• 제목/요약/키워드: Saturated Hydraulic Conductivity

검색결과 130건 처리시간 0.024초

인공지반의 녹화를 위해서 단용 또는 노지토양과 혼합하여 이용되는 인공토양의 특성 (Characteristics of artificial Soils Used alone or in a Blend with Field Soil for the Greening of Artificial Ground)

  • 허근영;심경구
    • 한국조경학회지
    • /
    • 제28권2호
    • /
    • pp.28-38
    • /
    • 2000
  • The aim of this study is evaluate artificial soils which are used alone or in a blend with field soil for the greening of artificial ground. To achieve these, determination of physicochemical properties was made in four artificial media[Perlite small grain(PSG), perlite large grain(PLG), crushed porous glass+bark(AS), crushed porous glass(CPG)] used alone and/or in a blend with field soil, then evaluation of their effect on th plant growth of Ligustrum obtusifolium and Syringa vulgaris were conducted. In bulk density of root media at field capacity and the saturated hydraulic conductivity, LG and AS showed good performance. But, PLG was though to be unsuitable as artificial soil when used alone because of poor plant growth. PLG, AS, and CPG were thought to be good when it is used in a blend with field soil. But, PSG was thought to be unsuitable. In the result, PSG is recommended as artificial soil which is used alone for greening of artificial ground. PLG is recommended as artificial soil which is used in a blend with field soil. AS is recommended as artificial soil which is used alone and in a blend with field soil. Thought CPG+field soil(v/v, 1:1) might be undesirable in consideration of the chemical properties in six months after planting, it was thought to be superior to th other treatments in the plant growth. CPG can be used as artificial soil which is used in a blend with field soil. Follow-up studies are being conducted to investigate their effects on the plant growth of the other plants and the practical use of them in artificial grounds.

  • PDF

식재지반 용토로서 준설토의 이화학적 특성 (Physico-Chemical Properties of Dredged Soils as Planting Soil)

  • 김원태;윤용한
    • 한국조경학회지
    • /
    • 제32권6호
    • /
    • pp.95-102
    • /
    • 2005
  • This study was carried out to find out the heavy metal contents and the physico-chemical properties for the improvement of dredged soils which widely exist in lowlands of Korea. At first all the average heavy metal contents were close to background level and were much lower than concern level of the Soil Environment Conservation Act of Korea. And the results of physical analyses of soils showed on the average $2.46\~2.74 Mg/m^3$ in Particle density, $0.45\~2.45 kg/kg$ in soil water contents, $0.34\~0.90 Mg/m^3$ in bulk density, $0.67\~0.87m^3/m^3$ in porosity, $2.18\times10^{-5}\~1.20\times10^{-8} m/s$ in saturated hydraulic conductivity, R0.12\~0.65 m^3/m^3$ in available water contents. Finally the results of chemical analyses of soils showed on the average $6.5\~8.2\;in\; pH,\;5\~48 g/kg\;in\; OM,\;0.48\~4.51g/kg\;in\;T-N,\;19\~25mg/kg$ in available phosphate, $0.28\~11.80 dS/m\;in\;EC,\;8.7\~38.1cmol/kg$ in CEC, respectively Accordingly, the physicochemical properties of soils ought to be analyzed accurately before dredging for effective using of dredged soils. And it will be more effective, if the dredged soils are used with proper balance among each content of components with consideration to the physicochemical properties of common soils.

Effect of Temperature and Plow Pan on Water Movement in Monolithic Weighable Lysimeter with Paddy Sandy Loam Soil during Winter Season

  • Seo, Mijin;Han, Kyunghwa;Jung, Kangho;Cho, Heerae;Zhang, Yongseon;Choi, Seyeong
    • 한국토양비료학회지
    • /
    • 제49권4호
    • /
    • pp.300-309
    • /
    • 2016
  • The monolithic weighing lysimeter is a useful facility that could directly measure water movement via layers, drainage, and evapotranspiration (ET) with precise sensors. We evaluated water movement through layers and water balance using the lysimeter with undisturbed paddy sandy loam soil, Gangseo soil series (mesic family of Anthraquic Eutrudepts classified by Soil Taxonomy) during winter season from Dec. 2014 to Feb. 2015. Daily ET indicated up to 1.5 mm in December and January and 2 mm in February. The abrupt increase of soil water tension at the depth of 0.1 m, when soil temperature at the same depth was below $2^{\circ}C$, was observed due to temporary frost heaving. The surface evaporation was less than reference ET below -15 kPa of soil water potential at the depth of 0.1 m. The maximum drainage rate was similar to the saturated hydraulic conductivity of a plow pan layer. Both upward and downward water movement, related to ET and drainage, were retarded by a plow pan layer. This study demonstrated that the lysimeter study could well quantify water balance components even under frost heaving during winter season and that a plow pan with low permeability could act as a boundary that affects drainage and evapotranspiration.

비균질 다공성 매질에서 선형 흡착 용질의 공간적 거동에 대한 수치적 연구 (A Numerical Study on Spatial Behavior of Linear Absorbing Solute in Heterogeneous Porous Media)

  • 정우창;이치헌;송재우
    • 한국지반환경공학회 논문집
    • /
    • 제4권3호
    • /
    • pp.79-88
    • /
    • 2003
  • 비균질 다공성 매질을 통과하는 선형 흡착 용질의 공간적 거동에 대한 특성이 수치적 기법을 통해 분석되었다. 공간적으로 서로 상관된 투수계수의 대수적 분포를 지구통계학적 기법인 TBM(Turning Bands Method)을 사용하여 2차원 공간 내에 발생시켰으며, 이를 통한 지하수 흐름의 수리수두분포와 유속벡터장은 정상상태의 포화된 2차원 지하수 흐름 방정식에 Galerkin 유한요소법을 적용하여 계산하였다. 또한, 용질이동에 대한 수치모의는 시간간격을 자동으로 보정해주는 CD(constant displacement)기법이 포함된 난보모형(Random Walk Particle Tracking Model, RWPTM)을 통해 수행되었다. 본 연구에서 용질의 공간적 거동의 특성은 종방향 질량중심 이동거리, 종방향 공간 퍼짐 모멘트 그리고 용질분포의 종방향 왜곡계수를 통해 분석되었다.

  • PDF

건설폐토석의 식생용토로서의 이화학적 특성 (Physico-Chemical Properties of the Recycled Waste Soils from Construction Site as Planting Soil)

  • 김원태;윤용한;박봉주
    • 한국환경복원기술학회지
    • /
    • 제10권5호
    • /
    • pp.31-39
    • /
    • 2007
  • This study was carried out to evaluation the recycled waste soils from construction site for planting soil. For this purpose, the concentrations of polluted materials and the physico-chemical properties were measured at recycled soil samples of an industrial waste treating company in the Metropolitan landfill area. The concentrations of polluted materials did not exceed to the standard critical levels of soil pollution in all analyzed items. The measures of the samples soil texture (loamy sand), bulk density (1.09~1.32g/$cm^3$), saturated hydraulic conductivity ($1.6{\times}10^{-3}{\sim}1.8{\times}10^{-3}$cm/sec), solid phase distribution (0.4~0.5$m^3/m^3$), porosity (0.5~0.6$m^3/m^3$), Ex. $K^+$ (1.0~1.2cmol/kg), Ex. $Mg^{2+}$ (0.2~0.6cmol/kg) were identified as not worse than those of conventional planting soil. But the sample soils have serious problems for planting soil such as high levels of pH (9.6~11.5), EC (0.78~1.84ds/m) and Ex. $Ca^{2+}$ (25.6~34.5cmol/kg), low level of organic matter (0.2~0.3%). It is required to improve pH, EC and Ex. $Ca^{2+}$ of sample soils. Consequently, the results suggested a high potential of recycling of the wastes soils for planting soil.

플라이애쉬의 차수 및 오염물 차단 능력 평가 연구 (Evaluation of Fly Ash as an Alternative to Clay Liner Material in Landfills)

  • 정문경;현재혁;김승현
    • 한국지반공학회지:지반
    • /
    • 제14권5호
    • /
    • pp.191-204
    • /
    • 1998
  • 플라이 애쉬의 폐기물 매립장 대용 차수재로서의 적용성을 평가하기 위하여 실내 실험과 모델 연구를 실시하였다. 실제의 매립장 차수층이 불포화 상태일 수 있는 점을 고려하여, 대용 차수재와 기존의 점토 차수재에서의 포화 및 불포화 상태에서의 물 흐름 특성을 비교하였다. 차수층에서의 오염물 이동 특성을 연구하기 위하여 오염물을 이용한 회분실험을 실시하였으며, 이때 폐놀을 대표 오염물질로 사용하였다. 모델은 물질 수지에 기초하였으며, 유한 차분법과 predictor-corrector법을 이용한 수치 해법으로 풀었고, 연립 미분방정식을 다루는테는 sequential method를 이용했다. 연구 결과 대용 차수재는 기존 차수재보다 폐놀 차단 능력이 더 크고 또 불포화대에서의 차수능력도 더 크다는 것을 알 수 있었다. 또한, 본 연구에서 고려된 흐름조건에서는 차수층을 포화대로 해석할 경우 통과하는 물의 양이 약간 과소평가되고 폐놀 차단 능력은 매우 과소평가됨을 알 수 있었다.

  • PDF

포화(飽和)된 사질토(砂質土)내로의 오염물(汚染物) 이동에 대한 시스템 신뢰성(信賴性) 모델의 응용(應用) (Reliability Analysis to Contaminant Migration in Saturated Sandy Soils : System Reliability Approach)

  • 장연수
    • 대한토목학회논문집
    • /
    • 제12권2호
    • /
    • pp.229-237
    • /
    • 1992
  • 2차원 수평흐름에서의 비반응성 오염물 이동에 대한 연속시스템(series system) 신뢰성해석을 농도와 노출시간의 두 극한상태 함수에 대해 시행하였다. 시간에 따라 변화하는 오염원에서의 오염이동모델을 시스템 신뢰해석 모델과 결합하여 오염이 예상되는 지점의 최대농도가 주어진 기간동안에 특정농도를 초과하거나 또는 오염예상 지점이 보통의 농도에 노출되어질 시간이 특정 한계를 초과할 확률을 구하였다. 본 신뢰성 해석의 결과 상기의 두조건을 초과할 확률은 각각의 조건을 초과할 확률보다 큰 것은 확인하였으며 보다 큰 초과확률을 갖는 요소에 의하여 지배되는 것을 발견하였다. 예민도 해석은 투수계수 외에도 횡단 분산계수(transverse dispersivity)도 이차원 오염이동 신뢰성 모델의 중요한 매개 변수임을 보여주었다. 시스템 예민도는 두 요소의 예민도를 동시에 반영하고 있으며 큰 초과확률을 갖는 요소가 해(解)에 보다 큰 영향을 미치는 것을 알게 되었다.

  • PDF

소성 점토다공체 및 코코넛 피트를 혼합한 인공토양의 물리화학적 특성과 식물생육에 미치는 영향 (Physicochemical Properties of Artificial Soil Formulated by Blending Calcined Clay and Coconut Peat and its Effect on Plant Growth)

  • 허근영;강호철;김인혜;심경구
    • 한국조경학회지
    • /
    • 제30권5호
    • /
    • pp.107-115
    • /
    • 2002
  • This study was carried out to compare artificial soil formulated by blending calcined clay and coconut peat with perlite, then to evaluate this soil as a perlite substitute for use as an artificial planting medium. To achieve this, a determination of the physico-chemical properties and it's effect on plant growth were conducted by comparing those with large perlite grains and small grains. The results are summarized as follows: 1) The bulk density was 0.41g/㎤. This density was lower than that of field soil, but higher than that of large perlite grain(0.23g/㎤) and small grain(0.25g/㎤). The porosity, field capacity, and saturated hydraulic conductivity were 71.3%, 49.2%, and 3.8$\times$10-2cm/s, respectively. The air-permeability, water holding capacity, and drainage were better than or equal to that both large and small perlite grain. 2) It was near-neutral in reaction(pH=6.6). It had a high organic carbon content(65.8g/kg) and a low available phosphoric acid content(84.7mg/kg). It was similar to crop soil in cation exchange capacity(11.4cmol/kg). It had a low exchangeable calcium content(0.71cmol/kg), a low exchangeable magnesium content(0.68cmol/kg), a high exchangeable potassium content(2.54cmol/kg), and a high exchangeable sodium content(1.12cmol/kg). Except for the exchangeable potassium and sodium content, the chemical properties were better than or equal to both large and small grain perlite. The excessive exchangeable potassium or sodium content will inhibit plant growth. 3) In Experiment 1, the plant growth tended to be higher compared to that of large and small perlite gains. But in Experiment 2, it tended to be lower. This might be linked to the excessive exchangeable potassium or sodium content. 4) It could be considered as a renewable perlite substitute for greening of artificial soil. But, it would be necessary to leach the excessive exchangeable potassium or sodium to avoid the risk of inhibiting plant growth.

몬테카를로 기법과 앙상블 유량모의 기법에 의한 SWAT 모형의 불확실성 분석 (Uncertainty Analysis of SWAT Model using Monte Carlo Technique and Ensemble Flow Simulations)

  • 김필식;김선주;이재혁;지용근
    • 한국농공학회논문집
    • /
    • 제51권4호
    • /
    • pp.57-66
    • /
    • 2009
  • 수학적 모델은 수량과 수질의 예측을 위해 현장 조사의 대안으로 사용되어지며 이러한 모델의 사용과 실측에 불확실성이 존재하게 된다. 불확실성에 대한 많은 연구들이 진행되어 왔으나 시나리오에 의한 모델링 과정에서 발생하는 불확실성에 대한 연구는 미흡한 실정이다. 본 연구에서는 산림이 농경지와 목초지로의 변화에 따른 시나리오를 설계한 후 시나리오 적용에 따른 SWAT (Soil and Water Assessment Tool) 매개변수의 불확실성을 분석하고자 하였다. 몬테카를로 기법 (Monte Carlo simulation)을 이용하여 각 매개변수별 1,000개의 난수를 발생하였으며 앙상블 유량모의 기법을 이용하여 미국 Alabama주 카하바강 상류 (50,967ha)를 대상으로 각 난수별 100개의 유량을 통해 불확실성을 분석하였다. 분석 결과 산림지역이 농경지와 목초지로 변화 되었을 때 유출량이 증가하는 것으로 분석되었으며, 임야가 목초지 보다 농경지로 변화되었을 때 유출량은 더욱 증가하는 것으로 나타났다. 각 시나리오별 SWAT 매개변수의 불확실성은 AWC (Available water capacity), CN (Curve number), GWREVAP (groundwater re-evaporation coeffeicient), REVAPMN (minimum depth of water in shallow aquifer for re-evaporation to occur)순으로 크게 나타났으며, Ksat (Saturated hydraulic conductivity)와 ESCO(Soil evaporation compensation factor)는 유출량의 변화에 큰 영향을 미치지 못하는 것으로 분석되었다. 토지피복별 산림 면적이 클 경우 불확실성이 크게 나타나 산림이 목초지와 농경지로 변함에 따라 불확실성은 감소하는 것으로 나타났다.

Implication of Soil Minerals on Formation of Impermeable Layers in Saprolite Surface-Piled Upland Fields at Highland

  • Zhang, Yongseon;Sonn, Yeon-Kyu;Moon, Yong-Hee;Jung, Kangho;Cho, Hye-Rae;Han, Kyeong-Hwa
    • 한국토양비료학회지
    • /
    • 제47권4호
    • /
    • pp.284-289
    • /
    • 2014
  • Farmers in highlands in South Korea pile up 20 to 30 cm of saprolites, mostly granite- or granite-gneiss-weathered materials, on surface of arable lands every three to five years to compensate eroded soil and sometimes to discontinue soil-borne diseases. Immediate increases of infiltration and percolation rates are expected with coarse textured saprolites while soil drainage becomes poorer in a long-term. In this study, we analyzed mineralogical characteristics and micro-morphology of plow pan to investigate processes making impermeable layers. Soil samples were collected from plow pan, usually located at approximately 20 cm soil depth and at the lower part of piled saprolites, in arable lands in Hoenggye 5-ri, Daekwanryeong-myeon, Gangwon-do (N37.7, E128.7) in which saprolites were added 2, 4, and 8 years ago; saprolites were transported from similar areas. The saturated hydraulic conductivity decreased over time. Based on soil thin section pedography, quartz and feldspar accounted for a majority of minerals. The size of feldspar decreased and macropores became filled with clay or silt particles over time, which implies that macropores were packed with particles weathered from feldspar. The X-ray diffraction (XRD) analysis indicated that intensity of feldspar decreased over time and the reverse was true for kaolinite and illite, indicating that feldspar and mica weathering induced formation of kaolinite and illite. Conclusively, deteriorated drainage by formation of impermeable layers in farms with piled saprolites was caused by accumulation of clay minerals such as kaolinite and illite in macropores; illite and kaolinite can be formed by weathering of mica and feldspar, respectively.