• Title/Summary/Keyword: Geologic Hazard

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Analysis of Regional Geologic Hazards Using Geographic Information System (GIS(Geographic Information System)를 이용한 광역 지질재해(산사태) 분석 연구)

  • 김윤종;김원영;유일현;박수홍;백종학;이현우
    • Korean Journal of Remote Sensing
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    • v.7 no.2
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    • pp.165-178
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    • 1991
  • A geologic hazard map has been produced in the suburbs of Seoul using GIS technology to analyse the degree of geologic hazard, particularly landslides. Topographic, geologic and soil data were incorporated in a map through GIS, which enable to interpret, analyse and predict the regional geologic hazards. Potential elements causing a landslide are slope geometry, geology, groundwater table, soil property, rainfall and vegetation etc. These elements analysed in the study area were input into GIS system through cartographic simulation to produce the regional geologic hazard map. For this work, ARC/INFO(GIS) and ERDAS(IP) system were used.

GIS technolgy for analysing regional geologic hazards (Landslides) (광역 지질재해분석(산사태)을 위한 GIS활용)

  • 김윤종;김원영;유일현
    • The Journal of Engineering Geology
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    • v.2 no.2
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    • pp.131-140
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    • 1992
  • GIS(Geographic Information System) technology was applied for analysis of the potential degree of regional geologic hazard, especially landslide hazards in the suburb of Seoul City, whereby a regional geologic hazard map was produced. The factors causing a landslide such as slope geometry, geology, groundwater, soil property, rainfall and vegetation were incorporated through GIS in order to predict the potential hazards in this area. Cartographic simulation was finally made with these factors to produce a regional geologic hazard map. For this study, ARC/INFO and ERDAS systems were used in SUN 4-390 workstation.

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Analysis of Slope Hazard Triggering Factors through Field Investigation in Korea Over the Past Four Years (최근 4년간 국내 사면재해 현장조사를 통한 유발인자 분석)

  • Jun, Kyoung-Jea;Yune, Chan-Young
    • Journal of the Korean Geotechnical Society
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    • v.31 no.5
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    • pp.47-58
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    • 2015
  • Triggering rainfall and geologic conditions with the state of slope hazard were investigated based on the field investigation and collected data on the slope hazard during the period between 2011 and 2014 in Korea. Analysis results showed that most of slope hazards occurred in metamorphic rock and debris flow was the most frequent type of slope hazard. Slope hazard increased when the higher monthly mean rainfall was recorded. However, most of slope hazard occurred when certain time elapsed after the moment of maximum hourly rainfall. Finally, more than one month of long-term rainfall was shown to be related to the frequency of slope hazard in the period.

Effects of Meteorological Variations and Sensor Burial Depths on HVSR Analysis (기상변화와 지진계 설치 깊이가 HVSR 분석결과에 미치는 영향)

  • Kang, Su Young;Kim, Kwang-Hee;Kim, Doyoung;Jeon, Byeong-Uk;Lee, Jin-Wook
    • Journal of the Korean earth science society
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    • v.41 no.6
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    • pp.658-669
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    • 2020
  • The horizontal-to-vertical spectral ratio (HVSR) analysis is conducted to estimate the site amplification effect and the thickness of the sedimentary layer beneath the measurement site. We investigated the effects of meteorological variations (wind and precipitation rate) and sensor burial depths on HVSR analysis. The HVSR results were unstable when seismographs were exposed on the ground. The HVSR results of ambient noise data measured under strong winds were also unstable. It is recommended to measure the ambient noise at wind speeds of <3 m s-1. Stable HVSR results were obtained when seismographs were buried, regardless of the precipitation rates. The results of this study provide the best observations and optimal weather conditions required to acquire accurate and reliable HVSR results.

Analysis of Regional Geologic hazards using GIS (지질재해 분석을 위한 GIS 응용연구)

  • 김윤종;김원영;유일현
    • Spatial Information Research
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    • v.1 no.1
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    • pp.89-94
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    • 1993
  • GIS was appl ied for analysis of the potfnt ial degree of regional geologic hazard, expecially landslide, in the suburb of Seoul city. Potential elements causing a landslide are geology, slope geometry, groundwater, soil property, rainfall and vegetation etc. These factors were incorporated through GIS in order to predict the potential hazards, and to produce a regional geologic hazard map in the study area, For this study, ARC/INFO and ERDAS systems were used in SUN4-390 workstation.

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A Case Study of GIS-Based Site Classification in the Gyeongsang Province Constrained by Geologic and Topographic Information (GIS기반의 지질·지형 자료를 활용한 경상도지역의 지반분류 사례)

  • Kang, Su-Young;Kim, Kwang-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.12 no.4
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    • pp.136-145
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    • 2009
  • Site characteristic is an important input parameter in the geologic hazard assessments including, but not limited to, earthquakes, liquefaction and landslides. Although it is a routine to use data collected by boreholes or seismic prospecting for site classifications, we used indirect methods using the geologic and the topographic maps. A site classification map in the Gyeongsang Province has been produced by GIS tools based on geologic age, rock types, and elevations from the geologic map and the topographic map of Korea. Site B (rock site) is dominant in the study area, although softer soils are observed along rivers and in reclaimed lands. We have found that 73% of the site classification results in the study are in concordance with those obtained from borehole data. Observed discrepancies are attributed to errors in the geologic and the topographic maps. For some sites, the origin of the differences is not clear, which requires a further field study or a drilling. Site classification from this study provides essential information for reliable hazard assessments of earthquakes, floods, landslides and liquefaction. Results obtained in the study also play a crucial role in land use planning for developing areas.

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Probabilistic Landslide Susceptibility Analysis and Verification using GIS and Remote Sensing Data at Penang, Malaysia

  • Lee, S.;Choi, J.;Talib, En. Jasmi Ab
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.129-131
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    • 2003
  • The aim of this study is to evaluate the hazard of landslides at Penang, Malaysia, using a Geographic Information System (GIS) and remote sensing. Landslide locations were identified in the study area from interpretation of aerial photographs and field surveys. The topographic and geologic data and satellite image were collected, processed and constructed into a spatial database using GIS and image processing. The used factors that influence landslide occurrence are topographic slope, topographic aspect topographic curv ature and distance from drainage from topographic database, geology and distance from lineament from the geologic database, land use from TM satellite image and vegetation index value from SPOT satellite image. Landslide hazardous area were analysed and mapped using the landslide-occurrence factors by probability - likelihood ratio - method. The results of the analysis were verified using the landslide location data. The validation results showed satisfactory agreement between the hazard map and the existing data on landslide location.

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GIS Technology for Environmental Gelolgic Mapping (환경 지질도 작성을 위한 GIS 응용연구)

  • 김윤종;유일현;김원영;신은선
    • The Journal of Engineering Geology
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    • v.4 no.3
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    • pp.321-331
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    • 1994
  • Environmental geologic maps were produced on the cheong-Ju area using GIS technique. They are GIS maps on land management and regional land use planning. In the last year, the model of environmental geologic map was established, and the digital database was constructed by environmental and geotechnical data collected form various sources. The special maps for environmental geologic study were also pnoduced ; landslide hazard and risk map, cut & fill map, actual run-off map and engineering geological map. The maps are secondary models (sub-model) in order to create final environmental geologic map. Finally, Environmental Geologic Unit(EGU) was evaluated for regional land use planning and land management by EGIS(Environmental Geologic Inforafion System). This unit is very important in order to assess environmental geologic impact on large construction works and detailed road design etc.

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Evaluation of the Safty for the Disposal of High-level Nuclear Waste in the Granite (화강암지역에 고준위 원자력 폐기물 처리에 대한 안정성 평가)

  • Oh, Chang Whan
    • Economic and Environmental Geology
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    • v.29 no.2
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    • pp.215-225
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    • 1996
  • All the radionuclides in high-level nuclear waste will decay to harmless levels eventually but for some radionuclides decay is so slow that their radiation remains dangerous for times on the order of tens or hundreds of thousands of years. At the present time, the most favorite disposal plan for high-level radioactive waste is a mined geological disposal in which canister enclosing stable solid form of radioactive waste is placed in mined cavities locating hundred meters below the surface. The chief hazard in such disposal is dissolution of radionuclides from the waste in the groundwater that will eventually carry the dissolved radionuclides to surface environments. The hazard from possible escape of the radionuclides through groundwater can be delayed by engineered and geologic barriers. The engineered barriers can become useless by unexpected geologic catastrophe such as volcanism, earthquake, and tectonic movement and by fraudulent work such as careless construction, improperly welded canisters within the first few decades or centuries. As a result, dangerously radioactive waste which is still intensively radioactive is directly exposed to attack by moving groundwater. All the more, it is almost impossible to control repositories for times more than 10,000 years. Therefore, naturally controlled geologic, barriers whose properties will not be changed within 10,000 years are important to guarantee the safety of repositories of high-level radioactive waste. In Sweden and France, the suitability of granite for the mined geological disposal of high-level waste has been studied intensively. According to the research in Sweden and France, granites has the following physio-chemical characteristics which can delay the transportation of radionuclide by groundwater. First, the permeabilities of granites decreases as the depth increases and is $10^{-8}{\sim}10^{-12}m/s$ at depth below 300 m. Second, groundwater at depth below 300 m has pH=7-9 and reducing condition (Eh=-0.1~0.4). This geochemical condition is desirable to prevent both canister and solid waste from corrosion. Third most radionuclides are not transported by low solubilities and some radionuclide with high solubility such as Cs and Sr are retarded by absorption of geologic media through which ground water flows. Therefore, if high-level waste is disposed at depth below 300 m in the granite body which has a low permeability and is geologically stable more than 10,000 years, the safety of repositories from the hazard due to radionuclide escape can guaranteed for more than 10,000 years.

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