• 한국산림과학회지
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• 제95권2호
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• pp.177-182
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• 2006

Little information is available on soil $CO_2$ efflux and crop yield under agroforestry systems. Soil $CO_2$ efflux, microbial biomass C, live fine root biomass, and cotton yield were measured under a pecan (Carya illinoinensis K. Koch)-cotton (Gossypium hirsutum L.) alley cropping system in southern USA. A belowground polyethylene root barrier was used to isolate tree roots from cotton which is to provide barrier and non-barrier treatments. The barrier and non-barrier treatment was randomly divided into three plots for conventional inorganic fertilizer application and the other three plots for organic poultry litter application. The rate of soil $CO_2$ efflux and the soil microbial biomass C were affected significantly (P < 0.05) by the fertilizer treatment while no significant effect of the barrier treatment was occurred. Cotton lint yield was significantly (P < 0.0 I) affected by the root barrier treatment while no effect was occurred by the fertilizer treatment with the yields being greatest ($521.2kg\;ha^{-1}$) in the root barrier ${\times}$ inorganic fertilizer treatment and lowest ($159.8kg\;ha^{-1}$) in the non-barrier ${\times}$ inorganic fertilizer treatment. The results suggest that the separation of tree-crop root systems with the application of inorganic fertilizer influence the soil moisture and soil N availability, which in tum will affect the magnitude of crop yield.

• 한국지리정보학회지
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• 제10권1호
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• pp.158-168
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• 2007

본 연구에서는 소양호유역의 탁수 및 토사유실 저감을 위해 수립중인 다양한 대책중 산림청과 지자체를 중심으로 계획중인 사방댐에 대한 저감효과를 분석하였다. 2005년 강우와 GIS 자료를 이용하여 분석한 결과 소양호유역의 토사유실은 4,819,494 ton으로 평가되었으며, 단위토사유실분석에서는 추곡천, 자운천 그리고 오항천이 다른 유역들에 비해 높은 값을 보였다. 94개의 사방댐 지점을 중심으로 GIS 공간분석을 이용하여 사방댐유역을 추출하였으며, 사방댐유역의 토사유실량과 유사운송비를 이용하여 저감효과를 분석한 결과, 2005년 사방댐의 토사유실저감효과는 6.8%(330,203 ton)으로 분석되었다. 또한 사방댐의 위치를 5,000 ton 이상인 지역으로 이동한 시나리오에서의 사방댐의 토사유실저감효과는 10.5%(506,783 ton)으로 증가되었다.

• 한국토양비료학회지
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• 제47권6호
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• pp.398-405
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• 2014

Salt accumulation at soil surface is one of the most detrimental factors for crop production in reclaimed tidal land. This study was conducted to investigate the effect of capillary barriers beneath the soil surface on dynamics of soil salts at coarse-textured reclaimed tidal land. A field experiment was conducted at Saemangeum reclaimed tidal land for two years (2012-2013). Capillary barriers ($3.5{\times}12m$) were treated with crushed-stone, oyster shell waste, coal briquette ash, coal bottom ash, rice hull and woodchip at 40-60 cm depth from soil surface. Silage corn (Zea mays) was cultivated during the experimental period and soil salinity was monitored periodically. Soil salinity was significantly reduced with capillary barrier compared to that of control. Oyster shell waste was one of the most effective capillary barrier materials to control soil salinity at Saemangeum reclaimed tidal land. At the first growing season capillary barrier did not influence on corn growth regardless of types of the material, but plant biomass and withering rate of corn were significantly improved with capillary barrier at the second growing season. The results of this study showed that capillary barrier was effective on the control of soil salinity and improvement of corn growth, which indicated that capillary barrier treatment can be considered one of the best management practices for stable crop production at Saemangeum reclaimed tidal land.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.98-101
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• 2002

Numerical experiments were performed to investigate horizontal barrier formation in unsaturated soils by permeation grouting through multiple vertical injection pipes. The results were compared with the horizontal barrier formation achieved by using multiple horizontal injection pipes. It was observed that tile point injection of the vertical pipe system generates a gel barrier that has a less lateral area than the injection through the horizontal pipe.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.189-196
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• 2003

Soil-cement column is often used as a contaminant barrier. This study presents the results of experimental study performed to investigate the changes of properties of soil-cement column under the attack of acids. Sulfuric nitric, and ascetic acid were used as contaminants. Specimen were made of clayey and sandy soils with addition of cement and water Permeability of soil-cement decreased with time during permeability test. When significant amount of acid percolated the specimen, permeability increased and compressive strength decreased due to the dissolution and leaching of cement and its chemical reaction compounds. Sulfuric and nitric acid were more effective than ascetic acid in deteriorating soil-cement column. Amount of acid required to lower the pH of soil cement below 12 was calculated from the results of permeability tests. This leads to a conclusion that, under the conditions employed in this study, the chemical stability of soil-cement column could be maintained against acid attack for longer than generally accepted lifetime of contaminant barriers.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 INTERNATIONAL SYMPOSIUM ON SOIL & GROUNDWATER ENVIRONMENT
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• pp.122-122
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• 2005

The remediation for contaminated soil and groundwater in contaminated site and waste site has to be compact and economic in maintaining and operating the system. In this study, the atomized slag was tested if they are an effective reactive material in permeable reactive barrier This novel reactive system technology was applied to the treatment of leachate from unplanned waste landfill. The system was optimized and developed to be commercialized.

• 한국지반신소재학회논문집
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• 제10권2호
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• pp.29-34
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• 2011

본 연구에서는 유류나 각종 비수용성 오염물질(DNAPL)로 오염된 지반에 인공동결공법을 이용한 차수벽을 형성하고 지하수의 이동으로 인한 오염물질의 확산 방지 효과를 확인하기 위한 초기연구로 인공동결공법을 통한 동결차수벽을 형성하기 위하여 모형실험을 수행하였다. 동결차수벽 형성의 확인을 위하여 실험조건에 따른 동결범위와 동결토의 강도를 분석하였다. 동결범위를 확인하기 위한 실험조건은 포화도가 80%, 90%인 표현을 실트를 대상으로 하였다. 또한, 동결토의 강도특성은 다짐도와 포화도를 변경하여 동결을 실시하였고, 일축압축강도 실험을 통하여 확인하였다.

• Computers and Concrete
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• 제6권1호
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• pp.79-93
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• 2009

In the present paper, a methodology has been presented for the reliability assessment of concrete barriers that lie at a certain depth in the soil, and a missile (a rigid projectile) impacts the top of the soil cover normally, and subsequently after penetrating the soil cover completely it hits the barrier with certain striking velocity. For this purpose, using expressions available in the literature, striking velocity of missile at any depth of soil has been derived and then expressions for the depths of penetration in crater and tunnel region of concrete barrier have been deduced. These depths of penetration have been employed for the derivation of limit state functions. Using the derived limit state functions reliability assessment of underground concrete barrier has then been carried out through First Order Reliability Method (FORM). To study the influence of various random variables on barrier reliability, sensitivity analysis has also been carried out. In addition, a number of parametric studies is conducted to obtain the results of practical interest.

• 대한환경공학회지
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• 제22권5호
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• pp.927-938
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• 2000

박테리아를 토양과 같은 다공성 매질에 주입시키고 적절한 기질과 영양분을 공급시키면 박테리아는 매질의 표면에 부착하여 성장한다. 그 결과 바이오필름이 생성되어 공극의 크기가 감소하여 매질의 투수계수가 감소되며, 오염물질을 분해시키는 생물학적 오염분해 능력을 갖게 된다. 본 연구는 투수계수가 비교적 큰 모래와 화강풍화토에 박테리아를 접종, 배양한 후 토양의 투수계수의 변화를 측정하였으며, 배양된 바이오필름의 화학물질에 대한 저항성 및 온도변화에 대한 내구성 실험을 통해 대용 차수재로의 가능성을 평가하였다. 또한 bio-barrier의 유기물질 분해능 및 bio-barrier의 두께에 따른 미생물의 생장도를 column test를 통하여 측정하여 bio-barrier 내에서의 기질의 이동 및 생분해와 박테리아 농도의 분포 변화간의 관계를 제시하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권1호
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• pp.1-5
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• 2016

Capillary barriers, consisting of relatively fine-over-coarse materials, have been suggested as an alternative to traditional compacted soil covers. So, We were analysed to capillary barrier effect according to five cases of multi-layer cover systems. Water balance simulation was conducted with unsaturated flow model HELP to assess unsaturated hydraulic parameters such as hydraulic conductivity, climate affecting the performance of capillary barriers. Simulation were conducted for 5 Cases in the Ulsan area. Result of simulation indicated that three cases was formed unsaturated condition and capillary barrier effect.