• 제목/요약/키워드: Forest-fire

검색결과 849건 처리시간 0.028초

A New Optimized Localized Technique of CG Return Stroke Lightning Channel in Forest

  • Kabir, Homayun;Kanesan, Jeevan;Reza, Ahmed Wasif;Ramiah, Harikrishnan;Dimyati, Kaharudin
    • Journal of Electrical Engineering and Technology
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    • 제10권6호
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    • pp.2356-2363
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    • 2015
  • Localization of lightning strike point (LSP) in the forest is modeled to mitigate the forest fire damage. Though forest fire ignited by lightning rarely happens, its damage on the forest is grievousness. Therefore, predicting accurate location of LSP becomes crucial in order to control the forest fire. In this paper, we proposed a new hybrid localization algorithm by combining the received signal strength (RSS) and the received signal strength ratio (RSSR) to improve the accuracy by mitigating the environmental effect of lightning strike location in the forest. The proposed hybrid algorithm employs antenna theory (AT) model of cloud-to-ground (CG) return stroke lightning channel to forecast the location of the lightning strike. The obtained results show that the proposed hybrid algorithm achieves better location accuracy compared to the existing RSS method for predicting the lightning strike location considering additive white Gaussian noise (AWGN) environment.

송전용 폴리머애자의 산불 영향 신뢰성 평가 (Reliability Assessment of Forest Fire on EHV Polymer Insulator Strings)

  • 민병욱;신태우;최인혁;최한열;박재웅;유근양
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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    • pp.436-437
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    • 2006
  • Porcelain insulators have generally been used in Korea but polymer insulators which are superior in that they are light weight, explosion proof, impact proof, economical with construction characteristics, have been in use for the 154kV transmission line since 1999 following a worldwide trend towards the reduced weight, simplification and compact usage of new material insulators. However there have been approximately 500 cases of forest fires in Korea, so the transmission lines that for the most part pass through mountainous areas have been highly effected and the highly polymerized compound polymer insulator has raised concern about reliability in cases of exposure to forest fires. Therefore for the reliability assessment of the effect of forest fires on polymer insulators, mechanical and electrical characteristics are analyzed by an artificial flare test device and transmission facility surrounding conditions along with forest fire characteristics are surveyed. In addition to this, actual 90kV energized transmission line was tested with an artificial forest fire and the expanded usage of polymer insulators is presented through the analysis of mechanical and electrical characteristics and physical properties, and a study on the influence of forest fires on polymer insulators.

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영동지역 소나무림에서 강우 후 임내 연료습도 변화분석 (Analysis of Fuel Moisture Contents Change after Precipitation in the Pine tree stand during Forest Fire Period in the East sea region)

  • 이시영;이명욱;권춘근;염찬호
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2008년도 정기총회 및 학술발표대회
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    • pp.149-152
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    • 2008
  • This study is the result between the variation of fuel moisture and the risk of forest fire through measuring the change of moisture containing ratio on-site and its average analysis for fallen leaves layer, humus layer, and soil layer in the forest. The measurement was performed on six days from the day after a rainfall. The fuel moisture on-site was measured on the day when the accumulated rainfall was above 5.0mm, and the measurements was 2 times in spring and 1 time in fall. From the pine forest which were distributed around Samcheok and Donghae in Kangwondo, three regions were selected by loose, medium, and dense forest density, and the fuel moisture was measured on fallen leaves layer, humus layer, and soil layer in the forest. for six days from the day after a rainfall. The study showed that the moisture containing ratio converged on 3 - 4 days in spring and fall for fallen leaves layer, and the convergence was made more than six days in spring and fall for the humus layer. In the other case of soil layer, the variation of moisture containing ratio after rainfall was not distinguishable regardless of season.

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산불지에서 절지동물 포식자(거미목, 딱정벌레과, 반날개과와 개미과)의 군집구조, 종풍부도 및 풍부도에 대한 교란강도의 영향 (Influences of Disturbance Intensity on Community Structure, Species Richness and Abundance of Arthropod Predators (Araneae, Carabidae, Staphylinidae, and Formicidae) in Burned-pine Forest)

  • 이철민;권태성;박영규;김병우
    • 한국산림과학회지
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    • 제101권3호
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    • pp.488-500
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    • 2012
  • 본 연구는 절지동물 포식자인 개미, 거미, 딱정벌레, 반날개의 산림교란에 대한 생물지표의 가능성을 평가하기 위해 수행되었다. 강원도 고성, 강릉, 삼척에서 다른 산불강도와 복원방법에 의해 생긴 교란강도에 따라 12개의 조사지를 선정했다. 조사지의 교란강도는 미피해지(DD=0), 지표화 피해지(DD=1), 수관화 피해지(DD=2), 수관화피해 후 인공복원지(DD=3)로 구분하였다. 절지동물 포식자는 함정트랩법을 이용하여 채집하였다. 거미, 딱정벌레, 반날개, 개미의 종수와 풍부도는 교란강도에 따라 뚜렷한 차이가 없었다. 그러나, 초지성 개미의 종수와 풍부도는 교란강도가 높을 수록 증가했고, 초지성 개미인 곰개미와 일본왕개미는 낙엽층 두께가 깊을 수록 선형적으로 감소했다. 또한, 개미의 군집구조는 교란강도별로 나누어졌다. 개미는 장기간에 걸쳐 먹이섭식활동을 활발하게 하기 때문에, 단 한 차례의 조사일 경우에는 4가지 포식자 분류군중에서 개미가 산림교란에 대한 생물지표로 가장 유용하였다.

Fire and Rangeland's Management in India

  • Paulsamy, S.;Manian, S.;Kil, Bong-Seop
    • The Korean Journal of Ecology
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    • 제28권1호
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    • pp.55-61
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    • 2005
  • Fire, usually a detrimental factor makes changes in commonly structure and functions when it is practiced properly. In countries like Australia, South Africa, Japan and Texas in USA etc., fire is used as a tool to manage the natural ecosystems in productive condition on the basis of ecological approach. However, in developing countries like India there is effective measure to use and control fire in rangelands. This review provides knowledge on changes in sociological characters of plants, biomass profile, cycling of materials and strategy to use fire for the shaping of communities in different rangelands located in India and other countries. Further, the informations furnished in this article will be more useful for the forest managers, planners of rangelands and administrators in countries like India and tropical countries with similar bioclimatic conditions to prepare appropriate management plans where the fire is an integral factor.

산불이 토양 미소절지동물상에 미치는 영향 (Influence of Forest Fire on Soil Microarthropod Fauna)

  • Choi, Seong Sik
    • The Korean Journal of Ecology
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    • 제19권3호
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    • pp.251-260
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    • 1996
  • The effect of forest fire on soil microarthropod fauna was investigated in the Inhoo Park, located at Deokjin-gu, Chonju city, where fire burned about 2 hectares on April 5, 1994. Vegetation of the area was covered with mixed forest such as 20 to 30 year old black locust, alder, and pine gree, etc., and also rich in understory plants, dead leaves, twigs, etc. The soil samples were taken from burnt soil and near-by control site on April 10, June 6 and Oct. 22 in 1994, and June 26, 1995. Soil microarthropods were extracted using Tullgren apparatus for 72 hours. Soil microarthropods collected in this experiment were 8, 013 at control and 3, 805 at the burnt site making a total of 11, 818 from 5 classes. Therefore, appearance of microarthropods was reduced to 52.5% at burnt site. Dominant animal groups were Acari (45%) and collembola (46%). The reduced rate of soil animal density by fire damage was 52.5% of the total soil microarthropods accounting 36% in Acari and 70% in collembola. The reduction of soil animal density by fire was 65.3% by habitat destruction and 51.7% by diret shock from fire heat. In Collembola, 89% was reduced by habitat destruction. Oribatid mites collected at sample plots included 29 families, 47 genera and 58 species. Forty-two species at burnt site and 47 species at unburnt site were identified, of these 32 being common species at both sites. The density ratio of soil animals at the burnt sites and those at unburnt sites was 38.6% va 61.4% resulting in 37% reduction due to fire. The dominant species with more than 5% in relative density were Trichogalumna nipponica (7.3%) and Eremobelba japonica (5.8%) at unburnt site, shereas 5 species including Eohypochthonius crassisetiger (8.5%) at the burnt site. The number of these species were 32.1% of total number. MGP analysis based on the number of oribatid mites indicated GP type at both unburnt and burnt sites, revealing domination of the P group in oribatid mites.

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2차산불피해저감기술개발을 위한 강원도 산불지토양 중 Fe-Mn원소의 분포특성 (Properties of the Variation of Fe and Mn in the Vicinity of Soil Affected by Forest Fire for the Development of Technics that Reduces Forest Fire-induced 2nd Damage from Gangwon Provinces, Korea)

  • 오근창;양동윤;김주영;남욱현;윤정한
    • 자원환경지질
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    • 제35권3호
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    • pp.285-297
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    • 2002
  • 본 연구는 물리화학적 분석을 토대로 산불지 토양에 영향을 미치는 중요한 인자의 특성을 파악하려 하였으며, 산불지 2차피해저감기법의 개발에 획득한 결과를 활용하는데 그 목적이 있다. 연구대상지는 강원도 강릉시와 동해시에 소재한 임야이며, 산불발생시기는 2000년 12월경이다. 토양시료는 산불발생후 약 1년이 지난 2001년 11월에 산불지와 비산불지, 표토와 심토를 대상으로 구분하여 채취하였다. 산불지 표토 (0-5 cm)중의 pH는 비교지에 비하여 높은 특성을 보였으며, 심토 (5-40 cm)중의 pH는 비교지에 비하여 낮은 특성을 보였다. 토성분류 결과, 산불로 소실된 초목류의 잔류물이 산불지 토성에 영향을 주었으며, 지질적 특성에 따라서도 토성의 차이가 있음을 확인하였다. 유기물함량은 산불지에서 높게 나타났지만 예외적으로 탄질셰일이 많이 분포하는 산불지에서는 비교지에 비하여 유기물함량이 낮은 것으로 나타났다. 풍화지수는 산불지에서 낮게 나타났으며 이는 산불지 표토의 유실과 관련이 있다. Fe(Fe$^{2+}$ or Fe$^{3+}$ )이온은 강우나 강설등에 의하여 산불지 표토로부터 쉽게 용탈되는 반면에 Mn이온은 콜로이드의 물리화학적 흡착작용에 의하여 산불지 토양 중에 그대로 잔류하는 특성을 확인하였다. 연속추출법을 통하여 산불지에서 Fe이온의 용탈이 있음을 확인하였으며, Mn이온의 용출특성이 교란되었음을 확인하였다. 요인분석결과에서도 산불로 인하여 인자들간의 수반특성이 교란되었음을 확인하였다.