scholarly journals Multi-Sensor, Active Fire-Supervised, One-Class Burned Area Mapping in the Brazilian Savanna

2021 ◽  
Vol 13 (19) ◽  
pp. 4005
Author(s):  
Allan A. Pereira ◽  
Renata Libonati ◽  
Julia A. Rodrigues ◽  
Joana Nogueira ◽  
Filippe L. M. Santos ◽  
...  
Keyword(s):  
Fire Regime ◽  
Training Sample ◽  
Burned Area ◽  
Mapping Accuracy ◽  
Mapping Algorithm ◽  
Burned Areas ◽  
Active Fire ◽  
Landsat Satellite ◽  
Omission Errors

Increasing efforts are being devoted to understanding fire patterns and changes highlighting the need for a consistent database about the location and extension of burned areas (BA). Satellite-derived BA mapping accuracy in the Brazilian savannas is limited by the underestimation of burn scars from small, fragmented fires and high cloudiness. Moreover, systematic mapping of BA is challenged by the need for human intervention in training sample acquisition, which precludes the development of automatic-generated products over large areas and long periods. Here, we developed a multi-sensor, active fire-supervised, one-class BA mapping algorithm to address several of these limitations. Our main objective is to generate a long-term, detailed BA atlas suitable to improve fire regime characterization and validation of coarse resolution products. We use composite images derived from the Landsat satellite to generate end-of-season maps of fire-affected areas for the entire Cerrado. Validation exercises and intercomparison with BA maps from a semi-automatic algorithm and visual photo interpretation were conducted for the year 2015. Our results improve the BA mapping by reducing omission errors, especially where there is high cloud frequency, few active fires are detected, and burned areas are small and fragmented. Finally, our approach represents at least a 45% increase in BA mapped in the Cerrado, in comparison to the annual extent detected by the current coarse global product from MODIS satellite (MCD64), and thus, it is capable of supporting improved regional emissions estimates.

scholarly journals Spatio-temporal patterns of wildfires in the Niassa Reserve –Mozambique, using remote sensing data

2020 ◽  
Author(s):  
Eufrásio Nhongo ◽  
Denise Fontana ◽  
Laurindo Guasselli
Keyword(s):  
Forest Fires ◽  
Forest Cover ◽  
Fire Regime ◽  
Spatial Dynamics ◽  
Remote Sensing Data ◽  
Fire Frequency ◽  
Ecosystem Change ◽  
Burned Area ◽  
Burned Areas ◽  
Active Fire

AbstractWildfires are among the biggest factors of ecosystem change. Knowledge of fire regime (fire frequency, severity, intensity, seasonality, and distribution pattern) is an important factor in wildfire management. This paper aims to analyze the spatiotemporal patterns of fires and burned areas in the Niassa Reserve between 2002-2015 using MODIS data, active fire product (MCD14ML) and burned area product (MCD64A1). For this, the annual and monthly frequencies, the trend of fires and the frequency by types of forest cover were statistically analyzed. For the analysis of the spatial dynamics of forest fires we used the Kernel density (Fixed Method). The results show a total of 20.449 forest fires and 171.067 km2 of burned areas in the period 2002-2015. Fire incidents were highest in 2015, while the largest burned areas were recorded in 2007. The relationship between increased fires and burned areas is not linear. There was a tendency for fires to increase, while for burnt areas there was stabilization. Forest fires start in May and end in December. August-October are the most frequent period, peaking in September. Fires occur predominantly in deciduous forests and mountain forests because of the type of vegetation and the amount of dry biomass. There is a monthly spatial dynamics of wildfires from east to west in the reserve. This behavior is dependent on vegetation cover type, fuel availability, and senescence.

An active-fire based burned area mapping algorithm for the MODIS sensor

2009 ◽  
Vol 113 (2) ◽  
pp. 408-420 ◽  
Author(s):  
Louis Giglio ◽  
Tatiana Loboda ◽  
David P. Roy ◽  
Brad Quayle ◽  
Christopher O. Justice
Keyword(s):  
Burned Area ◽  
Mapping Algorithm ◽  
Active Fire ◽  
Burned Area Mapping

scholarly journals Fire Activity and Their Relationship with the Global Fire Weather Index Database Components in Guinea

2019 ◽  
Vol 8 (2) ◽  
pp. 18
Author(s):  
Mamadou Baïlo Barry ◽  
Daouda Badiane ◽  
Saïdou Moustapha Sall ◽  
Moussa Diakhaté ◽  
Habib Senghor
Keyword(s):  
Statistical Analysis ◽  
Fire Behavior ◽  
Burned Area ◽  
Fire Weather ◽  
Weather Index ◽  
Fire Weather Index ◽  
Burned Areas ◽  
Active Fire ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer

The relationships between the Canadian Fire Weather Index (FWI) System components and the monthly burned area as well as the number of active fire which has taken from Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua/TERRA were investigated in 32 Guinean stations between 2003 and 2013. A statistical analysis based on a multi-linear regression model was used to estimate the skills of FWI components on the predictability of burned area and active fire. This statistical analysis gave performances explaining between 16 to 79% of the variance for the burned areas and between 29 and 82% of the variance for the number of fires (P<0.0001) at lag 0. Respectively 16 to 79 % and 29 to 82 % of the variance of the burned areas and variance for the number of fires (P<0.0001) at lag0 can be explained based on the same statistical analysis. All the combinations used gave significant performances to predict the burned areas and active fire on the monthly timescale in all stations excepted Fria and Yomou where the predictability of the burned areas was not obvious. We obtained a significant correlation between the average over all of the stations of burned areas, active fires and FWI composites with percentage of variance between (75 to 84% and 29 to 77%) for active fires and burned areas at lag0 respectively. While for burned area peak (January), the skill of the predictability remains significant only one month in advance, for the active fires, the model remains skilful 1 to 3 months in advance. Results also showed that active fires are more related to fire behavior indices while the burned areas are related to the fine fuel moisture codes. These outcomes have implications for seasonal forecasting of active fire events and burned areas based on FWI components, as significant predictability is found from 1 to 3 months and one month before respectively.

scholarly journals Spatial scales influence long-term response of herbivores to prescribed burning in a savanna ecosystem

2017 ◽  
Vol 26 (4) ◽  
pp. 287 ◽  
Author(s):  
Duncan M. Kimuyu ◽  
Ryan L. Sensenig ◽  
Robert M. Chira ◽  
John M. Githaiga ◽  
Truman P. Young
Keyword(s):  
Prescribed Burning ◽  
Spatial Scales ◽  
Fire Effects ◽  
Spatial Extent ◽  
Burned Area ◽  
Burned Areas ◽  
Spatial And Temporal Heterogeneity ◽  
Intermediate Size ◽  
Term Response

Both wild and prescribed fire in savanna ecosystems influence habitat use by herbivores by creating or maintaining spatial and temporal heterogeneity in forage quality and vegetation cover. Yet little is known about how spatial scales influence long-term persistence of fire effects. We examined changes over a 6-year period in herbivore preference for experimentally burned patches that varied in spatial extent and grain. Avoidance for the burns by elephants and preference for the burns by impala and Grant’s gazelle decreased significantly. For the rest of the species (zebra, eland, oryx, hartebeest, warthog and hare), there were no significant changes in preference for the burns. Changes in preference for the burned areas depended on the spatial extent and grain of the burn, with intermediate-size (9-ha) burns and large (8-ha) patchy burns being more preferred 6–7 years after fire. Grain, but not the spatial extent of the burned area, influenced changes in grass height. Fire resulted in a delayed reduced tree density irrespective of the spatial scale of the burn. Results of this study indicate that, depending on the scale of fire prescription, the impacts of fire on herbivores may last longer than previous studies suggest.

Accuracy and spatiotemporal distribution of fire in the Brazilian biomes from the MODIS burned-area products

2020 ◽  
Vol 29 (10) ◽  
pp. 907 ◽  
Author(s):  
Nickolas Castro Santana ◽  
Osmar Abílio de Carvalho Júnior ◽  
Roberto Arnaldo Trancoso Gomes ◽  
Renato Fontes Guimarães
Keyword(s):  
Confusion Matrix ◽  
Burned Area ◽  
Accuracy Analysis ◽  
Visual Interpretation ◽  
Burned Areas ◽  
Active Fire ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Area Product ◽  
Area Monitoring

The Moderate Resolution Imaging Spectroradiometer (MODIS) products are the most used in burned-area monitoring, on regional and global scales. This research aims to evaluate the accuracy of the MODIS burned-area and active-fire products to describe fire patterns in Brazil in the period 2001–2015. The accuracy analysis, in the year 2015, compared the MODIS products (MCD45/MCD64) and the burned areas extracted by the visual interpretation of the LANDSAT/Operational Land Imager (OLI) images from the confusion matrix. The accuracy analysis of the active-fire products (MOD14/MYD14) in the year 2015 used linear regression. We used the most accurate burned-area product (MCD64), in conjunction with environmental variables of land use and climate. The MCD45 product presented a high error of commission (&gt;36.69%) and omission (&gt;77.04%) for the whole country. The MCD64 product had fewer errors of omission (64.05%) compared with the MCD45 product, but increased errors of commission (45.85%). MCD64 data in 2001–2015 showed three fire domains in Brazil determined by the climatic pattern. Savanna and grassy areas in semi-humid zones are the most prone areas to fire, burning an average of 25% of their total area annually, with a fire return interval of 5–6 years.

Compositing MODIS time series for reconstructing burned areas in the taiga–steppe transition zone of northern Mongolia

2015 ◽  
Vol 24 (3) ◽  
pp. 419 ◽  
Author(s):  
Thuan Chu ◽  
Xulin Guo
Keyword(s):  
Time Series ◽  
Transition Zone ◽  
Land Surface ◽  
Natural Disturbance ◽  
Data Availability ◽  
Forest Recovery ◽  
Burned Area ◽  
Burned Areas ◽  
Active Fire ◽  
Northern Mongolia

Wildfire is the main natural disturbance in forest ecosystems; it controls and modifies vegetation compositions, landscape properties and global carbon cycle. Estimates of areas burned by wildfires vary greatly depending on the environmental conditions, data availability and methods used. This paper aims to develop a framework for reconstructing time series of burned areas in the taiga–steppe transition zone using MODIS composites. The estimated accuracy of the developed mapping algorithm and other statistical indications denote that the clear land surface composites of MODIS data in spring (Julian dates, JD 97–177), logistic regression and MODIS active fire product can be integrated successfully for reconstructing burned areas in the taiga–steppe transition zone. Time series of burned areas between 2000 and 2012 derived from the MODIS spring composite algorithm were validated using Landsat-based burned areas, showing average omission and commission errors of 18% and 31%. Compared with the MCD45A1 burned area product, the developed algorithm significantly improved the prediction of burned areas and successfully separated late-season from early-season burns. The derived long-term burned areas will assist in understanding the complex relationships among forest dynamics, forest recovery and fire in the vulnerable boreal forest ecosystem as well as its transition zone under climate change in northern Mongolia and Central Asia.

scholarly journals CONTRIBUTION OF SATELLITE IMAGERY TO THE CHARACTERIZATION OF THE RELATIONSHIP BETWEEN CLIMATE AND PYROLOGICAL VARIABLES OF BUSH FIRES IN THE SAVANNAH ZONE (case of the BOUNKANI REGION)

2021 ◽  
Vol 5 (1) ◽  
pp. 64-72
Author(s):  
Kambire Sie ◽  
Talnan Jean Honore Coulibaly ◽  
Naga Coulibaly ◽  
Issiaka Savane ◽  
Lanciné Droh Gone ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Fire Regime ◽  
Pearson Correlation ◽  
Climatic Variables ◽  
Fire Season ◽  
Burned Area ◽  
Fire Control ◽  
Burned Areas ◽  
Spatio Temporal ◽  
The Relationship

The present study was undertaken to characterize the bushfire regime and the climatic factors influencing its propagation in the Bounkani region. Thus, this work analyzes the spatio-temporal dynamics of fires and the relationship between climatic variables and pyrological variables. First, it exploits time series of active fires and burned areas from MODIS Active fires (MCD14ML) and MODIS Burned area (MCD60A1) data for the period from 2000 to 2017. The methodology is based on the evaluation of seasonality and fire occurrences, and on the spatio-temporal evolution of fires. The results obtained indicate that, on average, the fire season occurs between the months of November and March, generally corresponding to the dry season. Also, the number of fires and the area burned follow a decreasing trend during the 17 years of study. The months of December and January recorded the highest peaks of burned areas and fire outbreaks respectively. Finally, the analysis of the dependence between climatic variables and pyrological variables by the Pearson correlation method showed the influence of climatic parameters in the outbreak and spread of bushfires in the study area. Precipitation and relative humidity are the best predictors with a negative influence on fire activity, while the positive predictors remain temperature. These variables directly impact fire regime in general. The results of this study will assist policy makers and managers in decision making for the implementation of fire control strategies.

scholarly journals Fires Drive Long-Term Environmental Degradation in the Amazon Basin

2022 ◽  
Vol 14 (2) ◽  
pp. 338
Author(s):  
Carlos Antonio da Silva Junior ◽  
Mendelson Lima ◽  
Paulo Eduardo Teodoro ◽  
José Francisco de Oliveira-Júnior ◽  
Fernando Saragosa Rossi ◽  
...  
Keyword(s):  
Environmental Degradation ◽  
Amazon Basin ◽  
Gross Primary Production ◽  
Standardized Precipitation Index ◽  
Burned Area ◽  
Conservation Areas ◽  
Conservation Units ◽  
Burned Areas ◽  
Indigenous Lands

The Amazon Basin is undergoing extensive environmental degradation as a result of deforestation and the rising occurrence of fires. The degradation caused by fires is exacerbated by the occurrence of anomalously dry periods in the Amazon Basin. The objectives of this study were: (i) to quantify the extent of areas that burned between 2001 and 2019 and relate them to extreme drought events in a 20-year time series; (ii) to identify the proportion of countries comprising the Amazon Basin in which environmental degradation was strongly observed, relating the spatial patterns of fires; and (iii) examine the Amazon Basin carbon balance following the occurrence of fires. To this end, the following variables were evaluated by remote sensing between 2001 and 2019: gross primary production, standardized precipitation index, burned areas, fire foci, and carbon emissions. During the examined period, fires affected 23.78% of the total Amazon Basin. Brazil had the largest affected area (220,087 fire foci, 773,360 km2 burned area, 54.7% of the total burned in the Amazon Basin), followed by Bolivia (102,499 fire foci, 571,250 km2 burned area, 40.4%). Overall, these fires have not only affected forests in agricultural frontier areas (76.91%), but also those in indigenous lands (17.16%) and conservation units (5.93%), which are recognized as biodiversity conservation areas. During the study period, the forest absorbed 1,092,037 Mg of C, but emitted 2908 Tg of C, which is 2.66-fold greater than the C absorbed, thereby compromising the role of the forest in acting as a C sink. Our findings show that environmental degradation caused by fires is related to the occurrence of dry periods in the Amazon Basin.

scholarly journals Analysis of fire dynamics in the Brazilian savannas

2017 ◽  
Author(s):  
Guilherme Augusto Verola Mataveli ◽  
Maria Elisa Siqueira Silva ◽  
Gabriel Pereira ◽  
Francielle da Silva Cardozo ◽  
Fernando Shinji Kawakubo ◽  
...  
Keyword(s):  
Land Use ◽  
Condition Index ◽  
Burned Area ◽  
Spatial Correlations ◽  
Fire Dynamics ◽  
Burned Areas ◽  
Natural Fires ◽  
Active Fire ◽  
Vegetation Condition ◽  
Vegetation Condition Index

Abstract. Wildfires play a key role in the ecology of savannas. The Brazilian savannas (Cerrado biome), where the extension of burned areas and amount of fires can be more numerous than in the Amazon, is frequently burned due to natural fires or land-use and land-cover (LULC) changes. Thus, we aimed to understand the occurrence and the dynamics of fires in the Cerrado using active fire, burned area, precipitation, vegetation condition, estimated using the Vegetation Condition Index (VCI), and LULC data derived from orbital sensors. Results show that the Cerrado was, respectively, the second and first Brazilian biome for the occurrence of hotspots and burned area, which are concentrated during the dry season (May to September), especially in September, when the annual deficit in precipitation and extreme vegetation conditions reached maximum indices. Higher densities of hotspots concentrated in the Northern of the biome, while 75 % of the occurrences were found in the natural remnants of the Cerrado. Totals of hotspots and burned area were higher in years of lower precipitation, such as 2007 and 2010. Spatial correlations showed that hotspots and burned area are better correlated with precipitation than vegetation condition, especially in the Central North and Northeast of the Cerrado.

scholarly journals High-severity wildfires in temperate Australian forests have increased in extent and aggregation in recent decades

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242484
Author(s):  
Bang Nguyen Tran ◽  
Mihai A. Tanase ◽  
Lauren T. Bennett ◽  
Cristina Aponte
Keyword(s):  
Fire Regime ◽  
Fire Severity ◽  
Fire Regimes ◽  
Ecosystem Dynamics ◽  
Burned Area ◽  
Burned Areas ◽  
South Eastern ◽  
High Severity ◽  
Eastern Australia ◽  
South Eastern Australia

Wildfires have increased in size and frequency in recent decades in many biomes, but have they also become more severe? This question remains under-examined despite fire severity being a critical aspect of fire regimes that indicates fire impacts on ecosystem attributes and associated post-fire recovery. We conducted a retrospective analysis of wildfires larger than 1000 ha in south-eastern Australia to examine the extent and spatial pattern of high-severity burned areas between 1987 and 2017. High-severity maps were generated from Landsat remote sensing imagery. Total and proportional high-severity burned area increased through time. The number of high-severity patches per year remained unchanged but variability in patch size increased, and patches became more aggregated and more irregular in shape. Our results confirm that wildfires in southern Australia have become more severe. This shift in fire regime may have critical consequences for ecosystem dynamics, as fire-adapted temperate forests are more likely to be burned at high severities relative to historical ranges, a trend that seems set to continue under projections of a hotter, drier climate in south-eastern Australia.

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