• 제목/요약/키워드: Soil Characteristics

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개발가능지의 분포면적(分布面積) (Area of Potential Arable Land Distributed on Hill side)

  • 엄기태
    • 한국토양비료학회지
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    • 제11권4호
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    • pp.235-245
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    • 1979
  • The land utilization of Korea composed about 22.7% of arable land, 66.9% of forest land and 10.4% for the rest like a house site, road, and lake etc. The ratio of arable land is too small as compared with forest land which is occuping two-thirds of Korea. The expansion of arable land by the reclamation will solve the food problems for increasing populations. First, we have to know the exact extents and distribution of reclaimable land but the reported total extent of reclaimable land in Korea is variable according to the authority which carried out the soil survey. The different reported data of reclaimable land is owing to the method and criteria of soil survey. 840,522ha in Land Capability Survey of the Farm Land Improvement Association and 321,203ha in the Forest Land Survey by the Office of Forest was reported but the Office of Rural Development said that total reclaimable land was 1,400,540ha including grazing and fruit land. To assume the extent of reclaimable land, the soil survey method and criteria of soil survey should be considered. It can be considered that the main reasons of less in extent of reclaimable land in the other authorities than the Office of Rural Development is due to the following. The grazing land and the fruits land are not included by the Farm Land Improvement Association and only relative forest is considered by the Office of Forest. The main purpose of soil survey carried out by the Office of Rural Development is to utilize land of Korea at most. The soil characteristics and potential productivity are considered in soil survey and the reported data was based on reconnaissance soil survey. The more accurate data will be find out by the end of 1979 when the detailed soil survey will be done. In selection of cropping system and management, the soil condition should be considered, because the soil characteristics of reslaimed land is less fertile than the arable lands.

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희귀식물 가침박달(Exochorda serratifolia S.Moore)의 분포, 외부형태학적 형질 및 토양특성에 관한 연구 (A study on the Distribution, External Morphological Characteristics and Soil Condition of Exochorda serratifolia S.Moore)

  • 송준호;공민정;옥민경;홍석표
    • 한국환경생태학회지
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    • 제30권6호
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    • pp.929-938
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    • 2016
  • 본 연구에서는 희귀수종인 가침박달의 외부형태학적 형질을 재검토하여 기존 문헌 및 선행 연구와의 차이를 파악하였으며, 식물상 문헌 및 표본정보를 통해 국내 분포도를 작성하였다. 또한 토양의 이화학적 특성을 분석하여 외부형태형질과 토양 조건과의 상관성을 고찰하였다. 가침박달 자생지 토양분석 결과, 유기물함량 3.25-29.83%, 전질소함량 0.15-1.14%, 유효인산 3.0-156mg/kg, 치환성 $K^+$ $0.39-1.49cmol^+/kg$, 치환성 $Ca^{2+}$ $2.48-38.07cmol^+/kg$, 치환성 $Mg^{2+}$ $0.77-18.29cmol^+/kg$, 양이온치환용량 $7.3-23.0cmol^+/kg$으로 확인되었으며, 토양 pH는 4.6-7.1인 것으로 조사되었다. 대구 앞산 집단의 경우, 유기물함량, 전질소, 양이온치환용량이 가장 높았고, 화서의 길이가 길고, 꽃의 수가 많아 다른 지역에 비해 유의성 있게 차이를 나타냈다(P < 0.001). 또한, 집단의 유전적거리와 지리적 거리, 일부 외부형태형질의 차이를 통해 이들의 상관성을 확인할 수 있었다. 희귀 수종인 가침박달의 생육특성을 파악하고, 서식지 내 보존을 위해 외부형태형질, 유전적 구조, 생육상태, 식생구조, 환경특성 등 다양한 데이터의 종합적 고찰이 필요하다.

폭우시 산사태 특성에 관한 연구 (암종에 따른 특성 연구) (A study on the characteristics of landslide in heavy rainfall (a study by rock types))

  • 이수곤;박지호;선건규
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2003년도 봄 학술발표회 논문집
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    • pp.131-136
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    • 2003
  • Landslide is a natural disaster frequently noticed In korea during monsoon season in flicting nationwise damages on human lives, properties, transportation networks, construction sites, etc. This study is about landslide characteristic in rainfall. This study selects seven sites that occured in 2001 and 2002. So elect areas divide and studied special quality by carcinoma by igneous rock, metamorphic rock, sedimentary rock. According to study finding, because igneous rock area is very thin into 1m interior and exterior soil layer, failures happened much rock and soil interface. There was place that depth of soil layer becomes about 2∼3m being area that receive serious weathering case of metamorphic rock. Therefore, at collapse much debriflow occurrence expect. Case that sedimentary rock area is broken through stratification looked. When see such results, it may become many helps to study characteristics of landslide occurrence area grasping collapse special quality by rock type.

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캐나다 오일샌드 분포지역에서의 유체기계 주행성능 평가를 위한 지반공학적 특성 분석 (Geotechnical Properties of Muskeg Soil for Construction Machinery Distributed in Oil-sand Areas)

  • 홍승서;김영석
    • 한국유체기계학회 논문집
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    • 제19권3호
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    • pp.29-32
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    • 2016
  • A series of laboratory tests were conducted to investigate the geotechnical engineering characteristics of muskeg soil for construction machinery widely distributed in cambridge region in Canada which makes problems in construction works. Physical characteristics of cambridge region muskeg soil were measured in terms of such categories as nature water content, organic content, specfic gravity, liquid limit, and plasticity index. As the test result, it was found that nature water content, organic content, specific gravity, liquid limit, plasticity index, and compression strength were 50.8~343.8%, 12.1~42.5%, 1.76~2.57, 46.6~440.2%, 25.6~280.5, $0.665{\sim}1.537kg/cm^2$, respectively.

지반변동성을 고려한 액상화 진동전단응력비의 확률론적 해석 (Probabilistic Analysis of Liquefaction Cyclic Stress Ratio Considering Soil Variability)

  • 허준
    • 한국농공학회논문집
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    • 제60권2호
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    • pp.95-101
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    • 2018
  • The objective of this study is to evaluate the liquefaction cyclic shear stress ratio considering the soil uncertainty. In this study, the probabilistic ground response analysis and the cyclic shear stress ratio analysis for the liquefaction potential evaluation are performed considering the soil variability. The statistical properties of input ground parameters were analyzed to investigate the parameters affecting the seismic response analysis. The Probabilistic analysis was carried out by Monte Carlo Simulation method. The ground response analysis was performed considering the soil variability and the probability distribution characteristics of the ground acceleration. The probability distribution of the peak ground acceleration by seismic characteristics was presented. The differences of liquefaction shear stress ratio results according to soil variability were compared and analyzed. The maximum acceleration of the ground by the deterministic method was analyzed to be overestimation of the ground amplification phenomenon. Also, the shear stress ratio was overestimated.

Electrokinetic 기법에 의한 광산퇴적토내 Cd과 Pb의 제거 특성에 관한 연구 (The Study of Cd and Pb Characteristics on Electrokinetic Remediation of Mine Deposit)

  • 윤삼석;신현무;이창언
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2001년도 추계학술발표회
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    • pp.61-64
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    • 2001
  • In the remediation of contaminated soil by electrokinetic process, transport characteristics of contaminants are major factors. Pb is highly fixed to entire soil and not moved readily. High concentration of Cd was analyzed in the cathodic section but anodic section's concentration was lower than initial concentration. Although the Cd had high treatment effect, 50% of total mass was concentrated in cathodic section and was not flowed out readily. Most of transported Cd may be adsorbed in the cathodic side soil due to increased pH at adjacent to catholyte.

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안정처리토의 동상특성에 관한 실험적 연구 (An Experimental Study on Frost Heaving Characteristics of Soil Stabilized with the Additives)

  • 김재영;주재우;유병옥;양성기
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2003년도 학술발표논문집
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    • pp.215-218
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    • 2003
  • In order to study the frost heaving characteristics of soil stabilitized with a quick lime, a cement and a briquette ash, frost heaving tests were performed with 2 kinds of soil sampled at Chonbuk-Do area. Frost heaving of no-stabilizing soil compacted with water content greater than optimum water content was increased as the frost period was increased but in case of samples with water content smaller than optimum water content, the frost period gave no affect about increase and decrease of the frost heaving. Both frost heaving of stabilizing and no-stabilizing soil with water content greater than optimum water content was decreased with the increase of the repetition number of freezing and thawing. There was no increase or decrease of frost heaving in the frost heaving test after 5 times of freezing and thawing.

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우리 나라 토양의 입도특성 (The Particle Size Distribution of Korean Soils)

  • 우철웅;장병욱
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2003년도 학술발표논문집
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    • pp.163-166
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    • 2003
  • In this study, a grouping of particle-size distributions(PSDs) by means of the fuzzy c-means clustering method(FCM) was presented. The classification was performed with the whole and the major soil series representing pedological origin. In case of the major soil series, PSDs were clustered as $2{\sim}4$ groups and the characteristics of clustering results were quite different between the soil series. It was found that the characteristics of PSDs at center of each class can be explained by formation process of each soil series. In case of whole soil data, PSDs were classified to 8 classes in which 4 classes were single mode and 4 classes were bimode distributions. Through this study, it is concluded that pedogenetic process is a plausible explanation for grain size distribution of soils.

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Desorption-Resistance of Hydrophobic Organic Compounds in Natural Soils

  • Shin, Won-Sik
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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    • pp.26-29
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    • 2001
  • Sorption/desorption Study was conducted to determine desorption-resistance hydrophobic organic compounds in natural soils with low organic carbon content. Sorption/desorption characteristics of chlorobenzene and phenanthrene for both PPI (Petro Processors, Inc. Superfund site) and BM (Bayou Manchac), soils were investigated. Desorption was biphasic including reversible and desorption-resistant compartments. The biphasic sorption parameters indicated the presence of appreciable size of desorption-resistant phase in these soils. A finite maximum capacity of desorption-resistant fraction (equation omitted) was observed after several desorption steps. The apparent organic carbon based Partition coefficient, K(equation omitted) was 10$^{4.92{\pm}0.27}$ for PPI soil and 10$^{4.92{\pm}0.27}$ for BM soil, respectively. The difference in K(equation omitted) was attributed to different characteristics in soil organic matter. The results suggest that desorption-resistance should be considered in remediation and risk assessments in natural soils and sediments.

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불법매립폐기물에서 선별된 토사의 지반환경공학적 특성 분석 (Geoenvironmental Characteristics of Sorted Soil From Unregulated Landfill Wastes)

  • 정하익;김상근;류권;이용수
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2001년도 봄 학술발표회 논문집
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    • pp.605-610
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    • 2001
  • There has been a steady increase in geoenvironmental engineering projects where geotechnical engineering has been combined with environmental concerns. Many of these projects involve some investigation on geoenvironmental characteristics related to waste landfill and waste soil. This study was carried out to evaluate the geoenvironmental properties of sorted soil from unregulated landfill wastes. The physical, mechanical, and environmental Properties of sorted soil were investigated for utilization in civil works.

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