• Title/Summary/Keyword: Geologic condition

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GIS & GPS Application of Management of Granitic Flagstone from the Trifurcated Path at Jongmyo Royal Shrine, Seoul, Korea (종묘 어도박석 관리를 위한 GIS 및 GPS 활용)

  • Lee, Jin-Young;Hong, Sei-Sun;Yun, Hyun-Su
    • Journal of the Korean Association of Geographic Information Studies
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    • v.13 no.4
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    • pp.125-137
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    • 2010
  • Jongmyo royal shrine, located in Seoul, is a UNESCO World Heritage site, and a cultural relic of national value and significance. Examination of its udobakseok(granitic flagstone; thin, flat and even stepping-stones for the King) has shown that parts are in damaged condition. In this study, GIS and GPS technologies were applied to determine the extent of damage and to find granitic flagstone for replacement and restoration of the damaged stones. 1,158 out of 2,361 stone pieces of the udobakseok were damaged at Jongmyo. Replacement granitic flagstones are available on Seokmo Island, in Ganghwa County, and estimates show that approximately 100,000 pieces of stone can be quarried. This research aided the systematic management of information about availability and location of granitic flagstones for restoration of the Jongmyo udobakseok. It also demonstrated that GIS and GPS technologies can apply a critical role in managing cultural properties. The wide use of GIS and GPS technologies can be expected for survey and management of other cultural properties in addition to Jongmyo.

Assessment of Seismic Site Response at Hongseong in Korea Based on Two-dimensional Basin Modeling using Spatial Geotechnical Information (공간 지반 정보를 활용한 이차원 분지 모델링 기반의 국내 홍성 지역에서의 부지 지진 응답 평가)

  • Sun, Chang-Guk
    • The Journal of Engineering Geology
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    • v.19 no.1
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    • pp.15-23
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    • 2009
  • The site effects relating to the amplification of ground motion under earthquake loading are strongly influenced by both the subsurface soil condition and geologic structure. In this study, the site effects at the Hongseong area in Korea were examined by both the site investigation including borehole drilling and in-situ seismic tests and the site visit for acquiring geologic information of ground surface. Subsurface of Hongseong area with a major instrumental earthquake event in 1978 is composed of weathered layers of a maximum of 45 m thickness overlying bedrock. A geotechnical information system based on GIS framework was implemented to effectively find out spatial geologic structure of study area and it indicated Hongseong is a shallow and wide shaped basin. Two-dimensional finite element (FE) analyses for a representative cross-section of the Hongseong area were performed to evaluate seismic site responses. From the results of seismic responses, it was observed that the ground motions were amplified during the propagation of shear waves through the soil layer overlying the bedrock and the duration of shaking near the basin edges was prolonged due to the surface waves generated by interactions of shear waves with basin geometry. Furthermore, one-dimensional FE seismic response analyses were additionally conducted for soil sites selected in the basin, and it gives similar results to the two-dimensional seismic responses at most locations in the basin with the exception of the locations near the basin edges, because the basin in this study is very shallow and wide.

Quantitative Analysis of the Look Direction Bias in SAR Image for Geological Lineament Study (지질학적 선구조 분석을 위한 SAR 영상에서의 방향편차에 대한 정량적 분석)

  • 홍창기;원중선;민경덕
    • Korean Journal of Remote Sensing
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    • v.16 no.1
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    • pp.13-24
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    • 2000
  • SAR imagery usually reveals the influence of antenna look-direction on the delineation of geological structures. In this study, the look-direction bias in SAR image is quantitatively analyzed specifically for geological lineament study. Geologic lineaments are estimated using both Landsat TM and JERS-1 SAR images over the study area to quantitatively compare and analyze the look-direction bias in the SAR image. The standard geologic lineaments in the study area are established from lineaments estimated from TM images, field mapping, and fault lines in a published geologic map. The results show that lineaments normal to radar look-direction are extremely well enhanced while those parallel to look-direction are less visible as expected. However, certain lineaments even parallel to radar look-direction can still be detectable in a favorable topographic condition. Compared with TM image, the total number of detected lineaments in each direction in the SAR image increases or decreases ranging from 33% to 159% in length and from 28% to 187% in occurrence. The ratio of lineaments in SAR image to those in TM image with respect to direction can be fitted by a cosine function. The fitted function indicates that geological lineament is more easily detected in SAR image than in TM image within about $\pm$50$^{\circ}$ normal to radar look-direction. And lineaments with limited extension appear to be more sensitive to the look direction bias effect.

Characteristics of Lime-cavities and Survey Design for Bridge Foundation in the Karst Area (석회 공동의 특성과 카르스트 지역 내 교량 기초를 위한 조사 설계)

  • 윤운상;김학수;최원석
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.399-406
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    • 1999
  • Recently, the construction of the several highway bridges in the karst area have encountered severe problems associated with cavities and sinkholes. To solve this problems, it is important to understand the distribution characteristics of cavities in the construction site on limestone area. This paper briefly describes the different types, the distribution control factors and the infill sediment types of lime-cavities in the study area, bridge site in the karst area and propose the effective method of survey design. Cavity system may be divided into two main groups, 1)'slot and cave system'and 2)'sinkhole and cave system'. And the shape, the size and the distribution pattern of cavity are controlled by three main factors - rock type, geological structure and ground water condition. Additionally, infill sediment may be considered as one of the important design factors for foundation design and divided into four types by sediment properties. There are geophysical thechnics and geologic survey and drilling test, etc. by the survey method to interpretate characteristics of cavity system, and this methods are optimally designed at the site investigation stage.

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A study on Average CN Estimation in River Basin using Satellite Data

  • Kwon, Bong-kyum;Jo, Myung-Hee;Ahn, Seung-Sep;Kiyoshi, Yamada
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.499-499
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    • 2002
  • The goal of this study is to apply and evaluate the precipitation outflow in river basin using satellite data and GIS for proposing the efficient watershed management method. Not only precipitation outflow data but also various spatial data such as digital map, soil map, geologic map and multi-temporal TM images were used. Using landcover classification result and soil map were applied to estimate the average CN. The CN value of 63.37 by SCS method was produced in AMC-2 condition otherwise the result of direct estimation with observation method was 63 CN value. The relative error of two results was 0.59%. It can be possible to apply the satellite data for precipitation outflow analysis. For more accurate and credible analysis of this, the more multi-temporal satellite and real observation data will be needed.

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A Case Study of Landslides due to Heavy Rainfall (집중호우시 산사태 원인분석에 관한 사례연구)

  • Yoo, Nam-Jae;Park, Byung-Soo
    • Journal of Industrial Technology
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    • v.21 no.A
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    • pp.303-315
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    • 2001
  • This study is a research result of investigating causes of landslides occurred at Uijongbu in Kyonggi Province, Korea. For works of this research, informations and data about landslides occurred at the site, geological and topographical informations were collected to analyze causes of landslides, and mapping landslides was performed by using results of field investigation. Data about rainfall during occurrence of landslides around Uijongbu was also used to find the effect of intense rainfall on occurrence of landslides. Based on informations obtained from field investigation and collected data, the scale and the pattern of landslides were analyzed and influencing factors on landslide such as intensity and duration of rainfall, topography, geologic condition, geotechnical engineering properties of ground, forestry were investigated statistically to find causes of landslides. On the other hands, for geotechnical engineering respects, slope stability analysis was performed for the typical sites chosen from the sites where the landslides occurred, using informations obtained from detailed topographical survey with total stations, field reconnaissance and results from laboratory tests.

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An Investigation of Hydrologic by Spring Cheju Island (제주도의 용천기구에 관한 수문학적 연구)

  • 고병련;조현경
    • Journal of Environmental Science International
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    • v.6 no.4
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    • pp.303-311
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    • 1997
  • The characteristics of spring machanism In the Cheju Island were analyzed by statistical techniques. Basic characteristics, areal and altitudinal variations, and correlations of spring data were investigated. In this study. however, the subjects of the study are the 451 springs, the whole basin of Cheju Island derided Into four groups. In this study, analyzed the spring phenomena on the basis of both the geologic elements and the topogaphic elements. Also, the spring zone In Cheju Island are classified Into three types that the mountain area, the muddle area, the coastal area in spring distribution by attitude. The quentity of spring and variability show subvariety on the average according to Meinzer's classilfication and the whole basin of spring shows various distributions from Third to Sixth. The results of this study can be utilized to evaluate the condition of groundwater development In Cheju Island.

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Study on Analysis of Geophysical Data for Complex Geological Condition (복잡한 지하구조 해석을 위한 물리탐사 자료 분석에 관한 연구)

  • Shin, Deuck-Hyun;Kim, Hoon;Oh, Seok-Hoon;Suh, Baek-soo
    • Journal of Industrial Technology
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    • v.27 no.B
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    • pp.115-119
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    • 2007
  • Currently, geophysical method is applied for understanding the subsurface geologic structure economically and systematically, but there exists some limitations on recognizing complex subsurface structures precisely by a single geophysical method. In order to understand the complex subsurface structures, we applied various geophysical methods including seismic refraction survey, two-dimensional resistivity survey, seismic tomography survey, suspension-ps log, and understood distribution of low velocity, low resistivity range of resistivity survey and correlation of an intersecting point, velocity distribution of seismic tomography survey.

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Characterization of Groundwater Chemistry and Fluoride in Groundwater Quality Monitoring Network of Korea

  • Han, Jiwon
    • Journal of the Korean earth science society
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    • v.42 no.5
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    • pp.556-570
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    • 2021
  • This study presents the data analysis results of groundwater chemistry and the occurrence of fluoride in groundwater obtained from the groundwater quality monitoring network of Korea. The groundwater data were collected from the National Groundwater Information Center and censored for erratic values and charge balance (±10%). From the geochemical graphs and various ionic ratios, it was observed that the Ca-HCO3 type was predominant in Korean groundwater. In addition, water-rock interaction was identified as a key chemical process controlling groundwater chemistry, while precipitation and evaporation were found to be less important. According to a non-parametric trend test, at p=0.05, the concentration of fluoride in groundwater did not increase significantly and only 4.3% of the total groundwater exceeded the Korean drinking water standard of 1.5 mg/L. However, student t-tests revealed that the fluoride concentrations were closely associated with the lithologies of tuff, granite porphyry, and metamorphic rocks showing distinctively high levels. This study enhances our understanding of groundwater chemical composition and major controlling factors of fluoride occurrence and distribution in Korean groundwater.

CALCAREOUS NANNOPLANKTON FROM THE SEOGUIPO FORMATIN OF CHEJU ISLAND, KOREA AND ITS PALEOCEANOGRAPHIC IMPLICATIONS

  • Yi Songsuk;Yun Hyesu;Choi Duck-Keun;Yoon Sun;Koh Gi-Won
    • 한국석유지질학회:학술대회논문집
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    • spring
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    • pp.22-28
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    • 1998
  • Twenty species of calcareous nannofossils belonging to 11 genera are identified from the Seoguipo Formation in Cheju island, Korea. On the basis of the marker species, the Seoguipo Formation is biostratigraphically assigned to the Pseudoemiliania lacunosa Zone (NNl9), which corresponds to the combined zones of Emiliania annula - Emiliania ovata (CN13a-CN14a) of latest Pliocene and Early Pleistocene. Generally, cold-water species is dominant in the lower part, whereas warm-water one in the upper part. This is interpreted the palaeoceanographic condition has changed from cooling to warm phase. The change in floral composition and abundance of specific species allows the recognition of 4 ecostaratigraphic units in the Seoguipo Formation and the migration of oceanographic frontal boundary. According to nannofossil distribution in the study area, the position of an oceanographic boundary between warmer water and cooler water appeared to have oscillated north-south over the Korea Strait and Cheju island in response to glacial and interglacial cycles. The geologic time of the interpreted paleoceanographical changes determined by nannofossil biochronology is well agreed with the results obtained from the Japan Sea (East Sea) and Japan-Sea side of Japan.

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