimate burn probabilities and fire size distributions. To obtain stable estimates of these quantities, fire ignition and growth was simulated for...

Experimental and modeling study of forest fire effect on soil thermal conductivity

Treesearch

Kathleen M. Smits; Elizabeth Kirby; William J. Massman; Scott Baggett

2016-01-01

An understanding of soil thermal conductivity after a wildfire or controlled burn is important to land management and post-fire recovery efforts. Although soil thermal conductivity has been well studied for non-fire heated soils, comprehensive data that evaluate the long-term effect of extreme heating from a fire on the soil thermal conductivity are limited....

Combustion efficiency and emission factors for wildfire-season fires in mixed conifer forests of the northern Rocky Mountains, US

Treesearch

S. P. Urbanski

2013-01-01

In the US, wildfires and prescribed burning present significant challenges to air regulatory agencies attempting to achieve and maintain compliance with air quality regulations. Fire emission factors (EF) are essential input for the emission models used to develop wildland fire emission inventories. Most previous studies quantifying wildland fire EF of temperate...

Exploring the future change space for fire weather in southeast Australia

NASA Astrophysics Data System (ADS)

Clarke, Hamish; Evans, Jason P.

2018-05-01

High-resolution projections of climate change impacts on fire weather conditions in southeast Australia out to 2080 are presented. Fire weather is represented by the McArthur Forest Fire Danger Index (FFDI), calculated from an objectively designed regional climate model ensemble. Changes in annual cumulative FFDI vary widely, from - 337 (- 21%) to + 657 (+ 24%) in coastal areas and - 237 (- 12%) to + 1143 (+ 26%) in inland areas. A similar spread is projected in extreme FFDI values. In coastal regions, the number of prescribed burning days is projected to change from - 11 to + 10 in autumn and - 10 to + 3 in spring. Across the ensemble, the most significant increases in fire weather and decreases in prescribed burn windows are projected to take place in spring. Partial bias correction of FFDI leads to similar projections but with a greater spread, particularly in extreme values. The partially bias-corrected FFDI performs similarly to uncorrected FFDI compared to the observed annual cumulative FFDI (ensemble root mean square error spans 540 to 1583 for uncorrected output and 695 to 1398 for corrected) but is generally worse for FFDI values above 50. This emphasizes the need to consider inter-variable relationships when bias-correcting for complex phenomena such as fire weather. There is considerable uncertainty in the future trajectory of fire weather in southeast Australia, including the potential for less prescribed burning days and substantially greater fire danger in spring. Selecting climate models on the basis of multiple criteria can lead to more informative projections and allow an explicit exploration of uncertainty.

Post-fire ecosystem recovery trajectories along burn severity gradients

NASA Astrophysics Data System (ADS)

Newingham, B. A.; Hudak, A. T.; Bright, B. C.; Smith, A. G.; Henareh Khalyani, A.

2017-12-01

Burn severity is a term used to describe the longer-term, second-order effects of fire on ecosystems. Plant communities are assumed to recover more slowly at higher burn severities; however, this likely depends on plant community type and climate. We assessed vegetation recovery approximately a decade post-fire across North American forests (moist mixed conifer, dry mixed conifer, ponderosa pine) and shrublands (mountain big sagebrush and Wyoming big sagebrush) distributed across climate and burn severity gradients. We assessed vegetation recovery across these ecosystems as indicated by the differenced Normalized Burn Ratio derived from 1984-2016 Landsat time series imagery (LandTrendr). Additionally, we used field vegetation measurements to examine local topographic controls on burn severity and post-fire vegetation recovery. Ecosystem responses were related to climate predictors derived from downscaled 1993-2011 climate normals. We hypothesized that drier and hotter ecosystems would take longer to recover. We also predicted areas with higher burn severity to have slower recovery. We found post-fire recovery to be strongly predicted by precipitation with the slowest recovery in shrublands and ponderosa pine forest, the driest vegetation types considered. We conclude that climate and burn severity interact to determine ecosystem recovery trajectories after fire, with burn severity having larger influence in the short term, and climate having larger influence in the long term.

Seasonal Distribution of African Savanna Fires

NASA Technical Reports Server (NTRS)

Cahoon, Donald R.; Stocks, Brian J.; Levine, Joel S.; Cofer, Wesley R., III; O'Neill, Katherine P.

1992-01-01

Savannas consist of a continuous layer of grass interspersed with scattered trees or shrubs, and cover approx. 10 million square kilometers of tropical Africa. African savanna fires, almost all resulting from human activities, may produce as much as a third of the total global emissions from biomass burning. Little is known, however, about the frequency and location of these fires, and the area burned each year. Emissions from African savanna burning are known to be transported over the mid-Atlantic, south Pacific and Indian oceans; but to study fully the transport of regional savanna burning and the seasonality of the atmospheric circulation must be considered simultaneously. Here we describe the temporal and spatial distribution of savanna fires over the entire African continent, as determined from night-time satellite imagery. We find that, contrary to expectations, most fires are left to burn uncontrolled, so that there is no strong diurnal cycle in the fire frequency. The knowledge gained from this study regarding the distribution and variability of fires will aid monitoring of the climatically important trace gases emitted from burning biomass.

Ballistically Initiated Fire Ball Generation Using M&S: Innovation Grant (Briefing Charts)

DTIC Science & Technology

2012-01-26

isotropic in nature Phenomenological models for explosives initiation. – HVRB, forest fire etc. Equation of state – Ideal gas, Mie-Gruneisen, JWL ...perfectly plastic description • EOS • Mie Gruneisen • JWL for explosive • Phenomenological Model for EFP • High Explosive input for programmed burn

Burned areas for the conterminous U.S. from 1984 through 2015, an automated approach using dense time-series of Landsat data

NASA Astrophysics Data System (ADS)

Hawbaker, T. J.; Vanderhoof, M.; Beal, Y. J. G.; Takacs, J. D.; Schmidt, G.; Falgout, J.; Brunner, N. M.; Caldwell, M. K.; Picotte, J. J.; Howard, S. M.; Stitt, S.; Dwyer, J. L.

2016-12-01

Complete and accurate burned area data are needed to document patterns of fires, to quantify relationships between the patterns and drivers of fire occurrence, and to assess the impacts of fires on human and natural systems. Unfortunately, many existing fire datasets in the United States are known to be incomplete and that complicates efforts to understand burned area patterns and introduces a large amount of uncertainty in efforts to identify their driving processes and impacts. Because of this, the need to systematically collect burned area information has been recognized by the United Nations Framework Convention on Climate Change and the Intergovernmental Panel on Climate Change, which have both called for the production of essential climate variables. To help meet this need, we developed a novel algorithm that automatically identifies burned areas in temporally-dense time series of Landsat image stacks to produce Landsat Burned Area Essential Climate Variable (BAECV) products. The algorithm makes use of predictors derived from individual Landsat scenes, lagged reference conditions, and change metrics between the scene and reference predictors. Outputs of the BAECV algorithm, generated for the conterminous United States for 1984 through 2015, consist of burn probabilities for each Landsat scene, in addition to, annual composites including: the maximum burn probability, burn classification, and the Julian date of the first Landsat scene a burn was observed. The BAECV products document patterns of fire occurrence that are not well characterized by existing fire datasets in the United States. We anticipate that these data could help to better understand past patterns of fire occurrence, the drivers that created them, and the impacts fires had on natural and human systems.

Planning for prescribed burning in the inland northwest.

Treesearch

Robert E. Martin; John D. Dell

1978-01-01

Fire has historically played a role in forests and ranges of the inland Northwest. This guide has been prepared to help managers understand the role of fire and the potential uses of fire and to plan for fire use in managing these lands. Sections deal with these topics, and steps in planning a prescribed burn are outlined. A sample burning situation illustrates the...

Legal barriers to effective ecosystem management: exploring linkages between liability, regulations, and prescribed fire.

PubMed

Wonkka, Carissa L; Rogers, William E; Kreuter, Urs P

2015-12-01

Resistance to the use of prescribed fire is strong among many private land managers despite the advantages it offers for maintaining fire-adapted ecosystems. Even managers who are aware of the benefits of using prescribed fire as a management tool avoid using it, citing potential liability as a major reason for their aversion. Recognizing the importance of prescribed fire for ecosystem management and the constraints current statutory schemes impose on its use, several states in the United States have undertaken prescribed burn statutory reform. The stated purpose of these statutory reforms, often called "right to burn" or "prescribed burning" acts, is to encourage prescribed burning for resource protection, public safety, and land management. Our research assessed the consequences of prescribed burn statutory reform by identifying legal incentives and impediments to prescribed fire application for ecosystem restoration and management, as well as fuel reduction. Specifically, we explored the relationship between prescribed burning laws and decisions made by land managers by exploiting a geographic-based natural experiment to compare landowner-prescribed fire use in contiguous counties with different regulations and legal liability standards. Controlling for potentially confounding variables, we found that private landowners in counties with gross negligence liability standards burn significantly more hectares than those in counties with simple negligence standards (F6,72 = 4.16, P = 0.046). There was no difference in hectares burned on private land between counties with additional statutorily mandated regulatory requirements and those requiring only a permit to complete a prescribed burn (F6,72 = 1.42, P = 0.24) or between counties with burn ban exemptions for certified prescribed burn managers and those with no exemptions during burn bans (F6,72 = 1.39, P = 0.24). Lawmakers attempting to develop prescribed burning statutes to promote the safe use of prescribed fire should consider the benefits of lower legal liability standards in conjunction with regulatory requirements that promote safety for those managing forests and rangelands with fire. Moreover, ecologists and land managers might be better prepared and motivated to educate stakeholder groups who influence prescribed fire policies if they are cognizant of the manner in which policy regulations and liability concerns create legal barriers that inhibit the implementation of effective ecosystem management strategies.

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...

Understorey fire frequency and the fate of burned forests in southern Amazonia.

PubMed

Morton, D C; Le Page, Y; DeFries, R; Collatz, G J; Hurtt, G C

2013-06-05

Recent drought events underscore the vulnerability of Amazon forests to understorey fires. The long-term impact of fires on biodiversity and forest carbon stocks depends on the frequency of fire damages and deforestation rates of burned forests. Here, we characterized the spatial and temporal dynamics of understorey fires (1999-2010) and deforestation (2001-2010) in southern Amazonia using new satellite-based estimates of annual fire activity (greater than 50 ha) and deforestation (greater than 10 ha). Understorey forest fires burned more than 85 500 km(2) between 1999 and 2010 (2.8% of all forests). Forests that burned more than once accounted for 16 per cent of all understorey fires. Repeated fire activity was concentrated in Mato Grosso and eastern Pará, whereas single fires were widespread across the arc of deforestation. Routine fire activity in Mato Grosso coincided with annual periods of low night-time relative humidity, suggesting a strong climate control on both single and repeated fires. Understorey fires occurred in regions with active deforestation, yet the interannual variability of fire and deforestation were uncorrelated, and only 2.6 per cent of forests that burned between 1999 and 2008 were deforested for agricultural use by 2010. Evidence from the past decade suggests that future projections of frontier landscapes in Amazonia should separately consider economic drivers to project future deforestation and climate to project fire risk.

Understorey fire frequency and the fate of burned forests in southern Amazonia

PubMed Central

Morton, D. C.; Le Page, Y.; DeFries, R.; Collatz, G. J.; Hurtt, G. C.

2013-01-01

Recent drought events underscore the vulnerability of Amazon forests to understorey fires. The long-term impact of fires on biodiversity and forest carbon stocks depends on the frequency of fire damages and deforestation rates of burned forests. Here, we characterized the spatial and temporal dynamics of understorey fires (1999–2010) and deforestation (2001–2010) in southern Amazonia using new satellite-based estimates of annual fire activity (greater than 50 ha) and deforestation (greater than 10 ha). Understorey forest fires burned more than 85 500 km2 between 1999 and 2010 (2.8% of all forests). Forests that burned more than once accounted for 16 per cent of all understorey fires. Repeated fire activity was concentrated in Mato Grosso and eastern Pará, whereas single fires were widespread across the arc of deforestation. Routine fire activity in Mato Grosso coincided with annual periods of low night-time relative humidity, suggesting a strong climate control on both single and repeated fires. Understorey fires occurred in regions with active deforestation, yet the interannual variability of fire and deforestation were uncorrelated, and only 2.6 per cent of forests that burned between 1999 and 2008 were deforested for agricultural use by 2010. Evidence from the past decade suggests that future projections of frontier landscapes in Amazonia should separately consider economic drivers to project future deforestation and climate to project fire risk. PMID:23610169

Metapopulation Dynamics of the Mistletoe and Its Host in Savanna Areas with Different Fire Occurrence

PubMed Central

Teodoro, Grazielle Sales; van den Berg, Eduardo; Arruda, Rafael

2013-01-01

Mistletoes are aerial hemiparasitic plants which occupy patches of favorable habitat (host trees) surrounded by unfavorable habitat and may be possibly modeled as a metapopulation. A metapopulation is defined as a subdivided population that persists due to the balance between colonization and extinction in discrete habitat patches. Our aim was to evaluate the dynamics of the mistletoe Psittacanthus robustus and its host Vochysia thyrsoidea in three Brazilian savanna areas using a metapopulation approach. We also evaluated how the differences in terms of fire occurrence affected the dynamic of those populations (two areas burned during the study and one was fire protected). We monitored the populations at six-month intervals. P. robustus population structure and dynamics met the expected criteria for a metapopulation: i) the suitable habitats for the mistletoe occur in discrete patches; (ii) local populations went extinct during the study and (iii) colonization of previously non-occupied patches occurred. The ratio of occupied patches decreased in all areas with time. Local mistletoe populations went extinct due to two different causes: patch extinction in area with no fire and fire killing in the burned areas. In a burned area, the largest decrease of occupied patch ratios occurred due to a fire event that killed the parasites without, however, killing the host trees. The greatest mortality of V. thyrsoidea occurred in the area without fire. In this area, all the dead trees supported mistletoe individuals and no mortality was observed for parasite-free trees. Because P. robustus is a fire sensitive species and V. thyrsoidea is fire tolerant, P. robustus seems to increase host mortality, but its effect is lessened by periodic burning that reduces the parasite loads. PMID:23776554

Archaeology of fire: Methodological aspects of reconstructing fire history of prehistoric archaeological sites

NASA Astrophysics Data System (ADS)

Alperson-Afil, Nira

2012-07-01

Concepts which are common in the reconstruction of fire histories are employed here for the purpose of interpreting fires identified at archaeological sites. When attempting to evaluate the fire history of ancient occupations we are limited by the amount and quality of the available data. Furthermore, the identification of archaeological burned materials, such as stone, wood, and charcoal, is adequate for the general assumption of a "fire history", but the agent responsible - anthropogenic or natural - cannot be inferred from the mere presence of burned items. The large body of scientific data that has accumulated, primarily through efforts to prevent future fire disasters, enables us to reconstruct scenarios of past natural fires. Adopting this line of thought, this paper attempts to evaluate the circumstances in which a natural fire may have ignited and spread at the 0.79 Ma occupation site of Gesher Benot Ya'aqov (Israel), resulting with burned wood and burned flint within the archaeological layers. At Gesher Benot Ya'aqov, possible remnants of hearths are explored through analyses of the spatial distribution of burned flint-knapping waste products. These occur in dense clusters in each of the archaeological occupations throughout the long stratigraphic sequence. In this study, the combination between the spatial analyses results, paleoenvironmental information, and various factors involved in the complex process of fire ignition, combustion, and behavior, has enabled the firm rejection of recurrent natural fires as the responsible agent for the burned materials. In addition, it suggested that mainly at early sites, where evidence for burning is present yet scarce, data on fire ecology can be particularly useful when it is considered in relation to paleoenvironmental information.

Effects of Degree of Curing on Fire Spread

NASA Astrophysics Data System (ADS)

Chaivaranont, W.; Evans, J. P.; Liu, Y.

2016-12-01

During extreme summer conditions in Australia, bushfire can become an uncontrollable natural hazard. Various factors, such as geographical and meteorological parameters greatly influence the magnitude of bushfire. In a grassland fire, there is an important factor that affects the severity of fire called the degree of curing. Degree of curing is a percentage measurement of the proportion of dead material in grassland where a 100% curing indicates a totally dead grass field. It is usually assumed constant due to the cost and difficulty in obtaining accurate field observations.To examine the importance of curing, the Phoenix RapidFire fire spread model was used to observe the magnitude and direction of grassland fire spread due to variations in the degree of curing. Idealised experiments and experiments based on 3 past fire events in Australia were conducted, where the 100 by 200 km study area is considered to be all grassland. In the idealised experiments, homogeneous curing data in various patterns were used along with extreme climate data and prescribed topography. In the past fire event experiments, satellite-derived estimated curing data, observed climate data from the nearest weather stations, and real elevation maps were used. A remotely sensed burned area map (MODIS MCD64A1 product) is also used to compare the simulated burned area of past fire events with the satellite observation.The results from both experiments showed that: 1) the rate of spread of grassland fire is significantly impeded when curing is below 75%, 2) topography has insignificant effect on fire spread direction and speed, 3) wind and curing both influence the direction and speed of spread, and 4) the model can only recreate the burned area in one out of three of the past fire events due to various causes including the fact that all past events used here were not exclusively grassland fire.

Vulnerability and Resilience of Temperate Forest Landscapes to Broad-Scale Deforestation in Response to Changing Fire Regimes and Altered Post-Fire Vegetation Dynamics

NASA Astrophysics Data System (ADS)

Tepley, A. J.; Veblen, T. T.; Perry, G.; Anderson-Teixeira, K. J.

2015-12-01

In the face of on-going climatic warming and land-use change, there is growing concern that temperate forest landscapes could be near a tipping point where relatively small changes to the fire regime or altered post-fire vegetation dynamics could lead to extensive conversion to shrublands or savannas. To evaluate vulnerability and resilience to such conversion, we develop a simple model based on three factors we hypothesize to be key in predicting temperate forest responses to changing fire regimes: (1) the hazard rate (i.e., the probability of burning in the next year given the time since the last fire) in closed-canopy forests, (2) the hazard rate for recently-burned, open-canopy vegetation, and (3) the time to redevelop canopy closure following fire. We generate a response surface representing the proportions of the landscape potentially supporting closed-canopy forest and non-forest vegetation under nearly all combinations of these three factors. We then place real landscapes on this response surface to assess the type and magnitude of changes to the fire regime that would drive extensive forest loss. We show that the deforestation of much of New Zealand that followed initial human colonization and the introduction of a new ignition source ca. 750 years ago was essentially inevitable due to the slow rate of forest recovery after fire and the high flammability of post-fire vegetation. In North America's Pacific Northwest, by contrast, a predominantly forested landscape persisted despite two periods of widespread burning in the recent past due in large part to faster post-fire forest recovery and less pronounced differences in flammability between forests and the post-fire vegetation. We also assess the factors that could drive extensive deforestation in other regions to identify where management could reduce this potential and to guide field and modeling work to better understand the responses and ecological feedbacks to changing fire regimes.

Incorporating Anthropogenic Influences into Fire Probability Models: Effects of Human Activity and Climate Change on Fire Activity in California.

PubMed

Mann, Michael L; Batllori, Enric; Moritz, Max A; Waller, Eric K; Berck, Peter; Flint, Alan L; Flint, Lorraine E; Dolfi, Emmalee

2016-01-01

The costly interactions between humans and wildfires throughout California demonstrate the need to understand the relationships between them, especially in the face of a changing climate and expanding human communities. Although a number of statistical and process-based wildfire models exist for California, there is enormous uncertainty about the location and number of future fires, with previously published estimates of increases ranging from nine to fifty-three percent by the end of the century. Our goal is to assess the role of climate and anthropogenic influences on the state's fire regimes from 1975 to 2050. We develop an empirical model that integrates estimates of biophysical indicators relevant to plant communities and anthropogenic influences at each forecast time step. Historically, we find that anthropogenic influences account for up to fifty percent of explanatory power in the model. We also find that the total area burned is likely to increase, with burned area expected to increase by 2.2 and 5.0 percent by 2050 under climatic bookends (PCM and GFDL climate models, respectively). Our two climate models show considerable agreement, but due to potential shifts in rainfall patterns, substantial uncertainty remains for the semiarid inland deserts and coastal areas of the south. Given the strength of human-related variables in some regions, however, it is clear that comprehensive projections of future fire activity should include both anthropogenic and biophysical influences. Previous findings of substantially increased numbers of fires and burned area for California may be tied to omitted variable bias from the exclusion of human influences. The omission of anthropogenic variables in our model would overstate the importance of climatic ones by at least 24%. As such, the failure to include anthropogenic effects in many models likely overstates the response of wildfire to climatic change.

Incorporating Anthropogenic Influences into Fire Probability Models: Effects of Human Activity and Climate Change on Fire Activity in California

PubMed Central

Batllori, Enric; Moritz, Max A.; Waller, Eric K.; Berck, Peter; Flint, Alan L.; Flint, Lorraine E.; Dolfi, Emmalee

2016-01-01

The costly interactions between humans and wildfires throughout California demonstrate the need to understand the relationships between them, especially in the face of a changing climate and expanding human communities. Although a number of statistical and process-based wildfire models exist for California, there is enormous uncertainty about the location and number of future fires, with previously published estimates of increases ranging from nine to fifty-three percent by the end of the century. Our goal is to assess the role of climate and anthropogenic influences on the state’s fire regimes from 1975 to 2050. We develop an empirical model that integrates estimates of biophysical indicators relevant to plant communities and anthropogenic influences at each forecast time step. Historically, we find that anthropogenic influences account for up to fifty percent of explanatory power in the model. We also find that the total area burned is likely to increase, with burned area expected to increase by 2.2 and 5.0 percent by 2050 under climatic bookends (PCM and GFDL climate models, respectively). Our two climate models show considerable agreement, but due to potential shifts in rainfall patterns, substantial uncertainty remains for the semiarid inland deserts and coastal areas of the south. Given the strength of human-related variables in some regions, however, it is clear that comprehensive projections of future fire activity should include both anthropogenic and biophysical influences. Previous findings of substantially increased numbers of fires and burned area for California may be tied to omitted variable bias from the exclusion of human influences. The omission of anthropogenic variables in our model would overstate the importance of climatic ones by at least 24%. As such, the failure to include anthropogenic effects in many models likely overstates the response of wildfire to climatic change. PMID:27124597

The importance of plume rise on the concentrations and atmospheric impacts of biomass burning aerosol

NASA Astrophysics Data System (ADS)

Walter, Carolin; Freitas, Saulo R.; Kottmeier, Christoph; Kraut, Isabel; Rieger, Daniel; Vogel, Heike; Vogel, Bernhard

2016-07-01

We quantified the effects of the plume rise of biomass burning aerosol and gases for the forest fires that occurred in Saskatchewan, Canada, in July 2010. For this purpose, simulations with different assumptions regarding the plume rise and the vertical distribution of the emissions were conducted. Based on comparisons with observations, applying a one-dimensional plume rise model to predict the injection layer in combination with a parametrization of the vertical distribution of the emissions outperforms approaches in which the plume heights are initially predefined. Approximately 30 % of the fires exceed the height of 2 km with a maximum height of 8.6 km. Using this plume rise model, comparisons with satellite images in the visible spectral range show a very good agreement between the simulated and observed spatial distributions of the biomass burning plume. The simulated aerosol optical depth (AOD) with data of an AERONET station is in good agreement with respect to the absolute values and the timing of the maximum. Comparison of the vertical distribution of the biomass burning aerosol with CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) retrievals also showed the best agreement when the plume rise model was applied. We found that downwelling surface short-wave radiation below the forest fire plume is reduced by up to 50 % and that the 2 m temperature is decreased by up to 6 K. In addition, we simulated a strong change in atmospheric stability within the biomass burning plume.

Influence of savanna fire on Australian monsoon season precipitation and circulation as simulated using a distributed computing environment

NASA Astrophysics Data System (ADS)

Lynch, Amanda H.; Abramson, David; Görgen, Klaus; Beringer, Jason; Uotila, Petteri

2007-10-01

Fires in the Australian savanna have been hypothesized to affect monsoon evolution, but the hypothesis is controversial and the effects have not been quantified. A distributed computing approach allows the development of a challenging experimental design that permits simultaneous variation of all fire attributes. The climate model simulations are distributed around multiple independent computer clusters in six countries, an approach that has potential for a range of other large simulation applications in the earth sciences. The experiment clarifies that savanna burning can shape the monsoon through two mechanisms. Boundary-layer circulation and large-scale convergence is intensified monotonically through increasing fire intensity and area burned. However, thresholds of fire timing and area are evident in the consequent influence on monsoon rainfall. In the optimal band of late, high intensity fires with a somewhat limited extent, it is possible for the wet season to be significantly enhanced.

Potential release of fibers from burning carbon composites. [aircraft fires

NASA Technical Reports Server (NTRS)

Bell, V. L.

1980-01-01

A comprehensive experimental carbon fiber source program was conducted to determine the potential for the release of conductive carbon fibers from burning composites. Laboratory testing determined the relative importance of several parameters influencing the amounts of single fibers released, while large-scale aviation jet fuel pool fires provided realistic confirmation of the laboratory data. The dimensions and size distributions of fire-released carbon fibers were determined, not only for those of concern in an electrical sense, but also for those of potential interest from a health and environmental standpoint. Fire plume and chemistry studies were performed with large pool fires to provide an experimental input into an analytical modelling of simulated aircraft crash fires. A study of a high voltage spark system resulted in a promising device for the detection, counting, and sizing of electrically conductive fibers, for both active and passive modes of operation.

Experimental measurements and numerical modeling of marginal burning in live chaparral fuel beds

Treesearch

X. Zhou; D.R. Weise; S Mahalingam

2005-01-01

An extensive experimental and numerical study was completed to analyze the marginal burning behavior of live chaparral shrub fuels that grow in the mountains of southern California. Laboratory fire spread experiments were carried out to determine the effects of wind, slope, moisture content, and fuel characteristics on marginal burning in fuel beds of common...

Fire Effects on Microbial Enzyme Activities in Larch Forests of the Siberian Arctic

NASA Astrophysics Data System (ADS)

Ludwig, S.; Alexander, H. D.; Bulygina, E. B.; Mann, P. J.; Natali, S.

2012-12-01

Arctic forest ecosystems are warming at an accelerated rate relative to lower latitudes, with global implications for C cycling within these regions. As climate continues to warm and dry, wildfire frequency and severity are predicted to increase, creating a positive feedback to climate warming. Increased fire activity will also influence the microenvironment experienced by soil microbes in disturbed soils. Because soil microbes regulate carbon (C) and nitrogen (N) cycling between terrestrial ecosystems and the atmosphere, it is important to understand microbial response to fires, particularly in the understudied larch forests in the Siberian Arctic. In this project, we created experimental burn plots in a mature larch forest in the Kolyma River watershed of Northeastern Siberia. Plots were burned at several treatments: control (no burn), low, moderate, and severe. After, 1 and 8 d post-fire, we measured soil organic layer depth, soil organic matter (SOM) content, soil moisture, and CO2 flux from the plots. Additionally, we leached soils and measured dissolved organic carbon (DOC), total dissolved nitrogen (TDN), NH4, NO3, soluble reactive phosphorus (SRP), and chromophoric dissolved organic matter (CDOM). Furthermore, we measured extracellular activity of four enzymes involved in soil C and nutrient cycling (leucine aminopeptidase (LAP), β-glucosidase, phosphatase, and phenol oxidase). One day post-fire, LAP activity was similarly low in all treatments, but by 8 d post-fire, LAP activity was lower in burned plots compared to control plots, likely due to increased nitrogen content with increasing burn severity. Phosphatase activity decreased with burn severity 1 d post-fire, but after 8 d, moderate and severe burn plots exhibited increased phosphatase activity. Coupled with trends in LAP activity, this suggests a switch in nutrient limitation from N to phosphorus that is more pronounced with burn severity. β-glucosidase activity similarly decreased with burn severity 1 d post-fire, but by 8 d post-fire activity was the same in all treatments, indicating complete recovery of the microbial population. Phenol oxidase activity was low in all treatments 1 d post-fire, but by 8 d post-fire, severe plots had substantially increased phenol oxidase activity, likely due to microbial efforts to mitigate phenolic compound toxicity following severe fires. Both DOC and the slope ratio of CDOM absorbance increased with burn severity 1 d post-fire, indicating higher extractability of lighter molecular weight C from severe burns. These results imply that black C created from fires remains as a stable C pool while more labile C is mobilized with increasing burn severity. Our results suggest that the immediate effects of fire severity on microbial communities have the potential to change both nutrient use and the form and concentration of C being processed and mobilized from larch forest ecosystems. These findings highlight the importance of changing fire regimes on soil dynamics with implications for forest re-growth, soil-atmospheric feedbacks, and terrestrial inputs to aquatic ecosystems.

Global fire emissions and the contribution of deforestation, savanna, forest, agricultural, and peat fires (1997-2009)

NASA Astrophysics Data System (ADS)

van der Werf, G. R.; Randerson, J. T.; Giglio, L.; Collatz, G. J.; Mu, M.; Kasibhatla, P. S.; Morton, D. C.; Defries, R. S.; Jin, Y.; van Leeuwen, T. T.

2010-12-01

New burned area datasets and top-down constraints from atmospheric concentration measurements of pyrogenic gases have decreased the large uncertainty in fire emissions estimates. However, significant gaps remain in our understanding of the contribution of deforestation, savanna, forest, agricultural waste, and peat fires to total global fire emissions. Here we used a revised version of the Carnegie-Ames-Stanford-Approach (CASA) biogeochemical model and improved satellite-derived estimates of area burned, fire activity, and plant productivity to calculate fire emissions for the 1997-2009 period on a 0.5° spatial resolution with a monthly time step. For November 2000 onwards, estimates were based on burned area, active fire detections, and plant productivity from the MODerate resolution Imaging Spectroradiometer (MODIS) sensor. For the partitioning we focused on the MODIS era. We used maps of burned area derived from the Tropical Rainfall Measuring Mission (TRMM) Visible and Infrared Scanner (VIRS) and Along-Track Scanning Radiometer (ATSR) active fire data prior to MODIS (1997-2000) and estimates of plant productivity derived from Advanced Very High Resolution Radiometer (AVHRR) observations during the same period. Average global fire carbon emissions according to this version 3 of the Global Fire Emissions Database (GFED3) were 2.0 Pg C year-1 with significant interannual variability during 1997-2001 (2.8 Pg C year-1 in 1998 and 1.6 Pg C year-1 in 2001). Globally, emissions during 2002-2007 were relatively constant (around 2.1 Pg C year-1) before declining in 2008 (1.7 Pg C year-1) and 2009 (1.5 Pg C year-1) partly due to lower deforestation fire emissions in South America and tropical Asia. On a regional basis, emissions were highly variable during 2002-2007 (e.g., boreal Asia, South America, and Indonesia), but these regional differences canceled out at a global level. During the MODIS era (2001-2009), most carbon emissions were from fires in grasslands and savannas (44%) with smaller contributions from tropical deforestation and degradation fires (20%), woodland fires (mostly confined to the tropics, 16%), forest fires (mostly in the extratropics, 15%), agricultural waste burning (3%), and tropical peat fires (3%). The contribution from agricultural waste fires was likely a lower bound because our approach for measuring burned area could not detect all of these relatively small fires. Total carbon emissions were on average 13% lower than in our previous (GFED2) work. For reduced trace gases such as CO and CH4, deforestation, degradation, and peat fires were more important contributors because of higher emissions of reduced trace gases per unit carbon combusted compared to savanna fires. Carbon emissions from tropical deforestation, degradation, and peatland fires were on average 0.5 Pg C year-1. The carbon emissions from these fires may not be balanced by regrowth following fire. Our results provide the first global assessment of the contribution of different sources to total global fire emissions for the past decade, and supply the community with an improved 13-year fire emissions time series.

Spatial and temporal distribution of tropical biomass burning

NASA Astrophysics Data System (ADS)

Hao, Wei Min; Liu, Mei-Huey

1994-12-01

A database for the spatial and temporal distribution of the amount of biomass burned in tropical America, Africa, and Asia during the late 1970s is presented with a resolution of 5° latitude × 5° longitude. The sources of burning in each grid cell have been quantified. Savanna fires, shifting cultivation, deforestation, fuel wood use, and burning of agricultural residues contribute about 50, 24, 10, 11, and 5%, respectively, of total biomass burned in the tropics. Savanna fires dominate in tropical Africa, and forest fires dominate in tropical Asia. A similar amount of biomass is burned from forest and savanna fires in tropical America. The distribution of biomass burned monthly during the dry season has been derived for each grid cell using the seasonal cycles of surface ozone concentrations. Land use changes during the last decade could have a profound impact on the amount of biomass burned and the amount of trace gases and aerosol particles emitted.

Yellow pine regeneration as a function of fire severity and post-burn stand structure in the southern Appalachian Mountains

Treesearch

Michael A. Jenkins; Robert N. Klein; Virginia L. McDaniel

2011-01-01

We used pre- and post-burn fire effects data from six prescribed burns to examine post-burn threshold effects of stand structure (understory density, overstory density, shrub cover, duff depth, and total fuel load) on the regeneration of yellow pine (Pinus subgenus Diploxylon) seedlings and cover of herbaceous vegetation in six prescribed-fire management units located...

Post-fire Water Quality in the Western United States: Understanding and Predicting Short and Long-term Response

NASA Astrophysics Data System (ADS)

Hogue, T. S.; Rust, A.

2016-12-01

Fire frequency is increasing across mid-elevation forests, especially in the Northern Rockies, Sierra Nevada, southern Cascades, as well as the coastal ranges in California and southern Oregon. Numerous studies have noted increased discharge, floods and debris flows after wildfire. More recent work also shows increased water yield during dry seasons for up to ten years post-fire. However, few studies have evaluated long-term water quality response in fire-impacted watersheds. The current presentation will overview recent development of an extensive database on post-fire water quality response across the western U.S. A range of water quality parameters were gathered from 271 burned watersheds through local, state and federal agencies. Short and long-term response was evaluated for watersheds with at least 5 years of pre-fire data. Over 30 watersheds showed significant increases in NO3-, NO2-, NH3, and total nitrogen loading in the initial five years after fire and remained elevated ten years after fire. The burn severity influenced the degree of nitrogen response, where more severely burned watersheds showed higher nitrogen loading than less severely burned watersheds. Dissolved and total phosphorous showed significant increases in 32 watersheds for the first five years after fire. Dissolved ions such as calcium, magnesium, and chloride were also exported from over 32 watersheds, primarily during the first five years after fire, with the majority of impacted watersheds returning to pre-fire water quality conditions after ten years. Ongoing work includes evaluating key determinants that drive short and long-term response and developing predictive models for post-fire water quality. Watersheds impacted by wildfire are known to pose significant risks for downstream communities. Understanding short and long-term water quality change that can impact regional water supplies is critical for establishing potential treatment priorities and alternative source planning.

Wood crib fire free burning test in ISO room

NASA Astrophysics Data System (ADS)

Qiang, Xu; Griffin, Greg; Bradbury, Glenn; Dowling, Vince

2006-04-01

In the research of application potential of water mist fire suppression system for fire fighting in train luggage carriage, a series of experiments were conducted in ISO room on wood crib fire with and without water mist actuation. The results of free burn test without water mist suppression are used as reference in evaluating the efficiency of water mist suppression system. As part of the free burn test, several tests have been done under the hood of ISO room to calibrate the size of the crib fire and these tests can also be used in analyzing the wall effect in room fire hazard. In these free burning experiments, wood cribs of four sizes under the hood were tested. The temperature of crib fire, heat flux around the fire, gas concentration in hood of ISO room were measured in the experiments and two sets of thermal imaging system were used to get the temperature distribution and the typical shape of the free burning flames. From the experiments, the radiation intensity in specific positions around the fire, the effective heat of combustion, mass loss, oxygen consumption rate for different sizes of fire, typical structure of the flame and self extinguishment time was obtained for each crib size.

Modeling soil thermal and carbon dynamics of a fire chronosequence in interior Alaska

USGS Publications Warehouse

Zhuang, Q.; McGuire, A.D.; O'Neill, K. P.; Harden, J.W.; Romanovsky, V.E.; Yarie, J.

2003-01-01

In this study, the dynamics of soil thermal, hydrologic, and ecosystem processes were coupled to project how the carbon budgets of boreal forests will respond to changes in atmospheric CO2, climate, and fire disturbance. The ability of the model to simulate gross primary production and ecosystem respiration was verified for a mature black spruce ecosystem in Canada, the age-dependent pattern of the simulated vegetation carbon was verified with inventory data on aboveground growth of Alaskan black spruce forests, and the model was applied to a postfire chronosequence in interior Alaska. The comparison between the simulated soil temperature and field-based estimates during the growing season (May to September) of 1997 revealed that the model was able to accurately simulate monthly temperatures at 10 cm (R > 0.93) for control and burned stands of the fire chronosequence. Similarly, the simulated and field-based estimates of soil respiration for control and burned stands were correlated (R = 0.84 and 0.74 for control and burned stands, respectively). The simulated and observed decadal to century-scale dynamics of soil temperature and carbon dynamics, which are represented by mean monthly values of these variables during the growing season, were correlated among stands (R = 0.93 and 0.71 for soil temperature at 20- and 10-cm depths, R = 0.95 and 0.91 for soil respiration and soil carbon, respectively). Sensitivity analyses indicate that along with differences in fire and climate history a number of other factors influence the response of carbon dynamics to fire disturbance. These factors include nitrogen fixation, the growth of moss, changes in the depth of the organic layer, soil drainage, and fire severity.

Alaska's Changing Fire Regime - Implications for the Vulnerability of Its Boreal Forests

NASA Technical Reports Server (NTRS)

Kasischke, E. S.; Hoy, E. E.; Verbyla, D. L.; Rupp, T. S.; Duffy, P. A.; McGuire, A. D.; Murphy, K. A.; Jandt, R.; Barnes, J. L.; Calef, M.;

Vegetation dynamics after spring and summer fires in red and white pine stands at Voyageurs National Park

USGS Publications Warehouse

Weyenberg, Scott A.; Pavlovic, Noel B.

2014-01-01

Conducting dormant season or springtime prescribed fire treatments has become a common practice in many regions of the United States to restore ecosystems to their natural state. Despite the knowledge that historically, fires often occurred during the summer, the application of summer burns has been deterred, in part, by a lack of understanding of fire season effects on vegetation. We explored the differences in fire effects between spring and summer burns at Voyageurs National Park, Minnesota. The fire season effects on the ground layer vegetation were clearly different among the treatments: pre-burn, spring, and summer. Vegetation composition of pre-burn and after spring fires was similar, but differed significantly from the summer fires. Spring fires propagated the same species that were present prior to the fire, whereas summer fires promoted a new suite of species through the germination of seedbank and high seed dispersal species. Cover and richness of seed bank and intolerant species were greatest after the summer fires, which contributed to the peak in richness found across all reproductive and tolerance attributes five years after these fires. Post summer fire composition showed shifts in composition through time. Substantial differences in the effects of burn seasonality on ground layer vegetation should be considered in long term restoration efforts to help maintain species diversity in red and white pine forest ecosystems.

Alaska’s changing fire regime - Implications for the vulnerability of its boreal forests

USGS Publications Warehouse

Kasischke, Eric S.; Verbyla, David L.; Rupp, T. Scott; McGuire, A. David; Murphy, Karen A.; Jandt, R.; Barnes, Jennifer L.; Hoy, E.; Duffy, Paul A.; Calef, Monika; Turetsky, Merritt R.

2010-01-01

A synthesis was carried out to examine Alaska’s boreal forest fire regime. During the 2000s, an average of 767 000 ha·year–1 burned, 50% higher than in any previous decade since the 1940s. Over the past 60 years, there was a decrease in the number of lightning-ignited fires, an increase in extreme lightning-ignited fire events, an increase in human-ignited fires, and a decrease in the number of extreme human-ignited fire events. The fraction of area burned from human-ignited fires fell from 26% for the 1950s and 1960s to 5% for the 1990s and 2000s, a result from the change in fire policy that gave the highest suppression priorities to fire events that occurred near human settlements. The amount of area burned during late-season fires increased over the past two decades. Deeper burning of surface organic layers in black spruce (Picea mariana (Mill.) BSP) forests occurred during late-growing-season fires and on more well-drained sites. These trends all point to black spruce forests becoming increasingly vulnerable to the combined changes of key characteristics of Alaska’s fire regime, except on poorly drained sites, which are resistant to deep burning. The implications of these fire regime changes to the vulnerability and resilience of Alaska’s boreal forests and land and fire management are discussed.

Calibration and validation of the relative differenced Normalized Burn Ratio (RdNBR) to three measures of fire severity in the Sierra Nevada and Klamath Mountains, California, USA

USGS Publications Warehouse

Miller, J.D.; Knapp, E.E.; Key, C.H.; Skinner, C.N.; Isbell, C.J.; Creasy, R.M.; Sherlock, J.W.

2009-01-01

Multispectral satellite data have become a common tool used in the mapping of wildland fire effects. Fire severity, defined as the degree to which a site has been altered, is often the variable mapped. The Normalized Burn Ratio (NBR) used in an absolute difference change detection protocol (dNBR), has become the remote sensing method of choice for US Federal land management agencies to map fire severity due to wildland fire. However, absolute differenced vegetation indices are correlated to the pre-fire chlorophyll content of the vegetation occurring within the fire perimeter. Normalizing dNBR to produce a relativized dNBR (RdNBR) removes the biasing effect of the pre-fire condition. Employing RdNBR hypothetically allows creating categorical classifications using the same thresholds for fires occurring in similar vegetation types without acquiring additional calibration field data on each fire. In this paper we tested this hypothesis by developing thresholds on random training datasets, and then comparing accuracies for (1) fires that occurred within the same geographic region as the training dataset and in similar vegetation, and (2) fires from a different geographic region that is climatically and floristically similar to the training dataset region but supports more complex vegetation structure. We additionally compared map accuracies for three measures of fire severity: the composite burn index (CBI), percent change in tree canopy cover, and percent change in tree basal area. User's and producer's accuracies were highest for the most severe categories, ranging from 70.7% to 89.1%. Accuracies of the moderate fire severity category for measures describing effects only to trees (percent change in canopy cover and basal area) indicated that the classifications were generally not much better than random. Accuracies of the moderate category for the CBI classifications were somewhat better, averaging in the 50%-60% range. These results underscore the difficulty in isolating fire effects to individual vegetation strata when fire effects are mixed. We conclude that the models presented here and in Miller and Thode ([Miller, J.D. & Thode, A.E., (2007). Quantifying burn severity in a heterogeneous landscape with a relative version of the delta Normalized Burn Ratio (dNBR). Remote Sensing of Environment, 109, 66-80.]) can produce fire severity classifications (using either CBI, or percent change in canopy cover or basal area) that are of similar accuracy in fires not used in the original calibration process, at least in conifer dominated vegetation types in Mediterranean-climate California.

Comparison of AVIRIS and Landsat ETM+ detection capabilities for burn severity

USGS Publications Warehouse

Van Wagtendonk, Jan W.; Root, Ralph R.; Key, Carl H.

2004-01-01

Our study compares data on burn severity collected from multi-temporal Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) with similar data from the Enhanced Thematic Mapper Plus (ETM+) using the differenced Normalized Burn Ratio (dNBR). Two AVIRIS and ETM+ data acquisitions recorded surface conditions immediately before the Hoover Fire began to spread rapidly and again the following year. Data were validated with 63 field plots using the Composite Burn Index (CBI). The relationship between spectral channels and burn severity was examined by comparing pre- and post-fire datasets. Based on the high burn severity comparison, AVIRIS channels 47 and 60 at wavelengths of 788 and 913 nm showed the greatest negative response to fire. Post-fire reflectance values decreased the most on average at those wavelengths, while channel 210 at 2370 nm showed the greatest positive response on average. Fire increased reflectance the most at that wavelength over the entire measured spectral range. Furthermore, channel 210 at 2370 nm exhibited the greatest variation in spectral response, suggesting potentially high information content for fire severity. Based on general remote sensing principles and the logic of variable spectral responses to fire, dNBR from both sensors should produce useful results in quantifying burn severity. The results verify the band–response relationships to burn severity as seen with ETM+ data and confirm the relationships by way of a distinctly different sensor system.

Comparing fire spread algorithms using equivalence testing and neutral landscape models

Treesearch

Brian R. Miranda; Brian R. Sturtevant; Jian Yang; Eric J. Gustafson

2009-01-01

We demonstrate a method to evaluate the degree to which a meta-model approximates spatial disturbance processes represented by a more detailed model across a range of landscape conditions, using neutral landscapes and equivalence testing. We illustrate this approach by comparing burn patterns produced by a relatively simple fire spread algorithm with those generated by...

Northern California Fires

NASA Image and Video Library

2017-10-31

The October fires in Northern California were some of the most destructive in the state's history. The burned area on the right side of the image is the ATLAS fire, that burned east of Napa; the fire consumed 51,000 acres and destroyed almost 500 structures. The burned area on the left is part of the Nuns fire that burned between Sonoma and Napa; it consumed 110,000 acres, and destroyed almost 7,000 structures. The images were acquired September 7, 2016 and October 28, 2017, cover an area of 34.5 by 39 kilometers, and are located near 38.3 degrees north, 122.3 degrees east. https://photojournal.jpl.nasa.gov/catalog/PIA22019

A high-resolution open biomass burning emission inventory based on statistical data and MODIS observations in mainland China

NASA Astrophysics Data System (ADS)

Xu, Y.; Fan, M.; Huang, Z.; Zheng, J.; Chen, L.

2017-12-01

Open biomass burning which has adverse effects on air quality and human health is an important source of gas and particulate matter (PM) in China. Current emission estimations of open biomass burning are generally based on single source (alternative to statistical data and satellite-derived data) and thus contain large uncertainty due to the limitation of data. In this study, to quantify the 2015-based amount of open biomass burning, we established a new estimation method for open biomass burning activity levels by combining the bottom-up statistical data and top-down MODIS observations. And three sub-category sources which used different activity data were considered. For open crop residue burning, the "best estimate" of activity data was obtained by averaging the statistical data from China statistical yearbooks and satellite observations from MODIS burned area product MCD64A1 weighted by their uncertainties. For the forest and grassland fires, their activity levels were represented by the combination of statistical data and MODIS active fire product MCD14ML. Using the fire radiative power (FRP) which is considered as a better indicator of active fire level as the spatial allocation surrogate, coarse gridded emissions were reallocated into 3km ×3km grids to get a high-resolution emission inventory. Our results showed that emissions of CO, NOx, SO2, NH3, VOCs, PM2.5, PM10, BC and OC in mainland China were 6607, 427, 84, 79, 1262, 1198, 1222, 159 and 686 Gg/yr, respectively. Among all provinces of China, Henan, Shandong and Heilongjiang were the top three contributors to the total emissions. In this study, the developed open biomass burning emission inventory with a high-resolution could support air quality modeling and policy-making for pollution control.

Wildland fire emissions, carbon, and climate: wildland fire detection and burned area in the United States

Treesearch

Wei Min Hao; Narasimhan K. Larkin

2014-01-01

Biomass burning is a major source of greenhouse gases, aerosols, black carbon, and atmospheric pollutants that affects regional and global climate and air quality. The spatial and temporal extent of fires and the size of burned areas are critical parameters in the estimation of fire emissions. Tremendous efforts have been made in the past 12 years to characterize the...

Avifaunal responses to fire in southwestern montane forests along a burn severity gradient

Treesearch

Natasha B. Kotliar; Patricia L. Kennedy; Kimberly Ferree

2007-01-01

The effects of burn severity on avian communities are poorly understood, yet this information is crucial to fire management programs. To quantify avian response patterns along a burn severity gradient, we sampled 49 random plots (2001-2002) at the 17351-ha Cerro Grande Fire (2000) in New Mexico, USA. Additionally, pre-fire avian surveys (1986- 1988, 1990) created a...

Climate change and the eco-hydrology of fire: Will area burned increase in a warming western USA?

USGS Publications Warehouse

McKenzie, Donald; Littell, Jeremy

2017-01-01

Wildfire area is predicted to increase with global warming. Empirical statistical models and process-based simulations agree almost universally. The key relationship for this unanimity, observed at multiple spatial and temporal scales, is between drought and fire. Predictive models often focus on ecosystems in which this relationship appears to be particularly strong, such as mesic and arid forests and shrublands with substantial biomass such as chaparral. We examine the drought–fire relationship, specifically the correlations between water-balance deficit and annual area burned, across the full gradient of deficit in the western USA, from temperate rainforest to desert. In the middle of this gradient, conditional on vegetation (fuels), correlations are strong, but outside this range the equivalence hotter and drier equals more fire either breaks down or is contingent on other factors such as previous-year climate. This suggests that the regional drought–fire dynamic will not be stationary in future climate, nor will other more complex contingencies associated with the variation in fire extent. Predictions of future wildfire area therefore need to consider not only vegetation changes, as some dynamic vegetation models now do, but also potential changes in the drought–fire dynamic that will ensue in a warming climate.

Climate change and the eco-hydrology of fire: Will area burned increase in a warming western USA?

PubMed

McKenzie, Donald; Littell, Jeremy S

2017-01-01

Wildfire area is predicted to increase with global warming. Empirical statistical models and process-based simulations agree almost universally. The key relationship for this unanimity, observed at multiple spatial and temporal scales, is between drought and fire. Predictive models often focus on ecosystems in which this relationship appears to be particularly strong, such as mesic and arid forests and shrublands with substantial biomass such as chaparral. We examine the drought-fire relationship, specifically the correlations between water-balance deficit and annual area burned, across the full gradient of deficit in the western USA, from temperate rainforest to desert. In the middle of this gradient, conditional on vegetation (fuels), correlations are strong, but outside this range the equivalence hotter and drier equals more fire either breaks down or is contingent on other factors such as previous-year climate. This suggests that the regional drought-fire dynamic will not be stationary in future climate, nor will other more complex contingencies associated with the variation in fire extent. Predictions of future wildfire area therefore need to consider not only vegetation changes, as some dynamic vegetation models now do, but also potential changes in the drought-fire dynamic that will ensue in a warming climate. © 2016 by the Ecological Society of America.

Intercomparison of Near-Real-Time Biomass Burning Emissions Estimates Constrained by Satellite Fire Data

EPA Science Inventory

We compare biomass burning emissions estimates from four different techniques that use satellite based fire products to determine area burned over regional to global domains. Three of the techniques use active fire detections from polar-orbiting MODIS sensors and one uses detec...

Recent changes in annual area burned in interior Alaska: The impact of fire management

USGS Publications Warehouse

Calef, M.P.; Varvak, Anna; McGuire, A. David; Chapin, F. S.; Reinhold, K. B.

2015-01-01

The Alaskan boreal forest is characterized by frequent extensive wildfires whose spatial extent has been mapped for the past 70 years. Simple predictions based on this record indicate that area burned will increase as a response to climate warming in Alaska. However, two additional factors have affected the area burned in this time record: the Pacific decadal oscillation (PDO) switched from cool and moist to warm and dry in the late 1970s and the Alaska Fire Service instituted a fire suppression policy in the late 1980s. In this paper a geographic information system (GIS) is used in combination with statistical analyses to reevaluate the changes in area burned through time in Alaska considering both the influence of the PDO and fire management. The authors found that the area burned has increased since the PDO switch and that fire management drastically decreased the area burned in highly suppressed zones. However, the temporal analysis of this study shows that the area burned is increasing more rapidly in suppressed zones than in the unsuppressed zone since the late 1980s. These results indicate that fire policies as well as regional climate patterns are important as large-scale controls on fires over time and across the Alaskan boreal forest.

Experimental study on burning rates of square/rectangular gasoline and methanol pool fires under longitudinal air flow in a wind tunnel.

PubMed

Hu, L H; Liu, S; Peng, W; Huo, R

2009-09-30

Square pool fires with length of 5, 7.5, 10, 15, 20, 25 and 30 cm and rectangular pool fires with dimensions of 10 cm x 20 cm and 10 cm x 40 cm were burned in a wind tunnel, under a longitudinal air flow ranged from 0 to 3m/s with incremental change of about 0.5m/s. Methanol and gasoline were burned and compared, with results indicated that their burning rates showed different response to the longitudinal air flow. With the increase of the longitudinal air flow speed, the burning rates of methanol pool fires, except the 5 cm square one, first decreased and then increased, but those of the 5 cm methanol square one and the gasoline pool fires increased monotonously. The burning rate of smaller square pool fires increased more significantly than that of the larger ones, as well as the enlargement of their flame attachment length along the ground. The burning rate of a rectangular pool fire with longer rim parallel to the longitudinal flow increased faster, but the flame attachment length seemed to increase more gradually, with the increase of the longitudinal air flow speed than that perpendicular to.

A multi-satellite analysis of the direct radiative effects of absorbing aerosols above clouds

NASA Astrophysics Data System (ADS)

Chang, Y. Y.; Christopher, S. A.

2015-12-01

Radiative effects of absorbing aerosols above liquid water clouds in the southeast Atlantic as a function of fire sources are investigated using A-Train data coupled with the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard Suomi National Polar-orbiting Partnership (Suomi NPP). Both the VIIRS Active Fire product and the Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Thermal Anomalies product (MYD14) are used to identify the biomass burning fire origin in southern Africa. The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) are used to assess the aerosol type, aerosol altitude, and cloud altitude. We use back trajectory information, wind data, and the Fire Locating and Modeling of Burning Emissions (FLAMBE) product to infer the transportation of aerosols from the fire source to the CALIOP swath in the southeast Atlantic during austral winter.

Usability and Functional Enhancements to an Online Interface for Predicting Post Fire Erosion (WEPP-PEP)

NASA Astrophysics Data System (ADS)

Lew, Roger; Dobre, Mariana; Elliot, William; Robichaud, Pete; Brooks, Erin; Frankenberger, Jim

2017-04-01

There is an increased interest in the United States to use soil burn severity maps in watershed-scale hydrologic models to estimate post-fire sediment erosion from burned areas. This information is needed by stakeholders in order to concentrate their pre- or post-fire management efforts in ecologically sensitive areas to decrease the probability of post-fire sediment delivery. But these tools traditionally have been time consuming and difficult to use by managers because input datasets must be obtained and correctly processed for valid results. The Water Erosion Prediction Project (WEPP) has previously been developed as an online and easy-to-use interface to help land managers with running simulations without any knowledge of computer programming or hydrologic modeling. The interface automates the acquisition of DEM, climate, soils, and landcover data, and also automates channel and hillslope delineation for the users. The backend is built with Mapserver, GDAL, PHP, C++, Python while the front end uses OpenLayers, and, of course, JavaScript. The existing WEPP online interface was enhanced to provide better usability to stakeholders in United States (Forest Service, BLM, USDA) as well as to provide enhanced functionality for managing both pre-fire and post-fire treatments. Previously, only site administrators could add burn severity maps. The interface now allows users to create accounts to upload and share FlamMap prediction maps, differenced Normalized Burned Ratio (dNBR), or Burned Area Reflectance Classification (BARC) maps. All maps are loaded into a sortable catalog so users can quickly find their area of interest. Once loaded, the interface has been modified to support running comparisons between baseline condition with "no burn" and with a burn severity classification map. The interface has also been enhanced to allow users to conduct single storm analyses to examine, for example, how much soil loss would result after a 100-year storm. An OpenLayers map allows users to overlay the watershed hillslopes and channels, burn severity, and erosion. The interface provides flowpath results for each hillslope and at the outlet, as well as return period and frequency analysis reports. Once problematic areas have been identified, the interface allows users to export the watershed in a format that can be used by the Erosion Risk Management Tool (ERMiT) and Disturbed WEPP (post-disturbance modeling) for more detailed hillslope-level analyses. Numerous other changes were made to improve the overall usability of the interface: allow simulations in both SI and English units, added immovable pop-up dialogs to guide the users, and removed extraneous information from the interface. In upcoming months, a workshop will be conducted to demonstrate these new capabilities to stakeholders. Efforts are underway to use site-specific SSURGO soils to that are modified based on burn severity rather than using generic soil classes.

Biomass burning losses of carbon estimated from ecosystem modeling and satellite data analysis for the Brazilian Amazon region

NASA Astrophysics Data System (ADS)

Potter, Christopher; Brooks Genovese, Vanessa; Klooster, Steven; Bobo, Matthew; Torregrosa, Alicia

To produce a new daily record of gross carbon emissions from biomass burning events and post-burning decomposition fluxes in the states of the Brazilian Legal Amazon (Instituto Brasileiro de Geografia e Estatistica (IBGE), 1991. Anuario Estatistico do Brasil, Vol. 51. Rio de Janeiro, Brazil pp. 1-1024). We have used vegetation greenness estimates from satellite images as inputs to a terrestrial ecosystem production model. This carbon allocation model generates new estimates of regional aboveground vegetation biomass at 8-km resolution. The modeled biomass product is then combined for the first time with fire pixel counts from the advanced very high-resolution radiometer (AVHRR) to overlay regional burning activities in the Amazon. Results from our analysis indicate that carbon emission estimates from annual region-wide sources of deforestation and biomass burning in the early 1990s are apparently three to five times higher than reported in previous studies for the Brazilian Legal Amazon (Houghton et al., 2000. Nature 403, 301-304; Fearnside, 1997. Climatic Change 35, 321-360), i.e., studies which implied that the Legal Amazon region tends toward a net-zero annual source of terrestrial carbon. In contrast, our analysis implies that the total source fluxes over the entire Legal Amazon region range from 0.2 to 1.2 Pg C yr -1, depending strongly on annual rainfall patterns. The reasons for our higher burning emission estimates are (1) use of combustion fractions typically measured during Amazon forest burning events for computing carbon losses, (2) more detailed geographic distribution of vegetation biomass and daily fire activity for the region, and (3) inclusion of fire effects in extensive areas of the Legal Amazon covered by open woodland, secondary forests, savanna, and pasture vegetation. The total area of rainforest estimated annually to be deforested did not differ substantially among the previous analyses cited and our own.

Burn Severity Based Stream Buffers for Post Wildfire Salvage Logging Erosion

NASA Astrophysics Data System (ADS)

Bone, E. D.; Robichaud, P. R.; Brooks, E. S.; Brown, R. E.

2017-12-01

Riparian buffers may be managed for timber harvest disturbances to decrease the risk of hillslope erosion entering stream channels during runoff events. After a wildfire, burned riparian buffers may become less efficient at infiltrating runoff and reducing sedimentation, requiring wider dimensions. Testing riparian buffers under post-wildfire conditions may provide managers guidance on how to manage post-fire salvage logging operations on hillslopes and protect water quality in adjacent streams. We tested burned, unlogged hillslopes at the 2015 North Star Fire and 2016 Cayuse Mountain Fire locations in Washington, USA for their ability to reduce runoff flows and sedimentation. Our objectives were to: 1) measure the travel distances of concentrated flows using three sediment-laden flow rates, 2) measure the change in sediment concentration as each flow moves downslope, 3) test hillslopes under high burn-severity, low burn-severity and unburned conditions, and 4) conduct experiments at 0, 1 and 2 years since the fire events. Mean total flow length at the North Star Fire in year 1 was 211% greater at low burn-severity sites than unburned sites, and 467% greater at high burn-severity sites than unburned sites. Results decreased for all burned sites in year 2; by 40% at the high burn-severity sites, and by 30% at the low burn-severity sites, with no significant changes at the unburned sites. We tested only high burn-severity sites at the Cayuse Mountain Fire in year 0 and 1 where the mean total flow length between year 0 and year 1 decreased by 65%. The results of sediment concentration changes tracked closely with the magnitude of changes in flow travel lengths between treatments. Results indicate that managers may need to increase the widths of burned stream buffers during post-wildfire salvage logging for water quality protection, but stream buffer widths may decrease with less severe burn severity and increasing elapsed time (years) since fire.

Motor vehicle-related burns: a review of 107 cases.

PubMed

Papaevangelou, J; Batchelor, J S; Roberts, A H

1995-02-01

Motor vehicles are a major cause of morbidity and mortality. Burn injuries sustained from motor vehicles form a small but important subgroup. The authors have reviewed the case notes of 107 patients with motor vehicle-related burns over a 13-year period. The age ranged from 18 months to 65 years and the male to female ratio was 4:1. The mechanisms of injury were variable, although four major categories could be identified. These accounted for 83 per cent of the cases. Car fires following road traffic accidents was the largest group accounting for 48.5 per cent of cases. The remaining three groups were: motorcycle-related burns following road traffic accidents (6.5 per cent of cases), garage fire-related burns (15 per cent of cases) and car radiator-related burns (13 per cent of cases). Garage fire-related burns had the highest mortality of the four groups (25 per cent). This study demonstrated that garage fire burns are an important subgroup of motor vehicle-related burns.

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...

Synergy between land use and climate change increases future fire risk in Amazon forests

NASA Astrophysics Data System (ADS)

Le Page, Yannick; Morton, Douglas; Hartin, Corinne; Bond-Lamberty, Ben; Cardoso Pereira, José Miguel; Hurtt, George; Asrar, Ghassem

2017-12-01

Tropical forests have been a permanent feature of the Amazon basin for at least 55 million years, yet climate change and land use threaten the forest's future over the next century. Understory forest fires, which are common under the current climate in frontier forests, may accelerate Amazon forest losses from climate-driven dieback and deforestation. Far from land use frontiers, scarce fire ignitions and high moisture levels preclude significant burning, yet projected climate and land use changes may increase fire activity in these remote regions. Here, we used a fire model specifically parameterized for Amazon understory fires to examine the interactions between anthropogenic activities and climate under current and projected conditions. In a scenario of low mitigation efforts with substantial land use expansion and climate change - Representative Concentration Pathway (RCP) 8.5 - projected understory fires increase in frequency and duration, burning 4-28 times more forest in 2080-2100 than during 1990-2010. In contrast, active climate mitigation and land use contraction in RCP4.5 constrain the projected increase in fire activity to 0.9-5.4 times contemporary burned area. Importantly, if climate mitigation is not successful, land use contraction alone is very effective under low to moderate climate change, but does little to reduce fire activity under the most severe climate projections. These results underscore the potential for a fire-driven transformation of Amazon forests if recent regional policies for forest conservation are not paired with global efforts to mitigate climate change.

New Approach in Modelling Indonesian Peat Fire Emission

NASA Astrophysics Data System (ADS)

Putra, E. I.; Cochrane, M. A.; Saharjo, B.; Yokelson, R. J.; Stockwell, C.; Vetrita, Y.; Zhang, X.; Hagen, S. C.; Nurhayati, A. D.; Graham, L.

2017-12-01

Peat fires are a serious problem for Indonesia, producing devastating environmental effects and making the country the 3rd largest emitter of CO2. Extensive fires ravaged vast areas of peatlands in Sumatra, Kalimantan and Papua during the pronounced El-Nino of 2015, causing international concern when the resultant haze blanketed Indonesia and neighboring countries, severely impacting the health of millions of people. Our recent unprecedented in-situ studies of aerosol and gas emissions from 35 peat fires of varying depths near Palangka Raya, Central Kalimantan have documented the range and variability of emissions from these major fires. We strongly suggest revisions to previously recommended IPPC's emission factors (EFs) from peat fires, notably: CO2 (-8%), CH4 (-55%), NH3 (-86%), and CO (+39%). Our findings clearly showed that Indonesian carbon equivalent measurements (100 years) might have been 19% less than what current IPCC emission factors indicate. The results also demonstrate the toxic air quality in the area with HCN, which is almost only emitted by biomass burning, accounting for 0.28% and the carcinogenic compound formaldehyde 0.04% of emissions. However, considerable variation in emissions may exist between peat fires of different Indonesian peat formations, illustrating the need for additional regional field emissions measurements for parameterizing peatland emissions models for all of Indonesia's major peatland areas. Through the continuous mutual research collaboration between the Indonesian and USA scientists, we will implement our standardized field-based analyses of fuels, hydrology, peat burning characteristics and fire emissions to characterize the three major Indonesian peatland formations across four study provinces (Central Kalimantan, Riau, Jambi and West Papua). We will provide spatial and temporal drivers of the modeled emissions and validate them at a national level using biomass burning emissions estimations derived from Visible/Infrared Imager and Radiometer Suite (VIIRS). Multiple LiDAR datasets (2014, 2011, 2007) for Kalimantan will be used to quantify model accuracy, and new work will be undertaken to quantify uncertainty in our most recent LiDAR-based digital terrain model (DTM), further improving assessments of modelling errors.

Optimizing prescribed fire allocation for managing fire risk in central Catalonia.

PubMed

Alcasena, Fermín J; Ager, Alan A; Salis, Michele; Day, Michelle A; Vega-Garcia, Cristina

2018-04-15

We used spatial optimization to allocate and prioritize prescribed fire treatments in the fire-prone Bages County, central Catalonia (northeastern Spain). The goal of this study was to identify suitable strategic locations on forest lands for fuel treatments in order to: 1) disrupt major fire movements, 2) reduce ember emissions, and 3) reduce the likelihood of large fires burning into residential communities. We first modeled fire spread, hazard and exposure metrics under historical extreme fire weather conditions, including node influence grid for surface fire pathways, crown fraction burned and fire transmission to residential structures. Then, we performed an optimization analysis on individual planning areas to identify production possibility frontiers for addressing fire exposure and explore alternative prescribed fire treatment configurations. The results revealed strong trade-offs among different fire exposure metrics, showed treatment mosaics that optimize the allocation of prescribed fire, and identified specific opportunities to achieve multiple objectives. Our methods can contribute to improving the efficiency of prescribed fire treatment investments and wildfire management programs aimed at creating fire resilient ecosystems, facilitating safe and efficient fire suppression, and safeguarding rural communities from catastrophic wildfires. The analysis framework can be used to optimally allocate prescribed fire in other fire-prone areas within the Mediterranean region and elsewhere. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessment of fire-damaged mesquite trees 8 years following an illegal burn

Treesearch

Gerald J. Gottfried; Peter F. Ffolliott; Pablo Garcia; Diego Valdez-Zamudio; Akram Al-Khouri

2003-01-01

Effects of an illegal burn on the Santa Rita Experimental Range on mesquite (Prosopis velutina) survival in the semidesert grass-shrub ecosystem was initially assessed in terms of firedamage classes 18 months after the fire and again 8 years after the burn. While many of the mesquite trees on the burned site were damaged by the fire, some of the trees appear to have...

The effects of a low intensity fire on a mixed conifer forest in Bryce Canyon National Park, Utah

Treesearch

Henry V. Bastian

2001-01-01

Prescribed fire was used to reduce fuel loading and tree densities. Permanent vegetation and fuel loading plots were randomly established within prescribed burn units. The plots were established in 1995 and were sampled, immediately postburn (within 1 month of the fire), 1 year after the burn, and 2 years after the burn. The prescribed burns were implemented in August...

Fire severity and ecosytem responses following crown fires in California shrublands

USGS Publications Warehouse

Keeley, J.E.; Brennan, T.; Pfaff, A.H.

2008-01-01

Chaparral shrublands burn in large high-intensity crown fires. Managers interested in how these wildfires affect ecosystem processes generally rely on surrogate measures of fire intensity known as fire severity metrics. In shrublands burned in the autumn of 2003, a study of 250 sites investigated factors determining fire severity and ecosystem responses.Using structural equation modeling we show that stand age, prefire shrub density, and the shortest interval of the prior fire history had significant direct effects on fire severity, explaining >50% of the variation in severity.Fire severity per se is of interest to resource managers primarily because it is presumed to be an indicator of important ecosystem processes such as vegetative regeneration, community recovery, and erosion. Fire severity contributed relatively little to explaining patterns of regeneration after fire. Two generalizations can be drawn: fire severity effects are mostly short-lived, i.e., by the second year they are greatly diminished, and fire severity may have opposite effects on different functional types.Species richness exhibited a negative relationship to fire severity in the first year, but fire severity impacts were substantially less in the second postfire year and varied by functional type. Much of this relationship was due to alien plants that are sensitive to high fire severity; at all scales from 1 to 1000 m2, the percentage of alien species in the postfire flora declined with increased fire severity. Other aspects of disturbance history are also important determinants of alien cover and richness as both increased with the number of times the site had burned and decreased with time since last fire.A substantial number of studies have shown that remote-sensing indices are correlated with field measurements of fire severity. Across our sites, absolute differenced normalized burn ratio (dNBR) was strongly correlated with field measures of fire severity and with fire history at a site but relative dNBR was not. Despite being correlated with fire severity, absolute dNBR showed little or no relationship with important ecosystem responses to wildfire such as shrub resprouting or total vegetative regeneration. These findings point to a critical need for further research on interpreting remote sensing indices as applied to postfire management of these shrublands.

Fire severity and ecosytem responses following crown fires in California shrublands.

PubMed

Keeley, Jon E; Brennan, Teresa; Pfaff, Anne H

2008-09-01

Chaparral shrublands burn in large high-intensity crown fires. Managers interested in how these wildfires affect ecosystem processes generally rely on surrogate measures of fire intensity known as fire severity metrics. In shrublands burned in the autumn of 2003, a study of 250 sites investigated factors determining fire severity and ecosystem responses. Using structural equation modeling we show that stand age, prefire shrub density, and the shortest interval of the prior fire history had significant direct effects on fire severity, explaining > 50% of the variation in severity. Fire severity per se is of interest to resource managers primarily because it is presumed to be an indicator of important ecosystem processes such as vegetative regeneration, community recovery, and erosion. Fire severity contributed relatively little to explaining patterns of regeneration after fire. Two generalizations can be drawn: fire severity effects are mostly shortlived, i.e., by the second year they are greatly diminished, and fire severity may have opposite effects on different functional types. Species richness exhibited a negative relationship to fire severity in the first year, but fire severity impacts were substantially less in the second postfire year and varied by functional type. Much of this relationship was due to alien plants that are sensitive to high fire severity; at all scales from 1 to 1000 m2, the percentage of alien species in the postfire flora declined with increased fire severity. Other aspects of disturbance history are also important determinants of alien cover and richness as both increased with the number of times the site had burned and decreased with time since last fire. A substantial number of studies have shown that remote-sensing indices are correlated with field measurements of fire severity. Across our sites, absolute differenced normalized burn ratio (dNBR) was strongly correlated with field measures of fire severity and with fire history at a site but relative dNBR was not. Despite being correlated with fire severity, absolute dNBR showed little or no relationship with important ecosystem responses to wildfire such as shrub resprouting or total vegetative regeneration. These findings point to a critical need for further research on interpreting remote sensing indices as applied to postfire management of these shrublands.

Wetland fire scar monitoring and analysis using archival Landsat data for the Everglades

USGS Publications Warehouse

Jones, John W.; Hall, Annette E.; Foster, Ann M.; Smith, Thomas J.

2013-01-01

The ability to document the frequency, extent, and severity of fires in wetlands, as well as the dynamics of post-fire wetland land cover, informs fire and wetland science, resource management, and ecosystem protection. Available information on Everglades burn history has been based on field data collection methods that evolved through time and differ by land management unit. Our objectives were to (1) design and test broadly applicable and repeatable metrics of not only fire scar delineation but also post-fire land cover dynamics through exhaustive use of the Landsat satellite data archives, and then (2) explore how those metrics relate to various hydrologic and anthropogenic factors that may influence post-fire land cover dynamics. Visual interpretation of every Landsat scene collected over the study region during the study time frame produced a new, detailed database of burn scars greater than 1.6 ha in size in the Water Conservation Areas and post-fire land cover dynamics for Everglades National Park fires greater than 1.6 ha in area. Median burn areas were compared across several landscape units of the Greater Everglades and found to differ as a function of administrative unit and fire history. Some burned areas transitioned to open water, exhibiting water depths and dynamics that support transition mechanisms proposed in the literature. Classification tree techniques showed that time to green-up and return to pre-burn character were largely explained by fire management practices and hydrology. Broadly applicable as they use data from the global, nearly 30-year-old Landsat archive, these methods for documenting wetland burn extent and post-fire land cover change enable cost-effective collection of new data on wetland fire ecology and independent assessment of fire management practice effectiveness.

Fire activity as a function of fire-weather seasonal severity and antecedent climate across spatial scales in southern Europe and Pacific western USA

NASA Astrophysics Data System (ADS)

Urbieta, Itziar R.; Zavala, Gonzalo; Bedia, Joaquín; Gutiérrez, José M.; San Miguel-Ayanz, Jesús; Camia, Andrea; Keeley, Jon E.; Moreno, José M.

2015-11-01

Climate has a strong influence on fire activity, varying across time and space. We analyzed the relationships between fire-weather conditions during the main fire season and antecedent water-balance conditions and fires in two Mediterranean-type regions with contrasted management histories: five southern countries of the European Union (EUMED)(all fires); the Pacific western coast of the USA (California and Oregon, PWUSA)(national forest fires). Total number of fires (≥1 ha), number of large fires (≥100 ha) and area burned were related to mean seasonal fire weather index (FWI), number of days over the 90th percentile of the FWI, and to the standardized precipitation-evapotranspiration index (SPEI) from the preceding 3 (spring) or 8 (autumn through spring) months. Calculations were made at three spatial aggregations in each area, and models related first-difference (year-to-year change) of fires and FWI/climate variables to minimize autocorrelation. An increase in mean seasonal FWI resulted in increases in the three fire variables across spatial scales in both regions. SPEI contributed little to explain fires, with few exceptions. Negative water-balance (dry) conditions from autumn through spring (SPEI8) were generally more important than positive conditions (moist) in spring (SPEI3), both of which contributed positively to fires. The R2 of the models generally improved with increasing area of aggregation. For total number of fires and area burned, the R2 of the models tended to decrease with increasing mean seasonal FWI. Thus, fires were more susceptible to change with climate variability in areas with less amenable conditions for fires (lower FWI) than in areas with higher mean FWI values. The relationships were similar in both regions, albeit weaker in PWUSA, probably due to the wider latitudinal gradient covered in PWUSA than in EUMED. The large variance explained by some of the models indicates that large-scale seasonal forecast could help anticipating fire activity in the investigated areas.

Trace gas emissions to the atmosphere by biomass burning in the west African savannas

NASA Technical Reports Server (NTRS)

Frouin, Robert J.; Iacobellis, Samuel F.; Razafimpanilo, Herisoa; Somerville, Richard C. J.

1994-01-01

Savanna fires and atmospheric carbon dioxide (CO2) detection and estimating burned area using Advanced Very High Resolution Radiometer_(AVHRR) reflectance data are investigated in this two part research project. The first part involves carbon dioxide flux estimates and a three-dimensional transport model to quantify the effect of north African savanna fires on atmospheric CO2 concentration, including CO2 spatial and temporal variability patterns and their significance to global emissions. The second article describes two methods used to determine burned area from AVHRR data. The article discusses the relationship between the percentage of burned area and AVHRR channel 2 reflectance (the linear method) and Normalized Difference Vegetation Index (NDVI) (the nonlinear method). A comparative performance analysis of each method is described.

Burns in mobile home fires--descriptive study at a regional burn center.

PubMed

Mullins, Robert F; Alarm, Badrul; Huq Mian, Mohammad Anwarul; Samples, Jancie M; Friedman, Bruce C; Shaver, Joseph R; Brandigi, Claus; Hassan, Zaheed

2009-01-01

Death from fires and burns are the sixth most common cause of unintentional injury death in the United States. More than (3/4) of burn deaths occurring in the United States are in the home. Mobile home fires carry twice the death rate as other dwellings. The aim of the study was to describe the characteristics of deaths and injuries in mobile home fire admitted in a regional Burn Center and to identify possible risk factors. A cross-sectional retrospective study was carried out among all burn patients admitted to a regional Burn Center between January 2002 and December 2004 (3469 patients). The study included patients who suffered a burn injury from a mobile home fire. The demographic characteristics of the patients, location of mobile home, associated inhalation injury, source of fire, comorbidity of the victims, employment status, insurance status, family history of burns, and outcomes of the treatment were incorporated in a data collection record. There were 65 burn patients in mobile home fires admitted to the Burn Center during the studied period. The average age of the patients was 39 years (ranging from 2 to 81 years, SD=16.06), 77% were male, 67% were white, and 79% were the residents in the suburban areas of Georgia, South Carolina, North Carolina, and Florida. The average TBSA of burns was about 21% (ranging from 1 to 63%, SD=17.66), 63% of the patients had associated inhalation, three inhalation injury only, and 69% patients required ventilator support. The average length of stay per TBSA percentage of burn was 1.01 days (P=0.00), controlling for age, preexisting medical comorbidities, and inhalation injury. About 88% of the patients had preexisting medical comorbid conditions, 74% were smokers, 64% reported as alcoholic, and 72% had at least some form of health insurance coverage. In 40% of the cases, the cause of the fire was unknown, 31% were caused by accidental explosions, such as electric, gasoline, or kerosene appliances, and 29% were due to other causes. About 40% of burns took place between December and February. Among the studied cohorts, 32% were unemployed, 15% were disabled, and 14% did not have any information about their employment status. One in every four patients had a family history of a burn. Eight (12%) died in the hospital during treatment. There was a higher prevalence of inhalation injury and higher case fatality among the burn patients in mobile home fires compared with the statistics of the Burn Center. Observation showed a higher number of smokers and alcoholics among the burn patients. The main sources of fire were from home appliances. Fewer people had health insurance coverage than the national standard and more people suffered from some sort of chronic illness compared with the national morbidity data.

Influences of prior wildfires on vegetation response to subsequent fire in a reburned Southwestern landscape.

PubMed

Coop, Jonathan D; Parks, Sean A; McClernan, Sarah R; Holsinger, Lisa M

2016-03-01

Large and severe wildfires have raised concerns about the future of forested landscapes in the southwestern United States, especially under repeated burning. In 2011, under extreme weather and drought conditions, the Las Conchas fire burned over several previous burns as well as forests not recently exposed to fire. Our purpose was to examine the influences of prior wildfires on plant community composition and structure, subsequent burn severity, and vegetation response. To assess these relationships, we used satellite-derived measures of burn severity and a nonmetric multidimensional scaling of pre- and post- Las Conchas field samples. Earlier burns were associated with shifts from forested sites to open savannas and meadows, oak scrub, and ruderal communities. These non-forested vegetation types exhibited both resistance to subsequent fire, measured by reduced burn severity, and resilience to reburning, measured by vegetation recovery relative to forests not exposed to recent prior fire. Previous shifts toward non-forested states were strongly reinforced by reburning. Ongoing losses of forests and their ecological values confirm the need for restoration interventions. However, given future wildfire and climate projections, there may also be opportunities presented by transformations toward fire-resistant and resilient vegetation types within portions of the landscape.

The effect of azeotropism on combustion characteristics of blended fuel pool fire.

PubMed

Ding, Yanming; Wang, Changjian; Lu, Shouxiang

2014-04-30

The effect of azeotropism on combustion characteristics of blended fuel pool fire was experimentally studied in an open fire test space of State Key Laboratory of Fire Science. A 30 cm × 30 cm square pool filled with n-heptane and ethanol blended fuel was employed. Flame images, burning rate and temperature distribution were collected and recorded in the whole combustion process. Results show that azeotropism obviously dominates the combustion behavior of n-heptane/ethanol blended fuel pool fire. The combustion process after ignition exhibits four typical stages: initial development, azeotropic burning, single-component burning and decay stage. Azeotropism appears when temperature of fuel surface reaches azeotropic point and blended fuel burns at azeotropic ratio. Compared with individual pure fuel, the effect of azeotropism on main fire parameters, such as flame height, burning rate, flame puffing frequency and centerline temperature were analyzed. Burning rate and centerline temperature of blended fuel are higher than that of individual pure fuel respectively at azeotropic burning stage, and flame puffing frequency follows the empirical formula between Strouhal and Froude number for pure fuel. Copyright © 2014 Elsevier B.V. All rights reserved.

Global biomass burning - Atmospheric, climatic, and biospheric implications

NASA Technical Reports Server (NTRS)

Levine, Joel S. (Editor)

1991-01-01

The present volume discusses the biomass burning (BMB) studies of the International Global Atmospheric Chemistry project, GEO satellite estimation of Amazonian BMB, remote sensing of BMB in West Africa with NOAA-AVHRR, an orbital view of the great Chinese fire of 1987, BMB's role in tropical rainforest reduction, CO and O3 measurements of BMB in the Amazon, effects of vegetation burning on the atmospheric chemistry of the Venezuelan savanna, an assessment of annually-burned biomass in Africa, and light hydrocarbon emissions from African savanna burnings. Also discussed are BMB in India, trace gas and particulate emissions from BMB in temperate ecosystems, ammonia and nitric acid emissions from wetlands and boreal forest fires, combustion emissions and satellite imagery of BMB, BMB in the perspective of the global carbon cycle, modeling trace-gas emissions from BMB, NO(x) emissions from BMB, and cloud-condensation nuclei from BMB.

Modeling crop residue burning experiments to evaluate smoke emissions and plume transport.

PubMed

Zhou, Luxi; Baker, Kirk R; Napelenok, Sergey L; Pouliot, George; Elleman, Robert; O'Neill, Susan M; Urbanski, Shawn P; Wong, David C

2018-06-15

Crop residue burning is a common land management practice that results in emissions of a variety of pollutants with negative health impacts. Modeling systems are used to estimate air quality impacts of crop residue burning to support retrospective regulatory assessments and also for forecasting purposes. Ground and airborne measurements from a recent field experiment in the Pacific Northwest focused on cropland residue burning was used to evaluate model performance in capturing surface and aloft impacts from the burning events. The Community Multiscale Air Quality (CMAQ) model was used to simulate multiple crop residue burns with 2 km grid spacing using field-specific information and also more general assumptions traditionally used to support National Emission Inventory based assessments. Field study specific information, which includes area burned, fuel consumption, and combustion completeness, resulted in increased biomass consumption by 123 tons (60% increase) on average compared to consumption estimated with default methods in the National Emission Inventory (NEI) process. Buoyancy heat flux, a key parameter for model predicted fire plume rise, estimated from fuel loading obtained from field measurements can be 30% to 200% more than when estimated using default field information. The increased buoyancy heat flux resulted in higher plume rise by 30% to 80%. This evaluation indicates that the regulatory air quality modeling system can replicate intensity and transport (horizontal and vertical) features for crop residue burning in this region when region-specific information is used to inform emissions and plume rise calculations. Further, previous vertical emissions allocation treatment of putting all cropland residue burning in the surface layer does not compare well with measured plume structure and these types of burns should be modeled more similarly to prescribed fires such that plume rise is based on an estimate of buoyancy. Copyright © 2018 Elsevier B.V. All rights reserved.

Fire regimes, forest change, and self-organization in an old-growth mixed-conifer forest, Yosemite National Park, USA.

PubMed

Scholl, Andrew E; Taylor, Alan H

2010-03-01

Fire is recognized as a keystone process in dry mixed-conifer forests that have been altered by decades of fire suppression, Restoration of fire disturbance to these forests is a guiding principle of resource management in the U.S. National Park Service. Policy implementation is often hindered by a poor understanding of forest conditions before fire exclusion, the characteristics of forest changes since excluding fire, and the influence of topographic or self-organizing controls on forest structure. In this study the spatial and temporal characteristics of fire regimes and forest structure are reconstructed in a 2125-ha mixed-conifer forest. Forests were multi-aged, burned frequently at low severity and fire-return interval, and forest structure did not vary with slope aspect, elevation, or slope position. Fire exclusion has caused an increase in forest density and basal area and a compositional shift to shade-tolerant and fire-intolerant species. The median point fire-return interval and extent of a fire was 10 yr and 115 ha, respectively. The pre-Euro-American settlement fire rotation of 13 yr increased to 378 yr after 1905. The position of fire scars within tree rings indicates that 79% of fires burned in the midsummer to fall period. The spatial pattern of burns exhibited self-organizing behavior. Area burned was 10-fold greater when an area had not been burned by the previous fire. Fires were frequent and widespread, but patches of similar aged trees were < 0.2 ha, suggesting small fire-caused canopy openings. Managers need to apply multiple burns at short intervals for a sustained period to reduce surface fuels and create small canopy openings characteristic of the reference forest. By coupling explicit reference conditions with consideration of current conditions and projected climate change, management activities can balance restoration and risk management.

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...

Climate, fire size, and biophysical setting control fire severity and spatial pattern in the northern Cascade Range, USA

Treesearch

C. Alina Cansler; Donald. McKenzie

2014-01-01

Warmer and drier climate over the past few decades has brought larger fire sizes and increased annual area burned in forested ecosystems of western North America, and continued increases in annual area burned are expected due to climate change. As warming continues, fires may also increase in severity and produce larger contiguous patches of severely burned areas. We...

Rainfall and geomorphic aspects of post-fire soil erosion - Schultz Fire 2010

Treesearch

Ann Youberg; Karen A. Koestner; Daniel G. Neary; Peter E. Koestner

2011-01-01

The human-caused Schultz Fire near Flagstaff, Arizona burned 6,100 ha (15,075 acres) on the Coconino National Forest between June 20th and 30th, 2010. Ignited by an abandoned campfire, high winds drove the fire over approximately 60% of the total area burned during the first 12 hours (U.S. Forest Service, 2010). The majority of the area burned at moderate (27%) or high...

Global Pyrogeography: the Current and Future Distribution of Wildfire

PubMed Central

Krawchuk, Meg A.; Moritz, Max A.; Parisien, Marc-André; Van Dorn, Jeff; Hayhoe, Katharine

2009-01-01

Climate change is expected to alter the geographic distribution of wildfire, a complex abiotic process that responds to a variety of spatial and environmental gradients. How future climate change may alter global wildfire activity, however, is still largely unknown. As a first step to quantifying potential change in global wildfire, we present a multivariate quantification of environmental drivers for the observed, current distribution of vegetation fires using statistical models of the relationship between fire activity and resources to burn, climate conditions, human influence, and lightning flash rates at a coarse spatiotemporal resolution (100 km, over one decade). We then demonstrate how these statistical models can be used to project future changes in global fire patterns, highlighting regional hotspots of change in fire probabilities under future climate conditions as simulated by a global climate model. Based on current conditions, our results illustrate how the availability of resources to burn and climate conditions conducive to combustion jointly determine why some parts of the world are fire-prone and others are fire-free. In contrast to any expectation that global warming should necessarily result in more fire, we find that regional increases in fire probabilities may be counter-balanced by decreases at other locations, due to the interplay of temperature and precipitation variables. Despite this net balance, our models predict substantial invasion and retreat of fire across large portions of the globe. These changes could have important effects on terrestrial ecosystems since alteration in fire activity may occur quite rapidly, generating ever more complex environmental challenges for species dispersing and adjusting to new climate conditions. Our findings highlight the potential for widespread impacts of climate change on wildfire, suggesting severely altered fire regimes and the need for more explicit inclusion of fire in research on global vegetation-climate change dynamics and conservation planning. PMID:19352494