• 자원환경지질
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• 제25권2호
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• pp.145-151
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• 1992

In order to study the optimum depth for the soil geochemical exploration in the area which is affected by agricultural activities and waste disposal of metal mine, the soil samples were sampled from the B layer of residual soil and vertical 7 layers up to 250 cm in the rice field and 3 layers up to 90 cm in the ordinary field. They were analyzed for Au, As, Cu, Pb and Zn by AAS, AAS-graphite furnace and ICP. To investigate the proper depth for the soil sampling in the contaminated area, the data were treated statistically by applying correlation coefficient, factor analysis and trend analysis. It is conclude that soil geochemical exploration method could be applied in the farm-land and a little contaminated area. The optimum depth of soil sampling is 60 cm in the ordinary field, and 150~200 cm in the rice field. Soil sampling in the area of a huge mine waste disposal is not recommendable. Plotting of geochemical map with factor scores as a input data shows a clear pattern compared with the map of indicater element such as As or Au. The second or third degree trend surface analysis is effective in inferring the continuity of vein in the area where the outcrop is invisible.

• International Journal of Advanced Culture Technology
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• 제7권4호
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• pp.268-273
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• 2019

The apparent soil resistivity is used for estimating multilayer soil parameters, such as, layer's depth and soil resistivity. The soil parameters are estimated by continuously revising those parameters until the error between the measured and calculated apparent soil resistivity reaches to allowable level. The equation for calculating the apparent soil resistivity is complicated and time consumed, because it is composed of an infinite integral which includes a zero order Bessel's function of the first kind. In this paper, a fast algorithm for calculating the apparent soil resistivity of horizontal multilayer earth structure is proposed using exponential sampling method.

• 한국토양동물학회지
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• 제2권2호
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• pp.98-103
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• 1997

This study was investigated, from October to November, 1995, how environmental factors affected both the diversity and the ecology of soil microarthropods according to the sampling sites at althletic training park located in Chonju, Chonbuk. The results obtained are as follow: At the sampling areas, the soil microarthropods were identified into 6 classes, 15 orders, 17,145 individuals. Arachnida showed the highest individual rate (74.10%) in soil mictoarthropods and Acari occupied the great majority (97.98%) in Archinida. Collembola showed the highest individual rate (82.01%) in Insecta. Species planted at althletic training park were 10 famillies 12 genera 20 species 2 varietas 1 forma. In environmental factors which have an effect on the distribution of the soil microarthropods, acarina showed positive correlation for rate of carbon/nitrogen, soil moisture, soil acidity, and lead(Pb) and also negative correlation for solidity and intensity of lightness. Collembola and other animals showed negative correlation for solidity.

• 한국환경과학회지
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• 제18권10호
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• pp.1079-1088
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• 2009

The statistics of monitoring on soil quality is a report statistics which is made on the basis of Article 15, Environment Strategy Basic Law and Article 5, Soil Environment Conservation Law. This study was conducted according to quality assessment of Korea National Statistical Office. The assessment of quality infrastructure advised that the authority bring up and increase completely responsible officer and secure the budget. The assessment of user satisfaction and reflection of request propose that the statistics is focused on soil background concentration, decrease soil sampling points and extend survey period. The assessment of error management system per processes of detailed preparation suggest change of the statistics objective, a reduction of sampling points and improvement of survey period and soil measurement properties. Accuracy assessment of data proposed cuts of sampling points, accessibility increment and build up of management system linking subordinates and Ministry of Environment. The substantiality assessment of data service demonstrated information environment improvement for users including reference expression and records of statistics table and figure contents.

• 한국농공학회논문집
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• 제51권5호
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• pp.51-58
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• 2009

The total recovery ratio test on undisturbed clay soil sampling in the field and the finite element method analysis on modified static state of penetration process were conducted for the purpose of deciding the most important factor among the shape factors of thin wall tube. The adhesion between tube wall and soil did not decrease although internal clearance ratio of tube increased within the little change of tube area ratio. The most part of disturbance occurred in the tip of sampling tube during the penetration. The longitudinal displacement was larger than the lateral displacement because soil was confined laterally after being entered into tube, and also the longitudinal displacement was larger in the upper part of the sample tube than in the lower part.

• 한국토양비료학회지
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• 제40권4호
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• pp.326-329
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• 2007

Quantifying soil organic carbon (SOC) has long been considered to improve our understanding of soil productivity, soil carbon dynamics, and soil quality. And also SOC could contribute as a major soil management factor for prescribing fertilizers and controlling of soil erosion and runoff. Reducing tillage intensity has been recommended to sequester SOC into soil. On the other hand, determination of traditional SOC could barely identify the tillage practices effect. Physical soil fractionation has been reported to improve interpretation of soil tillage practices impact on SOC dynamics. However, most of these researches were focused onupland soils and few researches were conducted on paddy soils. Therefore, the objective of this research was to evaluate paddy soil tillage impact on SOC by physical soil fractionation. Soils were sampled in conventional-tillage (CT), partial-tillage (PT), no-tillage (NT), and shallow-tillage (ST)plots at the National Institute of Crop Science research farm. Samples were obtained at the three sampling depth with 7.5-cm increment from the surface and were sieved with 0.25- and 0.053-mm screen. Soil organic carbon was determined by wet combustion method. Significant difference of SOC contentwas found among sampling soil depth and soil particle size. SOC content tended to increase at the ST plot with increasing size of soil particle fraction. We conclude that quantifying soil organic carbon by physical soil particle fractionation could improve understanding of SOC dynamics by soil tillage practices.

• 한국습지학회지
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• 제3권1호
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• pp.61-73
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• 2001

This study was performed to survey the characteristics of surface water and soil in Wangdungjae wetland located at Chiri-Mountain. The results of survey summarized as follows; 1. The physico-chemical characteristics of surface water such as pH, temperature, and DO were in the range of 6.02-6.39, $13.5-24.3^{\circ}C$ and 3.81-9.97 mg/L, respectively. Also, the organic concentrations such as BOD and COD were in the range of 1.3-1.61 mg/L and 3.55-9.97 mg/L, respectively. The water quality of five different sampling sites showed the similar characteristics. 2. The physico- chemical characteristics of soil showed the different properties with the soil sampling depth. According to increasing sampling depth, cation exchange capacity (CEC) and electric conductivity (EC) increased but pH decreased. 3. The future survey and researches on surface water and soil environments are needed to preserve the Wangdungjae wetland at Chiri-mountain marsh.

• 한국환경복원기술학회지
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• 제18권1호
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• pp.153-163
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• 2015

The study was conducted to develop ecological restoration method of damaged area in DMZ vicinities. As the material for the ecological restoration, forest soil and trees waste have been used. Forest soils were collected for experiments in Yanggu, Gangwon Province. Effect of ecological restoration was analyzed through germination experiment. Germination experiment was performed using 12 kinds of woody and herbaceous seeds. Woody and herbaceous seed germination in test pot was relatively evenly. Mixed material consisting of forest soil and trees waste seemed a possibility as the material for the restoration. The effects on seed germination were higher in the case of mixing more than 70% by volume ratio of local resources. Total number germinated individuals were different depending on the mixing ratio of soil sampling depth. Individual plants showed different trends depending on the experimental combination. Results of the woody seed germination were affected only in the soil sampling depth. Seed germination of herbaceous received a combined effect on soil sampling depth and mixing ratio.

• Journal of Biosystems Engineering
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• 제33권4호
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• pp.260-268
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• 2008

Optical diffuse reflectance sensing has potential for rapid and reliable on-site estimation of soil properties. For good results, proper calibration to measured soil properties is required. One issue is whether it is necessary to develop calibrations using samples from the specific area or areas (e.g., field, soil series) in which the sensor will be applied, or whether a general "factory" calibration is sufficient. A further question is if specific calibration is required, how many sample points are needed. In this study, these issues were addressed using data from 42 paddy fields representing 14 distinct soil series accounting for 74% of the total Korean paddy field area. Partial least squares (PLS) regression was used to develop calibrations between soil properties and reflectance spectra. Model evaluation was based on coefficient of determination ($R^2$) root mean square error of prediction (RMSEP), and RPD, the ratio of standard deviation to RMSEP. When sample data from a soil series were included in the calibration stage (full information calibration), RPD values of prediction models were increased by 0.03 to 3.32, compared with results from calibration models not including data from the test soil series (calibration without site-specific information). Higher $R^2$ values were also obtained in most cases. Including some samples from the test soil series (hybrid calibration) generally increased RPD rapidly up to a certain number of sample points. A large portion of the potential improvement could be obtained by adding about 8 to 22 points, depending on the soil properties to be estimated, where the numbers were 10 to 18 for pH, 18-22 for EC, and 8 to 22 for total C. These results provide guidance on sampling and calibration requirements for NIR soil property estimation.

• 한국지하수토양환경학회지:지하수토양환경
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• 제7권3호
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• pp.71-77
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• 2002

본 연구는 비교적 인위적 오염의 개연성이 있다고 판단되는 난지도 주변 지역 토양을 대상으로 2001년 4월부터 5월까지 표토에서 깊이 3m까지 표토, 표토 1m깊이, 표토 2m깊이, 표토 3m깊이로 하여 중금속 오염농도를 조사 분석하였다. 조사대상 중금속은 Cd, Cu, Pb, As, $Cr^{+6}$ Hg의 6개 항목이였으며 농도 정량은 원자흡광광도 방법을 사용하였다. 결과로는 난지도 주변지역에서 중금속 평균도가 Cd 0.229mg/kg. Cu는 8.349mg/kg, Pb 11.083mg/kg, As 0.298mg/kg, $Cr^{+6}$ 0.124mg/kg, Hg 0.134mg/kg로 나타났다. 표토 평균농도는 Cd 0.305mg/kg, Cu 8.464mg/kg, Pb 11.383mg/kg, As 0.128mg/kg, $Cr^{+}$60.153mg/kg, and Hg 0.092mg/kg로 나타났다. 이는 Cd 과 $Cr^{+6}$가 조사대상 전체 평균농도의 80%수준으로 나타났다. Hg과 As는 전체 평균농도와 비슷한 수준으로 나타났다. 조사대상을 중심으로 살펴본 난지도 주변 지역의 중금속 농도조사에서 깊이별 변화 추이의 일관성은 찾을 수 없었으나 C지점과 D지점에서의 금속 수준은 오염된 향동천의 영향과 매립된 폐기물에 영향을 받은 것으로 생각되었다.