scholarly journals Impact of large wildfires on PM<sub>10</sub> levels and human mortality in Portugal

2021 ◽  
Vol 21 (9) ◽  
pp. 2867-2880
Author(s):  
Patricia Tarín-Carrasco ◽  
Sofia Augusto ◽  
Laura Palacios-Peña ◽  
Nuno Ratola ◽  
Pedro Jiménez-Guerrero
Keyword(s):  
Fire Season ◽  
Burned Area ◽  
Substantial Impact ◽  
Burned Areas ◽  
The North ◽  
Mainland Portugal ◽  
Large Fires ◽  
European Forest ◽  
Air Quality Monitoring Stations ◽  
June July

Abstract. Uncontrolled wildfires have a substantial impact on the environment, the economy and local populations. According to the European Forest Fire Information System (EFFIS), between 2000 and 2013 wildfires burned up to 740 000 ha of land annually in the south of Europe, Portugal being the country with the highest percentage of burned area per square kilometre. However, there is still a lack of knowledge regarding the impacts of the wildfire-related pollutants on the mortality of the country's population. All wildfires occurring during the fire season (June–July–August–September) from 2001 and 2016 were identified, and those with a burned area above 1000 ha (large fires) were considered for the study. During the studied period (2001–2016), more than 2 million ha of forest (929 766 ha from June to September alone) were burned in mainland Portugal. Although large fires only represent less than 1 % of the number of total fires, in terms of burned area their contribution is 46 % (53 % from June to September). To assess the spatial impact of the wildfires, burned areas in each region of Portugal were correlated with PM10 concentrations measured at nearby background air quality monitoring stations. Associations between PM10 and all-cause (excluding injuries, poisoning and external causes) and cause-specific mortality (circulatory and respiratory) were studied for the affected populations using Poisson regression models. A significant positive correlation between burned area and PM10 was found in some regions of Portugal, as well as a significant association between PM10 concentrations and mortality, these being apparently related to large wildfires in some of the regions. The north, centre and inland of Portugal are the most affected areas. The high temperatures and long episodes of drought expected in the future will increase the probabilities of extreme events and therefore the occurrence of wildfires.

scholarly journals Impact of large wildfires on PM10 levels and human mortality in Portugal

2021 ◽  
Author(s):  
Patricia Tarín-Carrasco ◽  
Sofia Augusto ◽  
Laura Palacios-Peña ◽  
Nuno Ratola ◽  
Pedro Jiménez-Guerrero
Keyword(s):  
Burned Area ◽  
Substantial Impact ◽  
Mainland Portugal ◽  
Large Fires ◽  
External Causes ◽  
Environment Agency ◽  
European Forest ◽  
Air Quality Monitoring Stations ◽  
June July ◽  
Background Air

Abstract. Uncontrolled wildfires have a substantial impact on the environment, the economy and local populations. According to the European Forest Fire Information System (EFFIS), between the years 2000 and 2013 wildfires burnt about 170,000–740,000 ha of land annually on the south of Europe (Portugal, Spain, Italy, Greece and France). Although most southern European countries have been impacted by wildfires in the last decades, Portugal was the most affected, having the highest percentage of burned area comparing to its whole territory. For this reason, it deserves a closer attention. However, there is a lack of knowledge regarding the impacts of the wildfire-related pollutants on the mortality of the population. All wildfires occurring during the fire seasons (June-July-August-September) from 2001 and 2016 were identified and those with a burned area above 1000 ha were considered for the study. To assess the spatial impact of the wildfires, these were correlated with PM10 concentrations measured at nearby background air quality monitoring stations, provided by the Portuguese Environment Agency (APA). Associations between PM10 and all-cause (excluding injuries, poisoning and external causes) and cause-specific mortality (circulatory and respiratory), provided by Statistics Portugal, were studied for the affected populations, using Poisson regression models. During the studied period (2001–2016), more than 2 million ha of forest were burned in mainland Portugal and the 48 % of wildfires occurred were large fires. A significant correlation between burned area and PM10 have been found in some NUTS III (regions) on Portugal, as well as a significant correlation between burned area and mortality. North, centre and inland of Portugal are the most affected areas. The high temperatures and long episodes of drought expected on the future will increase the probabilities of extreme events and therefore, the occurrence of wildfires.

scholarly journals Understanding the Impact of Different Landscape-Level Fuel Management Strategies on Wildfire Hazard in Central Portugal

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 522
Author(s):  
Akli Benali ◽  
Ana C. L. Sá ◽  
João Pinho ◽  
Paulo M. Fernandes ◽  
José M. C. Pereira
Keyword(s):  
Management Strategies ◽  
Treatment Strategies ◽  
Fire Season ◽  
Burned Area ◽  
Treatment Area ◽  
Fuel Treatment ◽  
The North ◽  
Wildfire Hazard ◽  
Central Portugal ◽  
The Impact

The extreme 2017 fire season in Portugal led to widespread recognition of the need for a paradigm shift in forest and wildfire management. We focused our study on Alvares, a parish in central Portugal located in a fire-prone area, which had 60% of its area burned in 2017. We evaluated how different fuel treatment strategies may reduce wildfire hazard in Alvares through (i) a fuel break network with different extents corresponding to different levels of priority and (ii) random fuel treatments resulting from a potential increase in stand-level management intensity. To assess this, we developed a stochastic wildfire simulation system (FUNC-SIM) that integrates uncertainties in fuel distribution over the landscape. If the landscape remains unchanged, Alvares will have large burn probabilities in the north, northeast and center-east areas of the parish that are very often associated with high fireline intensities. The different fuel treatment scenarios decreased burned area between 12.1–31.2%, resulting from 1–4.6% increases in the annual treatment area and reduced the likelihood of wildfires larger than 5000 ha by 10–40%. On average, simulated burned area decreased 0.22% per each ha treated, and cost-effectiveness decreased with increasing area treated. Overall, both fuel treatment strategies effectively reduced wildfire hazard and should be part of a larger, holistic and integrated plan to reduce the vulnerability of the Alvares parish to wildfires.

scholarly journals Estimates of biomass burning emissions in tropical Asia based on satellite-derived data

2010 ◽  
Vol 10 (5) ◽  
pp. 2335-2351 ◽  
Author(s):  
D. Chang ◽  
Y. Song
Keyword(s):  
Biomass Burning ◽  
Atmospheric Chemistry ◽  
Crop Residue ◽  
Fire Season ◽  
Burned Area ◽  
Published Data ◽  
Tropical Asia ◽  
Fire Emissions ◽  
Burned Areas ◽  
In Fire

Abstract. Biomass burning in tropical Asia emits large amounts of trace gases and particulate matter into the atmosphere, which has significant implications for atmospheric chemistry and climatic change. In this study, emissions from open biomass burning over tropical Asia were evaluated during seven fire years from 2000 to 2006 (1 March 2000–31 February 2007). The size of the burned areas was estimated from newly published 1-km L3JRC and 500-m MODIS burned area products (MCD45A1). Available fuel loads and emission factors were assigned to each vegetation type in a GlobCover characterisation map, and fuel moisture content was taken into account when calculating combustion factors. Over the whole period, both burned areas and fire emissions showed clear spatial and seasonal variations. The size of the L3JRC burned areas ranged from 36 031 km2 in fire year 2005 to 52 303 km2 in 2001, and the MCD45A1 burned areas ranged from 54 790 km2 in fire year 2001 to 148 967 km2 in 2004. Comparisons of L3JRC and MCD45A1 burned areas using ground-based measurements and other satellite data were made in several major burning regions, and the results suggest that MCD45A1 generally performed better than L3JRC, although with a certain degree of underestimation in forest areas. The average annual L3JRC-based emissions were 123 (102–152), 12 (9–15), 1.0 (0.7–1.3), 1.9 (1.4–2.6), 0.11 (0.09–0.12), 0.89 (0.63–1.21), 0.043 (0.036–0.053), 0.021 (0.021–0.023), 0.41 (0.34–0.52), 3.4 (2.6–4.3), and 3.6 (2.8–4.7) Tg yr−1 for CO2, CO, CH4, NMHCs, NOx, NH3, SO2, BC, OC, PM2.5, and PM10, respectively, whereas MCD45A1-based emissions were 122 (108–144), 9.3 (7.7–11.7), 0.63 (0.46–0.86), 1.1 (0.8–1.6), 0.11 (0.10–0.13), 0.54 (0.38–0.76), 0.043 (0.038–0.051), 0.033 (0.032–0.037), 0.39 (0.34–0.47), 3.0 (2.6–3.7), and 3.3 (2.8–4.0) Tg yr−1. Forest burning was identified as the major source of the fire emissions due to its high carbon density. Although agricultural burning was the second highest contributor, it is possible that some crop residue combustion was missed by satellite observations. This possibility is supported by comparisons with previously published data, and this result may be due to the small size of the field crop residue burning. Fire emissions were mainly concentrated in Indonesia, India, Myanmar, and Cambodia. Furthermore, the peak in the size of the burned area was generally found in the early fire season, whereas the maximum fire emissions often occurred in the late fire season.

Changes in the timing and length of the fire season in Spain

2020 ◽  
Author(s):  
Itziar R. Urbieta ◽  
Gonzalo Arellano ◽  
José M. Moreno
Keyword(s):  
Fire Suppression ◽  
Generalized Additive Models ◽  
Summer Season ◽  
Additive Models ◽  
Fire Season ◽  
Burned Area ◽  
Burned Areas ◽  
Spatial Differences ◽  
Mediterranean Regions ◽  
In Fire

&lt;p&gt;Fire activity has decreased in the last decades in Spain, as a whole and in most regions. However, little is known about the changes in the fire season peak, timing, and length. Here we studied the temporal variation in the fire season since the 1970&amp;#8217;s for different Spanish regions. We analyzed weekly time series of annually burned area by fitting GAMs (Generalized Additive Models) models in R. Area burned was log transformed and smoothing P-splines were fit to study weekly seasonality. GAMS allowed us to model spring, summer, and autumn fire seasons. Changes in the sign of the smoothing parameter determined the timing (onset/end dates) of each fire season, while the maximum value of the parameter established the peak of the fire season. We applied trend analysis to study inter-annual variation in fire season timing, length, and amplitude. We found temporal and spatial differences in the fire season across regions. In the northern Atlantic regions, models performed better, and captured a bimodal fire season (spring-summer). Nonetheless, the bimodal fire-season structure is no longer distinguishable in recent years, since both are increasing in duration. In the Mediterranean regions, larger peaks of burned areas occur in shorter time spans. The amplitude and duration of the summer season is decreasing, probably due to the increase in fire suppression during the summer. The summer season is starting earlier, while, in general, no trend was found for the end of the season. Furthermore, spring fire peaks in Mediterranean regions are becoming more frequent, suggesting that more attention should be paid to these out-of-season conditions.&lt;/p&gt;

Assessment of the impacts of PM10 due to wildfires on human mortality in Portugal

2020 ◽  
Author(s):  
Pedro Jiménez-Guerrero ◽  
Sofia Augusto ◽  
Laura Palacios-Peña ◽  
Nuno Ratola ◽  
Patricia Tarín-Carrasco
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Human Health ◽  
Health Resources ◽  
Fire Season ◽  
Respiratory Morbidity ◽  
Burned Area ◽  
Population Mortality ◽  
June July ◽  
The Impact

&lt;p&gt;Wildfires are a major environmental problem that the current society must face and climate change will increase the number and intensity of wildfires during the next years. One of the problems is the toxicity of the pollutants emitted from biomass burning, including particulate matter (PM), carbon monoxide, methane, nitrogen oxides, volatile organic carbon, and some secondary pollutants. Some of these chemicals have demonstrated to impact human health, being responsible for increases on cardiovascular and respiratory morbidity and mortality (Johnston et al., 2012). These facts contribute to the deterioration of the air quality, therefore causing afflictions that may even end up in death. Wildfires are a worldwide concern, but in Europe the southern countries are the most affected. Thus, the estimation of the effects of wildfires on human health due to PM exposure is fundamental to manage health resources and public funds. Portugal was one of the European countries most affected by wildfires in the last decade, yet there is a lack of knowledge regarding impacts of the wildfire-related pollutants on the population mortality.&lt;/p&gt;&lt;p&gt;This study aims to describe the pattern of wildfires occurring in a period of 16 years (2001-2016) during the fire season (June, July, August and September) and to assess the impact of wildfire-generated PM&lt;sub&gt;10&lt;/sub&gt; on the Portuguese population mortality, considering the fires that produced a burned area equal or above 1000 ha.&lt;/p&gt;&lt;p&gt;Data for PM&lt;sub&gt;10&lt;/sub&gt; measured in background air quality monitoring stations was obtained from the Portuguese Environment Agency. All-cause (excluding injuries, poisoning and external causes) and cause-specific mortality (circulatory and respiratory) data was provided by Statistics Portugal. PM&lt;sub&gt;10&lt;/sub&gt; concentrations were correlated with the burned area. Associations between PM&lt;sub&gt;10&lt;/sub&gt; exposure and all-cause and cause-specific mortalities were studied using Poisson regression models. We found significant correlation between burned area and mortality in some NUTS, in particular, inland and north of Portugal mainland. Also, a good and significant correlation between burned area and PM&lt;sub&gt;10 &lt;/sub&gt;is found. This means that big fires have an impact on the dwellers health due to Particulate Matter causing diseases and even provoking the death.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Acknowledgements&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;This work was financially supported by project UID/EQU/00511/2019 - Laboratory for Process Engineering, Environment, Biotechnology and Energy &amp;#8211; LEPABE funded by national funds through FCT/MCTES (PIDDAC). S. Augusto was supported by FCT-MCTES (SFRH/BPD/109382/2015). L. Palacios-Pe&amp;#241;a thanks to the scholarship FPU14/05505 of the Education, Culture and Sport Ministry. We acknowledge the project ACEX (CGL-2017-87921-R) of the Spanish Ministry of Economy and Competitiveness, the Fundaci&amp;#243;n Biodiversidad of the Spanish Ministry for the Ecological Transition, and the FEDER European program, for support to conduct this research.&lt;/p&gt;

scholarly journals Contrasting large fire activity in the French Mediterranean

2019 ◽  
Vol 19 (5) ◽  
pp. 1055-1066 ◽  
Author(s):  
Anne Ganteaume ◽  
Renaud Barbero
Keyword(s):  
Fire Suppression ◽  
Sharp Decrease ◽  
Weather Conditions ◽  
Fire Spread ◽  
Return Level ◽  
Fire Season ◽  
Burned Area ◽  
The West ◽  
Forest Resilience ◽  
Large Fires

Abstract. In the French Mediterranean, large fires have significant socioeconomic and environmental impacts. We used a long-term georeferenced fire time series (1958–2017) to analyze both spatial and temporal distributions of large fires (LFs; ≥100 ha). The region was impacted in some locations up to six times by recurrent LFs and 21 % of the total area burned by LFs occurred on a surface that previously burned in the past, with potential impact on forest resilience. We found contrasting patterns between the east and the west of the study area, the former experiencing fewer LFs but of a larger extent compared to the latter, with an average time of occurrence between LFs exceeding 4000 ha < 7 years mostly in the eastern coastal area and > 50 years in the west. This longitudinal gradient in LF return level contrasts with what we would expect from mean fire weather conditions strongly decreasing eastwards during the fire season but is consistent with larger fuel cover in the east, highlighting the strong role of fuel continuity in fire spread. Additionally, our analysis confirms the sharp decrease in both LF frequency and burned area in the early 1990s, due to the efficiency of fire suppression and prevention reinforced at that time, thereby weakening the functional climate–fire relationship across the region.

Remote sensing of burned areas in tropical savannas

2003 ◽  
Vol 12 (4) ◽  
pp. 259 ◽  
Author(s):  
José M. C. Pereira
Keyword(s):  
Remote Sensing ◽  
Canopy Cover ◽  
Stand Density ◽  
Fire Season ◽  
Burned Area ◽  
Tropical Savannas ◽  
Remotely Sensed Data ◽  
Area Index ◽  
Major Satellite ◽  
Burned Areas

Problematic aspects of fire in tropical savannas are reviewed, from the standpoint of their impact on the detection and mapping of burned areas using remotely sensed data. Those aspects include: the heterogeneity of savanna—resulting in heterogeneity of fire-induced spectral changes; fine fuels and low fuel loadings—resulting in short persistence of the char residue signal; tropical cloudiness—which makes multitemporal image compositing important; the frequent presence of extensive smoke aerosol layers during the fire season—which may obscure fire signals; and the potential problem of detecting burns in the understory of woody savannas with widely variable tree stand density, canopy cover and leaf area index. Finally, the capabilities and limitations of major satellite remote sensing systems for pan-tropical burned area mapping are addressed, considering the spatial, spectral, temporal and radiometric characteristics of the instruments.

scholarly journals Understanding the impact of different landscape-level fuel management strategies on wildfire hazard

2021 ◽  
Author(s):  
Akli Benali ◽  
Ana C.L. Sá ◽  
João Pinho ◽  
Paulo Fernandes ◽  
José M.C. Pereira
Keyword(s):  
Management Strategies ◽  
Treatment Strategies ◽  
Fire Season ◽  
Burned Area ◽  
Treatment Area ◽  
Fuel Treatment ◽  
Fuel Distribution ◽  
The North ◽  
Wildfire Hazard ◽  
The Impact

The disastrous 2017 fire season in Portugal lead to widespread recognition of the need for a paradigm shift in forest and fire management. We focused our study on Alvares, a parish in central Portugal which had 60% of its area burned in 2017, with a large record of historical. We evaluated how different fuel treatment strategies can reduce wildfire hazard in Alvares, through i) a fuel break network with different priorities and ii) random fuel treatments resulting from stand-level management intensification. To assess this, we developed a stochastic fire simulation system (FUNC-SIM) that integrates uncertainties in fuel distribution over the landscape. If the landscape remains unchanged, Alvares will have large burn probabilities in the north, northeast, and center-east areas of the parish that are very often associated with high fire line intensities. The different fuel treatment scenarios decreased burned area between 12.1-31.2%, resulting from 1%-4.6% increases in annual treatment area, and reduced 10%-40% the likelihood of wildfires larger than 5000 ha. On average, simulated burned area decreased 0.22% per each ha treated, and effectiveness decreased with increasing area treated. Overall, both fuel treatment strategies effectively reduced wildfire hazard and should be part of a larger, holistic and integrated plan to reduce the vulnerability of the Alvares parish to wildfires.

scholarly journals Forest Burned Area Mapping Using Bi-Temporal Sentinel-2 Imagery Based on a Convolutional Neural Network: Case Study in Golestan Forest

2021 ◽  
Vol 10 (1) ◽  
pp. 6
Author(s):  
Fattah Hatami Maskouni ◽  
Seyd Teymoor Seydi
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Burned Area ◽  
Kappa Score ◽  
Burned Areas ◽  
The North ◽  
North Of Iran ◽  
Decision Making Processes ◽  
Sentinel 2

Forest areas are profoundly important to the planet, since they offer considerable advantages. The mapping and estimation of burned areas covered with trees are critical during decision making processes. In such cases, remote sensing can be of great help. This paper presents a method to estimate burned areas based on the Sentinel-2 imagery using a convolutional neural network (CNN) algorithm. The framework touches change detection using pre- and post-fire datasets. The proposed framework utilizes a multi-scale convolution block to extract deep features. We investigate the performance of the proposed method via visual and numerical analyses. The case study for this research is Golestan Forest, which is located in the north of Iran. The results of the burned area detection process show that the proposed method produces a performance accuracy rate of more than 97% in terms of overall accuracy, with a Kappa score greater than 0.933.

Mapping and comparing wildfire progressions using freely available, multi-source satellite data

2020 ◽  
Author(s):  
Morgan Crowley ◽  
Jeffrey Cardille ◽  
Joanne White ◽  
Michael Wulder
Keyword(s):  
Time Series ◽  
Satellite Imagery ◽  
Wildland Fire ◽  
Google Earth ◽  
Optical Data ◽  
Fire Season ◽  
Burned Area ◽  
Burned Areas ◽  
The Individual ◽  
Area Classification

&lt;p&gt;Extreme wildfire seasons are becoming the new normal in Canada, and satellite imagery is a useful way to map these fires as they grow across the vast, fire-prone regions of the country. However, single-date and single-sourced imagery of active fires often contain clouds, flares, smoke, and haze that can create challenges for monitoring &amp;#160;burned areas over time. To address this gap, we applied rapid and scalable methods for synthesizing information on fire progressions using freely available satellite imagery, novel image fusion algorithms, and cloud-based data processing platforms. We identified images from Landsat-7, -8, Sentinel-2, and MODIS (MCD64A1 burned-area dataset) for the 2017 and 2018 British Columbia fire seasons that intersect the buffered extents of Canadian wildfires as determined by Canadian National Fire Database. We classified each raw image individually using a standard burned-area classification protocol related to each data source. We used the Bayesian Updating of Land Cover Classifications (BULC) algorithm to create coherent time series from the single-date classifications of optical data sources in Google Earth Engine. From the BULC classification stack, we calculated within-year, intra-annual fire progression metrics to compare satellite-derived fire behaviours between the 2017 and 2018 fire seasons, both at the whole fire season and the individual fire level. End-of-season burned-area estimates corresponded with estimates derived from the National Burned Area Composite (NBAC) product that is generated retrospectively from best-available fire mapping approaches. Additionally, we compared the BULC time series with fire progression estimates from MCD64A1 burned-area dataset to evaluate the influence of spatial resolution on burned-area estimates. Information outputs from this research enable cross-validation of fire behaviour models for different fire seasons and comparison of fire progression metrics between historic fires and fire seasons in Canada. The approach presented can be used to provide rapid and reliable information about active wildland fire progressions to better understand fire growth and associated drivers.&lt;/p&gt;

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