• Title/Summary/Keyword: Forest-fire

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Mechanical Deterioration Characteristics of ACSR due to a Flame (화염으로 인한 ACSR의 기계적 열화 특성)

  • 박창기;이광식;강지원;김영달
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.17 no.6
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    • pp.160-168
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    • 2003
  • In Korea, a large portion of aerial power-transmission cables is installed in the mountains. In the case of a fire in the mountains, steel wires coated with zinc and aluminum wires of those power cables exposed to the fire or near around will be deteriorated by the blaze and the high temperature. Deterioration proceeds by interactions of a variety of factors like quality, manufacturing process, the condition of installation and exposure environment of a wire, and so on. Generally, the characteristic of a conductor affect by a forest fire can not be analyzed without the effect through simulating a forest fire. However, there are little research accomplishments of that kind of simulation about it, and there's been no analysis of a sample exposed to an actual forest fire. This thesis shows the experimental results that apply to a new wire by an artificial flame-maker because it's difficult to directly analyze the characteristic of deterioration by a forest fire. Those results include the intensity of extension and wrench for a conductor. In addition, there's been an experiment and analysis about the mechanical characteristics of the wire of ACSR 480[$\textrm{mm}^2$] which was removed from Pohang area by a forest fire. Then, the database will be made to predict the state of deteriorated wires by a forest fire using those two data, and data necessary to diagnose the life state of an ACSR wire affected by a forest fire will be given.

Regional Optimization of Forest Fire Danger Index (FFDI) and its Application to 2022 North Korea Wildfires (산불위험지수 지역최적화를 통한 2022년 북한산불 사례분석)

  • Youn, Youjeong;Kim, Seoyeon;Choi, Soyeon;Park, Ganghyun;Kang, Jonggu;Kim, Geunah;Kwon, Chunguen;Seo, Kyungwon;Lee, Yangwon
    • Korean Journal of Remote Sensing
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    • v.38 no.6_3
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    • pp.1847-1859
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    • 2022
  • Wildfires in North Korea can have a directly or indirectly affect South Korea if they go south to the Demilitarized Zone. Therefore, this study calculates the regional optimized Forest Fire Danger Index (FFDI) based on Local Data Assessment and Prediction System (LDAPS) weather data to obtain forest fire risk in North Korea, and applied it to the cases in Goseong-gun and Cheorwon-gun, North Korea in April 2022. As a result, the suitability was confirmed as the FFDI at the time of ignition corresponded to the risk class Extreme and Severe sections, respectively. In addition, a qualitative comparison of the risk map and the soil moisture map before and after the wildfire, the correlation was grasped. A new forest fire risk index that combines drought factors such as soil moisture, Standardized Precipitation Index (SPI), and Normalized Difference Water Index (NDWI) will be needed in the future.

Effects of Forest Fire on the Water Storage Characteristics of Forest Land (산불이 임지(林地)의 수저류(水貯留) 특성(特性)에 미치는 영향(影響))

  • Lee, Heon Ho
    • Journal of Korean Society of Forest Science
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    • v.85 no.1
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    • pp.66-75
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    • 1996
  • This study was carried out to examine the forest fire effect on water storage characteristics in the forests. Water storage capacity of the burned area was analyzed by several major factors, such as soil pore, maximum water content, effective water storage, and percolation rate. The results obtained from the analysis of major factors are as follows; The deeper soil depth, the less total pore, coarse pore, effective water storage, and percolation rate. However, fine pore increased slightly in both burned area and control plot. As compared with control plot, burned area showed lower percolation rate, coarse pore, and effective water storage, but higher values of fine pore. Directly after forest fire, the soil pore is little affected. But as the time passes, top soil structure changes and soil pore also is affected even in a deep soil. Estimated effective water storage was lower at top soil of Namcheon and at deep soil of Namha in all the burned areas, but slowly decreased in deep soil compared to control plots. Therefore it was concluded that forest water storage capacity was greatly affected by the forest fire.

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Comparative Analysis between Normalized Burn Ration and Normalized Difference Vegetation Index in Forest Fire Damage Area (산불피해지역에서 정규산화율지수와 정규식생지수의 비교분석)

  • Choi Seung Pil;Park Jong Sun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.22 no.3
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    • pp.261-268
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    • 2004
  • Analysis on forest through satellite image data can be obtained from normalized burn ration (NBR) and normalized difference vegetation index (NDVI) from descriptive information of reflection on the earth's surface recorded each waveband. This study focuses on the efficiency of NBR through comparative analysis after obtaining NBR and NDVI of images form 1 you, 2 years and just after the forest fire and the time of forest-preserved of the area before the forest fire in Sacheon myeon, Cangneung City where the forest fro broke out. As a result, it shows dynamic changes with greater range that differences between NBR images rather than differences between NDVI images, which means it would be better to use NBR image for the analysis of the degrees of damages from forest fire or the status of vegetation restoration and also NBR image more distinctly shows both than NDVI image in forest fro damage area.

Projecting forest fire potential in the Baekdudaegan of the Chungcheong region under the SSP scenario climate change using KBDI Drought Index (KBDI 가뭄지수를 이용한 SSP 기후변화 시나리오하의 충청지역 백두대간 산불 잠재력 전망)

  • Choi, Jaeyong;Kim, Su-Jin;Jung, Huicheul;Kim, Sung-Yeol;Moon, Geon-Soo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.25 no.6
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    • pp.1-11
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    • 2022
  • Recently, climate change has been regarded as a major cause of large-scale forest fires worldwide, and there is concern that more frequent and severe forest fires will occur due to the level of greenhouse gas emissions. In this study, the daily Keetch and Byram Drought Index (KBDI) of the Baekdudaegan in Chungcheong region including Sobaeksan, Songnisan, and Woraksan National Parks were calculated to assess effect of climate change on the forest fire potential- severity of annual maximum KBDI and frequency of high KBDI days. The present (2000~2019) and future KBDI(2021~2040, 2041~2060, 2081~2090) were calculated based on the meteorological observation and the ensemble regional climate model of the SSP1-2.6 and SSP5-8.5 scenarios with a spatial resolution of 1-km provided by Korea Meteorological Administration(KMA). Under the SSP5-8.5 scenario, 6.5℃ increase and 14% precipitation increase are expected at the end of the 21st century. The severity of maximum daily KBDI increases by 48% (+50mm), and the frequency of high KBDI days (> 100 KBDI) increases more than 100 days, which means the high potential for serious forest fires. The analysis results showed that Songnisan National Park has the highest potential for forest fire risk and will continue to be high in intensity and frequency in the future. It is expected that the forest vulnerability of the Baekdudaegan in the Chungcheong region will greatly increase and the difficulty in preventing and suppressing forest fires will increase as the abundance of combustible materials increases along with climate changes.

Long-Term Change of the Amount of Soil Erosion in Forest Fire (산불 피해지 토양침식량의 장기적인 변화에 관한 연구)

  • Ma, Ho-Seop;Jeong, Won-Ok
    • Journal of Korean Society of Forest Science
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    • v.97 no.4
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    • pp.363-367
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    • 2008
  • The purpose of this study was to evaluate the change of the amount of soil erosion by comparisons between burned and unburned area after forest fire. The amount of soil erosion in burned area was more high 11.2 times in year of fire, 8.4 times in 1 later year, 2 times in 5 later year and 1.3 times in 10 later year than in unburned area. The ratio of soil erosion in burned area was reduced to 98% of 10 later year as compared to the year of fire. Therefore, the soil erosion in the burned area almost tended to stabilization like unburned area passing ten year after forest fire. The most affecting factors on the amount of soil erosion in burned and unburned area were unit rainfall, number of unit rainfall and number of rainfall accumulated.

Detection of Forest Fire Damage from Sentinel-1 SAR Data through the Synergistic Use of Principal Component Analysis and K-means Clustering (Sentinel-1 SAR 영상을 이용한 주성분분석 및 K-means Clustering 기반 산불 탐지)

  • Lee, Jaese;Kim, Woohyeok;Im, Jungho;Kwon, Chunguen;Kim, Sungyong
    • Korean Journal of Remote Sensing
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    • v.37 no.5_3
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    • pp.1373-1387
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    • 2021
  • Forest fire poses a significant threat to the environment and society, affecting carbon cycle and surface energy balance, and resulting in socioeconomic losses. Widely used multi-spectral satellite image-based approaches for burned area detection have a problem in that they do not work under cloudy conditions. Therefore, in this study, Sentinel-1 Synthetic Aperture Radar (SAR) data from Europe Space Agency, which can be collected in all weather conditions, were used to identify forest fire damaged area based on a series of processes including Principal Component Analysis (PCA) and K-means clustering. Four forest fire cases, which occurred in Gangneung·Donghae and Goseong·Sokcho in Gangwon-do of South Korea and two areas in North Korea on April 4, 2019, were examined. The estimated burned areas were evaluated using fire reference data provided by the National Institute of Forest Science (NIFOS) for two forest fire cases in South Korea, and differenced normalized burn ratio (dNBR) for all four cases. The average accuracy using the NIFOS reference data was 86% for the Gangneung·Donghae and Goseong·Sokcho fires. Evaluation using dNBR showed an average accuracy of 84% for all four forest fire cases. It was also confirmed that the stronger the burned intensity, the higher detection the accuracy, and vice versa. Given the advantage of SAR remote sensing, the proposed statistical processing and K-means clustering-based approach can be used to quickly identify forest fire damaged area across the Korean Peninsula, where a cloud cover rate is high and small-scale forest fires frequently occur.

Reliability Assessment of Forest Fire on Transmission Lines Polymer Insulator(I) (송전용 폴리머 애자의 산불영향 신뢰성 평가(I))

  • Choi, In-Hyuk;Lee, Il-Dong;Jeon, Young-Joon;Lee, Chul-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.425-428
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    • 2004
  • 65% of the Korean peninsula is composed of mountainous area, 97% of which is composed of forest. Therefore, there is high possibility of mountain fire because a lot of potential inflammables such as fallen leaves are stacked on the ground. Moreover, most of the overhead transmission lines in Korea are operated on the mountain. However, there has been very little study for the effect of mountain fire on polymeric insulator for transmission line, though the study is significantly required Therefore, in this study the authors observed the deformation of the housing of the insulator under fire with respect to the ignition time, using artificial ignition testing equipment, and investigated electrical and mechanical characteristics of the insulator by dry withstand voltage test, impulse flashover test and tensile load test.

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Reliance Analysis for Mechanical Characteristics of ACSR Transmission Line due to a Flame (화염에 의한 ACSR 송전선의 기계적 특성에 관한 신뢰성 분석)

  • 김영달
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.17 no.6
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    • pp.138-146
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    • 2003
  • This paper deals with the experimental results that apply to a new wire by an artificial flame-maker because it's difficult to directly analyze the characteristic of deterioration by a forest fire. Those results include tension load, extension rate and torsion number for a conductor. In addition, there's been an experiment and analysis about the mechanical characteristics of the wire of ACSR 480$\textrm{mm}^2$ which was removed from Pohang area by a forest fire. Then, the database will be made to predict the state of deteriorated wires by a forest fire using those two data, and data necessary to diagnose the life state of an ACSR wire affected by a forest fire will be given.

A Study on Surface Characteristics of ACSR Transmission Line due to a Flame (화염에 의한 ACSR 송전선의 표면 특성에 관한 연구)

  • 김영달
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.17 no.6
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    • pp.173-180
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    • 2003
  • This paper deals with the experimental results that apply to a new wire by an artificial flame-maker because it's difficult to directly analyze the characteristic of deterioration by a forest fire. Those results include surface characteristics for a conductor. In addition, there's been an experiment and analysis about the surface characteristics of the wire of ACSR 480$\textrm{mm}^2$ which was removed from Pohang area by a forest fire. Then, the database will be made to predict the state of deteriorated wires by a forest fire using those two data, and data necessary to diagnose the life state of an ACSR wire affected by a forest fire will be given.