• Title/Summary/Keyword: natural hazards

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The Current Methods of Landslide Monitoring Using Observation Sensors for Geologic Property (지질특성 관측용 센서를 이용한 산사태 모니터링 기법 현황)

  • Chae, Byung-Gon;Song, Young-Suk;Choi, Junghae;Kim, Kyeong-Su
    • Journal of Sensor Science and Technology
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    • v.24 no.5
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    • pp.291-298
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    • 2015
  • There are many landslides occurred by typhoons and intense rainfall during the summer seasons in Korea. To predict a landslide triggering it is important to understand mechanisms and potential areas of landslides by the geological approaches. However, recent climate changes make difficult to predict landslide based on only conventional prediction methods. Therefore, the importance of a real-time monitoring of landslide using various sensors is emphasized in recent. Many researchers have studied monitoring techniques of landslides and suggested several monitoring systems which can be applicable to the natural terrain. Most sensors of landslide monitoring measure slope displacement, hydrogeologic properties of soils and rocks, changes of stress in soil and rock fractures, and rainfall amount and intensity. The measured values of each sensor are transmitted to a monitoring server in real-time. The ultimate goal of landslide monitoring is to warn landslide occurrence in advance and to reduce damages induced by landslides. This study introduces the current situation of landslide monitoring techniques in each country.

Research Trends on External Event Identification and Screening Methods for Safety Assessment of Nuclear Power Plant (원자력발전소 안전성 평가를 위한 외부사건 식별 및 선별 방법 연구동향)

  • Kim, Dongchang;Kwag, Shinyoung;Kim, Jitae;Eem, Seunghyun
    • Journal of the Society of Disaster Information
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    • v.18 no.2
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    • pp.252-260
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    • 2022
  • Purpose: As the intensity and frequency of natural hazards are increasing due to climate change, external events that affecting nuclear power plants(NPPs) may increase. NPPs must be protected from external events such as natural hazards and human-induced hazards. External events that may occur in NPPs should be identified, and external events that may affect NPPs should be identified. This study introduces the methodology of identification and screening methods for external events by literature review. Method: The literature survey was conducted on the identification and screening methods of external events for probabilistic safety assessment of NPPs. In addition, the regulations on the identification and screening of external events were investigated. Result: In order to minimize the cost of external event impact analysis of nuclear power plants, research on identifying and screening external events is being conducted. In general, in the identification process, all events that can occur at the NPPs are identified. In the screening process, external events are selected based on qualitative and quantitative criteria in most studies. Conclusions: The process of identifying and screening external events affecting NPPs is becoming important. This paper, summarize on how to identify and screen external events for a probabilistic safety assessment of NPPs. It is judged that research on bounding analysis and conservative analysis methods performed in the quantitative screening process of external events is necessary.

Ensuring Economic Benefits of Mitigation Projects for Improving the Image of Construction Industry

  • Son, Chang-Baek;Shin, Won-Sang;Kim, Dae Young
    • Journal of Korea Society of Industrial Information Systems
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    • v.19 no.3
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    • pp.67-74
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    • 2014
  • Over the last several decades, the United States has experienced a great number of natural disasters. To minimize the impact of the natural hazard events, the U.S. government spent a tremendous amount of money through federal assistant programs. To be eligible for the programs, a mitigation project must be cost effective (more benefits compared to project costs). However, the state and local communities suffering from the natural disasters generally have difficulty in collecting reliable evidence for their damages which can be converted later into benefits when a mitigation project is implemented. Therefore, this paper shows the process of conducting a benefit cost analysis with limited data. Besides, it also provides how to apply the limited data to the analysis through a case study. Consequently, this paper help state and local communities get funding from the federal government, which in turns will improve the image of construction industry by preventing people from natural disasters.

Development of analysis technique of landslide hazards in natural slopes (자연사면 산사태재해 해석기법 개발)

  • Kim, Kyeong-Su;Song, Young-Suk;Cho, Yong-Chan;Chae, Byung-Gon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.1092-1099
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    • 2009
  • Landslide researches are divided to a method of interrelationship for various factors, method of predicting landslide possibility, and method of estimating landslide risk which are occurring landslides in the natural slope. Most of landslides occurred in natural slope are caused by a heavy rainfall in summer season. Weathered soil layer located in upper side of rock mass was occurred. As well as, they are announced to have an influence to geometry, geology, soil characteristics, and precipitation in the natural slope. In order to investigate and interpret the variety of landslides from field investigation to risk analysis, landslide analysis process due to geotechnical and geological opinions are systematically demanded. In this research, the study area is located in Macheon area, Gyeongsangnam-do and performed the landslide investigation. From the results of landslide investigation and analysis, optimized standard model based on natural landslide is proposed to high technical method of landslide investigation and interpretation.

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The Relationship between Soil Erosion and Cultivation in the Bockha Stream Watershed Area (복하천 유역의 토양유실량 및 경작지의 상관 분석)

  • Lee, Jin-Young;Yang, Dong-Yun;Kim, Ju-Young;Hong, Sea-Sun;Kim, Jin-Kwan
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.1
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    • pp.56-65
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    • 2006
  • In the past, flooding is commonly occurred in the Bockha stream watershed area with inundation by the water and eroded sediments. The purpose of this study is to find the relationship between area under cultivation and amount of soil erosion in each watershed areas using geographic information system(GIS) for decreasing the damages of flooding. The soil erosion amounts were computed on GIS using by universal soil loss equation(USLE). Small catchment areas was divided by topography and computed soil erosion amounts. The mean amount of soil erosion is 0.03 $ton/ha{\cdot}yr$ on the condition of the 1,329 mm/yr annual precipitation. The high erosion area(0.05 $ton/ha{\cdot}yr$) is shown in farm areas of the Sangyong-ri in Baeksa-myeon. The high erosion watershed area is related on the slopes of the farm lands and bare soil areas adjoining between the mountain slope and fluvial streams show much amount of soil erosion.

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A Prediction Model of Landslides in the Tertiary Sedimentary Rocks and Volcanic Rocks Area (제3기 퇴적암 및 화산암 분포지의 산사태 예측모델)

  • Chae Byung-Gon;Kim Won-Young;Na Jong-Hwa;Cho Yong-Chan;Kim Kyeong-Su;Lee Choon-Oh
    • The Journal of Engineering Geology
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    • v.14 no.4 s.41
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    • pp.443-450
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    • 2004
  • This study developed a prediction model of debris flow to predict a landslide probability on natural terrain composed of the Tertiary sedimentary and volcanic rocks using a logistic regression analysis. The landslides data were collected around Pohang, Gyeongbuk province where more than 100 landslides were occurred in 1998. Considered with basic characteristics of the logistic regression analysis, field survey and laboratory soil tests were performed for both slided points and not-slided points. The final iufluential factors on landslides were selected as six factors by the logistic regression analysis. The six factors are composed of two topographic factors and four geologic factors. The developed landslide prediction model has more than $90\%$ of prediction accuracy. Therefore, it is possible to make probabilistic and quantitative prediction of landslide occurrence using the developed model in this study area as well as the previously developed model for metamorphic and granitic rocks.

Analysis of Seasonal Importance of Construction Hazards Using Text Mining (텍스트마이닝을 이용한 건설공사 위험요소의 계절별 중요도 분석)

  • Park, Kichang;Kim, Hyoungkwan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.3
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    • pp.305-316
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    • 2021
  • Construction accidents occur due to a number of reasons-worker carelessness, non-adoption of safety equipment, and failure to comply with safety rules are some examples. Because much construction work is done outdoors, weather conditions can also be a factor in accidents. Past construction accident data are useful for accident prevention, but since construction accident data are often in a text format consisting of natural language, extracting construction hazards from construction accident data can take a lot of time and that entails extra cost. Therefore, in this study, we extracted construction hazards from 2,026 domestic construction accident reports using text mining and performed a seasonal analysis of construction hazards through frequency analysis and centrality analysis. Of the 254 construction hazards defined by Korea's Ministry of Land, Infrastructure, and Transport, we extracted 51 risk factors from the construction accident data. The results showed that a significant hazard was "Formwork" in spring and autumn, "Scaffold" in summer, and "Crane" in winter. The proposed method would enable construction safety managers to prepare better safety measures against outdoor construction accidents according to weather, season, and climate.

A Study on the Geomorphological Characteristics of Development and Flood Hazards in Watershed (유역분지의 개발 및 수해 발생과 관련된 지형 인자 분석 -용인시 서북부 지역을 사례로-)

  • Seong, Hyo-Hyeon;Ban, Hyo-Won
    • 한국지형공간정보학회:학술대회논문집
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    • 2002.11a
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    • pp.101-109
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    • 2002
  • Since the industrialization spread out, the metropolitan areas of Seoul have been urbanized rapidly in Korea, without concern for the quality of further development and sufficient environmental management. Due to this fact, it has become increasingly more apparent that natural hazards, such as floods and landslides, occur frequently after the summer's heavy rains, and because of that, the scale of damage is getting larger. The purpose of this study is first to analyze the relationship between development and floods in the sub-basins of the study area. In addition to this, I would like to compare the influences of geomorphological characteristics upon the floods occurring in both the whole study area and the developed area in sub-basins.

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Determination of indoor doses and excess lifetime cancer risks caused by building materials containing natural radionuclides in Malaysia

  • Abdullahi, Shittu;Ismail, Aznan Fazli;Samat, Supian
    • Nuclear Engineering and Technology
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    • v.51 no.1
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    • pp.325-336
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    • 2019
  • The activity concentrations of $^{226}Ra$, $^{232}Th$, and $^{40}K$ from 102 building materials samples were determined using a high-purity germanium (HPGe) detector. The activity concentrations were evaluated for possible radiological hazards to the human health. The excess lifetime cancer risks (ELCR) were also estimated, and the average values were recorded as $0.42{\pm}0.24{\times}10^{-3}$, $3.22{\pm}1.83{\times}10^{-3}$, and $3.65{\pm}1.85{\times}10^{-3}$ for outdoor, indoor, and total ELCR respectively. The activity concentrations were further subjected to RESRAD-BUILD computer code to evaluate the long-term radiation exposure to a dweller. The indoor doses were assessed from zero up to 70 years. The simulation results were $92{\pm}59$, $689{\pm}566$, and $782{\pm}569{\mu}Sv\;y^{-1}$ for indoor external, internal, and total effective dose equivalent (TEDE) respectively. The results reported were all below the recommended maximum values. Therefore, the radiological hazards attributed to building materials under study are negligible.

Assessment of geological hazards in landslide risk using the analysis process method

  • Peixi Guo;Seyyed Behnam Beheshti;Maryam Shokravi;Amir Behshad
    • Steel and Composite Structures
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    • v.47 no.4
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    • pp.451-454
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    • 2023
  • Landslides are one of the natural disasters that cause a lot of financial and human losses every year It will be all over the world. China, especially. The Mainland China can be divided into 12 zones, including 4 high susceptibility zones, 7 medium susceptibility zones and 1 low susceptibility zone, according to landslide proneness. Climate and physiography are always at risk of landslides. The purpose of this research is to prepare a landslide hazard map using the Hierarchical Analysis Process method. In the GIS environment, it is in a part of China watershed. In order to prepare a landslide hazard map, first with Field studies, a distribution map of landslides in the area and then a map of factors affecting landslides were prepared. In the next stage, the factors are prioritized using expert opinion and hierarchical analysis process and nine factors including height, slope, slope direction, geological units, land use, distance from Waterway, distance from the road, distance from the fault and rainfall map were selected as effective factors. Then Landslide risk zoning in the region was done using the hierarchical analysis process model. The results showed that the three factors of geological units, distance from the road and slope are the most important have had an effect on the occurrence of landslides in the region, while the two factors of fault and rainfall have the least effect The landslide occurred in the region.