• Title/Summary/Keyword: 토양발달

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Tafoni Geomorphic Development in the Western Coast of Dongdo of Dokdo, Korea (독도 동도 서쪽 해안의 타포니 지형 발달)

  • Hwang, Sang-Ill;Park, Kyung-Geun
    • Journal of the Korean association of regional geographers
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    • v.13 no.4
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    • pp.422-437
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    • 2007
  • Dokdo has historical and political meaning in relation to the territorial problems with Japan. The area can be the main factor to explain the formation and development process of East-Sea as exposure volcanic island at East-Sea with Ulreong-island. Accordingly, it also has an important meaning of physical geography aspects In this research, it is perceived the geomorphological development process of slope due to the salt weathering which is considered as the most important factor to understand whole geomorphology of Dokdo. And researched how a geomorphology of this sort affects to animal and plants. The peculiar geomorphology is tafoni which is a weathering geomorphology and one of the remarkable geomorphology in preservation of Dokdo. Tafoni at west part of Dongdo is distributed intensively near shoreline which is composed tuff. The shape of tafoni is mainly massive, circle and oval in Massive tuff breccia layer also is formed toward horizontality bedding direction in Bedded lapilli tuff. Tafoni in Dokdo is constituted after middle of Holocene. This fact can be proved by ranging at surface of sea-cliff which is formed wave erosion after middle of Holocene sea-level reaching to present level. Tafoni is also the most contribute factor of geomorphology dissection of Dokdo as it is eroded the bed rock with salt weathering. In bottom part of tafoni it has an important function for habitat of birds. Herbaceous plants are on it. To procrastinate of bed rock dissection by growth of Tafoni, conservation of vegetation and soil are most important factor.

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Case study of landslide types in Korea (우리나라 산사태의 형태분류에 따른 사례)

  • 김원영;김경수;채병곤;조용찬
    • The Journal of Engineering Geology
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    • v.10 no.2
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    • pp.18-35
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    • 2000
  • The most dominant type of landslide in Korea is debris flows which mostly take place along mountain slopes during the rainy season, July to August. The landslides have been reported to begin activation when rainfall is more than 200mm within 2days. The debris flows are usually followed by translational slips which occur upper part of mountain slopes and they transit to debris flow as getting down to the valleys. Lithology, location, slope inclination, grain size distribution of soil, permeability, dry density and porosity have been proved as triggering factor causing translational slides. The triggering data taken from mapping are statistically analysed to get landslide potential quantitatively. Rock mass creeps mostly occur on well bedded sedimentary rocks in Kyeongsang Basin. Although the displacement of rock mass creep is relatively small about 1m, the creep can cause severe hazards due to relatively large volume of the involved rock mass. Examples are rock mass creep occurred in the mouth of Hwangryongsan Tunnel, in Chilgok and in Sachon in 1999. Although the direct factor of the creeps are due to slope cutting at the foot area, more attention is required A rotational slide occurring within thick soil formation or weathered rock is also closely related to bottom part of slope cutting. It is propagated circular or semi-circular type. Especially in korea, the rotational slide may be frequently occurred in Tertiary tuff area. Because they are mainly composed of volcanic ash and pyroclastic materials, well developed joints and high degree of swelling and absorption can easily cause the slide. The landslide among the Pohang-Guryongpo national road is belong to this type of slide.

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Geomorphological Development and Paleoenvironment around Sinsong-ri, Gobuk-myeon, Seosan-si, South Korea (서산시 고북면 신송리 유적 일대의 지형 발달과 고환경 분석)

  • Hwang, Sang-Ill;Kim, Hyo-Seon;Yoon, Soon-Ock
    • The Korean Journal of Quaternary Research
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    • v.24 no.2
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    • pp.23-34
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    • 2010
  • The purpose of this study is to clarify the characteristics of geomorphic surfaces and investigate their geomorphological development at Sinsong-ri archaeological sites by the classification of geomorphic surfaces. The sedimentary facies of trench 1, 2 and 3 were identified and pollen analysis was performed at site 3. The geomorphic surfaces are classified by hillslope, valley plain, alluvial fan and river terrace. Most of the study area is located on low hillsides and valley plains are connected with tidal flats extended from small river valley. Also, alluvial fans are distributed over the piedmont and narrow, long river terraces are developed downstream along the Sojeong-stream flowing between valley plain and hillsides. River valleys were deeply eroded during the Last Glacial Maximum (LGM) periods, responded to the lowest sea level among the hillslopes and valley plains are formed during the Holocene. The sedimentary facies are identified composed of basal gravel layers with coarse gravels and sands, relatively thick culture layer of the Bronze Age and thin layer during the early Iron Age in upper part study area. Thus, land uses during the Bronze Age people was performed more intensively comparing to the early Iron Age by deforestation for habitation.

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GIS spatial D/B formation of geothermal data and Distribution of Heat Flow of Korea (한국의 지열자료 GIS 공간 D/B 구축과 지열류량 분포)

  • Kim, Hyoung-Chan;Lee, Young-Min;Park, Jeong-Min
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.459-460
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    • 2006
  • 현재 남한의 지열류량 측정값으로는 총 363개 지점의 자료가 측정 및 수집되어 있다. 이것은 Mizutani et at. (1970), 장정진 외(1970), 그리고 서정희(1976) 등의 자료, 총 35개의 자료도 추가된 것이다. 1989년 이후부터 측정된 지열류량 자료는 217개 자료이며(임정웅 외, 1989; 임정웅 외, 1996; Lim and Kim, 1997; 염병우 외, 1997), 모두 직접 측정한 것이나, 1989년 이후 보고된 지열류량 자료에 약간의 오류가 있어 이번 연구에서 수정 보완하였다. 또한 과거의 자료 35개 자료는 이미 지열류량 측정치가 논문화 되어 있는 것으로 암석시료는 없다 1989년 이후 2004년까지 자료 217개 2005년도 추가 자료 111개의 지열류량 자료는 암석시료도 있으며, 측정기기가 서로 달라 오차가 있을 수 있어 서로 보정을 해야 할 필요가 있어 시추공 주변 암석을 새로 수집해서 신장비로 다시 측정 보정하였다. 지열류량 D/B 구축은 각 자료의 일련번호, 고유번호 (Sn.), 위경도 좌표 (longitude, lattitude), 암석의 열전도도(thermal conductivity), 지온경사 (thermal gradient), 지열류량 (heat flow)등으로 구성되어 있다. 지열류량 자료 공간 데이터베이스는 점 속성을 가지며 자료형태는 각종 소프트웨어와 호환성이 좋은 shape 파일 형태로 작성하였다. 또만 최근 천부 토양 및 암석 열물성을 이용한 냉난방시스템 즉, Heat Pump System 설계를 위하여 반드시 들어가야 하는 요소인 열확산율, 공극율, 밀도, 비열 등 열물성 특성을 추가하여 GIS 공간 D/B구축하였다. 대륙붕 자료 4개 자료를 제외하고 359개의 지열류량 자료를 이용하여 한반도 남부, 즉 남한의 지열류량 분포도를 작성 분석해 본 결과(그림 1), 우리나라의 지열류량 이상대는 아산만 주변, 보령, 유성, 진안, 울진, 포항, 부산 지역과 포천, 속초, 충주, 수안보 등 지역에서 나타난다 이러한 이상대 주변에는 대개 온천이 발달되어 있었거나 새로 개발되어 있는 곳이다. 온천에 이용하고 있는 시추공의 자료는 배제하였으나 온천이응으로 직접적으로 영향을 받지 않은 시추공의 자료는 사용하였다 이러한 온천 주변 지역이라 하더라도 실제는 온천의 pumping 으로 인한 대류현상으로 주변 일대의 온도를 올려놓았기 때문에 비교적 높은 지열류량 값을 보인다. 한편 한반도 남동부 일대는 이번 추가된 자료에 의해 새로운 지열류량 분포 변화가 나타났다 강원 북부 오색온천지역 부근에서 높은 지열류량 분포를 보이며 또한 우리나라 대단층 중의 하나인 양산단층과 같은 방향으로 발달한 밀양단층, 모량단층, 동래단층 등 주변부로 NNE-SSW 방향의 지열류량 이상대가 발달한다. 이것으로 볼 때 지열류량은 지질구조와 무관하지 않음을 파악할 수 있다. 특히 이러한 단층대 주변은 지열수의 순환이 깊은 심도까지 가능하므로 이러한 대류현상으로 지표부근까지 높은 지온 전달이 되어 나타나는 것으로 판단된다.

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A Study on characteristics of planosols in korea -Part I Yeongog series (우리나라에 분포(分布)된 반층토(盤層土)의 특성(特性)에 관(關)한 연구(硏究) -제(第)1보(報) 연용통(延谷統)에 관(關)하여)

  • Um, Ki Tae;Cho, Seong Jin
    • Korean Journal of Soil Science and Fertilizer
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    • v.8 no.2
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    • pp.45-51
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    • 1975
  • The morphological, physical, chemical, and mineralogical characteristics of planosols in Korea were studied in an effort to establish the suitabilition of the planosols for agricultural development. The Yeongog series which are planosols were established in Korea. Results from the Yeongog series are briefly as follows : 1. Morphologically, the surface soils are brown to dark brown friable loam and subsoils are of varied colors but mainly are dark brown, black and pale brown mottles. The texture of these horizons are silty clay loam with moderate to strong platy structure and clay cutans are on the ped faces. The consistences of these horizons are extremely compact and hard when moist and sticky, plastic when wet. The substrata show varied soil colors and loam to clay loam. 2. Physically, the clay content of the Yeongog soils is highest in the subsoils and gradually decreases below the subsoils. Water holding capacity and bulk desity is higher than in other mineral soils. 3. Chemically, the organic matter content is low and soil reaction ranges from very strongly to strongly acid. The cation exchange capacity is medium and base saturation a high. Active iron, easily reducible manganese and available silicate are high compared with normal soils. 4. In chemical composition of clay fraction of the Yeongog series, sesquioxide ratio, $Fe_2O_3$, $K_2O$ and MgO are high. The cation exchange capacity of the clay fraction is also very high. 5. The clay minerals in Yeongog series are mainly kaoline, vermiculite with Al interlayers and illite. The quarts, primary minerals are in the Yeongog soils. 6. These soils are formed in a warm, humid climate under native grasses on the terraces and rolling or hilly footslopes. In soil classification, the Yeongog soils are classified planosols with claypan. According to 7th approximation system in U.S.A., the Yeongog series are classified as Fragiudalfs because they have an argillic horizon, a hard pan and a high base saturation which is more than 35 percent and classified as Eutric Planosols by FAO/UNESCO classification system.

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Tephra Origin of Goryeri Archaeological Site, Milyang Area, Korea (밀양 고례리 화산 유리물질 기원 해석)

  • 김주용;양동윤;박영철
    • The Korean Journal of Quaternary Research
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    • v.13 no.1
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    • pp.35-43
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    • 1999
  • Goryeri archaeological site is located in the upstream valley of the Danjang River. The basement rocks of the area are composed of the Cretaceous to Palaeogene biotite granite (KbGr), acidic dyke (Kad), Milyang Andesite (Kma) and Jyunggagsan Formation. Among them Milyang Andesite and Jyunggagsan Formation are prevailed in archaeological site and they are composed of reddish brown tuffaceous shale, sandstone and conglomerate, with intercalations of acidic tuffs and lapilli tuffs. The purpose of this research is not only to compare REE pattern of the soil-sedimentary deposits with those of surrounding rocks, but also to identify vitric tephra in the soil-sedimentary deposits derived from the andesite, acidic tuff and lapilii tuff, in order to illucidate the provenance of the vitric tephra. The rare earth element(REE) of the soils and sedimentary deposits results in the same REE pattern with those analyzed from the surrounding basement rocks. This indicates that the soils and sedimentary deposits are originated from the surrounding basement rocks, most probably from the andesite and lapilli tuff. In addition, vitric tephra were identified both in the Quaternary in-situ weathered soils and sedimentary deposits (PMU-13 and PMU-17), and in the weathered surrounding lapilli tuff. These vitric tephra are considered to be different from those of Japanese AT(Aira Tanzawa) -tephra. The latter is predominant with clean, platty, bubble-walled and Y-shaped vitrics, while the former is conspicuous with those shapes of large and diverse size and devitrified, as well as having secondarily bubbled-surfaces reflecting surface weathering. The size of vitric fragments in the Goryeri site is about 300${\mu}{\textrm}{m}$ and large in size in compasion to 150${\mu}{\textrm}{m}$ of Japanese AT-Tephra. The interim results of the research are contradictary to the explanations based on a series of AT-tephra researches carried by Japanese scholar. In short, the vitric materials of the Goryeri archaeological site are most probably originated from the weathering products of the surrounding basement rocks, and are different from the AT-tephra in their size, shape and devitrification properties. Thus it is highly recommended to have a further comprehensive research which is more emphasized the magmatic genesis of these vitric tephra in addition to the external shape and morphology.

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Forest Vegetation and Soil Environment on Mt. Paekun (백운산의 삼림식생과 토양환경)

  • 이호준;배병호;정흥락;전영문;홍문표
    • Korean Journal of Environmental Biology
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    • v.17 no.1
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    • pp.35-50
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    • 1999
  • The relationship between floristic composition and soil environmental conditions was investigated in the forest vegetation of Mt. Paekun. The forest vegetation unit of Mt. Paekun was divided into six plant communities by Zurich-Montpellier method, such as Quercus mongelica community (Typical subcommunity, Rhododendron schlippenbaohii subcommunity), Q. variabilis community, Fraxinus rhynchophylla community, Pinus densiflora community, Larix Eeptolepis community and Pinus koraiensis community. Q. mongolica community group was distributed at the altitude over 500 meter, Q. variabilis and P. densiflora communities appeared on the southwestern slope at the altitudes of 600 ~ 700 m and 290 ~ 700 m. However, L. leptolepis and P. koraiensis plantation were distributed at lower altitude, on hillside or around homestead. The DBH class distribution of dominant species in each community showed that Q. mongolica had 10.9 individuals/a at 6~10 cm class, Q. variabilis 2.5 individuals/a at 11~15 cm class, P. densiflora 1.8 individuals/a at 26~30 cm class, F. rhynchophylla 3.3 individuals/a at 2~5 cm class, and L. leptolepis 5.9 individuals/a at 11~ 15 cm class. Q. mongolica and Q. variabilis communities showed a stable bell-shaped pattern of distribution. The contents of organic matters and soil water, and cation exchange capacity of the soil increased, and the pH decreased as the altitude gets higher increased altitude at the each communities. The contents of the soil water and organic matters of the forest soil collected in Q. mongolica community were in the 17.81% to 51.20% and 5.51% to 14.90%, respectively. These tendency is similar to the contents of N, P and K, but those of Ca, Mg, and CEC was lower than in other communities. Cation exchange capacity was suspected to be correlated to the pH. The hypothetical successional sere of the forest vegetation of Mt. Paekun is as follows: Pinus densiflora community longrightarrowQ. variabilis community longrightarrowQ. mongolica community.

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Rainfall Pattern in Jeju-do and Rainwater Utilizing System at Domestic District (제주지역의 강우패턴과 가정용 우수이용시스템)

  • Jang, Kyung-Soo;Jun, Ji-Young;Seo, Young-Min;Lee, Seung-Yun;Jee, Hong-Kee
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.1420-1424
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    • 2006
  • 제주도는 연 평균 강우량이 전국 평균의 1.5배에 해당하는 다우지역이다. 그러나 화산섬으로서의 특수한 지형 및 지질구조 때문에 지표수가 거의 발달하지 않았으며, 이러한 수문지질여건으로 인하여 수자원의 대부분을 지하수 개발에 의존할 수 밖에 없어 용수 수요량의 증가를 충족시키기 위한 지하수 개발이 가속화되어 왔다. 그러나 지하수의 과다개발 등으로 지하수의 부존량은 점차 감소할 수 밖에 없는 실정이며, 제주도의 투수성이 높은 지질과 토양으로 지하수 오염에 취약해 최근 수질기준을 초과하는 지역이 늘어나고 있는 실정이다. 이에 제주 당국은 국제자유도시특별법 규정에 권장대상 빗물이용시설에 대한 시설비 보조에 관한 사항 등을 정하여 우수이용을 권장하고 있다. 본 연구에서는 제주도지역의 강우패턴과 세대별 생활용수량 자료를 조사 분석하여 효율적인 가정용 우수 이용 시스템으로서 갈수기에도 안정적으로 용수를 공급받을 수 있는 저류탱크의 크기 및 우수배관의 관경결정 기법을 개발하고 수질의 안정화를 위한 우수수질 안정화 기법을 제시하였다. 우수이용 시스템의 설계를 위하여 개발한 모형인 DDP, DOS 모형을 이용하여 강우 및 용수의 기초자료가 비교적 풍부한 제주도 지역에 적용함으로써 국내의 다른 산간지역과 도서지역에서도 본 시스템의 적용이 용이하게 될 수 있을 것으로 판단되며, 본 시스템 및 시스템 모형화에 대한 지속적인 연구를 통하여 보다 경제적이고 안정적인 시스템 설계가 가능한 범용적인 모형의 개발을 할 수 있을 것으로 사료된다.

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Archaeological Reaserach of the Isimila Site, Tanzania and A Comparative Archaeology of Acheulean Industries in East Africa and East Asia. (탄자니아 이시밀라 아슐리안 유적발굴 조사 연구)

  • Bae Ki-dong
    • KOMUNHWA
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    • no.63
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    • pp.5-42
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    • 2004
  • Several new results were come from the third excavation of the Isimila site in Tanzania which is well known for typical Acheulean industry from the late Middle Pleistocene deposits. The research was carried out in 2003 by the Institute of Cultural Propert

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Effect of Siderophore on Biological Control of Plant Pathogens and Promotion of Plant Growth by Pseudomonas fluorescens ps88 (Pseudomonas fluorescens ps88이 생성하는 siderophore가 병원균의 생물학적 방제와 식물생육에 미치는 영향)

  • Seong, Ki-Young;Shin, Pyung-Gyun
    • Applied Biological Chemistry
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    • v.39 no.1
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    • pp.20-24
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    • 1996
  • Pseudomonas fluorescens ps88 was isolated from the rhizosphere soil produced the secondary metabolite called siderophore under iron Limited conditions. On iron limiting KMB medium this strain inhibited the growth of Pythium ultimum, Pyricularia oryzae, Rhizoctonia solani and Xanthomonas oryzae. Cucumber seeds were coated with the strain ps88 and were grown in green house soil. Forty days after the seed emergence, disease incidence caused by Fusarium oxysporium was reduced up to 50%. When the cucumber plants were grown in vermiculite, a significant fresh weight was increased. Root development of red pepper plants was also enhanced on MS medium supplemented with siderophore.

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