• The Journal of Engineering Geology
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• v.17 no.1 s.50
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• pp.143-150
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• 2007

AMD (Acid mine drainage) from disused mines is one or the most significant pollutant problems to make harmful effect to human health. We demonstrated the mechanism of resolution and adsorption reaction for arsenic, manganese and zink from the soil and mine tailings which were located in the vicinity of a disused mine in Kyoungnam area. The resolution experiments were carried with a column test f3r 45 days continuously. Metal chemical forms in water were changed with the condition of solution pH and ORP (oxidation-reduction potential). Metal chemical forms affected on the reaction of resolution and adsorption of metals in water environments. Even though the sampling was carried in very closed location, there was significant different results of pollution level and ORP changes in terms of column operations. Hence It was important to note the pH and ORP in AMD to evaluate a risk assessment and a soil management using monitoring metals. When we operate AMD management with the mechanism of resolution and adsorption it can be achieved better economic solution.

• Applied Biological Chemistry
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• v.23 no.1
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• pp.58-63
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• 1980

Present investigation is undertaken to evaluate residues of organochlorine pesticides and PCBs in river sediments and cultivated soils by GLC. Main sampling areas chosen were three industrial estates, Suwon, Iri and Kumi. Samples consist of river sediments and cultivated soils, in Suwon, Iri and Chilgok, which are likely to be accumulated with PCBs from nearby factories. Organochlorine pesticide residues were found in all sediments and soil samples while no PCBs residue was detected in all samples analyzed. The pesticide residues were greatest in the Suwon and least in Chilgok soils. p,p'-DDT and BHC isomers $({\alpha}-,\;and\;{\gamma}-)$ were found in all soil samples. p,p'-DDT, at the range of 0.006-0.840 ppm, was the most abundant residues among organochlorine insecticides.

• Journal of Soil and Groundwater Environment
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• v.16 no.2
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• pp.61-76
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• 2011

This study was objected to provide suggestions for best management practices to restore the cultural and historical values of the wells in Palaces as well as their water qualities. Water resources in the five Palaces in Seoul Metropolitan, including Gyeongbokgung, Changdeokgung, Changgyeonggung, Jongmyo Shrine, and Deoksugung, were surveyed for their physical flows and chemical compositions from April to July in 2010. Ground waters in most wells were found at depths within 5 m from the ground surface, showing typical water-table aquifer systems. Hydraulic gradients indicate water resources in Gyeongbokgung, Changdeokgung, and Changgyeonggung flowing toward south, and toward east in Deoksugung area. Especially, water-level fluctuation data at S-10 in Deoksugung implied the influence of groundwater discharge facility. In Jongmyo Shrine, water was not detected in wells, indicating the water level was lower than the well depth. Based on the water chemistry and stable isotope analyses, water resources and their qualities appeared to be formed by the water-rock interaction along the groundwater paths. S-10 (Deoksugung) and S-14 (Changgyeonggung) samples were contaminated with nitrate ($NO_3$) in levels of higher than Korean drinking water standard, 10 mg/L as $NO_3$-N, but once in four sampling campaigns. In the situation that water resources in Palaces still maintain natural characteristics, the materials that will be used for the restoration and improvement of the Palace water supplies should be carefully selected not to disturb the natural integrity. In addition, because the wells are located in the center of metropolitan area, a systematic monitoring should be applied to detect and to manage the potential impacts of underground construction and various pollution sources.

• Journal of the Korean Institute of Landscape Architecture
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• v.14 no.3
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• pp.33-45
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• 1987

The Seonjeong royal tomb is one of many historic sites in and around Seoul city and its natural environment and landscape have born damaged seriously by heavy use. So conservation planning with an estimation of reasonable carrying capacity shall be required In aspect of not only historic site conservation, but also urban forest and nature park management. Eight sites were sampled with clumped sampling method during July of 1986 and five quadrats were examined in each site. Environmental factors, actual vegetation, and environmental impact grade were investigated in field and vegetational structure was analyzed by estimation of importance value, species diversity, similarity index, DBH class distribution, etc. The result of this study can be summarized as follows. 1. Damage on soil and vegetation of middle and lower layer increased according to amount of users'impact. 2. Semi - natural vegetation covered 63% of the total area(22.2 ha) and its major species were Pinus densiflora, Quercus aliena, Q mongolica, Sorbus alnifolia, etc. Pinus densiflora was a dominant species in heavy impact area. 3. Environmental impact grade 3, 4 and 5 area covered 51% of the seminatural vegetation, Especially, the area of impact grade 4 and 5 should be restored because self-refair seemed to be impossible. 4. The semi-natural vegetation was classified with four plant communities; two P.densiflora comm., Q. mongolica-P. densiflora comm. and Q. aliena comm. One of the P. densifolra comm. was destroyed seriously with no younger trees in middle and lower layer by overuse impact and would be bareland soon. But Q. aliena comm.in light impact area showed just completion of plant succession from P. densiflora comm.

• Geophysics and Geophysical Exploration
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• v.7 no.3
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• pp.197-206
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• 2004

Because the minute displacement of ground accompanied by excessive pumping of groundwater at specified site is mainly generated from ill-balancing of water budget within groundwater basin, It is necessary to monitor the variation of micro-subsidence for a long time at representative points. We made up the conceptual model using two-dimensional electrical resistivity survey and three-dimensional soil profile consisted of loam and sand. In verifying the reliability of this conceptual model using numerical modeling for ground settlement and groundwater flowing, two-dimensional electrical resistivity survey with short distance of electrode following soil sampling with hand auger would be useful for interpreting hydrogeological structure related to the minute displacement of ground consisted of loam and sand.

• Journal of Ecology and Environment
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• v.38 no.1
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• pp.75-84
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• 2015

Tropical forests play a critical role in mitigating climate change, and therefore, an accurate and precise estimation of tropical forest carbon (C) is needed. However, there are many uncertainties associated with C stock estimation in a tropical forest, mainly due to its large variations in biomass. Hence, we quantified C stocks in an intact lowland mixed dipterocarp forest (MDF) in Brunei, and investigated variations in biomass and topography. Tree, deadwood, and soil C stocks were estimated by using the allometric equation method, the line intersect method, and the sampling method, respectively. Understory vegetation and litter were also sampled. We then analyzed spatial variations in tree and deadwood biomass in relation to topography. The total C stock was 321.4 Mg C $ha^{-1}$, and living biomass, dead organic matter, and soil C stocks accounted for 67%, 11%, and 23%, respectively, of the total. The results reveal that there was a relatively high C stock, even compared to other tropical forests, and that there was no significant relationship between biomass and topography. Our results provide useful reference data and a greater understanding of biomass variations in lowland MDFs, which could be used for greenhouse gas emission-reduction projects.

• Journal of the Korean Geotechnical Society
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• v.27 no.3
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• pp.5-17
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• 2011

Sampling disturbance can often introduce considerable errors in the laboratory estimation of geotechnical properties of soils. Accordingly, it causes inappropriative results in analysing field behavior. Therefore, a screw plate load test, one of in-situ test technique, is developed in this study, because in-situ testing techniques have advantages for the estimation of reliable geotechnical parameters. The screw plate load test, which was modified from the plate load test, conducts an experiment underneath ground by inserting a spiral type of auger screw. In this study, the structure and characteristics of the screw plate load test device are introduced in detail and the reliability of the device is examined through the analysis of the laboratory test results.

• Microbiology and Biotechnology Letters
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• v.43 no.1
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• pp.65-78
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• 2015

The bacterial diversity of the rhizosphere soil of S. japonica native to Suncheon bay was analyzed. Ninety two strains showing different morphological characteristics were isolated from the soils around the community of S. japonica. Bacterial diversity and distributions were studied by phylogenetic analysis of the partial 16S rDNA sequences. Ninety two strains were partially sequenced and analyzed phylogenetically. These strains were composed of 5 phyla firmicutes (56.5%), gamma-proteobacteria (29.3%), alpha-proteobacteria (5.4%), actinobacteria (5.4%), bacteroidetes (3.3%) and Shannon’s diversity index (H') were different from each of sampling sites (1.675, 1.924 and 2.04). Eleven isolates were presumed to be novel species candidates based on similarity analysis of the 16s rRNA gene sequences. Overall, Firmicutes and gamma-proteobacteria of the rhizosphere soil of S. japonica showed a high diversity.

• Journal of Soil and Groundwater Environment
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• v.15 no.6
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• pp.17-28
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• 2010

As a preliminary survey to improve efficiency of well-based permeable reactive barrier system for groundwater remediation, this site-scale study was carried to identify the flowpaths and controlling factors of plume at a remediation site in Suwon City, Korea. A total of 22 monitoring wells were installed as a grid system in the $4m{\times}4m$ square area by 1-m interval. For the groundwater characterization, various tests were performed including water-level monitoring, water sampling & analysis, pumping and slug tests, and tracer tests. The aquifer appeared to be unconfined with hydraulic conductivities (K) ranging from $2.6{\times}10^{-4}cm/s$ to $9.5{\times}10^{-3}cm/s$. The average linear velocity of groundwater was estimated to be $2.94{\times}10^{-6}m/s$, and the longitudinal dispersivity of a conservative tracer to be $5.94{\times}10^{-7}m^2/s$. Groundwater plume moves preferentially through the high-K zones, and the relatively high ion concentrations along the low-K zones implying deterred groundwater flow. Consequently, the spatial variation of hydraulic conductivity caused by aquifer heterogeneity and anisotropy appears to be the most important factor to maximize the effect of plume treatment system for application of in-situ groundwater remediation techniques.

• Journal of Soil and Groundwater Environment
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• v.15 no.6
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• pp.9-16
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• 2010

Groundwater sampling was performed at 38 wells where they are located in the areas with high uranium and radon (marked as A and B, respectively) concentrations, which were based on the previous research results. In-situ parameters (temperature, pH, EC, Eh, DO) and natural radionuclides (uranium and radon) were analyzed to figure out the characteristics of groundwater environments. In-situ data did not show any relations to natural radionuclide data, which could be caused by groundwater mixing, depths of wells, and geological settings, etc. But the highest radon well presented relatively low temperature value and the highest uranium well presented relatively low pH values The highest uranium concentration ranging $1.14{\sim}188.19{\mu}g/L$ showed in the area of A region consisted of Jurassic two-mica granite. The areas of Jurassic biotite granite and Cretaceous granite in the A region have the uranium concentrations ranging $0.10{\sim}49.78{\mu}g/L$ and $0.36{\sim}3.01{\mu}g/L$, respectively. The uranium values from between wells of community water systems (CWSs) penetrating fractured bed-rock aquifers and personal boreholes settled in shallow aquifers near the wells of CWSs show big differences. It implies that the groundwaters of the two areas have evolved from different water-rock interaction paths that may caused by various types of wells having different aquifers. High radon activities in the area of B region composed of Precambrian gneiss showed ranging from 6,770 to 64,688 pCi/L. Even though the wells are located in the same geological settings, their rodon concentration presented different according to depth and distance.