There is a complex interaction between lightning-caused fire behavior and the flora and fauna of the forest, which involves the influence of a large number of ecological factors. However, more comprehensive simulation studies under multi-system interactions between lightning ignition, forest fire spread, and animal behavior are not well developed. In this paper, we propose a forest ecosystem model based on the Agent-based modelling approach to explore the detailed linkages between different forms of lightning-caused fires and forest biodiversity. The model simulates the lightning ignition, fire spread, vegetation burning and recovery, and multi-species-survival dynamics. The experimental results show the sensitivity between environmental parameters and the magnitude of lightning-caused fires, and the beneficial ecological consequences of lightning-caused fires on forest ecosystems. By exploring detailed linkages between different forms of lightning-caused fires and forest biodiversity, we provide theoretical insights and reference suggestions for forest system governance and biodiversity conservation.
{"title":"Simulation Study of an Abstract Forest Ecosystem with Multi-Species under Lightning-Caused Fires","authors":"O. Zhi, Shiying Wang, Nisuo Du","doi":"10.3390/fire6080308","DOIUrl":"https://doi.org/10.3390/fire6080308","url":null,"abstract":"There is a complex interaction between lightning-caused fire behavior and the flora and fauna of the forest, which involves the influence of a large number of ecological factors. However, more comprehensive simulation studies under multi-system interactions between lightning ignition, forest fire spread, and animal behavior are not well developed. In this paper, we propose a forest ecosystem model based on the Agent-based modelling approach to explore the detailed linkages between different forms of lightning-caused fires and forest biodiversity. The model simulates the lightning ignition, fire spread, vegetation burning and recovery, and multi-species-survival dynamics. The experimental results show the sensitivity between environmental parameters and the magnitude of lightning-caused fires, and the beneficial ecological consequences of lightning-caused fires on forest ecosystems. By exploring detailed linkages between different forms of lightning-caused fires and forest biodiversity, we provide theoretical insights and reference suggestions for forest system governance and biodiversity conservation.","PeriodicalId":36395,"journal":{"name":"Fire-Switzerland","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45700327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Ding, Lingfeng He, Zijian Yan, Yuyao Li, Shuangyang Ma, Yan Jiao
A fire whirl, a unique fire behavior, occurs when a vertical vortex of flames skyrockets due to specific surrounding temperatures and thermal gradient conditions during a fire. Compared with conventional fire plumes, fire whirls exhibit a higher air entrainment rate, tangential velocity, and axial velocity, thus presenting greater risks and destructive capabilities. Thus, studying the combustion characteristics of fire whirls becomes necessary. This experiment employed a small-scale, fixed-frame fire whirl generator. We investigated how varying air-inlet widths and fuel pan diameters influence the fire whirl’s combustion characteristics. Experimental images indicated a negative correlation between the fire whirl’s flame height and the air-inlet width, and a positive correlation with the fuel pan diameter. Our findings showed that the burning rate of the fire whirl during the quasi-steady-state combustion phase initially increased and then decreased as the air-inlet width expanded, peaking at a width of 7 cm. The data demonstrated a corresponding power-law relationship between the fire whirl’s dimensionless flame height and excess temperature. Ultimately, our results indicated a positive correlation between the 2/5 power of the fire whirl’s dimensionless heat release rate and the dimensionless flame height. The ratios of maximum to mean flame height and mean to continuous flame height are 1.35 and 1.5, respectively. Significantly, these ratios remain unaffected by the air-inlet width, fuel pan diameter, environmental temperature, and heat release rate.
{"title":"Experimental Investigation on the Impact of Varying Air-Inlet Widths and Fuel Pan Diameters on Fire Whirls’ Combustion Characteristics","authors":"C. Ding, Lingfeng He, Zijian Yan, Yuyao Li, Shuangyang Ma, Yan Jiao","doi":"10.3390/fire6080309","DOIUrl":"https://doi.org/10.3390/fire6080309","url":null,"abstract":"A fire whirl, a unique fire behavior, occurs when a vertical vortex of flames skyrockets due to specific surrounding temperatures and thermal gradient conditions during a fire. Compared with conventional fire plumes, fire whirls exhibit a higher air entrainment rate, tangential velocity, and axial velocity, thus presenting greater risks and destructive capabilities. Thus, studying the combustion characteristics of fire whirls becomes necessary. This experiment employed a small-scale, fixed-frame fire whirl generator. We investigated how varying air-inlet widths and fuel pan diameters influence the fire whirl’s combustion characteristics. Experimental images indicated a negative correlation between the fire whirl’s flame height and the air-inlet width, and a positive correlation with the fuel pan diameter. Our findings showed that the burning rate of the fire whirl during the quasi-steady-state combustion phase initially increased and then decreased as the air-inlet width expanded, peaking at a width of 7 cm. The data demonstrated a corresponding power-law relationship between the fire whirl’s dimensionless flame height and excess temperature. Ultimately, our results indicated a positive correlation between the 2/5 power of the fire whirl’s dimensionless heat release rate and the dimensionless flame height. The ratios of maximum to mean flame height and mean to continuous flame height are 1.35 and 1.5, respectively. Significantly, these ratios remain unaffected by the air-inlet width, fuel pan diameter, environmental temperature, and heat release rate.","PeriodicalId":36395,"journal":{"name":"Fire-Switzerland","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43442030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jun Guo, Yanping Quan, H. Wen, Xuezhao Zheng, Guobin Cai, Yani Jin
The functional group structures of coal molecules are one of the most important factors affecting spontaneous combustion. However, it is difficult to determine the exact effects of such structures. Extraction technology is able to modify the functional groups in coal as a means of inhibiting spontaneous combustion reactions. The present work extracted coal from the Caojiatan mine in northern Shaanxi, China, with various solvents. The extraction effectiveness of these solvents was found to decrease in the order of dioctyl sulfosuccinate (AOT) > water > n-hexane > cyclohexane + AOT + ethanol > cyclohexane > ethanol > methanol. With the exception of the AOT, the concentration of functional groups in the extracted coal was decreased compared with that in a control specimen extracted using only water. Ethanol, n-hexane, and methanol provided the optimal extraction efficiencies in terms of capturing coal molecules with aromatic structures, aliphatic structures, and oxygen-containing groups, respectively. The results of this work are expected to assist in future research concerning the extraction of coal molecules with specific functional groups. This work also suggests new approaches to the active prevention and control of spontaneous combustion during the mining, storage, and transportation of coal.
{"title":"The Effects of Solvent Extraction on the Functional Group Structure of Long-Flame Coal","authors":"Jun Guo, Yanping Quan, H. Wen, Xuezhao Zheng, Guobin Cai, Yani Jin","doi":"10.3390/fire6080307","DOIUrl":"https://doi.org/10.3390/fire6080307","url":null,"abstract":"The functional group structures of coal molecules are one of the most important factors affecting spontaneous combustion. However, it is difficult to determine the exact effects of such structures. Extraction technology is able to modify the functional groups in coal as a means of inhibiting spontaneous combustion reactions. The present work extracted coal from the Caojiatan mine in northern Shaanxi, China, with various solvents. The extraction effectiveness of these solvents was found to decrease in the order of dioctyl sulfosuccinate (AOT) > water > n-hexane > cyclohexane + AOT + ethanol > cyclohexane > ethanol > methanol. With the exception of the AOT, the concentration of functional groups in the extracted coal was decreased compared with that in a control specimen extracted using only water. Ethanol, n-hexane, and methanol provided the optimal extraction efficiencies in terms of capturing coal molecules with aromatic structures, aliphatic structures, and oxygen-containing groups, respectively. The results of this work are expected to assist in future research concerning the extraction of coal molecules with specific functional groups. This work also suggests new approaches to the active prevention and control of spontaneous combustion during the mining, storage, and transportation of coal.","PeriodicalId":36395,"journal":{"name":"Fire-Switzerland","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47407194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Targeting the challenges in the risk analysis of laboratory fire accidents, particularly considering fire accidents in Chinese universities, an integrated approach is proposed with the combination of association rule learning, a Bayesian network (BN), and fuzzy set theory in this study. The proposed approach has the main advantages of deriving conditional probabilities of BN nodes based on historical accident data and association rules (ARs) and making good use of expert elicitation by using an augmented fuzzy set method. In the proposed approach, prior probabilities of the cause nodes are determined based on expert elicitation with the help of an augmented fuzzy set method. The augmented fuzzy set method enables the effective aggregation of expert opinions and helps to reduce subjective bias in expert elicitations. Additionally, an AR algorithm is applied to determine the probabilistic dependency between the BN nodes based on the historical accident data of Chinese universities and further derive conditional probability tables. Finally, the developed fuzzy Bayesian network (FBN) model was employed to identify critical causal factors with respect to laboratory fire accidents in Chinese universities. The obtained results show that H4 (bad safety awareness), O1 (improper storage of hazardous chemicals), E1 (environment with hazardous materials), and M4 (inadequate safety checks) are the four most critical factors inducing laboratory fire accidents.
{"title":"Risk Analysis of Laboratory Fire Accidents in Chinese Universities by Combining Association Rule Learning and Fuzzy Bayesian Networks","authors":"Fuqiang Yang, X. Li, Shuaiqi Yuan, G. Reniers","doi":"10.3390/fire6080306","DOIUrl":"https://doi.org/10.3390/fire6080306","url":null,"abstract":"Targeting the challenges in the risk analysis of laboratory fire accidents, particularly considering fire accidents in Chinese universities, an integrated approach is proposed with the combination of association rule learning, a Bayesian network (BN), and fuzzy set theory in this study. The proposed approach has the main advantages of deriving conditional probabilities of BN nodes based on historical accident data and association rules (ARs) and making good use of expert elicitation by using an augmented fuzzy set method. In the proposed approach, prior probabilities of the cause nodes are determined based on expert elicitation with the help of an augmented fuzzy set method. The augmented fuzzy set method enables the effective aggregation of expert opinions and helps to reduce subjective bias in expert elicitations. Additionally, an AR algorithm is applied to determine the probabilistic dependency between the BN nodes based on the historical accident data of Chinese universities and further derive conditional probability tables. Finally, the developed fuzzy Bayesian network (FBN) model was employed to identify critical causal factors with respect to laboratory fire accidents in Chinese universities. The obtained results show that H4 (bad safety awareness), O1 (improper storage of hazardous chemicals), E1 (environment with hazardous materials), and M4 (inadequate safety checks) are the four most critical factors inducing laboratory fire accidents.","PeriodicalId":36395,"journal":{"name":"Fire-Switzerland","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45318149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
U. Cosgun, Mücahit Coşkun, Ferhat Toprak, Damla Yıldız, S. Coşkun, Enes Taşoğlu, Ahmet Öztürk
The effectiveness of fire towers in combating forest fires relies on their appropriate observation angles, enabling a swift and efficient response to fire incidents. The purpose of this study is to examine the effectiveness of 49 fire towers located within the Antalya Forestry Regional Directorate, situated in the Mediterranean basin—a region prone to frequent forest fires. The assessment encompasses the visibility of the entire study area, including forested regions, as well as the visibility of 2504 forest fires recorded by the towers between 2008 and 2021. Furthermore, the evaluation considers the objectives based on Forest Management Directorates and conducts a location suitability analysis for the six towers with the lowest visibility. We utilized the Viewshed Tool in the ArcGIS application and employed the Best–Worst approach. Two scenarios were devised, considering smoke height at 0 m or 100 m, to determine the visibility of fire lookout towers. In Scenario I, assuming a smoke height of 100 m, only three towers exhibited visibility above 70%. However, in Scenario II, assuming a smoke height of 0 m, no towers achieved visibility above 70%. Scenario I indicated that only two towers possessed a view of more than 70% of the forested region, while Scenario II suggested that no towers met this criterion. For the visibility of forest fires, Scenario I identified seven towers capable of observing more than 70%, whereas Scenario II indicated that no towers possessed such capability. In the tower suitability analysis, the visibility rates varied from 41.18% to 1016.67%. Based on the evaluation results, the current visibility capacities of the 49 fire towers proved insufficient for effective preventive measures.
{"title":"Visibility Evaluation and Suitability Analysis of Fire Lookout Towers in Mediterranean Region, Southwest Anatolia/Türkiye","authors":"U. Cosgun, Mücahit Coşkun, Ferhat Toprak, Damla Yıldız, S. Coşkun, Enes Taşoğlu, Ahmet Öztürk","doi":"10.3390/fire6080305","DOIUrl":"https://doi.org/10.3390/fire6080305","url":null,"abstract":"The effectiveness of fire towers in combating forest fires relies on their appropriate observation angles, enabling a swift and efficient response to fire incidents. The purpose of this study is to examine the effectiveness of 49 fire towers located within the Antalya Forestry Regional Directorate, situated in the Mediterranean basin—a region prone to frequent forest fires. The assessment encompasses the visibility of the entire study area, including forested regions, as well as the visibility of 2504 forest fires recorded by the towers between 2008 and 2021. Furthermore, the evaluation considers the objectives based on Forest Management Directorates and conducts a location suitability analysis for the six towers with the lowest visibility. We utilized the Viewshed Tool in the ArcGIS application and employed the Best–Worst approach. Two scenarios were devised, considering smoke height at 0 m or 100 m, to determine the visibility of fire lookout towers. In Scenario I, assuming a smoke height of 100 m, only three towers exhibited visibility above 70%. However, in Scenario II, assuming a smoke height of 0 m, no towers achieved visibility above 70%. Scenario I indicated that only two towers possessed a view of more than 70% of the forested region, while Scenario II suggested that no towers met this criterion. For the visibility of forest fires, Scenario I identified seven towers capable of observing more than 70%, whereas Scenario II indicated that no towers possessed such capability. In the tower suitability analysis, the visibility rates varied from 41.18% to 1016.67%. Based on the evaluation results, the current visibility capacities of the 49 fire towers proved insufficient for effective preventive measures.","PeriodicalId":36395,"journal":{"name":"Fire-Switzerland","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45934765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Large areas of forests burn annually in Siberia. Pyrogenic organic matter (PyOM) generated by wildfires acts as a stable carbon deposit and plays an important role in the global carbon cycle. Little is known about the properties of PyOM formed during fires in Siberian forests. In this work, we report the results of thermogravimetry (TG), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy applied to the study of the chemical composition, structure, and thermal stability of PyOM formed during surface and crown fires of moderate to high severity in southern Siberia. We studied the PyOM produced from the forest floor, down wood, cones, and outer bark of tree stems in Scots pine, larch, spruce, and birch forests. We calculated the thermal recalcitrance indexes (R50, Q3) based on TG/DSC data. We found that wildfires resulted in a strong decrease in thermolabile components in burned fuels, enrichment by aromatic structures, and a significant increase in thermal stability (T50) compared to unburned samples. In all the studied forests, bark PyOM revealed the highest value of T50 while forest floor PyOM had the lowest one. At the same time, our results indicated that the properties of PyOM were more strongly driven by wildfire severity than by fuel type. Overall, the thermal recalcitrance R50 index for PyOM samples increased by 9–29% compared to unburned plant residues, indicating a shift from low to intermediate carbon sequestration potential class in the majority of cases and hence less susceptibility of PyOM to biodegradation.
{"title":"Alteration of Organic Matter during Wildfires in the Forests of Southern Siberia","authors":"O. Shapchenkova, S. Loskutov, E. Kukavskaya","doi":"10.3390/fire6080304","DOIUrl":"https://doi.org/10.3390/fire6080304","url":null,"abstract":"Large areas of forests burn annually in Siberia. Pyrogenic organic matter (PyOM) generated by wildfires acts as a stable carbon deposit and plays an important role in the global carbon cycle. Little is known about the properties of PyOM formed during fires in Siberian forests. In this work, we report the results of thermogravimetry (TG), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy applied to the study of the chemical composition, structure, and thermal stability of PyOM formed during surface and crown fires of moderate to high severity in southern Siberia. We studied the PyOM produced from the forest floor, down wood, cones, and outer bark of tree stems in Scots pine, larch, spruce, and birch forests. We calculated the thermal recalcitrance indexes (R50, Q3) based on TG/DSC data. We found that wildfires resulted in a strong decrease in thermolabile components in burned fuels, enrichment by aromatic structures, and a significant increase in thermal stability (T50) compared to unburned samples. In all the studied forests, bark PyOM revealed the highest value of T50 while forest floor PyOM had the lowest one. At the same time, our results indicated that the properties of PyOM were more strongly driven by wildfire severity than by fuel type. Overall, the thermal recalcitrance R50 index for PyOM samples increased by 9–29% compared to unburned plant residues, indicating a shift from low to intermediate carbon sequestration potential class in the majority of cases and hence less susceptibility of PyOM to biodegradation.","PeriodicalId":36395,"journal":{"name":"Fire-Switzerland","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42302138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Benjamin Bleiman, T. Rolinski, E. Hoffman, E. Kelsey, David Bangor
Efforts to delineate the influence of atmospheric variability on regional wildfire activity have previously been complicated by the stochastic occurrence of ignition and large fire events, particularly for Southern California, where anthropogenic modulation of the fire regime is extensive. Traditional metrics of wildfire activity inherently contain this stochasticity, likely weakening regional fire–climate relationships. To resolve this complication, we first develop a new method of quantifying regional wildfire activity that aims to more clearly capture the atmospheric fire regime component by aggregating four metrics of fire activity into an annual index value, the Annual Fire Severity Index (AFSI), for the 27-year period of 1992–2018. We then decompose the AFSI into trend and oscillatory components using singular spectrum analysis (SSA) and relate each component to a set of five climate predictors known to modulate macroscale fire activity in Southern California. These include the Atlantic Multidecadal Oscillation (AMO), Pacific Decadal Oscillation (PDO), El Niño–Southern Oscillation (ENSO), and Santa Ana wind (SAW) events, and marine layer frequency. The results indicate that SSA effectively isolates the individual influence of each predictor on AFSI quantified by generally moderate fire–climate correlations, |r|>0.4, over the full study period, and |r|>0.5 over select 13–15-year periods. A transition between weaker and stronger fire–climate relationships for each of the oscillatory PC–predictor pairs is centered around the mid-2000s, suggesting a significant shift in fire–climate variability at this time. Our approach of aggregating and decomposing a fire activity index yields a straightforward methodology to identify the individual influence of climatic predictors on macroscale fire activity even in fire regimes heavily modified by anthropogenic influence.
{"title":"Refining Fire–Climate Relationship Methodologies: Southern California","authors":"Benjamin Bleiman, T. Rolinski, E. Hoffman, E. Kelsey, David Bangor","doi":"10.3390/fire6080302","DOIUrl":"https://doi.org/10.3390/fire6080302","url":null,"abstract":"Efforts to delineate the influence of atmospheric variability on regional wildfire activity have previously been complicated by the stochastic occurrence of ignition and large fire events, particularly for Southern California, where anthropogenic modulation of the fire regime is extensive. Traditional metrics of wildfire activity inherently contain this stochasticity, likely weakening regional fire–climate relationships. To resolve this complication, we first develop a new method of quantifying regional wildfire activity that aims to more clearly capture the atmospheric fire regime component by aggregating four metrics of fire activity into an annual index value, the Annual Fire Severity Index (AFSI), for the 27-year period of 1992–2018. We then decompose the AFSI into trend and oscillatory components using singular spectrum analysis (SSA) and relate each component to a set of five climate predictors known to modulate macroscale fire activity in Southern California. These include the Atlantic Multidecadal Oscillation (AMO), Pacific Decadal Oscillation (PDO), El Niño–Southern Oscillation (ENSO), and Santa Ana wind (SAW) events, and marine layer frequency. The results indicate that SSA effectively isolates the individual influence of each predictor on AFSI quantified by generally moderate fire–climate correlations, |r|>0.4, over the full study period, and |r|>0.5 over select 13–15-year periods. A transition between weaker and stronger fire–climate relationships for each of the oscillatory PC–predictor pairs is centered around the mid-2000s, suggesting a significant shift in fire–climate variability at this time. Our approach of aggregating and decomposing a fire activity index yields a straightforward methodology to identify the individual influence of climatic predictors on macroscale fire activity even in fire regimes heavily modified by anthropogenic influence.","PeriodicalId":36395,"journal":{"name":"Fire-Switzerland","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46716167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study developed an objective approach for determining fire source location based on an artificial neural network (ANN) model. The samples for the ANN model were obtained from computational fluid dynamics simulations. A data preprocessor was devised to transform numerical simulation results into a format that could be used by the ANN model prior to network training, and bootstrap aggregation was used to improve the model’s predictive performance, which was evaluated by the leave-one-out approach. The results show that the 95% left-tailed confidence limit was 0.7921 m for planar dimensions of 5 m × 5 m, which is sufficiently accurate for practical application. Additionally, comprehensive experiments were conducted in the confined space of a fire compartment that was geometrically similar to various fire source locations to explore soot patterns and verify the ANN model. The experimental results reveal that the differences between the locations determined in scaling experiments and the locations predicted by the ANN were invariably less than 1 m. In particular, the difference was only 0.17 m when the fire source was located in the centre of the fire compartment. These results demonstrate the feasibility of the devised ANN model for reconstructing fire source location in engineering applications.
{"title":"Development and Application of an Intelligent Approach to Reconstruct the Location of Fire Sources from Soot Patterns Deposited on Walls","authors":"Meng Shi, Hanbo Li, Zhichao Zhang, E. Lee","doi":"10.3390/fire6080303","DOIUrl":"https://doi.org/10.3390/fire6080303","url":null,"abstract":"This study developed an objective approach for determining fire source location based on an artificial neural network (ANN) model. The samples for the ANN model were obtained from computational fluid dynamics simulations. A data preprocessor was devised to transform numerical simulation results into a format that could be used by the ANN model prior to network training, and bootstrap aggregation was used to improve the model’s predictive performance, which was evaluated by the leave-one-out approach. The results show that the 95% left-tailed confidence limit was 0.7921 m for planar dimensions of 5 m × 5 m, which is sufficiently accurate for practical application. Additionally, comprehensive experiments were conducted in the confined space of a fire compartment that was geometrically similar to various fire source locations to explore soot patterns and verify the ANN model. The experimental results reveal that the differences between the locations determined in scaling experiments and the locations predicted by the ANN were invariably less than 1 m. In particular, the difference was only 0.17 m when the fire source was located in the centre of the fire compartment. These results demonstrate the feasibility of the devised ANN model for reconstructing fire source location in engineering applications.","PeriodicalId":36395,"journal":{"name":"Fire-Switzerland","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44704685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Kharuk, E. Shvetsov, L. Buryak, A. S. Golyukov, M. Dvinskaya, I. Petrov
Throughout the larch range, warming leads to frequent fires and an increase in burned areas. We test the hypothesis that fires are an essential natural factor that reset larch regeneration and support the existence of larch forests. The study area included Larix sibirica and L. gmelinii ranges within the permafrost zone. We used satellite-derived and field data, dendrochronology, and climate variables analysis. We found that warming led to an increase in fire frequency and intensity, mean, and extreme (>10,000 ha) burned areas. The burned area is increasing in the northward direction, while fire frequency is decreasing. The fire rate exponentially increases with decreasing soil moisture and increasing air temperature and air drought. We found a contrasting effect of wildfire on regeneration within continuous permafrost and within the southern lowland boundary of the larch range. In the first case, burnt areas regenerated via abounded larch seedlings (up to 500,000+ per ha), whereas the south burns regenerated mostly via broadleaf species or turned into grass communities. After the fire, vegetation GPP was restored to pre-fire levels within 3–15 years, which may indicate that larch forests continue to serve as carbon stock. At the southern edge of the larch range, an amplified fire rate led to the transformation of larch forests into grass and shrub communities. We suggested that the thawing of continuous permafrost would lead to shrinking larch-dominance in the south. Data obtained indicated that recurrent fires are a prerequisite for larch forests’ successful regeneration and resilience within continuous permafrost. It is therefore not necessary to suppress all fires within the zone of larch dominance. Instead, we must focus fire suppression on areas of high natural, social, and economic importance, permitting fires to burn in vast, larch-dominant permafrost landscapes.
{"title":"Wildfires in the Larch Range within Permafrost, Siberia","authors":"V. Kharuk, E. Shvetsov, L. Buryak, A. S. Golyukov, M. Dvinskaya, I. Petrov","doi":"10.3390/fire6080301","DOIUrl":"https://doi.org/10.3390/fire6080301","url":null,"abstract":"Throughout the larch range, warming leads to frequent fires and an increase in burned areas. We test the hypothesis that fires are an essential natural factor that reset larch regeneration and support the existence of larch forests. The study area included Larix sibirica and L. gmelinii ranges within the permafrost zone. We used satellite-derived and field data, dendrochronology, and climate variables analysis. We found that warming led to an increase in fire frequency and intensity, mean, and extreme (>10,000 ha) burned areas. The burned area is increasing in the northward direction, while fire frequency is decreasing. The fire rate exponentially increases with decreasing soil moisture and increasing air temperature and air drought. We found a contrasting effect of wildfire on regeneration within continuous permafrost and within the southern lowland boundary of the larch range. In the first case, burnt areas regenerated via abounded larch seedlings (up to 500,000+ per ha), whereas the south burns regenerated mostly via broadleaf species or turned into grass communities. After the fire, vegetation GPP was restored to pre-fire levels within 3–15 years, which may indicate that larch forests continue to serve as carbon stock. At the southern edge of the larch range, an amplified fire rate led to the transformation of larch forests into grass and shrub communities. We suggested that the thawing of continuous permafrost would lead to shrinking larch-dominance in the south. Data obtained indicated that recurrent fires are a prerequisite for larch forests’ successful regeneration and resilience within continuous permafrost. It is therefore not necessary to suppress all fires within the zone of larch dominance. Instead, we must focus fire suppression on areas of high natural, social, and economic importance, permitting fires to burn in vast, larch-dominant permafrost landscapes.","PeriodicalId":36395,"journal":{"name":"Fire-Switzerland","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48553482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Caitlyn Reilley, Mindy S. Crandall, J. Kline, John B. Kim, J. de Diego
Historical land and fire management practices coupled with climate change and modern human development pressures are contributing to larger, more frequent, and more severe wildfires across Western U.S. forests. Human ignitions are the predominant cause of wildfire throughout the United States, necessitating wildfire management strategies that consider both the causes of human ignitions and the factors that influence them. Using a dataset of over 104,000 ignitions from 1992 to 2018 for Oregon and Washington (U.S), we examine the major causes of wildfire ignitions and build regression models to evaluate the potential influence of both biophysical and socioeconomic factors on human and natural ignitions across distinct fire regimes west and east of the Cascade Range. Our results corroborate prior findings that socioeconomic factors such as income, employment, population density, and age demographics are significantly correlated with human ignitions. In the Pacific Northwest, we found that the importance of socioeconomic factors on human ignitions differs significantly between the west and east sides of the Cascade Range. We also found that most human ignitions are linked to escaped fires from recreation or debris and open burning activities, highlighting opportunities to tailor wildfire prevention efforts to better control higher risk activities and reduce accidental ignitions.
{"title":"The Influence of Socioeconomic Factors on Human Wildfire Ignitions in the Pacific Northwest, USA","authors":"Caitlyn Reilley, Mindy S. Crandall, J. Kline, John B. Kim, J. de Diego","doi":"10.3390/fire6080300","DOIUrl":"https://doi.org/10.3390/fire6080300","url":null,"abstract":"Historical land and fire management practices coupled with climate change and modern human development pressures are contributing to larger, more frequent, and more severe wildfires across Western U.S. forests. Human ignitions are the predominant cause of wildfire throughout the United States, necessitating wildfire management strategies that consider both the causes of human ignitions and the factors that influence them. Using a dataset of over 104,000 ignitions from 1992 to 2018 for Oregon and Washington (U.S), we examine the major causes of wildfire ignitions and build regression models to evaluate the potential influence of both biophysical and socioeconomic factors on human and natural ignitions across distinct fire regimes west and east of the Cascade Range. Our results corroborate prior findings that socioeconomic factors such as income, employment, population density, and age demographics are significantly correlated with human ignitions. In the Pacific Northwest, we found that the importance of socioeconomic factors on human ignitions differs significantly between the west and east sides of the Cascade Range. We also found that most human ignitions are linked to escaped fires from recreation or debris and open burning activities, highlighting opportunities to tailor wildfire prevention efforts to better control higher risk activities and reduce accidental ignitions.","PeriodicalId":36395,"journal":{"name":"Fire-Switzerland","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46630952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：