• Title/Summary/Keyword: Fire severity

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Forest Fire Damage Analysis Using Satellite Images (위성영상을 이용한 산불재해 분석)

  • Kang, Joon-Mook;Zhang, Chuan;Park, Joon-Kyu;Kim, Min-Gyu
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.1
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    • pp.21-28
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    • 2010
  • Forest fire is one of the main factor disturbing the environment of forest, and it influences greatly the structure and function on forest. The process of vegetation recovery could be decided according to the extent of the damage. It is required a lot of man powers and budgets to understand born severity and process of vegetation rehabilitation at the damaged area after large-fire. However, the analysis of born severity in the forest area using satellite imagery can acquire rapidly information and more objective results remotely in the large-fire area. In this study, the space sensors have been used to map area burned, assess characteristics of active fires. For classifying fire damaged area and analyzing severity of Cheongyang-Yesan fire in 2002, in this paper we use pre- and post-fire imagery from the Landsat TM and ETM+ to compute the evaluate large-scale patterns of burn severity, use the digital stock map to calculate the damaged condition about the forest fires damaged regions and use the NDVI to monitoring the situation of the revegetation.

Assessment of Vegetation Recovery after Forest Fire

  • Yu, Xinfang;Zhuang, Dafang;Hou, Xiyong
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.328-330
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    • 2003
  • The land cover of burned area has changed dramatically since Daxinganling forest fire in Northeastern China during May 6 ? June 4, 1987. This research focused on determining the burn severity and assessment of forest recovery. Burned severity was classified into three levels from June 1987 Landsat TM data acquired just after the fire. A regression model was established between the forest canopy closure from 1999 forest stand map and the NDVI values from June 2000 Landsat ETM+ data. The map of canopy closure was got according to the regression model. And vegetation cover was classified into four types according to forest closure density. The change matrix was built using the classified map of burn severity and vegetation recovery. Then the change conversions of every forest type were analyzed. Results from this research indicate: forest recovery status is well in most of burned scars; and vegetation change detection can be accomplished using postclassification comparison method.

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Evaluation of the Normalized Burn Ratio (NBR) for Mapping Burn Severity Base on IKONOS-Images (IKONOS 화상 기반의 산불피해등급도 작성을 위한 정규산불피해비율(NBR) 평가)

  • Kim, Choen
    • Korean Journal of Remote Sensing
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    • v.24 no.2
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    • pp.195-203
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    • 2008
  • Burn severity is an important role for rehabilitation of burned forest area. This factor led to the pilot study to determine if high resolution IKONOS images could be used to classify and delinenate the bum severity over burned areas of Samchock Fire and Cheongyang-Yesan Fire. The results of this study can be summarized as follows: 1. The modified Normalized Bum Ratio (NBR) for IKONOS imagery can be evaluated using burn severity mapping. 2. IKONOS-derived NBR imagery could provide fire scar and detail mapping of burned areas at Samchock fire and Cheongyang-Yesan Burns.

Designing method for fire safety of steel box bridge girders

  • Li, Xuyang;Zhang, Gang;Kodur, Venkatesh;He, Shuanhai;Huang, Qiao
    • Steel and Composite Structures
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    • v.38 no.6
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    • pp.657-670
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    • 2021
  • This paper presents a designing method for enhancing fire resistance of steel box bridge girders (closed steel box bridge girder supporting a thin concrete slab) through taking into account such parameters namely; fire severity, type of longitudinal stiffeners (I, L, and T shaped), and number of longitudinal stiffeners. A validated 3-D finite element model, developed through the computer program ANSYS, is utilized to go over the fire response of a typical steel box bridge girder using the transient thermo-structural analysis method. Results from the numerical analysis show that fire severity and type of longitudinal stiffeners welded on bottom flange have significant influence on fire resistance of steel box bridge girders. T shaped longitudinal stiffeners applied on bottom flange can highly prevent collapse of steel box bridge girders towards the end of fire exposure. Increase of longitudinal stiffeners on bottom flange and web can slightly enhance fire resistance of steel box bridge girders. Rate of deflection-based criterion can be reliable to evaluate fire resistance of steel box bridge girders in most fire exposure cases. Thus, T shaped longitudinal stiffeners on bottom flange incorporated into bridge fire-resistance design can significantly enhance fire resistance of steel box bridge girders.

Differences in Incidence of Lower Back Pain according to Fire Fighters' Duty Type (외근직 소방공무원의 직무유형에 따른 요통발생의 차이)

  • Hong, Sung-Gi;Im, Jeong-Soo;Youn, Sung-Tae;Yim, Jun
    • Health Policy and Management
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    • v.17 no.4
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    • pp.99-112
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    • 2007
  • The purpose of this study was to analyze the effect of fire fighters' duty type on occurrence and severity of low back pain. Data were collected with questionnaire to 450 fire fighters working at 119 safety center and rescue unit of 30 fire stations in Gyeonggi-do. Finally the study was analyzed for 360 persons among them. The risk of experiencing of lower back pain occurred in the order of Rescue[odds ratio(OR) 3.36, 95% confidence interval(95% CI) 1.18-9.52], Vehicle operation(OR 2.63, 95% CI 1.26-5.50), First aid(OR 2.18, 95% CI 1.03-4.59), and Putting out a fire. The risk on severity of lower back pain occurred in the order of Vehicle operation(OR 4.00, 95% CI 1.57-9.80), First aid(OR 1.88, 95% CI 1.00-4.81), Putting out a fire, and Rescue. These result suggest that duty type of fire fighters may be a prognostic factor for occurrence and severity of low back pain. The potential implications of these findings are discussed about different approach for primary and secondary prevention by duty type of fire fighters.

An Analysis of Factors Affecting Severity of Elderly Driver in Frontal Collision (정면충돌에서 노인운전자의 중증도에 영향을 주는 요인 분석)

  • Jeon, Hyeok-Jin
    • Fire Science and Engineering
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    • v.33 no.2
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    • pp.139-144
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    • 2019
  • The increase in the elderly population also increased the damage and deaths of the elderly drivers. However, studies on the severity and severity of the elderly driver are not actively conducted and the factors are unknown. In this study, I tried to find out the factors affecting the damage and severity of the elderly driver in the frontal collision and to utilize them additionally in the severity classification. Collision Deformation Classification (CDC) Code was used to check the extent of damage to the vehicle. Abbreviated Injury Scale (AIS) was used to determine the injury parts and severity of injury, and the Injury Severity Score (ISS) to confirm the severity of the patient. The odds ratios of severe injury patients were found to be 7.381 in the subjects with 5 or more deformation extent and the ${\beta}$ value of the deformation extent was 0.453 in the analysis of the severity by linear regression analysis. Therefore, the degree of deformation extent of 5 or more can be suggested as a criterion that can be used additionally to the severity classification in the elderly driver.

Analysis of Availability of High-resolution Satellite and UAV Multispectral Images for Forest Burn Severity Classification (산불 피해강도 분류를 위한 고해상도 위성 및 무인기 다중분광영상의 활용 가능성 분석)

  • Shin, Jung-Il;Seo, Won-Woo;Kim, Taejung;Woo, Choong-Shik;Park, Joowon
    • Korean Journal of Remote Sensing
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    • v.35 no.6_2
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    • pp.1095-1106
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    • 2019
  • Damage of forest fire should be investigated quickly and accurately for recovery, compensation and prevention of secondary disaster. Using remotely sensed data, burn severity is investigated based on the difference of reflectance or spectral indices before and after forest fire. Recently, the use of high resolution satellite and UAV imagery is increasing, but it is not easy to obtain an image before forest fire that cannot be predicted where and when. This study tried to analyze availability of high-resolution images and supervised classifiers on the burn severity classification. Two supervised classifiers were applied to the KOMPSAT-3A image and the UAV multispectral image acquired after the forest fire. The maximum likelihood (MLH) classifier use absolute value of spectral reflectance and the spectral angle mapper (SAM) classifier use pattern of spectra. As a result, in terms of spatial resolution, the classification accuracy of the UAV image was higher than that of the satellite image. However, both images shown very high classification accuracy, which means that they can be used for classification of burn severity. In terms of the classifier, the maximum likelihood method showed higher classification accuracy than the spectral angle mapper because some classes have similar spectral pattern although they have different absolute reflectance. Therefore, burn severity can be classified using the high resolution multispectral images after the fire, but an appropriate classifier should be selected to get high accuracy.

Applying Fire Risk Analysis to Develop Fire-safe Modular Walls: Guidance to Material Selection, Design Approach and Construction Method

  • Lim, Seokho;Chung, Joonsoo;Kim, Mihyun Esther
    • Architectural research
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    • v.24 no.2
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    • pp.21-27
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    • 2022
  • For the past decade, South Korea had experienced catastrophic building fires, which resulted in consider-ably high number of casualties. This motivated research to develop fire-safe wall assemblies. In this study Fire Risk Analysis (FRA) is conducted as part of the project designing phase to ensure fire safety of the final product. Traditional approach was to consider fire performance at the end of the designing stage, when PASS/FAIL fire test results are required to be submitted to the Authority Having Jurisdiction (AHJ). By applying a fire risk analysis to guide the designing phase, overall fire safety of a wall assembly can be achieved more systematically as conducting FRA allows designers to clearly identify elements that are more vulnerable to fire and simply replace them with other practical options. Severity of fire risk is determined by considering the fire hazards of a wall assembly such as the exterior layer, insulation, vertical connectivity, and external ignition sources (e.g., photovoltaic panels). Frequency of fire risk is assessed based on the factors affecting fire likelihood, which are air cavity and fire-stopping applied in the design, and random design changes occurring during on-site construction. Fire risk matrix is proposed based on these fire risk factors and efforts to reduce the fire risk level associated with the wall assembly are given by systematically assessing the fire risk factors identified from fire risk analysis. Current study demonstrates how fire risk analysis can be applied to develop fire-safe walls by reducing the relevant fire risks- both severity and frequency.

A Study on the loading test for of slab by Fire damaged (화재피해를 입은 RC 슬래브의 재하실험에 관한 연구)

  • Lee, Kyu Min;Kang, Seung Goo;Kim, Dong Jun;Kwon, Young Jin
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.11a
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    • pp.50-51
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    • 2013
  • In case of Korea, it goes frequently that underground parks has been burned. Based on standard temperature time curve(ISO-834), gerber, walls, slab of structures are constructed. However, Standard temperature time Curve is not considered that buildings are affected by vehicle fire. that is why it has the hazard that makes building reinforcement feeble. Based on the result that got from vehicle experiment before, we made four RC slab in this experiment and set the fire severity. according to the loading experiment after heating, we measured the effects that makes reinforcement and shape changes. Furthermore, we examined the safty of the structure by comparing before and after heating.

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Estimation of non-CO2 Greenhouse Gases Emissions from Biomass Burning in the Samcheok Large-Fire Area Using Landsat TM Imagery (Landsat TM 영상자료를 활용한 삼척 대형산불 피해지의 비이산화탄소 온실가스 배출량 추정)

  • Won, Myoung-Soo;Koo, Kyo-Sang;Lee, Myung-Bo;Son, Yeong-Mo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.10 no.1
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    • pp.17-24
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    • 2008
  • This study was performed to estimate non-$CO_2$ greenhouse gases (i.e., GHGs) emission from biomass burning at a local scale. Estimation of non-$CO_2$ GHGs emission was conducted using Landsat TM satellite imagery in order to assess the damage degree in burnt area and its effect on non-$CO_2$ GHGs emission. This approach of estimation was based on the protocol of the 2003 IPCC Guidelines. In this study, we used one of the most severe fire cases occurred Samcheock in April, 2004. Landsat TM satellite imageries of pre- and post-fire were used 1) to calculate delta normalized burn ratio (dNBR) for analyzing burnt area and burn severity of the Samcheok large-fire and 2) to quantify non-$CO_2$ GHGs emission from different size of the burnt area and the damage degree. The analysis of dNBR of the Samcheok large-fire indicated that the total burnt area was 16,200ha and the size of the burnt area differed with the burn severity: out of the total burnt area, the burn severities of Low (dNBR < 152), Moderate (dNBR = 153-190), and High (dNBR = 191-255) were 35%, 33%, and 32%, respectively. It was estimated that the burnt areas of coniferous forest, deciduous forest, and mixed forest were about 11,506ha (77%), 453ha (3%), and 2,978ha (20%), respectively. The magnitude of non-$CO_2$ GHGs emissions from the Samcheok large-fire differed significantly, showing 93% of CO (44.100Gg), 6.4% of CH4 (3.053Gg), 0.5% of $NO_x$ (0.238Gg), and 0.1% of $N_2O$ (0.038Gg). Although there were little changes in the total burnt area by the burn severity, there were differences in the emission of non-$CO_2$ GHGs with the degree of the burn severity. The maximum emission of non-$CO_2$ GHGs occurred in moderate burn severity, indicating 47% of the total emission.