• Title/Summary/Keyword: geological distribution

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The Research on the Management Plan of Geological Heritage in Korea using GIS (지리정보를 활용한 한국의 지질유산 정보화 구축 및 관리방안 제시)

  • Lee, SooJae;Lee, MoungJin
    • Journal of Environmental Policy
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    • v.14 no.4
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    • pp.103-123
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    • 2015
  • To provide effective management policy of geo-heritages, concept of Korean geo-heritage has been organized based on geo-diversity, geo-conservation, geo-tourism, and earth-heritage. In addition, current status of geo-heritage in Korea has been grasped, and categorized. In case GPS (Global Positioning System) coordinates exist, spatial information was constructed as GIS (Geographic Information System). Geo-heritages were classified into a total of six categories of natural monument, scenic site, coastal sand-dune, natural cave, world nature heritage, and other types of geo-heritage. By mapping 991 geo-heritages scattered nationwide using geographical information, all statuses can now be readily identified and enable the analysis of the distribution tendencies and correlation with topography. This study was aimed at searching the political connection based on quantitatively organized and analyzed geo-heritages, which have not been mapped thus far. In addition, this study organized data that have existed only in literature, and presented example verification. Moreover, these can be used as guidelines for the future search, discovery, registration and management of geo-heritage. If additional geo-heritages are discovered in field studies or with satellite images, then more correlations may be identified and help facilitate the research on geo-heritages management plans.

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Wedge Failure Probability Analysis for Rock Slope Based on Non-linear Shear Strength of Discontinuity (불연속면의 비선형 전단강도를 이용한 암반사면 쐐기파괴 확률 해석)

  • 윤우현;천병식
    • Journal of the Korean Geotechnical Society
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    • v.19 no.6
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    • pp.151-160
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    • 2003
  • The stability of the designed rock slope is analysed based on two kinds of shear strength model. Besides the deterministic analysis, a probabilistic approach on Monte Carlo simulation is proposed to deal with the uncertain characteristics of the discontinuity and the results obtained from two models are compared to each other. To carry out the research of characteristics of the discontinuity, BIPS, DOM Scanline survey data and direct shear test data are used, and chi-square test is used for determining the probability distribution function. The rock slope is evaluated to be stable in the deterministic analysis, but in the probabilistic analysis, the probability of failure is more than 5%, so, it is considered that the rock slope is unstable. In the shear strength models, the probability of the failure based on the Mohr-Coulomb model(linear model) is higher than that of the Barton model. It is supported by the fact that the Mohr-Coulomb model is more sensitive to block size than the Barton model. In fact, there is no reliable way to estimate the unit cohesion of the Mohr-Coulomb model except f3r back analysis and in the case of small block failure in the slope, Mohr-Coulomb model may excessively evaluate the factor of the safety. So, the Barton model of which parameters are easily acquired using the geological survey is more reasonable for the stability of the studied slope. Also, the selection of the proper shear strength model is an important factor for slope failure analysis.

Comparison of Texture Images and Application of Template Matching for Geo-spatial Feature Analysis Based on Remote Sensing Data (원격탐사 자료 기반 지형공간 특성분석을 위한 텍스처 영상 비교와 템플레이트 정합의 적용)

  • Yoo Hee Young;Jeon So Hee;Lee Kiwon;Kwon Byung-Doo
    • Journal of the Korean earth science society
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    • v.26 no.7
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    • pp.683-690
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    • 2005
  • As remote sensing imagery with high spatial resolution (e.g. pixel resolution of 1m or less) is used widely in the specific application domains, the requirements of advanced methods for this imagery are increasing. Among many applicable methods, the texture image analysis, which was characterized by the spatial distribution of the gray levels in a neighborhood, can be regarded as one useful method. In the texture image, we compared and analyzed different results according to various directions, kernel sizes, and parameter types for the GLCM algorithm. Then, we studied spatial feature characteristics within each result image. In addition, a template matching program which can search spatial patterns using template images selected from original and texture images was also embodied and applied. Probabilities were examined on the basis of the results. These results would anticipate effective applications for detecting and analyzing specific shaped geological or other complex features using high spatial resolution imagery.

Investigation of fault in the Kyungju Kaekok-ri area by 2-D Electrical Resistivity Survey (2차원 전기비저항 탐사를 이용한 경주 개곡리 지역의 단층조사)

  • Lee, Chi-Seop;Kim, Hee-Joon;Kong, Young-Sae;Lee, Jung-Mo;Chang, Tae-Woo
    • Geophysics and Geophysical Exploration
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    • v.4 no.4
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    • pp.124-132
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    • 2001
  • Electrical resistivity survey has been conducted for delineating geological fault structure in Kaekok-ri near Kyungju. In general, electrical resistivity survey has an advantage of searching buried faults and its traces compared with other geophysical survey methods. Distribution of electrical conductivity in the ground is influenced by the ratio of pores, groundwater and clay minerals. These properties are evidenced indirectly to explain for weathering condition, faults and fracture Bones. Thus the electrical resistivity survey can be an effective method to find buried faults. We have carried out two dimensional (2-D) interpretation by means of smoothness-constrained least-squares and finite element method. Field data used in this paper was acquired at Kaekok-ri, Wuedong-eup, Kyungju-si, where is Ulsan Fault and is close to the region in which debatable quaternary fault traces were found recently. The dipole-dipole array resistivity survey which could show the 2-D subsurface electrical resistivity structure, was carried out in the area with three lines. The results showed good property of fault, fracture zone and fault traces which we estimated were congruous with the results. Through this study, 2-D electrical resistivity survey interpretation for fault is useful to apply.

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Study on Landslide Hazard Possibility for Mt. Hwangryeong in Busan Metropolitan City Using the Infinite Slope Model (무한사면 모델을 이용한 부산 황령산 산사태 재해 평가 가능성 검토)

  • Kim, Jae Min;Choi, Jung Chan
    • The Journal of Engineering Geology
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    • v.26 no.3
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    • pp.413-422
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    • 2016
  • With the rapidly increasing population density and development of infrastructure, the loss of life and property damage caused by landslides has increased gradually in urban area. Especially, Because Busan has high percentage of mountainous terrain among the metropolitan in Korea, it is unavoidable to develop mountainous region excessively. The objective of this evaluation is to study on landslide hazard possibility for Mt. Hwangryeong in Busan Metropolitan City using the infinite slope model considering the groundwater level. All data related to creating the thematic maps was carried out using ArcGIS 10.0. The results show that FS (Factor of Safety) for landslide is inversely proportional to groundwater level change as expected. Most area indicates stable state in dry condition, and unstable area increase due to high pore water pressure when the groundwater level rise. However, several places in high lineament density area where landslide has been previously occurred, are more stable than other places according to the analysis. This inconsistency between real situation and analysis results indicates that additional analytical method would be necessary to solve the problem. Therefore, we suggest that development of new infiltration theory for unsaturated zone would be helpful to evaluate groundwater level distribution as time goes by.

The Study on the Water Quality Characteristics of Barium in the Raw Water of Domestic Natural Mineral Water (국내 먹는샘물 원수 중 바륨(Ba)의 수질 특성에 관한 연구)

  • Lee, Leenae;Ahn, Kyunghee;Yang, Mihee;Choi, Incheol;Chung, Hyenmi;Lee, Wonseok;Park, Juhyun
    • Journal of Korean Society on Water Environment
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    • v.33 no.4
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    • pp.416-423
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    • 2017
  • The subject samples include 150 and 170 samples collected from intake holes in the former and latter half of 2015, respectively. They were analyzed with ICP-MS. The average concentration of detected barium was $10.54{\mu}g/L$ ($0.23{\sim}168.22{\mu}g/L$) and $8.21{\mu}g/L$ ($0{\sim}255.65{\mu}g/L$) for the former and latter halves of 2015, respectively. The concentration distribution was the highest for the precambrian era at $19.07{\mu}g/L$ and the lowest Cenozoic era at $4.92{\mu}g/L$. The average value for sedimentary, metamorphic, and igneous rocks was $7.84{\mu}g/L$, $20.84{\mu}g/L$, and $9.47{\mu}g/L$, respectively, which indicates that it was the highest for metamorphic rocks. The study also analyzed correlations between barium and other minerals and found that magnesium recorded 0.44 and 0.71 for the former and latter half of 2015, respectively. As for barium concentration according to depth, it was relatively low in shallow groundwater (under 200 m) with its average concentration at $14.33{\mu}g/L$ and $14.71{\mu}g/L$ for the former and latter half of 2015, respectively. It was $8.53{\mu}g/L$ and $4.04{\mu}g/L$ in deep groundwater (over 200 m) for the two periods, respectively, The risk assessment results show that its average risk was HQ 0.00139 and HQ 0.00163 for the former and latter half of 2015, respectively, being considerably lower than "1", which suggests that barium poses few possibilities of consumption risk.

Geophysical Responses of the Yangsan Fault Zone at Eonyang Area (언양 일대 양산단층에서의 지구물리학적 반응)

  • Kwon Byung-Doo;Lee Heuisoon;Lee Choon-Ki;Park Gyesoon;Oh Seokhoon;Lee Duk Kee
    • Journal of the Korean earth science society
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    • v.26 no.5
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    • pp.436-442
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    • 2005
  • We have performed multiple geophysical surveys comprised of gravity, magnetic and resistivity methods at the Yangsan fault zone which runs through the Eonyang area, the eastern part of Kyeongsang in southeast Korea. The gravity and magnetic data provide information about geological structures. Furthermore, sections of electrical resistivity show the sharp contrast of electrical resistivity distribution across the fault zone. Since the fractured zone tends to be more conductive than fresh host rocks, the electrical resistivity survey is effective in determining the detailed structure of the fault zone. We have made gravity measurements at a total of 71 points alongside two profiles across the fault zone, and carried out an electrical resistivity survey with a dipole-dipole array at the same location using 40m dipole length. In addition, we have analyzed the aeromagnetic data on the corresponding area. The multiple geophysical properties appear to be abruptly changed in electrical resistivity, gravity and aeromagneticclearly show the different appearance across the fault zone. The fault is identified by its sub vertical attitude which is well known in the Yangsan fault zone. We have also confirmed that the magnitude of the response of the fault is much larger in the southern part of the survey area than the northern area. These results most likely to provide basic information for the further studies about the physical properties and the structures at the Yangsan fault.

Physical property analysis of sediments for development of maritime archaeological survey techniques (수중문화재 탐사기법 개발을 위한 퇴적물 물성분석)

  • Kim, Sung-Bo;Ko, Eun-Ji;Jung, Yong-Hwa;Lee, Young-Hyun;Kim, Jin-Hoo
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.3
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    • pp.333-341
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    • 2014
  • Since distribution and preservation of cultural artifacts in the submarine sediments are directly affected by not only ocean currents and tides, but also their composition, it is very important to investigate geological characteristics of sediments and ocean-sediment interactions for maritime archaeological survey. Physical properties of submarine sediments, which are collected by grab sampler and vibro-corer, are analyzed in order to investigate effects of submarine environment on development of maritime archaeological survey techniques. Result of physical property analysis showed that bulk density, shear strength, and magnetic susceptibility increase with depth, while water contents and porosity decrease with depth. Since the magnetic susceptibility of bedrock is about 40 times that of submarine sediments, it might impact greatly on the response of magnetic survey. Physical properties of sediments with depth and sediment classification by Folk's ternary diagram indicate that submarine sediment mainly consists of silt, and cultural artifacts can not penetrate no deeper than 1.5 m in sediments.

The Distribution Characteristics and Contamination of Heavy Metals in Soil from Dalcheon Mine (달천광산 토양 내 중금속의 존재형태 및 오염도)

  • Suh, Ji-Won;Yoon, Hye-On;Jeong, Chan-Ho
    • Journal of the Mineralogical Society of Korea
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    • v.21 no.1
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    • pp.57-65
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    • 2008
  • The geochemical partitioning of arsenic in contaminated soils from a of wet land and tailing of the abandoned mine is examined. Chemical analysis and sequential extraction method by ultrasound-sonication extraction are applied to investigate the mobility and chemical existence conditions of arsenic as well as heavy metals. The results of this study showed that heavy metals concentration of tailings showed as a following order: Fe > As > Cu > Pb > Cr. The highest metal concentration was recognized in samples less than $63\;{\mu}m$ fraction in their particle sizes. Exchangeable and carbonate fractions in soil samples showed following Cu > As > Pb > Fe > Cr for tailings, and Fe > Pb > Cu > As > Cr for reservoir soils, respectively. Arsenic was bound as exchangeable fraction in tailings and its concentration appeared higher than those of the other metals. Thus, As can be easily dispersed into soil and water environments. The obtained results can be used to design soil remediation plan in the study area and require further detailed study to investigate severe environmental pollution of surface water as well as rivers with respect to heavy metals in terms of speciation analysis of toxic elements such as As and Cr.

Differentiation Trend of Rare Earth Elements of the Skaergaard Intrusion (Skaergaard 암체의 희토류의 분화경향)

  • Yun D. Jang
    • Economic and Environmental Geology
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    • v.34 no.6
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    • pp.617-625
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    • 2001
  • The Skaergaard intrusion is widely considered a type example of a strongly fractionated, layered intrusion that has undergone extensive in situ igneous differentiation. The Intrusion, therefore, should be a good locality for modeling trace element vriation in a closed system. Previous studios (Haskin and Haskin, 1968; Faster et al., 1974), however, have suggested thats the rare earth elements in whole rocks and mineeral separates from the Intrusion did not fellow the expected trend for closed system crystatllization. Trace element modeling using published distribution coefficients, modal abundances of the coexisting minerals, and the concentration of trace elements In whole rocks and mineral separates from the Skaergaard Intrusion, reveals that the rare earth elements were significantly Influenced by the crystallization of abundant apatite in the Layered Series suring the final stages of crystallization. The results of trace element modeling also suggcsts that apatite, which appears sporadically in the UBS, is not a primary liquidus phase in these samples as previously suggested (Naslund, 1984) but an interstitial phase that (lid not directly effect trace element abundances In the evolving magma As the Skaergaard magma coaled convection, or convected as small Isolated cells during the final stages of differentiation, an elebated $P_{H2O}$ Induced by accumulation of volatile elements near the roof of the magma chamber ingibited or delayed the precipitation of primary apatite in the UBS If the Skaergaard differentiation Is modeler assuming primary apatite crystallization In the upper par of the LS where abundant modal apatite is present, and only late stage crystallization of apatite In the UBS where apatite Is less abundant, rare earth elements abundances follow a closed system variation trend. These results rule but any differentiation model for the Skaergaard Intrusion that Includesvolumetrically significant injections or discharges of magma Into or out of the chamber during the final 20% of the crystallization history.

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