• Title/Summary/Keyword: Two-Layer Soil Structure

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Vegetation Structure of Warm Temperate Evergreen Forest at Ch'omch'alsan, Chimdo, Korea (진도 첨찰산 상록활엽수림의 식생구조)

  • Oh, Koo-Kyoon;Cho, Woo
    • Korean Journal of Environment and Ecology
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    • v.10 no.1
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    • pp.66-75
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    • 1996
  • To propose basic information for national resource management and planting disign, plant community structure of evergreen broad-leaved forest was investigated. Fifty-two plots(each size 300m$^{2}$) were set up at Ch'omch'alsan area of Chindo, Korea. TWINSPAN and DCA methods were used for classification and ordination analysis. Fifty-two plots were divided into seven groups, which were Quercus variabilis-Carpinus tschonoskii community, Q. glauca community, Castanepsis cuspidata var. sieboldii-Q. stenophylla community, Castanopsis cuspidata var. sieboldii-Camelia japonica community, Q. acuta-Camelia japonica community, Carpinus coreaca-Q spp. community, C. coreana community. Pinus densiflora almost have been selected. Carpinus tschomoskii, Q. variabillis and Q. serrata were to be succeeded by Castanea cuspidata var. sieboldii, Q. stenophylla, Q. acuta and Neolitsea sericea in canopy layer. And Neolitsea sericea, Q. glauca and Camellia japonica was showed high importance values in fertile soil condition. Future restoration plan was necessary for a tourist resort or national forest in warm temperate region. And evergreen broad-leaved plants shall be planted in considering of environmental condition at warm temperate and industrial complex area.

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Environment and Vegetation Characteristics of Aconitum austrokoreense Koidz. habitats (세뿔투구꽃의 자생지 식생과 환경특성)

  • Park, Jeong-Geun;Pi, Jung-hun;Jung, Ji-young;Park, Jeong-seok;Yang, Hyung-ho;Lee, Cheul-ho;Suh, Gang-uk;Son, Sung-won
    • Korean Journal of Environment and Ecology
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    • v.30 no.5
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    • pp.896-907
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    • 2016
  • The habitat characteristics of Aconitum austrokoreense Koidz. were investigated to provide basic data for conservation and restoration. The altitude ranged from 260m to 728m with inclinations of $4-39^{\circ}$. As a result of vegetation survey within natural populations, a total of 147 taxa were identified inside 20 quadrates in 7 natural habitats. The importance value of Aconitum austrokoreense was 23.0% based on the coverage and frequency of the herbaceous layer and sat is more dominant. Species diversity was 1.23, and dominace and evenness were found to be 0.22 and 0.77, respectively. The soil type were silty loam (four sites), sandy loam (two sites) and loam (one site). The average field organic matter was 7.83% and the total nitrogen and pH were 0.35, and 5.69. Correlation analysis between environmental factors and population characteristic showed the correlations between chlorophyll content and slope, flowering rate and soil humidity. Conservation on habitats conditions is important for stable maintenance the flora and the surrounding area including habitats has to be designated a protection area for habitats conservation.

Ecological Renewal Plan of Urban Parks for the Revitalization of Urban Green Axis in Gangdong-Gu (강동구 도시 녹지축 기능 활성화를 위한 도시공원의 생태적 리뉴얼 방안 연구)

  • Park, Jeong-Ah;Han, Bong-Ho;Kwak, Jeong-In
    • Journal of the Korean Institute of Landscape Architecture
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    • v.51 no.2
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    • pp.12-27
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    • 2023
  • In this study, among the construction-type parks in Gangdong-gu, targeting parks with high environmental and ecological value located on the urban green axis, a plan was prepared for the ecological renewal of urban parks, and a design that applied to them was proposed. The renewal target site was selected by analyzing the general condition of Gangdong-gu and urban parks, the land use and green area ratio, park green area, and the green axis of Gangdong-gu. Gangdong-gu has 54 parks, including 2 neighborhood parks and 52 children's parks. In the first stage of the current status review, 17 parks were extracted through locational value analysis, such as location and adjacency to the natural axis and green axis. In the second stage, eight parks were selected among the first-stage extraction parks based on the ratio of green spaces and open spaces within each park service area. In the third stage, two of the second stage extraction parks were selected based on whether the legal standard of the park area was met, and in the fourth stage, one of the third stage extraction parks was selected through an aging survey of the park. As for the urban ecological status of the renewal target site, the status of land use in the aspect of entropy reduction, the status of soil cover in the aspect of water circulation, and the status of planting structure in the aspect of biodiversity were investigated. As for the status of the three renewal sites, the green area was insufficient at 18.3-45.3%, and the facility area was 54.7%-81.7%, which was judged to have low urban temperature reduction effects. The impervious pavement area accounted for 34.5% to 48.9% of the park area, accounting for most of the facility area, and it was judged that the water circulation function was insufficient. The planting structure consisted of a single layer and a double layer structure, and although the tree layer was good, the lower vegetation was poor, and there was no planting site of edible plants or large hardwood trees, so the biodiversity was low. After the ecological renewal design of Seonrin Children's Park, Dangmal Children's Park, and Saemmul Children's Park, which were selected as the renewal targets in this study, the ecological area ratio of each park increased by 1.4 to 3 times than before the renewal. If the urban parks located on the urban green axis are examined from the perspective of the urban ecosystem and renewed ecologically, it is judged that the expected effect will be high in reducing entropy, improving water circulation, and laying the foundation for biodiversity in terms of the urban ecosystem.

Geophysical and Geological Investigation for Selecting a Dinosaur Museum Site in the Dinosaur Egg Fossil Area, Gojeong-ri, Hwasung, Gyeonggi Province (경기도 화성 고정리 공룡알 화석지 공룡생태박물관 부지선정을 위한 지구물리 및 지질조사)

  • Kim, Han-Joon;Jeong, Gap-Sik;Yi, Bo-Yeon;Jo, Churl-Hyun;Lee, Kwang-Bae;Lee, Jun-Ho;Jou, Hyeong-Tae;Lee, Gwang-Hoon
    • Geophysics and Geophysical Exploration
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    • v.13 no.4
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    • pp.357-363
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    • 2010
  • In this study, we investigated the geologic structure of the basement and overlying sediments of the construction site of the dinosaur egg fossil museum in Hwasung, Gyeonggi Province through refraction seismology, drilling, and downward seismic velocity measurements in the drill holes. The construction site ($350{\times}750\;m^2$) is located in the reclaimed area south of Sihwa Lake, Gojeong-ri. About 6,950 m of seismic refraction data consisting of 11 lines were acquired using a sledge hammer source. Drilling to the basement was performed at five sites. Sediment samples from drilling were analysed for grain-size distribution and age dating. At two drill holes, seismic velocity was measured with depth using a hammer as a seismic source. The geological structure of the study area consists of, from top to bottom, a tidal flat layer (5 ~ 12 m thick), a weathered soil layer (2 ~ 8 m thick), and the basement. The basement is interpreted as Cretaceous sedimentary rocks that tend to be shallow eastward. The volume of the tidal flat sediments and weathered soil in the study area is estimated as $1.4{\times}10^6\;m^3$, weighing $3.5{\times}10^6$ tons. The rate of sea level rise since 8,000 yrs BP is estimated to be 0.1 ~ 0.15 cm/yr.

Evaluation of Bearing Capacity of Waveform Micropile by Numerical Analyses (수치해석을 이용한 파형 마이크로파일의 지지거동 분석)

  • Han, Jin-Tae;Kim, Sung-Ryul;Jang, Young-Eun;Lee, Seung-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.11
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    • pp.5906-5914
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    • 2013
  • Recently in Korea, the policy is being proceeded to build a intergenerational housing on artificial ground of railroad site for utilizing rental house. Due to narrow space of rail road site, suitable method have to be developed such as micropiles which is known as a method of a fast construction. However, If micropile is used as foundations for the super structure, construction cost is increases compared with other pile. Consequently, new concept micropile proposed to improve both bearing capacity and cost efficiency of general micropile. New concept micropile consists of waveform cement grout surrounding tread bar that formed by grouting the soil layer with jet grouting method as control the grout pressure and flow. The micropile with waveform is expected to decrease the construction cost by cut down pile length of general micropile. This paper examined the behavior of the new concept micropile with waveform subjected to axial load using two-dimensional axisymmetric numerical analyses method. According to the numerical result, there will cost effectiveness as the pile displacement decreased despite the length of waveform micropile is down about 5% from a general micropile under the same loading condition. Also, the effect of skin friction force which mobilized from the waveform of micropile appeared at relatively soft ground.