• Title/Summary/Keyword: GrassFire

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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.

Comparative Analysis of Forest Fire Danger Rating on the Forest Characteristics of Thinning Area and Non-thinning Area (숲 가꾸기 실행 및 미 실행지의 임분특성에 따른 산불위험성 비교분석)

  • Lee, Si-Young;Lee, Myung-Woog
    • Fire Science and Engineering
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    • v.21 no.4
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    • pp.52-58
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    • 2007
  • The effect of stand-growing-stock characteristics of thinning area and non-thinning area on forest fire was studied in this work. 14 spots were selected from 3 counties such as Yangyang, Injae, and Gapyeong and on-the-spot investigations were performed to evaluate the effect of forest fire. The stand-growing-stock characteristics on the spots were analyzed through the height of tree, breast height diameter, clear length, mortality of branch, forest tree standing crop density, degree of closure, and shrub and grass cover degree. The relation between forest fire and the risk of spread of forest fire were analyzed from the analysis of the stand-growing-stock characteristics. It is considered from this work that the possibility of forest fire is decreased on the thinning area compared to the non-thinning area because of higher clearlength, lower number of tree, lower mortality of branch and higher shrub and grass cover degree.

Numerical Simulation of a Forest Fire Spread (산불 전파의 수치 시뮬레이션)

  • Lee, Myung-Sung;Won, Chan-Shik;Hur, Nahm-Keon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.2
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    • pp.137-143
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    • 2008
  • In the present study, a forest fire spread was simulated with a three-dimensional, fully-transient, physics-based, computer simulation program. Physics-based fire simulation is based on the governing equations of fluid dynamics, combustion and heat transfer. The focus of the present study is to perform parametric study to simulate fire spread through flat and inclined wildland with vegetative fuels like trees or grass. The fire simulation was performed in the range of the wind speeds and degrees of inclination. From the results, the effect of the various parameters of the forest fire on the fire spread behavior was analyzed for the future use of the simulation in the prediction of fire behavior in the complex terrain.

Ecological Indicators of Forest Degradation after Forest Fire and Clear-cutting in the Siberian Larch (Larix sibirica) Stand of Mongolia

  • Park, Yeong Dae;Lee, Don Koo;Stanturf, John A.;Woo, Su Young;Zoyo, Damdinjav
    • Journal of Korean Society of Forest Science
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    • v.98 no.5
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    • pp.609-617
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    • 2009
  • This study was conducted to investigate ecological indicators of forest degradation after forest fire and clear-cutting in the Siberian larch (Larix sibirica Ledeb.) stand of Mongolia. The species abundance and biodiversity indices were higher in burned and clear-cut stands than those of reference stand, but boreal understory species, such as Vaccinium vitis-idaea, Pyrola incarnata, Linnea borealis and Maianthemum bifolium, completely disappeared and was replaced by sedge species, such as Carex duriuscula, C. lanceolata, C. pediformis, Poa attenuata and P. pratensis. During the research period, temperature increased by an average of $1.6^{\circ}C$ in burned stand and $1.7^{\circ}C$ in clear-cut stand compared to reference stand, but RH sharply decreased up to 15.7% in clear-cut stand. This result indicates that Larix sibirica stand became warmer and drier after forest fire and clear-cutting, and contributed to the abundance of sedge and grass species in the understory. Moreover, intense occupation of tall sedge grass after forest fire and clear-cutting had a vital role as obstacle on natural regeneration of Larix sibirica. The similarity of species composition between reference and burned stands was higher (73.6%) than between reference and clear-cut stands (63.8%). Soil moisture significantly decreased after forest fire and clear-cutting, and the extent of decrease was more severe in the clear-cut stand. The chemical properties at soil organic layer were significantly affected by forest fire and clear-cutting but not the mineral horizons. Inorganic nitrogen of the forest floor significantly decreased in the clear-cut stand ($1.1{\pm}0.4mg{\cdot}kg^{-1}$) than that of the burned ($4.5{\pm}2.3mg{\cdot}kg^{-1}$) and reference stands ($5.0{\pm}2.3mg{\cdot}kg^{-1}$). Available P of the forest floor significantly increased after fire, whereas it decreased after clear-cutting. These results indicate that existence of boreal understory vegetation, and changes in soil moisture and available P are distinct attributes applicable as ecological indicators for identifying forest degradation in Mongolia.

Ecological Studies on the Montane Grassland of Mt. Soback in Korea (소백산 산지초원의 생태학적 연구 1. 환경요소와 식피조사)

  • Kim, Joon Ho;Hyeong Tae Mun
    • The Korean Journal of Ecology
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    • v.4 no.1_2
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    • pp.1-7
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    • 1981
  • Montane grassland at the summit of Mt. Soback, Korea, was studied to verify the relationships between environmental factors and vegetations on the different slopes. The contents of total nitrogen and excangeable cation and thickness of A-layer of soil in the east slope were greater and thicker than those of the northwest one. Two different community types were observed one, on the east slope, was a grass community and the other, on the northwest, was a grass community. Plant height and annual production of the forb community were taller and greater than those of the grass community. These differences might be correlated with the different of snow depth between two slopes caused by wind in witner. It is clear that the formation of the montane grassland at the study area is mainly caused by fire, wind and topography at the summit.

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Moisture Content of Litter Layer and Its Combustibility by Cigarette Light in Forests (森林內 落葉層의 含水量과 담뱃불에 의한 可燃性)

  • 김관수;장인수;김수정
    • The Korean Journal of Ecology
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    • v.17 no.1
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    • pp.1-9
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    • 1994
  • This study focuses on forest fires attributed to cigarette light, the main source of wild fires, by examining the characteristics of the fire types. It aims to present useful data for preventive measures. Statistics show that the average length of cigarette butts left after smoking is 30mm excluding filter for domestic cigarette smokers. Also the average thickness of litter layer in forests is 58.2mm throughout the nation. The value varies according to how often leaves were trodden by hikers : the accumulation amount of Mt. Sunchi. which is relatively protected from human disturbances, is 29.6% more than that of Mt. Kye-Ryong National Park. Aged trees such as Pznus rzgidu, Quercus acutissima and Larix leptolepis have relatively large inflammable contents, 2.43kg in 15 year-old stand and 2.55kg in 10 year-old stand. This study found out the following fact with regard to the start of lighting and the out-break of fire. Fire breaks out within five minutes in the sample(C), in which Zoysza gaponica and Populus X tomentiglandulosu has been tramped when the sample has 2~6 percent of moisture contents. Coniferous trees such as Pinus rigida and Larzx leptolepis do not burn easily while leaving charcoal. In contrast, deciduous trees with Zoysia japonzca and Populus X tomentiglandulosu are quick to catch fire. As a result of the experiments, it is proved that cigarette light is a very dangerous cause of wild fire especially for dry grass like Zoysia gaponica.

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Biomass Structure and Dry Matter Dynamics in a Fire Influencing Montane Subtropical Humid Grassland, Western Ghats Southern India

  • Paulsamy, S;Manian, S.;Udaiyan, K.;Arumugasamy, K.;Nagarajan, N.;Kil, B.S.
    • The Korean Journal of Ecology
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    • v.24 no.4
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    • pp.227-232
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    • 2001
  • The biomass structure for three major components viz., the dominant grass, Chrysopogon zeylanicus Thw., the 'other grasses' and the'remaining species'and dry matter dynamics for total community were studied over a period of one year in an annual fire influenced subtropical humid grassland community in Western Ghats, India. The biomass of aboveground, belowground and litter compartments were high as in other humid grasslands and generally have positive correlation with rainfall, rainy days and relative humidity with the exception of litter parts. The above and belowground net primary productions (4,561 and 722 g/㎡, respectively) were also higher and were comparable with other humid tropical grasslands. The turnover of organic matter was rapid, Of the total input of 14.47 g/㎡ into the system, about 86.3% was allocated to above ground parts and 13.7% to below ground parts. The total disappearance was 2.56 g/㎡ and it was accounted to be 17.68% of the total output. The net surplus of dry matter (82.32%) in the post fire community indicates that the grassland was maintained in a seral stage. Hence it is suggested that prescribed burning may keep this ecosystem in a highly productive and seral stage.

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Development of Stochastic Model and Simulation for Spatial Process Using Remotely Sensed Data : Fire Arrival Process (원격탐사자료를 이용한 공간적 현상의 모형화 및 시뮬레이션 : 자연화재발생의 경우)

  • 정명희
    • Spatial Information Research
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    • v.6 no.1
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    • pp.77-90
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    • 1998
  • The complex interactions of climate, topography, geology, biota and hwnan activities result in the land cover patterns, which are impacted by natural disturbances such as fire, earthquake and flood. Natural disturbances disrupt ecosystem communities and change the physical environment, thereby generating a new landscape. Community ecologists believe that disturbance is critical in determining how diverse ecological systems function. Fires were once a major agent of disturbance in the North American tall grass prairies, African savannas, and Australian bush. The major focus of this research was to develop stochastic model of spatial process of disturbance or spatial events and simulate the process based on the developed model and it was applied to the fire arrival process in the Great Victoria Desert of Australia, where wildfires generate a mosaic of patches of habitat at various stages of post-fire succession. For this research, Landsat Multi-Spectral Scanner(MSS) data covering the period from 1972 to 1994 were utilized. Fire arrival process is characterized as a spatial point pattern irregularly distributed within a region of space. Here, nonhomogeneous planar Poisson process is proposed as a model for the fire arrival process and rejection sampling thinning the homogeneous Poisson process is used for its simulation.

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Regulation of Fruit and Seed Production in Selfing Annual, Vigna unguiculata (일년생 자가수분 식물인 동부의 열매 및 종자 생산의 조절에 관한 연구)

  • 이수진;장남기
    • Asian Journal of Turfgrass Science
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    • v.9 no.2
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    • pp.137-157
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    • 1995
  • Some indices of species of the Arundinella hirta communities in Cheolwon area were studied and the following results were obtained. The vegetational date was analyzed from six grass stands selected with the distance away from the DMZ in Cheolwon area. Species diversity was higher in the stand away from the DMZ than in that neat to it. All six stands are not considered to be free of disturbance. Species composition of the stands might be related to the degree of disturbance. It can be said that the destruction of the vegetation by periodical fire or cutting simplifies the species composition. In the rear district the human inter ference is supposed to be more frequent. But it is supposed to be slight in near the DMZ and that the degree of disturbance is not so destructive. This could be the explanation of high diversity in these stands.

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