• Title/Summary/Keyword: Burn Severity

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An Quantitative Analysis of Severity Classification and Burn Severity At the targe-fire Areas Using NBR Index of Landsat Imagery (Landsat NBR지수를 이용한 대형산불 피해지 구분 및 피해강도의 정량적 분석)

  • Won, Myoung-Soo;Koo, Kyo-Sang;Lee, Myung-Bo
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.231-237
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    • 2007
  • To monitor process of vegetation rehabilitation at the damaged area after large-fire is required a lot of manpowers and budgets. However the analysis of vegetation recovery using satellite imagery can be obtaining rapid and objective result remotely in the large damaged area. Space and airbone sensors have been used to map area burned, assess characteristics of active fires, and characterize post-fire ecological effects. Burn severity incorporates both short- and long-term post-fire effects on the local and regional environment. Burn severity is defined by the degree to which an ecosystem has changed owing to the fire. To classify fire damaged area and analyze burn severity of Samcheok fire area occurred in 2000, Cheongyang fire 2002, and Yangyang fire 2005 was utilized Landsat TM and ETM+ imagery. Therefore the objective of the present paper is to quantitatively classify fire damaged area and analyze burn severity using normalized burn index(NBR) of pre- and post-fire's Landsat satellite imagery.

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Analysis of Burn Severity in Large-fire Area Using SPOT5 Images and Field Survey Data (SPOT5영상과 현장조사자료를 융합한 대형산불지역의 피해강도 분석)

  • Won, Myoungsoo;Kim, Kyongha;Lee, Sangwoo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.2
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    • pp.114-124
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    • 2014
  • For classifying fire damaged areas and analyzing burn severity of two large-fire areas damaged over 100 ha in 2011, three methods were employed utilized supervised classification, unsupervised classification and Normalized Difference Vegetation Index (NDVI). In this paper, the post-fire imageries of SPOT were used to compute the Maximum Likelihood (MLC), Minimum Distance (MIN), ISODATA, K-means, NDVI and to evaluate large-scale patterns of burn severity from 1 m to 5 m spatial resolutions. The result of the accuracy verification on burn severity from satellite images showed that average overall accuracy was 88.38 % and the Kappa coefficient was 0.8147. To compare the accuracy between burn severity and field survey at Uljin and Youngduk, two large fire sites were selected as study areas, and forty-four sampling plots were assigned in each study area for field survey. The burn severities of the study areas were estimated by analyzing burn severity (BS) classes from SPOT images taken one month after the occurrence of the fire. The applicability of composite burn index (CBI) was validated with a correlation analysis between field survey data and burn severity classified by SPOT5, and by their confusion matrix. The result showed that correlation between field survey data and BS by SPOT5 were closely correlated in both Uljin (r = -0.544 and p<0.01) and Youngduk (r = -0.616 and p<0.01). Thus, this result supported that the proposed burn severity analysis is an adequate method to measure burn severity of large fire areas in Korea.

Recoverability analysis of Forest Fire Area Based on Satellite Imagery: Applications to DMZ in the Western Imjin Estuary (위성영상을 이용한 서부임진강하구권역 내 DMZ 산불지역 회복성 분석)

  • Kim, Jang Soo;Oh, Jeong-Sik
    • Journal of The Geomorphological Association of Korea
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    • v.28 no.1
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    • pp.83-99
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    • 2021
  • Burn severity analysis using satellite imagery has high capabilities for research and management in inaccessible areas. We extracted the forest fire area of the DMZ (Demilitarized Zone) in the western Imjin Estuary which is restricted to access due to the confrontation between South and North Korea. Then we analyzed the forest fire severity and recoverability using atmospheric corrected Surface Reflectance Level-2 data collected from Landsat-8 OLI (Operational Land Imagery) / TIRS (Thermal Infrared Sensor). Normalized Burn Ratio (NBR), differenced NBR (dNBR), and Relative dNBR (RdNBR) were analyzed based on changes in the spectral pattern of satellite images to estimate burn severity area and intensity. Also, we evaluated the recoverability after a forest fire using a land cover map which is constructed from the NBR, dNBR, and RdNBR analyzed results. The results of dNBR and RdNBR analysis for the six years (during May 30, 2014 - May 30, 2020) showed that the intensity of monthly burn severity was affected by seasonal changes after the outbreak and the intensity of annual burn severity gradually decreased after the fire events. The regrowth of vegetation was detected in most of the affected areas for three years (until May 2020) after the forest fire reoccurred in May 2017. The monthly recoverability (from April 2014 to December 2015) of forests and grass fields was increased and decreased per month depending on the vegetation growth rate of each season. In the case of annual recoverability, the growth of forest and grass field was reset caused by the recurrence of a forest fire in 2017, then gradually recovered with grass fields from 2017 to 2020. We confirmed that remote sensing was effectively applied to research of the burn severity and recoverability in the DMZ. This study would also provide implications for the management and construction statistics database of the forest fire in the DMZ.

An Quantitative Analysis of Severity Classification and Burn Severity for the Large Forest Fire Areas using Normalized Burn Ratio of Landsat Imagery (Landsat 영상으로부터 정규탄화지수 추출과 산불피해지역 및 피해강도의 정량적 분석)

  • Won, Myoung-Soo;Koo, Kyo-Sang;Lee, Myung-Bo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.3
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    • pp.80-92
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    • 2007
  • Forest fire is the dominant large-scale disturbance mechanism in the Korean temperate forest, and it strongly influences forest structure and function. Moreover burn severity incorporates both short- and long-term post-fire effects on the local and regional environment. Burn severity is defined by the degree to which an ecosystem has changed owing to the fire. Vegetation rehabilitation may specifically vary according to burn severity after fire. To understand burn severity and process of vegetation rehabilitation at the damaged area after large-fire is required a lot of man powers and budgets. However the analysis of burn severity in the forest area using satellite imagery can acquire rapidly information and more objective results remotely in the large-fire area. Space and airbone sensors have been used to map area burned, assess characteristics of active fires, and characterize post-fire ecological effects. For classifying fire damaged area and analyzing burn severity of Samcheok fire area occurred in 2000, Cheongyang fire in 2002, and Yangyang fire in 2005 we utilized Normalized Burn Ratio(NBR) technique. The NBR is temporally differenced between pre- and post-fire datasets to determine the extent and degree of change detected from burning. In this paper we use pre- and post-fire imagery from the Landsat TM and ETM+ imagery to compute the NBR and evaluate large-scale patterns of burn severity at 30m spatial resolution. 65% in the Samcheok fire area, 91% in the Cheongyang fire area and 65% in the Yangyang fire area were corresponded to burn severity class above 'High'. Therefore the use of a remotely sensed Differenced Normalized Burn Ratio(${\Delta}NBR$) by RS and GIS allows for the burn severity to be quantified spatially by mapping damaged domain and burn severity across large-fire area.

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Linking Spatial Characteristics of Forest Structure and Burn Severity (산림 공간구조 특성과 산불 연소강도와의 관계에 관한 연구)

  • Lee, Sang-Woo;Lim, Joo-Hoon;Won, Myoung-Su;Lee, Joo-Mee
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.5
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    • pp.28-41
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    • 2009
  • Because fire has significant impacts on fauna and flora in forest ecosystems, as well as socioeconomic influences to local community, it has been an important field of study for decades. One of the most common ways to reduce fire risk is to enhance fire-resilience of forest through fuel treatments including thinning and prescribed burning. Since fuel treatment can't be practiced over all forested areas, appropriate and effective strategies are needed. The present study aims to look at the relationship between spatial characteristics of forest structure measured with landscape pattern metrics and burn severity to provide guidelines for effective fuel treatments. Samchuck fire was selected for the study, and 232 grids covering the study areas were generated, and the grid size was 1km. The burn severity is measured with dNBR derived from satellite imagery, and spatial characteristics of forest structure were measured using FRAGSTATS for both landscape and class levels for each 1km grid. The results of this study strongly indicated that heterogeneity in composition and configuration of forests may significantly reduce burn severity. By enhancing heterogeneity of forests, fuel treatments for fire-resilience forest could be more effective.

Histogram Matching of Sentinel-2 Spectral Information to Enhance Planetscope Imagery for Effective Wildfire Damage Assessment

  • Kim, Minho;Jung, Minyoung;Kim, Yongil
    • Korean Journal of Remote Sensing
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    • v.35 no.4
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    • pp.517-534
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    • 2019
  • In abrupt fire disturbances, high quality images suitable for wildfire damage assessment can be difficult to acquire. Quantifying wildfire burn area and severity are essential measures for quick short-term disaster response and efficient long-term disaster restoration. Planetscope (PS) imagery offers 3 m spatial and daily temporal resolution, which can overcome the spatio-temporal resolution tradeoff of conventional satellites, albeit at the cost of spectral resolution. This study investigated the potential of augmenting PS imagery by integrating the spectral information from Sentinel-2 (S2) differenced Normalized Burn Ratio (dNBR) to PS differenced Normalized Difference Vegetation Index (dNDVI) using histogram matching,specifically for wildfire burn area and severity assessment of the Okgye wildfire which occurred on April 4th, 2019. Due to the difficulty in acquiring reference data, the results of the study were compared to the wildfire burn area reported by Ministry of the Interior and Safety. The burn area estimates from this study demonstrated that the histogram-matched (HM) PS dNDVI image produced more accurate burn area estimates and more descriptive burn severity intervals in contrast to conventional methods using S2. The HM PS dNDVI image returned an error of only 0.691% whereas the S2 dNDVI and dNBR images overestimated the wildfire burn area by 5.32% and 106%, respectively. These improvements using PS were largely due to the higher spatial resolution, allowing for the detection of sparsely distributed patches of land and narrow roads, which were indistinguishable using S2 dNBR. In addition, the integration of spectral information from S2 in the PS image resolved saturation effects in areas of low and high burn severity.

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.

Delta Neutrophil Index as an Early Marker of Sepsis in Burn Patients (화상환자에서 패혈증의 조기 예측인자로서의 DNI)

  • Kim, Chong Myung;Ha, Chul Min
    • Journal of the Korean Burn Society
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    • v.22 no.2
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    • pp.38-44
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    • 2019
  • Purpose: The immature granulocyte count has been reported to be a marker of infection and sepsis. The difference in leukocyte subfractions (delta neutrophil index, DNI) in ADVIA 2120 reflects the fraction of circulating immature granulocytes in the blood. This study evaluated the clinical utility of DNI as a severity and prediction marker in critically ill patients with burn sepsis. Methods: One hundred and sixty nine patients admitted to the burn care unit were studied. DNI (the difference in leukocyte subfractions identified by myeloperoxidase and nuclear lobularity channels) was determined using a specific blood cell analyzer. Results: Seventy one patients (42 %) were diagnosed with burn sepsis. DNI was significantly higher in patients with burn sepsis than in patients without (P<0.01). Delta neutrophil index was a better indicator of burn sepsis than C-reactive protein, lactate, white blood cell count, HCO3, base excess, lactate, procalcitonin (odds ratio, 6.31; confidence interval 2.36~16.90; P<0.01). And the receiver operating characteristic curves showed that delta neutrophil index, AUC 0.795 (95% confidence interval, 0.721~0.869; P<0.05) was a better predictor of burn sepsis than lactate, procalcitonin, white blood cell, base excess and abbreviated burn severity index. Conclusion: Delta neutrophil index may be used as a early marker of patients with burn sepsis.

Characteristics of Burn Types, Causes, and Treatment in Hospitalized Female Patients with Industrial Injuries (화상으로 입원한 여성 근로자의 화상유형 및 발생원인, 치료적 특성)

  • Kim, Ji-Na;Kang, Hee Sun
    • Korean Journal of Occupational Health Nursing
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    • v.25 no.2
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    • pp.85-95
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    • 2016
  • Purpose: The purpose of this study was to examine the burn characteristics of female patients hospitalized in a burn center. Methods: This is a retrospective descriptive study. The subjects were 222 female patients aged over 19 years old having burn injuries from work sites between January 1, 2012 and December 31, 2014. Data were collected using electronic medical records about the burn-related characteristics. The data were analyzed descriptively. Results: Many of the subjects were in their forties and fifties. Most subjects showed burns with an area of less than 10% of the body surface with a severity of second degree. Scalding burns were the most frequent. Contact burns were usually of third-degree severity and occurred on hands and wrists. Flame burns affected the largest body surface area and frequently occurred on the face and mainly caused by explosion of a stove or kitchen gas. Chemical burns frequently occurred on the lower limbs. Conclusion: Female workers are exposed to the hazards of burn injuries in industrial accidents. Types of burn differ depending on the workplace conditions. Therefore, preventative measures for burn injuries should be established in accordance with the characteristics of each industry to which female workers belong.

Development and Validation of Korean Composit Burn Index(KCBI) (한국형 산불피해강도지수(KCBI)의 개발 및 검증)

  • Lee, Hyunjoo;Lee, Joo-Mee;Won, Myoung-Soo;Lee, Sang-Woo
    • Journal of Korean Society of Forest Science
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    • v.101 no.1
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    • pp.163-174
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    • 2012
  • CBI(Composite Burn Index) developed by USDA Forest Service is a index to measure burn severity based on remote sensing. In Korea, the CBI has been used to investigate the burn severity of fire sites for the last few years. However, it has been an argument on that CBI is not adequate to capture unique characteristics of Korean forests, and there has been a demand to develop KCBI(Korean Composite Burn Index). In this regard, this study aimed to develop KCBI by adjusting the CBI and to validate its applicability by using remote sensing technique. Uljin and Youngduk, two large fire sites burned in 2011, were selected as study areas, and forty-four sampling plots were assigned in each study area for field survey. Burn severity(BS) of the study areas were estimated by analyzing NDVI from SPOT images taken one month later of the fires. Applicability of KCBI was validated with correlation analysis between KCBI index values and NDVI values and their confusion matrix. The result showed that KCBI index values and NDVI values were closely correlated in both Uljin (r = -0.54 and p<0.01) and Youngduk (r = -0.61 and p<0.01). Thus this result supported that proposed KCBI is adequate index to measure burn severity of fire sites in Korea. There was a number of limitations, such as the low correlation coefficients between BS and KCBI and skewed distribution of KCBI sampling plots toward High and Extreme classes. Despite of these limitations, the proposed KCBI showed high potentials for estimating burn severity of fire sites in Korea, and could be improved by considering the limitations in further studies.