• 제목/요약/키워드: Damaged areas

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Can the Expansion of Forest Roads Prevent Large Forest Fires? (산림 내 도로의 확대는 대형산불을 막을 수 있는가?)

  • Suk-Hwan Hong;Mi-Yeon An;Jung-Suk Hwang
    • Korean Journal of Environment and Ecology
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    • v.37 no.6
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    • pp.439-449
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    • 2023
  • This study was conducted to verify the role of forest roads in the extinction of large forest fires in Korea. The study area was the forest fire-damaged area of Gangneung City, Gangwon Special Self-Governing Province, in April 2023, which is one of the areas with the highest road density among the major forest fires that have occurred so far. The scope of the forest fire damage area was confirmed through on-site survey, and the intensity of the fire was carried out through Sentinel-2 satellite imagery analysis. After that, the relationship between the damage range and intensity and the forest road was examined. About 59.6 km of roads were built within 50 m from the boundary of the forest fire damage area, which can easily access the entire 149.1 ha of forest fire damaged area. The road density is as high as 168.9 m/ha. All forests that were fragmented by roads were fragmented into 83 places, and all of these forests could be judged to have spread by spotting fire. As a result of analyzing the distribution of damage intensity by distance from the road to see the extent of damage according to the ease of access of fire extinguishing vehicles, it was confirmed that the proportion of areas with low-intensity damage has increased sharply even from 75 m or more away from the road. The results of analyzing the distribution of damage intensity by altitude to see the extent of damage according to the ease of access of fire extinguishing showed that the proportion of areas with low-intensity damage increased as the altitude increased, while the proportion of areas with damage of more than strong intensity decreased as the altitude increased. It was confirmed that there is no data that roads inside or adjacent to forests in the forest fire area of Gangneung City are effective in extinguishing forest fires. These results are contrary to the logic that increasing the road density in forests is effective in extinguishing forest fires. In the case of this fire area in Gangneung City, the road density is 43 times higher than the current road density in Korea claimed by the Korea Forest Service of 3.9 m/ha. This study suggests that roads can be a hindrance to extinguishing forest fires.

Development of Ecological Restoration Model Consider Analysis on the Vegetation Structure of Burned Area (산불지역 식생구조 분석을 통한 식생복원 모델 개발)

  • Kim, Jeong-Ho;Lee, Soo-Dong
    • Korean Journal of Environment and Ecology
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    • v.21 no.5
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    • pp.400-414
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    • 2007
  • This study has analyzed the vegetation structure to suggest a vegetation ecological restoration model by using the case of the afforestation for erosion control area with Pinus koreaiensis and Betula platyphylla, etc., on the hills of the Young-in mountains after its great fire in 2000. Of the area having a dimension of $1,152,404.3m^2$ selected as a survey site for the existing vegetation, the forest fire area accounted for 69.2% among which, brushwoods accounted the most for 24.67%. As a result of analysis of the 27 surveyed unit plots[unit dimension: $100m^2$] set up in consideration of the existing vegetation pattern and damaged state from the forest fire, the surveyed area was classified into 10 communities. Shrub layer's vegetation was found to be dominant in forest fire areas and the surveyed sites were classified into 5 plant communities, i.e. P. koraiensis community, Quercus variabilis community, P. thunbergii community, Q. serrata community, B. platyphylla community in forest fire areas, while non-forest fire areas were classified into 5 plant communities, such as P. densiflora community, Q. acutissima community, Q. serrata community, Q. mongolica-Q. serrata community, B. platyphylla community. Species diversity of forest fire areas was $0.3679{\sim}0.5907$ and that of non-forest fire areas was $0.5728{\sim}0.8865$. In addition, the number of the species in the forest fire areas was $5{\sim}8$ and that of non-forest areas was $8{\sim}12$; however, the population of forest fire areas$(156{\sim}456)$ was higher than that of non-forest fire areas$(61{\sim}227)$. In the analysis of growth density per layer$[of\;100m^2]$, there appeared $1{\sim}8$ trees of Q. mongolica and $3{\sim}5$ trees of Q. serrata in the upper layer species; $2{\sim}4$ trees of Q. serrata and one tree of Q. mongolica in the canopy layer. As for the characteristics of soil, acidity of forest fire areas was pH 5.45 and that of non-forest fire was pH 5.25. By setting up the middle D.B.H range of Q. mongolica-Q. serrata community as the vegetation restoration model, planting species, planting density and planting models are suggested.

Analysis of the Case of the Rehabilitation Quarrying After Using Quarrying Site (채석 완료 후 부지 활용성을 고려한 복구사례 분석)

  • Park, Jae-Hyeon;Lee, Joon-Woo;Park, Chong-Min
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.3
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    • pp.152-162
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    • 2010
  • This study provides preliminary data to support the need for appropriate and thorough restoration of quarries through investigating both domestic and overseas cases of sites that were restored in environment-friendly ways to make them re-usable after extraction. In cases of areas where it is difficult to restore the cut slope, putting it to other uses such as engraving buddhist images would be helpful to reduce the restoration cost and enhance the utilization of the slope. Phased land use conversion after exploitation needs to be considered in advance; for example, the location and size of the quarry should be determined according to the pre-planned use or development of the site. Considering the circumstances in the country, serious consideration should be given to methods that allow the restoration or recovery of the damaged sites to be completed in short periods of time. Quarry restoration needs to be approached from the view of ecological restoration and if a site is deemed to be usable for another purpose, land use conversion should be considered to enhance the utilization.

The Spatial Issues of Tsunami Recovery: Case from the Great East Japan Earthquake (동일본대지진과 재해부흥의 공간적 쟁점 -미야기 현(宮城県) 세 도시를 중심으로-)

  • Cho, Ara
    • Journal of the Korean Geographical Society
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    • v.47 no.5
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    • pp.700-717
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    • 2012
  • This study aims to discuss the spatial issues of disaster recovery from the Great East Japan Earthquake. Focused on tsunami-damaged regions, this study examines how major regional development issues have been dealt with. In the case study areas, the following ideal spatial methodologies have been suggested for tsunami recovery: building a compact city, intensifying fishing villages, and making a sustainable city. However, as the spatial restructuring have encountered practical barriers, reconstruction has been delayed, and the regional decline have been accelerating. To prevent regional decline which is inevitable after a disaster, this paper suggests that the area of disaster studies should be expanded to long-term recovery process beyond emergency response.

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Seismic Performance Evaluation of Unreinforced Masonry Buildings Retrofitted by Strengthening External Walls (외부벽체 강도증진형 보강이 적용된 비보강 조적조 건물의 내진성능평가)

  • Seol, Yun Jeong;Park, Ji-Hun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.24 no.2
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    • pp.77-86
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    • 2020
  • Nonlinear static analysis and preliminary evaluation were performed in this study to evaluate the seismic performance of unreinforced masonry buildings subjected to various soil conditions based on the revised Korean Building Code. Preliminary evaluation scores and nonlinear static analyses indicated that all buildings were susceptible to collapse and did not reach their target performance. Therefore, retrofit of those building models was carried out through a systematic procedure to determine areas to be strengthened. It was possible to make most building models satisfy performance objectives through the reinforcement alone of damaged external shear walls. However, the application of a preliminary evaluation procedure to retrofit design was found to be too conservative because all the retrofitted building models verified with nonlinear static analysis failed to satisfy performance objectives. Therefore, it is possible to economically retrofit unreinforced masonry buildings through the fortification of external walls if a simple evaluation procedure that can efficiently specify vulnerable parts is developed.

Damage detection of plate-like structures using intelligent surrogate model

  • Torkzadeh, Peyman;Fathnejat, Hamed;Ghiasi, Ramin
    • Smart Structures and Systems
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    • v.18 no.6
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    • pp.1233-1250
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    • 2016
  • Cracks in plate-like structures are some of the main reasons for destruction of the entire structure. In this study, a novel two-stage methodology is proposed for damage detection of flexural plates using an optimized artificial neural network. In the first stage, location of damages in plates is investigated using curvature-moment and curvature-moment derivative concepts. After detecting the damaged areas, the equations for damage severity detection are solved via Bat Algorithm (BA). In the second stage, in order to efficiently reduce the computational cost of model updating during the optimization process of damage severity detection, multiple damage location assurance criterion index based on the frequency change vector of structures are evaluated using properly trained cascade feed-forward neural network (CFNN) as a surrogate model. In order to achieve the most generalized neural network as a surrogate model, its structure is optimized using binary version of BA. To validate this proposed solution method, two examples are presented. The results indicate that after determining the damage location based on curvature-moment derivative concept, the proposed solution method for damage severity detection leads to significant reduction of computational time compared with direct finite element method. Furthermore, integrating BA with the efficient approximation mechanism of finite element model, maintains the acceptable accuracy of damage severity detection.

Carrying Capacity Estimation and Management Planning of the Seonjeong Royal Tomb(II) (선정릉의 적정수용능력추정 및 관리방안(II))

  • 이경재;오구균;조재창
    • Journal of the Korean Institute of Landscape Architecture
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    • v.15 no.2
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    • pp.79-90
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    • 1987
  • This second consecutive research was connected to 7he previous first research with same title. The purpose of this research is to estimate the carrying capacity for the Seonjeong royal tomb and to propose its management planning. User's characteristics and relationship between user's density and vegetational environment were analized for the above objective. The result of this research shall be summarized as follows. 1. The site was damaged seriously by pupils and social groups'picnic activities concentrated in special periods of Friday and weekend during April and May. 2. Social-psychological carrying capacity estimation would be impossible due to lack of relationship between user's density and satisfaction. 3. Maximum user's density limits as a ecological carrying capacity was 1.4 persons per 100 square meters and modified optimum ecological carrying capacity was estimated as 1.0persons per 100 square meters. Maximum visitors as a optimum carrying capacity of the Seonjeong royal tomb area was estimated as 6,000 persons when supposing the proposed landuse planning. 4. To restore and preserve the tomb landscape as a traditional historic site, Seonjeong royal tomb shall be managed by three landuse areas ; protection and control area, natural picnic area and shaded picnic area. And the protection and control area include three sites ; natural reclamation site, natural preservation site and tomb landscape conservation site.

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Susceptibility of rat hippocampal neurons to hypothermia during development

  • Seo, Kyung Ah;Kim, Sehhyun;Lee, Na Mi;Chae, Soo Ahn
    • Clinical and Experimental Pediatrics
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    • v.56 no.10
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    • pp.446-450
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    • 2013
  • Purpose: This study evaluated the extent of damage due to hypothermia in the mature and immature brain. Methods: Hippocampal tissue cultures at 7 and 14 days in vitro (DIV) were used to represent the immature and mature brain, respectively. The cultures were exposed at $25^{\circ}C$ for 0, 10, 30, and 60 minutes (n=30 in each subgroup). Propidium iodide fluorescent images were captured 24 and 48 hours after hypothermic injury. Damaged areas of the cornu ammonis 1 (CA1), CA3, and dentate gyrus (DG) were measured using image analysis. Results: At 7 DIV, the tissues exposed to cold injury for 60 minutes showed increased damage in CA1 (P<0.001) and CA3 (P=0.005) compared to the control group at 48 hours. Increased damage to DG was observed at 24 (P=0.008) and 48 hours (P=0.011). The 14 DIV tissues did not demonstrate any significant differences compared with the control group, except for the tissues exposed for 30 minutes in which DG showed less damage at 48 hours than the control group (P=0.048). In tissues at 7 DIV, CA1 (P=0.040) and DG (P=0.013) showed differences in the duration of cold exposure. Conclusion: The immature brain is more vulnerable to hypothermic injury than the mature brain.

Estimating Real-time Inundation Vulnerability Index at Point-unit Farmland Scale using Fuzzy set (Fuzzy set을 이용한 실시간 지점단위 농경지 침수위험 지수 산정)

  • Eun, Sangkyu;Kim, Taegon;Lee, Jimin;Jang, Min-Won;Suh, Kyo
    • Journal of Korean Society of Rural Planning
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    • v.20 no.2
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    • pp.1-10
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    • 2014
  • Smartphones change the picture of data and information sharing and make it possible to share various real-time flooding data and information. The vulnerability indicators of farmland inundation is needed to calculate the risk of farmland flood based on changeable hydro-meteorological data over time with morphologic characteristics of flood-damaged areas. To find related variables show the vulnerability of farmland inundation using the binary-logit model and correlation analysis and to provide vulnerability indicators were estimated by fuzzy set method. The outputs of vulnerability indicators were compared with the results of Monte Carlo simulation (MCS) for verification. From the result vulnerability indicators are applicable to mobile_based information system of farmland inundation.

Investigation on the Enhancement of Water Purification Functions in Forest Watershed (수변구역 산림에 의한 수질정화기능 증진에 관한 고찰)

  • Park, Jae-Hyeon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.4 no.4
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    • pp.72-81
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    • 2001
  • This study is aimed to review the previous research accomplishments with analysis of problems and to suggest the counter plan for the watershed management and the ongoing research strategy. Phytoremediation provides a cost-effective techniques having a merit of low investment and maintenance cost. It could be one of the best techniques, which is an alternative plan to overcome economical situation and lack of experts in our country. In forest watershed affected by waste water and heavy metal pollutants should be controlled by vegetative remediation system, but the disposal techniques of harvested plant materials should be developed. Also, high degree areas of natural vegetation as a key model to recover the vegetation should be well conserved. It is important to restore forest continuity between upper stream and lower stream basin with the restoration of damaged in forest watershed. It is established to integrated protection system for land use and management plan and to natural environment evaluation methods affected by projects such as erosion control and developments in stream and forest. In addition, I suggest the continuous environmental monitoring system to treat the pollutions concerned.

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