• Title/Summary/Keyword: 토양단면

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Spatial and Seasonal Variability of Soil Moisture Responses along Transect Line on a Forest Hillslope in the Cheong-Mi Catchment (청미천 유역 내 산림사면에서 단면선에 따른 토양수분특성의 공간적 및 계절적 변동)

  • Gwak, Yong Seok;Kim, Sang Hyun;Lee, Jung Hun;Lee, Yeun Gil;Jung, Sung Won;Kim, Su Jin
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.473-473
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    • 2015
  • 토양수분은 수문학적 과정의 시공간적 변동과 수자원 관리 및 계획 그리고 기후변화에 따른 자연재해의 원인규명에 중요한 부분이다. 본 연구에서는 사면의 단면선에 따른 토양수분의 분포 및 변동을 파악하기 위해, 청미천 유역내의 사면에서 10개월 동안의 토양수분들을 측정하여, 토양깊이별, 계절별로 분석하였다. 토양수분특성은 간단한 통계적 방법을 이용하여, 평균, 표준편차 그리고 토양수분의 감쇄기울기 값으로 표현하였다. 추가적 연구로, 측정지점의 위치, 지형, 토성의 토양수분에 대한 반응분석을 하였다. 깊은 토양층에서의 토양수분의 공간적 분포는 지표층에서의 공간적 분포 경향과는 상이하게 나타났으며, 사면의 지형 및 위치 그리고 토성의 공간적 분포는 토양수분의 시 공간적 분포특징에 큰 영향을 주는 것으로 나타났다. 특히 상부흐름의 기여를 받는 측정지점에서는 토양수분 변동의 안정화가 진행이 되는 것으로 보이며, 수문학적 경계(Hydrologic Threshold)에 대한 추가연구가 진행되어야 할 것으로 판단된다. 상부사면에서의 높은 토양수분 변동성 및 뷸 균질적인 공간적 분포는 우선적 흐름발달의 영향과 관련이 있다고 판단된다.

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Finite Difference Model of Unsaturated Soil Water Flow Using Chebyshev Polynomials of Soil Hydraulic Functions and Chromatographic Displacement of Rainfall (Chebyshev 다항식에 의한 토양수분특성 및 불포화 수리전도도 추정과 부분 치환 원리에 의한 강우 분포를 이용한 토양수분 불포화 이동 유한차분 수리모형)

  • Ro, Hee-Myong;Yoo, Sun-Ho;Han, Kyung-Hwa;Lee, Seung-Heon;Lee, Goon-Taek;Yun, Seok-In;Noh, Young-Dong
    • Korean Journal of Soil Science and Fertilizer
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    • v.36 no.4
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    • pp.181-192
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    • 2003
  • We developed a mathematical simulation model to portray the vertical distribution of soil water from the measured weather data and the known soil hydraulic properties, and then compared simulation results with the periodically measured soil water profiles obtained on Jungdong sandy loam to verify the model, In this model, we solved potential-based Richards' equation by the implicit finite difference method superimposed on the predictor-corrector scheme. We presumed that: soil hydraulic properties are homogeneous; soil water flows isothermally; hysteresis is not considered; no vapor flows; no heat transfers into the soil profiles; and water added to soil surface is distributed along the soil profile following partial displacement principle. The input data were broadly classified into two groups: (1) daily weather data such as rainfall, maximum and minimum air temperatures, relative humidity and solar radiation and (2) soil hydraulic data to approximate unsaturated hydraulic conductivity and water retention. Each hydraulic polynomial function approximated using the Chebyshev polynomial and least square difference technique in tandem showed a fairly good fit of the given set of data. Vertical distribution of soil water as approximations to the Richards' equation subject to changing surface and phreatic boundaries was solved numerically during 53 days with a comparatively large time increment, and this pattern agreed well with field neutron scattering data, except for the surface 0.1 m slab.

Soil Characteristics on the Fluvial Terrace in the Basin of Ssangcheon (쌍천 하성단구의 토양 특성)

  • 강영복;박종원
    • Journal of the Korean Geographical Society
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    • v.35 no.2
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    • pp.159-176
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    • 2000
  • 본 연구는 남한강 상류의 소지류인 쌍천 유역에 발달한 하성단구의 퇴적물을 모재로 발달한 토양 특성을 조사.분석하였다. 중위 단구의 A1층은 갈색(10YR 4/3)의 미사질토양이고 발달도가 낮은 입상구조이며 B1층은 황갈색(10YR 5/8)의 사질식양토로 아각괴상구조이다. 고위단구의 A1층은 옅은 적갈색(5YR 4/3)의 미사질양토 내지 황갈색(10YR 5/8)의 미사질식토로 발달도가 낮은 아각괴상구조이다. B1층은 적색(2.5YR 3/6)의 사질식토 내지 밝은 적갈색(2.5YR 4/6)의 식양토로 발달도가 양호한 아각괴상구조이다. 고위단구 퇴적층을 모재로 발달한 토양의 구조는 중정도의아각괴상구조이고 조직이 치밀하다. 토양은 A1층, B1층,B2층으로 되어 있으며 또한 B층은 점토가 집적되어 있고 점토 피막이 나타난다. 쌍천의 중위단구상에 발달한 토양은 황갈색토이고 고위 단구상의 토양은 적색토이다. 고위단구 퇴적물을 모재로 발달한 본 적색토는 생성시가가 민델-리스 간빙기의 이전에 생성된 것으로 현재보다 온난한 생물-기후 조건하에서 탈규산화를 동반하는 적색토화작용에 의해 형성된 것으로 추정된다. 고위단구에 발달한 적색토는 토양단면의 형태적 및 물리 화학적인 특성등으로 보아 고적색토로 분류된다.

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A Scheme of Drainage Classification based on "Redness Rating" of the Profiles and Taxonomic Classification of Paddified Clayey Terrace Soils in Korea (토양단면(土壤斷面)의 적색도(赤色度)에 의한 식질단구답(埴質段丘畓)의 배수등급(排水等級) 결정(決定) 및 분류단위(分類單位) 설정(設定))

  • Jung, Youn-Tae;Um, Ki-Tae;Ha, Ho-Sung
    • Korean Journal of Soil Science and Fertilizer
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    • v.17 no.2
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    • pp.96-100
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    • 1984
  • To give basic information on the agricultural mechanization and multiple cropping adoptability of the paddified clayey terrace soils which have poor permeability and poor adoptability to mechanization, a scheme of drainage classification as well as taxonomic classification was intended. 1. The degrees of gleization of terrace paddy soils were well distinguished by the comparison of "Redness rating" of their profiles. 2. When the criteria of "Imperfectly drained" soils were defined as follows; Soils have more than 50cm of accumulated depth which has less than 0.5 in Redness rating within 1.2m of the profile, the Geugrag series could be classified to "Imperfectly drained." The tentative classification of drainage class of Geugrag soils seemed to well matching with land suitability groups, and give possibility of drainage recommendation in the case of dry land crop cultivation. 3. The Geugrag soil which was well paddified by artificial surface irrigation, could be proposed to classify "Anthroaquic Ochraqualfs."

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Formation and sedimentary environment of loess-paleosolsequence in the Jincheon Basin, Chungbuk Province, Korea (진천분지 뢰스-고토양 연속층의 형성과 퇴적 환경)

  • Yoon, Soon-Ock;Park, Chung-Sun;Hwang, Sangill
    • Journal of The Geomorphological Association of Korea
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    • v.20 no.3
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    • pp.1-14
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    • 2013
  • This study aims to investigate the formation and sedimentary environment including formative period, grain composition and climate change from loess-paleosol sequence deposited on a gravel bed of river terrace in the Jincheon Basin, Chungbuk Province. The Jincheon section consists downward of a surface layer, loess-paleosol sequence, transitional layer I, transitional layer II and gravel bed. It can be suggested from the OSL age dating that the sequence was deposited during MIS 6 to 4. The sequence can be divided into four horizons based on the variation in the magnetic susceptibility values. Grain size analysis reveals that the sequence indicates similar properties of grain size to loess deposits in Korea and especially, the Y values in the sequence are lower than those in the loess and paleosol horizons in the Chinese Loess Plateau and similar to those in the Red Clay in the Chinese Loess Plateau and Xiashu loess in the lower reaches of the Yangtze River. These Y values in the sequence can be attributed to the remote source and/or experience of intensive weathering process after deposition in the Korean Peninsula.

유류오염 현장의 자연저감 특성연구

  • Kim Jin-Hun;Seok Hui-Jun;Kim Hyeong-Su
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2005.04a
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    • pp.223-227
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    • 2005
  • 본 연구에서는 과거 주요소로 사용되었던 유류오염 현장에서 BTEX의 오염 현황과 자연저감기법을 통해 저감되는 BTEX 양을 계산하였다. 일정 시간 간격으로 시료를 채취, 분석한 결과, 2곳에서 NAPL이 존재하고 있다는 것을 알 수 있었다. 조사 지역은 지하수 흐름방향에 따라 3개의 단면으로 나눈 후 각각의 단면을 통과하는 mass flux를 계산하였다. 약 40일정도 지난 후 BTEX 양은 각각 20.2%, 33.5%, 그리고 25.4% 감소되는 것으로 나타났다.

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Soil Characteristics in Fagus multinervis Subcommunities at Songinbong Area of Ullungdo (울릉도 성인봉 주변 너도밤나무 하위군락별 토양 특성)

  • Park, Kwan-Soo;Song, Ho-Kyung;Lee, Sun
    • Korean Journal of Environmental Biology
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    • v.18 no.3
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    • pp.299-305
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    • 2000
  • To determine the effects of underlayer vegetation on soil properties, the profiles, physical, and chemical properties of soil were investigated upon Fagus multinervis -Rumohra standishii, Fagus multinervis - typical, and Fagus multinervis -Sasa kurilensis subcommunities that was growing at Songinbong area of Ullungdo. There were little differences in soil profile properties among the three subcommunities. Also, there were little differences in physical and chemical properties of soil among the three subcommunities, except exchangeable Ca concentration in 0-10 cm soil depth. However, the soils of the study area in 0-10 cm soil depth comprised high organic matter and total N concentration as in an average value of 21.6% and 0.74%, respectively. Also, the soil showed very low bulk density and pH as in an average value of 0.43 g/㎤ and 4.4 in 0-10 cm soil depth, respectively. Due to the high soil organic matter and total N concentrations and the low bulk density and pH, the soil properties of Songinbong area are different from those of other forest in Korea.

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Geochemistry of the Major and Trace Elements in a Soil Profile of the Hyangdeung Area, Gwangju City, Korea (광주광역시 향등지역의 토양단면에서 주성분원소 및 미량성분원소의 지화학적 특성)

  • Shin, In-Hyun;Ahn, Kun-Sang;Kang, Jong-Hyun
    • Journal of the Korean earth science society
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    • v.26 no.8
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    • pp.800-808
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    • 2005
  • Elemental mobility during the weathering of granite in the Gwangju Hyangdeung area was investigated using ICP-MS analysis. It appeared that Al, Fe, Ti, K were lost from the profile, whereas Si, Ca, Na Mg, P and Mn were immobile during chemical weathering. In less weathered soil, large enrichment of K and Ti were found relative to Al, whereas other elements such as Si, Ca, Na, Mg and P are deplete. Fe content is constant throughout the weathered profiles. Amounts of Rb, Sr, Y, Cs, Pb, Th and U increased toward the surface. Nb, and Co have accumulated in the deepest parts of the weathered soil profile. These results agree with similar published studies. In addition, the analytical data shows that Ba and Ga increased, while Cu, Zn, Cr and Ni were relatively constant in this area. REE tend to increase in most samples, while LREEs, relative to Al, were enriched in the lower and upper saprolite. HREEs were enriched in the lower and upper saprolite.