• Title/Summary/Keyword: Forest fire severity

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Development of Crown Fire Propagation Probability Equation Using Logistic Regression Model (로지스틱 회귀모형을 이용한 수관화확산확률식의 개발)

  • Ryu, Gye-Sun;Lee, Byung-Doo;Won, Myoung-Soo;Kim, Kyong-Ha
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.1
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    • pp.1-12
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    • 2014
  • Crown fire, the main propagation type of large forest fire, has caused extreme damage with the fast spread rate and the high flame intensity. In this paper, we developed the probability equation to predict the crown fires using the spatial features of topography, fuel and weather in damaged area by crown fire. Eighteen variables were collected and then classified by burn severity utilizing geographic information system and remote sensing. Crown fire ratio and logistic regression model were used to select related variables and to estimate the weights for the classes of each variables. As a results, elevation, forest type, elevation relief ratio, folded aspect, plan curvature and solar insolation were related to the crown fire propagation. The crown fire propagation probability equation may can be applied to the priority setting of fuel treatment and suppression resources allocation for forest fire.

Change Detection of Damaged Area and Burn Severity due to Heat Damage from Gangwon Large Fire Area in 2019 (2019년 강원도 대형산불지역의 열해 피해로 인한 피해강도 변화 탐색)

  • Won, Myoungsoo;Jang, Keunchang;Yoon, Sukhee;Lee, HoonTaek
    • Korean Journal of Remote Sensing
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    • v.35 no.6_2
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    • pp.1083-1093
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    • 2019
  • The purpose of this study is to detect the burned area change by direct burning of tree canopies and post-fire mortality of trees via analyzing satellite imageries from the Korea multi-purpose satellite-2 and -3 (KOMPSAT-2 and -3) for two large-fires over the Goseong-Sokcho and Gangneung-Donghae regions in April 2019. For each case, the burned area was compared between two dates: the day when the fire occurred and 15-18 days after it. As the results, within these two dates, there was no substantial difference in burned area of sites whose severities were marked as "Extreme", but sites with "High" and "Low" severities showed significant differences in burned area between the two dates. These differences were resulted from the lagged post-fire browning of canopies which was detected by images from in-situ observation,satellite, and the unmanned aerial vehicle. The post-fire browning started after 3-4 days and became apparent after 10-15 days. This study offers information about the timing to quantify the burned area by large fire and about the mechanism of post-fire mortality. Also, the findings can support policy makers in planning the restoration of the damaged areas.

Fire-Induced Forest Disturbance Mapping by Using QuickBird Imagery (QuickBird 화상을 이용한 산불 삼림교란도 작성)

  • Kim, Choen
    • Korean Journal of Remote Sensing
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    • v.25 no.1
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    • pp.85-94
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    • 2009
  • This paper presents the capability to use QuickBird imagery for effects of forest disturbance in Okgye burned area. Particular attention of this paper deals with the NBR-derived mapping burn severity on QuickBird imagery to locate reliable rehabilitation(namely, secondary succession) over postfire surface. Comparisons of the mapping forest disturbance derived from QuickBird NBR data and the mapping burn severity derived from Landsat ${\Delta}NBR$ data show substantial agreement (KHAT value =0.7886). The method calculated from the correlation between QuickBird wetness and Landsat ETM+ band7 may have application to forest harvest disturbance.

A Study on Winter-Covered Optical Satellite Imagery for Post-Eire Forest Monitoring

  • Kim, Choen;Park, Seung-Hwan
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.274-274
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    • 2002
  • Damage to forest trees, caused by wildfire, changes their spectral reflectance signature. This factor led to the initiation of a research project at the Remote Sensing & GIS Laboratory, Kookmin University, to determine if multispectral data acquired by IKONOS could provide fire scar and bum severity mapping. This paper will present detail mapping of burned areas in the eastern coast of Korea with IKONOS imagery. In addition, a single post-burn Landsat-7 ETM+ data was used to compare with IKONOS, the study area. Burn severity map based on IKONOS image was found to be affected by strong topographic illumination effects in the mountain forest. But it has better the delineation of the bum-scarred area. In this study the NDVI was analyzed for geometric illumination conditions influenced by topography(slop, aspect and elevation) and shadow(solar elevation and azimuth angle).

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Sensitivity Analysis on Ecological Factors Affecting Forest Fire Spreading: Simulation Study (산불확산에 영향을 미치는 생태학적 요소들간의 민감도 분석: 시뮬레이션 연구)

  • Song, Hark-Soo;Lee, Sang-Hee
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.15 no.3
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    • pp.178-185
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    • 2013
  • Forest fires are expected to increase in severity and frequency under global climate change and thus better understanding of fire dynamics is critical for mitigation and adaptation. Researchers with different background, such as ecologists, physicists, and mathematical biologists, have developed various simulation models to reproduce forest fire spread dynamics. However, these models have limitations in the fire spreading because of the complicated factors such as fuel types, wind, and moisture. In this study, we suggested a simple model considering the wind effect and two different fuel types. The two fuels correspond to susceptible tree and resistant tree with different probabilities of transferring fire. The trees were randomly distributed in simulation space with a density ranging from 0.0 (low) to 1.0 (high). The susceptible tree had higher value of the probability than the resistant tree. Based on the number of burnt trees, we then carried out the sensitivity analysis to quantify how the forest fire patterns are affected by wind and tree density. The statistical analysis showed that the total tree density had greatest effect on the forest fire spreading and wind had the next greatest effect. The density of the susceptible tree was relatively lower factor affecting the forest fire. We believe that our model can be a useful tool to explore forest fire spreading patterns.

Natural Regeneration Patten of Pine Seedlings on the Burned Forest Site in Gosung, Korea (고성 산불피해지에서 소나무 치수의 자연복원 패턴)

  • Lim, Joo-Hoon;Kim, Jeong-Hwan;Bae, Sang-Won
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.14 no.4
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    • pp.222-228
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    • 2012
  • This study was conducted to determine the natural succession process after forest fire by comparing height, relative growth rates in height (RGH), and tree density of pine seedlings with different fire severity. In the area damaged by surface fire, tree density was highest during the first 5 years after fire. However, in the area damaged by crown fire, tree density rapidly increased during first 5 years after fire. Pine seedlings were found only on the place with ridges, barren soil, and the aspect of north. Annual height growth of pine seedlings was decreased with time in all study sites. The empty space in pine stands gradually decreased by the invasion of Quercus species. The forest fire altered the pine forest into oak forest rapidly. In contrast, pine seedlings invaded steadily on the oak forest in the rocky area or the area with ridges.

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.

Detection of Forest Fire and NBR Mis-classified Pixel Using Multi-temporal Sentinel-2A Images (다시기 Sentinel-2A 영상을 활용한 산불피해 변화탐지 및 NBR 오분류 픽셀 탐지)

  • Youn, Hyoungjin;Jeong, Jongchul
    • Korean Journal of Remote Sensing
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    • v.35 no.6_2
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    • pp.1107-1115
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    • 2019
  • Satellite data play a major role in supporting knowledge about forest fire by delivering rapid information to map areas damaged. This study, we used 7 Sentinel-2A images to detect change area in forests of Sokcho on April 4, 2019. The process of classify forest fire severity used 7 levels from Sentinel-2A dNBR(differenced Normalized Burn Ratio). In the process of classifying forest fire damage areas, the study selected three areas with high regrowth of vegetation level and conducted a detailed spatial analysis of the areas concerned. The results of dNBR analysis, regrowth of coniferous forest was greater than broad-leaf forest, but NDVI showed the lowest level of vegetation. This is the error of dNBR classification of dNBR. The results of dNBR time series, an area of forest fire damage decreased to a large extent between April 20th and May 3rd. This is an example of the regrowth by developing rare-plants and recovering broad-leaf plants vegetation. The results showed that change area was detected through the change detection of danage area by forest category and the classification errors of the coniferous forest were reached through the comparison of NDVI and dNBR. Therefore, the need to improve the precision Korean forest fire damage rating table accompanied by field investigations was suggested during the image classification process through dNBR.

Effects of Edge Area and Burn Severity on Early Vegetation Regeneration in Damaged Area (가장자리와 산불피해강도가 산불피해지역 초기식생재생에 미치는 효과)

  • Lee, Joo-Mee;Won, Myoung-Soo;Lim, Joo-Hoon;Lee, Sang-Woo
    • Journal of Korean Society of Forest Science
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    • v.101 no.1
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    • pp.121-129
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    • 2012
  • The edge area with burn severity is known as significant factor that has great effects on the ecosystem recovery. However, there is little study on the edge area and its effects in the South Korea. Thus, this study aimed to analyze immediate responses of vegetation following forest fires due to combined effect of burn severity and edge-interior effect. Burn Severity (BS), or ${\Delta}NBR$ values were computed using satellite images of pre and post-forest fire in Samcheock areas. The burn forest was classified 231 $1-km^2$ girds and these grids were further reclassified into 4 groups by BS type (low BS and high BS areas) and forest areas (edge areas and interior areas). These four groups of grids including low BS-interior (group A), low BS-edge (group B), high BS-interior (group C) and high BS-edge (group D). Post-fire vegetation responses measured with (${\Delta}NDVI$) among four groups were then compared and tested by T-test. The results indicated that group C (${\Delta}NDVI$=0.047) and D (${\Delta}NDVI$ = 0.059) showed considerably greater vegetation regeneration than those of low BS areas including group A (${\Delta}NDVI$ = -0.039) and group B (${\Delta}NDVI$ = -0.036). It was also observed that edges areas showed greater vegetation regeneration than interior areas when BS is the same. Group B (${\Delta}NDVI$ = -0.036) showed greater (${\Delta}NDVI$) values than group A (${\Delta}NDVI$ = -0.039) in low BS condition. Similar relationship is observed between group C and group D in high BS condition. Thus adequate restoration practices for burned areas might need to pay close attention to interior areas with low BS to minimize the secondary damages and to rehabilitate the burned forests.

Prediction of Potential Habitat and Damage Amount of Rare·Endemic Plants (Sophora Koreensis Nakai) Using NBR and MaxEnt Model Analysis - For the Forest Fire Area of Bibongsan (Mt.) in Yanggu - (NBR과 MaxEnt 모델 분석을 활용한 희귀특산식물(개느삼) 분포 및 피해량 예측 - 양구 비봉산 산불피해지를 대상으로-)

  • Yun, Ho-Geun;Lee, Jong-Won;An, Jong-Bin;Yu, Seung-Bong;Bak, Gi-Ppeum;Shin, Hyun-Tak;Park, Wan-Geun;Kim, Sang-Jun
    • Korean Journal of Plant Resources
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    • v.35 no.2
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    • pp.169-182
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    • 2022
  • This study was conducted to predict the distribution of rare·endemic plants (Sophora koreensis Nakai) in the border forests where wildfire damage occurred and to quantify the damage. For this purpose, we tried to derive more accurate results through forest area damage (NBR) according to the Burn severity of wildfires, damage by tree species type (Vegetation map), and MaxEnt model. For Burn severity analysis, satellite imagery (Landsat-8) was used to analyze Burn severity (ΔNBR2016-2015) and to derive the extent of damage. To prepare the Vegetation map, the land cover map prepared by the Ministry of Environment, the Vegetation map prepared by the Korea Forest Service, and the vegetation survey conducted by itself were conducted to prepare the clinical map before and after the forest fire. Lastly, for MaxEnt model analysis, the AUC value was derived by using the habitat coordinates of Sophora koreensis Nakai based on the related literature and self-report data. As a result of combining the Maxent model analysis data with the Burn severity data, it was confirmed that 45.9% of the 44,760 m2 of habitat (predicted) area of Sophora koreensis Nakai in the wildfire damaged area or 20,552 m2, was damaged.