Fire Burnt Area Research Articles

Linear fractional-based filter as a pre-classifier to map burned areas in Mediterranean countries

Wildfires in Southern Europe burn thousands of square kilometres every year, causing extensive economic and ecological losses. Accurate mapping of fire-burned areas is a decisive factor in guiding forest management decisions. In this work a linear fractional-based filter is considered as a pre-classifier for burned area estimation from Moderate Resolution Imaging Spectroradiometer (MODIS) accurate satellite imagery. Three vegetation indices (normalized difference vegetation index, enhanced vegetation index, and global environment monitoring index) and three spectral indices specifically designed for burned area identification (normalized burnt ratio, burned area index, and burned area adapted for MODIS) have been used as inputs for the proposed filter. The filtered images were classified and the accuracy of the burned area estimates was computed by kappa () statistic. Burned area perimeters measured on the ground by global positioning system were used as reference truth. A linear Gaussian pre-classification filter was used as reference to check the burned area estimates accuracy improvements. When using the proposed fractional-type filter, an accurate estimation () of areas burned by forest fires in the four study areas located in Central Spain was achieved. The results showed that the non-local filter, used as a pre-classifier, allowed higher accuracy than the same inputs both without filtering and with the Gaussian filter ( index increased up to 30% with statistical significance). McNemar test confirmed that such accuracy improvement had statistical significance, and a statistical separability test showed that filtering increased the inter-class distance, helping to improve the latter classification. Burned areas in Central Spain were accurately mapped when the linear fractional-based filter proposed here was used as a pre-classifier.

Gamma generalized linear model to investigate the effects of climate variables on the area burned by forest fire in northeast China

The purpose of this study was to determine a suitable model for investigating the effects of climate factors on the area burned by forest fire in the Tahe forest region, Daxing’an Mountains, in northeast China. The response variables were the area burned by lightning-caused fire, human-caused fire, and total burned area. The predictor variables were nine climate variables collected from the local weather station. Three regression models were utilized, including multiple linear regression, log-linear model (log-transformation on both response and predictor variables), and gamma-generalized linear model. The goodness-of-fit of the models were compared based on model fitting statistics such as R2, AIC, and RMSE. The results revealed that the gamma-generalized linear model was generally superior to both multiple linear regression model and log-linear model for fitting the fire data. Further, the best models were selected based on the criteria that the climate variables were statistically significant at α = 0.05. The gamma best models indicated that maximum wind speed, precipitation, and days that rainfall greater than 0.1 mm had significant impacts on the area burned by the lightning-caused fire, while the mean temperature and minimum relative humidity were the main drivers of the burned area caused by human activities. Overall, the total burned area by forest fire was significantly influenced by days that rainfall greater than 0.1 mm and minimum relative humidity, indicating that the moisture condition of forest stands determine the burned area by forest fire.

A MODIS time series data based algorithm for mapping forest fire burned area

Burned area mapping is an essential step in the forest fire research to investigate the relationship between forest fire and climate change and the effect of forest fire on carbon budgets. This study proposed an algorithm to map forest fire burned area using the Moderate-Resolution Imaging Spectroradiameter (MODIS) time series data in Heilongjiang Province, China. The algorithm is divided into two steps: Firstly, the ‘core’ pixels were extracted to represent the most possible burned pixels based on the comparison of the temporal change of Global Environmental Monitoring Index (GEMI), Burned Area Index (BAI) and MODIS active fire products between pre- and post-fires. Secondly, a 15-km distance was set to extract the entire burned areas near the ‘core’ pixels as more relaxed conditions were used to identify the fire pixels for reducing the omission error as much as possible. The algorithm comprehensively considered the thermal characteristics and the spectral change between pre- and post-fires, which are represented by the MODIS fire products and the spectral index, respectively. Tahe, Mohe and Huma counties of Heilongjiang Province, China were chosen as the study area for burned area mapping and a time series of burned maps were produced from 2000 to 2011. The results show that the algorithm can extract burned areas more accurately with the highest accuracy of 96.61%.

Detection of vegetation fires and burnt areas by remote sensing in insular Southeast Asian conditions: current status of knowledge and future challenges

The humid tropical insular Southeast Asian region is one of the most biologically diverse areas in the world. It contains around 70 Gt of carbon stored in peat deposits susceptible to burning when drained and it has significantly higher population density than any other humid tropical region. This region experiences yearly fire activity of anthropogenic origin with widely varying extent and severity. At the same time, there are several geographic, climatic, and social aspects that complicate fire monitoring in the region. In this review article, we analyse the current knowledge and limitations of active fire detection and burnt area mapping in insular Southeast Asia, highlighting the special characteristics of the region that affect all types of remote-sensing-based regional-level fire monitoring. We conclude that the monitoring methods currently employed have serious limitations that directly affect the reliability of results for fire and burnt area monitoring in this region. With the materials and methods presently available, the regional and global effects of fire activity taking place in insular Southeast Asia are in danger of being underestimated. New approaches utilizing higher spatial and temporal resolution remote-sensing data are needed for more detailed quantification of fire activity and subsequently improved estimation of the effects of fires in this region.

Effects of Fire Regulation Revisions on Building Fire Damage

Between 1965 and 1974, there were many large building fires in Japan which resulted in numerous fatalities. In response, several revisions were made to the fire regulations for large buildings in the Building Standard Law and the Fire Service Law, leading to a decrease in such fires until about 1980. Extensive fire damage was frequently seen in old buildings with insufficient fire prevention features, so application of the fire regulation revisions to existing buildings was a crucial problem.This paper compares the content and timing of fire regulation revisions, retroactive application to existing buildings, and time limits for retroactive application of each fire regulation with the average fire burned area of buildings in which fires originated according to usage and construction.I examine the main causes of the sudden decrease in fire damage to large buildings from about 1970 to 1980, and show that the decrease is due to a sharp reduction in the number of large fires, owing to the retroactive installation of automatic fire alarm systems.

Global burned area and biomass burning emissions from small fires

In several biomes, including croplands, wooded savannas, and tropical forests, many small fires occur each year that are well below the detection limit of the current generation of global burned area products derived from moderate resolution surface reflectance imagery. Although these fires often generate thermal anomalies that can be detected by satellites, their contributions to burned area and carbon fluxes have not been systematically quantified across different regions and continents. Here we developed a preliminary method for combining 1‐km thermal anomalies (active fires) and 500 m burned area observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) to estimate the influence of these fires. In our approach, we calculated the number of active fires inside and outside of 500 m burn scars derived from reflectance data. We estimated small fire burned area by computing the difference normalized burn ratio (dNBR) for these two sets of active fires and then combining these observations with other information. In a final step, we used the Global Fire Emissions Database version 3 (GFED3) biogeochemical model to estimate the impact of these fires on biomass burning emissions. We found that the spatial distribution of active fires and 500 m burned areas were in close agreement in ecosystems that experience large fires, including savannas across southern Africa and Australia and boreal forests in North America and Eurasia. In other areas, however, we observed many active fires outside of burned area perimeters. Fire radiative power was lower for this class of active fires. Small fires substantially increased burned area in several continental‐scale regions, including Equatorial Asia (157%), Central America (143%), and Southeast Asia (90%) during 2001–2010. Globally, accounting for small fires increased total burned area by approximately by 35%, from 345 Mha/yr to 464 Mha/yr. A formal quantification of uncertainties was not possible, but sensitivity analyses of key model parameters caused estimates of global burned area increases from small fires to vary between 24% and 54%. Biomass burning carbon emissions increased by 35% at a global scale when small fires were included in GFED3, from 1.9 Pg C/yr to 2.5 Pg C/yr. The contribution of tropical forest fires to year‐to‐year variability in carbon fluxes increased because small fires amplified emissions from Central America, South America and Southeast Asia—regions where drought stress and burned area varied considerably from year to year in response to El Nino‐Southern Oscillation and other climate modes.

Forest fires in Northern region of Portugal: Impact on PM levels

Every year European citizens become victims of devastating fires, which are especially disastrous for Southern European countries. Apart from the numerous health and economic consequences, fires generate hazardous pollutants that are introduced into the environment, thus representing serious risks for public health. In that regard, particulate matter (PM) is of a major concern. Thus, the objectives of this work were to characterize the trend of forest fire occurrences and burnt area during the period of 2005 and 2010 and to study the influence of forest fires on levels of particulate matter PM10 and PM2.5. In 2010, 22,026 forest fires occurred in Portugal. The northern region was the most affected by forest fires, with 27% of occurrences in Oporto district. The annual means of PM10 and PM2.5 concentrations at two urban background sites were 25±14μgm−3 and 8.2±4.9μgm−3, and 17±13μgm−3 and 7.3±5.9μgm−3, respectively. At both sites the highest levels of PM fractions were observed during July and August of 2010, corresponding to the periods when majority (66%) of forest fires occurred. Furthermore, PM10 daily limit at the two sites was exceeded during 20 and 5days, respectively; 56%, and respectively 60% of those exceedances occurred during the forest fire season. Considering that the risks of forest fire ignition and severity are enhanced with elevated temperatures, the climate change might increase the environmental impacts of forest fires.

Value of a Dual-Polarized Gap-Filling Radar in Support of Southern California Post-Fire Debris-Flow Warnings

AbstractA portable truck-mounted C-band Doppler weather radar was deployed to observe rainfall over the Station Fire burn area near Los Angeles, California, during the winter of 2009/10 to assist with debris-flow warning decisions. The deployments were a component of a joint NOAA–U.S. Geological Survey (USGS) research effort to improve definition of the rainfall conditions that trigger debris flows from steep topography within recent wildfire burn areas. A procedure was implemented to blend various dual-polarized estimators of precipitation (for radar observations taken below the freezing level) using threshold values for differential reflectivity and specific differential phase shift that improves the accuracy of the rainfall estimates over a specific burn area sited with terrestrial tipping-bucket rain gauges. The portable radar outperformed local Weather Surveillance Radar-1988 Doppler (WSR-88D) National Weather Service network radars in detecting rainfall capable of initiating post-fire runoff-generated debris flows. The network radars underestimated hourly precipitation totals by about 50%. Consistent with intensity–duration threshold curves determined from past debris-flow events in burned areas in Southern California, the portable radar-derived rainfall rates exceeded the empirical thresholds over a wider range of storm durations with a higher spatial resolution than local National Weather Service operational radars. Moreover, the truck-mounted C-band radar dual-polarimetric-derived estimates of rainfall intensity provided a better guide to the expected severity of debris-flow events, based on criteria derived from previous events using rain gauge data, than traditional radar-derived rainfall approaches using reflectivity–rainfall relationships for either the portable or operational network WSR-88D radars. Part of the reason for the improvement was due to siting the radar closer to the burn zone than the WSR-88Ds, but use of the dual-polarimetric variables improved the rainfall estimation by ~12% over the use of traditional Z–R relationships.

Influences to Forest Fire Occurrence of Climate Change: A Study in Ta He Forestry Bureau in Great Xing’an Mountain

Forest fire is one of the most important ecological factors in the forest ecosystem. The Daxinanling forest region has not only the largest forest areas, but also the biggest forest fire burned area in China. By analyzing the recorded climate and forest fire data of Ta He forestry bureau from 1974 to 2004, the following results can be concluded: (1) There were 298 forest fires recorded by Ta He forestry bureau during 31 years and the burned area were 1.63 million hectares totally with 9.6 forest fires per year, unpredictable and short fire cycle as characters. (2) According to the occurrence time of forest fires, the Julian date concentrated between 102~181 and 240~293, corresponding April 12th to June 30th and August 28th to October 20th, which were spring and autumn fire prevention periods. Major fires mainly occurred in spring of 1974~1982, 1986~1987, 1993, and 1998~2002. The major fires cycle were 4 to 5 years. (3) The related indices of temperature, relative humidity, rainfall, and wind speed recorded in June in Ta He forestry bureau were 0.3929, 0.5274, 0.6136 and 0.1679. Temperature, relative humidity and rainfall factors in June had obvious linear relationships to forest fires, while the relationship between wind speed and forest fires is unobvious.

Timing Constraints on Remote Sensing of Wildland Fire Burned Area in the Southeastern US

Remote sensing using Landsat Thematic Mapper (TM) satellite imagery is increasingly used for mapping wildland fire burned area and burn severity, owing to its frequency of collection, relatively high resolution, and availability free of charge. However, rapid response of vegetation following fire and frequent cloud cover pose challenges to this approach in the southeastern US. We assessed these timing constraints by using a series of Landsat TM images to determine how rapidly the remotely sensed burn scar signature fades following prescribed burns in wet flatwoods and depression swamp community types in the Apalachicola National Forest, Florida, USA during 2006. We used both the Normalized Burn Ratio (NBR) of reflectance bands sensitive to vegetation and exposed soil cover, as well as the change in NBR from before to after fire (dNBR), to estimate burned area. We also determined the average and maximum amount of time following fire required to obtain a cloud-free image for burns in each month of the year, as well as the predicted effect of this time lag on percent accuracy of burn scar estimates. Using both NBR and dNBR, the detectable area decreased linearly 9% per month on average over the first four months following fire. Our findings suggest that the NBR and dNBR methods for monitoring burned area in common southeastern US vegetation community types are limited to an average of 78–90% accuracy among months of the year, with individual burns having values as low as 38%, if restricted to use of Landsat 5 TM imagery. However, the majority of burns can still be mapped at accuracies similar to those in other regions of the US, and access to additional sources of satellite imagery would improve overall accuracy.

Effects to Forest Fire Occurrence of Climate Change in Ta He Forestry Bureau in Great Xing’an Mountain

Forest fire is one of the most important ecological factors in the forest ecosystem. The Great Xing’an Mountain region has not only the largest forest areas, but also the biggest forest fire burned area in China. By analyzing the recorded climate and forest fire data of Ta He forestry bureau from 1974 to 2004, the following results can be concluded: (1) There were 298 forest fires recorded by Ta He forestry bureau during 31 years and the burned area were 1.63 million hectares totally with 9.6 forest fires per year, unpredictable and short fire cycle as characters. (2) According to the occurrence time of forest fires, the Julian date concentrated between 102~181 and 240~293, corresponding April 12th to June 30th and August 28th to October 20th, which were spring and autumn fire prevention periods. Major fires mainly occurred in spring of 1974~1982, 1986~1987, 1993, and 1998~2002. The major fires cycle were 4 to 5 years. (3) The related indices of temperature, relative humidity, rainfall, and wind speed recorded in June in Ta He forestry bureau were 0.3929, 0.5274, 0.6136 and 0.1679. Temperature, relative humidity and rainfall factors in June had obvious linear relationships to forest fires, while the relationship between wind speed and forest fires is unobvious.

THE EXTRACTING OF FIRE SCARS FROM TM IMAGE

Based on an analysis of the spectral characteristics of the fire burned areas in ETM image,the authors have studied the methods for rapid extraction of the burned areas.In this paper,four methods were set up.They are the supervised classification method,the supervised classification method with the participation of NDVI,the supervised classification method of the combination image of the NDVI difference between two-period image and the first two principal components(NDVI difference method for short),and the method based on relations of the spectral characteristics(spectral relationship method).The results of the extraction are evaluated in this paper.

Operational active fire mapping and burnt area identification applicable to Mexican Nature Protection Areas using MODIS and NOAA-AVHRR direct readout data

Since 1999, the National Commission for the Knowledge and Use of the Biodiversity (CONABIO) in Mexico has been developing and managing the “Operational program for the detection of hot-spots using remote sensing techniques”. This program uses images from the MODerate resolution Imaging Spectroradiometer (MODIS) onboard the Terra and Aqua satellites and from the Advanced Very High Resolution Radiometer of the National Oceanic and Atmospheric Administration (NOAA-AVHRR), which are operationally received through the Direct Readout station (DR) at CONABIO. This allows the near-real time monitoring of fire events in Mexico and Central America. In addition to the detection of active fires, the location of hot spots are classified with respect to vegetation types, accessibility, and risk to Nature Protection Areas (NPA). Besides the fast detection of fires, further analysis is necessary due to the considerable effects of forest fires on biodiversity and human life. This fire impact assessment is crucial to support the needs of resource managers and policy makers for adequate fire recovery and restoration actions. CONABIO attempts to meet these requirements, providing post-fire assessment products as part of the management system in particular for satellite-based burnt area mapping. This paper provides an overview of the main components of the operational system and will present an outlook to future activities and system improvements, especially the development of a burnt area product. A special focus will also be placed on the fire occurrence within NPAs of Mexico.

Canary Islands burned land mapping using MODIS and HOTSPOT data

This study presents a rapid, accurate and economic methodology for forest fire burned areas estimation using remote sensing techniques. The algorithm used is based on thresholds identifications from infrared spectral band, using MODIS images and hotspots time series delivered from NASA. The threshold is defined by the maximum correlation between the infrared band and hotspot influence area. The results show the usefulness of the presented methodology in forest fire burned area estimation and its relevance for prioritizing forest management activities and for planning future reforestations work in the affected area.

Linking Forest Fire Regimes and Climate—A Historical Analysis in a Dry Inner Alpine Valley

Forest fire regimes are likely to experience considerable changes in the European Alps due to climatic changes. However, little is known about the recent regional fire history and the impact of local climate on the fire regime during the 20th century. We therefore reconstructed the fire history in a dry continental valley of the Swiss Alps (Valais) over the past 100 years based on documentary evidence, and investigated the relationship between the reconstructed fire regime and the local climatic variability. We compared the impact of temperature, precipitation, drought and dry foehn winds on fire frequency, extent of burnt area, and fire seasonality on various spatial and temporal scales. In the subalpine zone, the fire regime appears to have been mainly driven by temperature and precipitation, whereas these variables seem to have played only a secondary role in the colline-montane zones. Here, foehn winds and, probably, non-climatic factors seem to have been more important. Temperature and precipitation played a major role in shaping fire frequency and burnt area in the first half of the 20th century, but lost their importance during the second half. Our case study illustrates the occurrence of different fire regime patterns and their driving forces on small spatial scales (a few hundred square kilometers). We conclude that the strong rise in temperature over the past century has not profoundly changed the fire regime in Valais, but in the second half of the 20th century temperature was no longer a strong determinant for forest fires as compared to human activities or biomass availability in forests.

An Integrated Approach to Wildland Fire Mapping of California, USA Using NOAA/AVHRR Data

To map wildland fires for emission estimation in California, this paper presents an integrated approach to wildfire mapping using daily data of the Advanced Very High Resolution Radiometer (AVHRR) on board a National Oceanic and Atmospheric Administration's (NOAA) satellite. The approach consists of two parts: active fire detection and burnt area mapping. In active fire detection, we combined the strengths of a fixed multi-channel threshold algorithm and an adaptive-threshold contextual algorithm and modified the fire detection algorithm developed by the Canada Center for Remote Sensing (CCRS) for fire detection in boreal forest ecosystems. We added a contextual test, which considers the radiometric difference between a fire pixel and its surrounding pixels, and a sun glint elimination test to the CCRS algorithm. This can effectively remove false alarms caused by highly reflective clouds and surfaces and by warm backgrounds. In burnt area mapping, we adopted and modified the Hotspot and NDVI Differencing Synergy (HANDS) algorithm, which combines the strengths of hotspot detection and multi-temporal NDVI differencing. We modified the HANDS procedure in three ways: normalizing post-fire NDVI to pre-fire NDVI by multiplying an NDVI ratio coefficient, calculating mean and standard deviation of NDVI decrease of land-cover types separately, and adding a new iteration procedure for confirming potential burnt pixels. When the integrated method was applied to the mapping of wildland fires in California during the 1999 fire season, it produced comparable results. Most of the wildfires mapped were found to be correct, especially for those in forested ecosystems. Validation was based both on limited ground truth from the California Department of Forestry and Fire Protection and on interpreted burnt areas from Landsat 7 TM scenes.

Validation and Calibration of Canada-Wide Coarse-Resolution Satellite Burned-Area Maps

Satellite-based mapping can provide a timely and efficient means of identifying burned vegetation at continental scales for estimating greenhouse gas emissions and impacts on the terrestrial carbon budget. In this study, we used a sample of 55 Landsat Thematic Mapper (TM) scenes distributed across Canada to validate and calibrate 1998 and 1999 national­ level burned areas maps produced using coarse resolution (approx. 1-km) SPOT VEGETATION and NOAA AVHRR imagery. Commission and omissions errors, based on fire events greater than 200 ha, were found to be small in the coarse resolution maps (4 percent and 1 percent, respectively). However, the coarse resolution burned-area estimates were 72 percent larger than the crown fire burned area mapped at 30 musing Landsat TM (11,039 versus 6,403 ha average area). This bias was attributed to spatial aggregation effects in which the coarse resolution product included the tree crown fire, partial burn, and unburned fractions of a pixel. A regression calibra­ tion model (R2 = 0.95, P < 0.0005, RMSE = 3,015 ha, n = iSS) based on a VGT/TM double sampling approach was derived to correct for the aggregation bias and to provide Canada-wide estimates of crown fire burned area.

THE DETERIORATION OF FIRE-KILLED WHITE SPRUCE BY WOOD-BORING INSECTS IN NORTHERN SASKATCHEWAN

The problem of determining the rate of deterioration from the attacks of wood-boring insects on white spruce saw timber and pulpwood killed and damaged by fire is of considerable importance to foresters, owners and operators. In order that salvage operations may be undertaken promptly to utilize the timber, it is necessary to be able to determine values soon after the damage and to make plans to harvest first those classes of timber subject to the most rapid depreciation, leaving until later those trees least subject to value loss.This investigation initiated in 1941 with the early observation of the prevalence of wood-borers in fire burned areas of white spruce on the Carrot River watershed in Saskatchewan, was followed by intensive investigation during the summer months of 1942 to 1944.The investigation and report will be of great value to those concerned with the salvage utilization of fire-killed and damaged spruce and this work warrants the highest praise for those who undertook this valuable study. Extensive forest fires in 1942 damaged many spruce stands in Manitoba and Saskatchewan which totalled millions of board feet of saw timber and thousands of cords of pulpwood. Due to war-time demand and the high prices prevailing, it was possible and practical to produce and market a high percentage of the accessible stands during the three to four years subsequent to the fire damage.