• Title/Summary/Keyword: Mountain hazard

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Experiments Study on Critical Strain Properties of Sedimentary Rocks based on Mohr-Coulomb Strength Criterion (Mohr-Coulomb의 파괴기준을 기본으로한 퇴적암의 한계변형률 특성에 관한 연구)

  • Kim, Young-Su;Lee, Jae-Ho;Jin, Guang-Ril;Shin, Shi-Un;Kwon, Tea-Soon;Han, Hee-Su
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.821-832
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    • 2008
  • The hazard warning levels are necessary for the rational design and safety construction of underground space, as mountain and urban tunnel. Sakurai provided the hazard warning levels for assessing the stability of tunnels using the critical strain of rock mass, which is defined as a ratio between uni-axial compressive strength and the Young's modulus. The concept of critical strain guidelines is introduced in this study for the assessment of tunnel safety during excavation. Moreover, in this paper, the critical strain properties of sedimentary rock in Korea has investigated and analysed in detail by Lab. test, as the uniaxial and triaxial compression tests. Finally, critical strain properties of sedimentary rock on uniaxial and triaxial stress condition is discussed the relationship of failure strain values, uniaxial and triaxial compression strengths, confining pressure and Young's modulus.

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Utilization of SAR Data for Baseline Environmental Studies of Central Cebu Island, Philippines ? Phase 1

  • Lituanas, Michael B.;Salvador, Jerry Hervacio G.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.981-983
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    • 2003
  • The Remote Sensing Group of the Mines and Geosciences Bureau (MGB) has acquired SAR data of the Central Cebu Island for its research study area. The MGB is one of the proponent of DOST-NASA PACRIM II Project, which is composed of eleven (11) agencies and institutions in the Philippines, that focuses on the scientific application of radar data with the theme on hazard and natural resources management. The PACRIM II Project, being done on three-year term, is slated for completion in the year 2004. The main thrust of the project study of the MGB is the baseline environmental monitoring studies, on which the data are to be fused with some other available data from LandSAT and photogrammetry. The generated data is part of the information for the update of thematic mapping being done. The 12 ${\times}$ 60 km swath AirSAR data covers the Central Cebu Island. The highlights of conducting this research project are: Extent of Watershed Basin boundaries - identification of the tributaries that drain water supply to the metropolitan area; Monitoring of the mountain highways - identification of landslide risk prone sites as part of natural hazard monitoring on a national highway that cuts along the mountainous areas; and Coastline change assessment - monitoring the coastline activities relative to the rapid urbanization and exposure as part of coastal management. The Phase 1 of this report discusses the fusion with the ArcView generated data as baseline studies on the monitoring activities.

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Evaluation of GIS-based Landslide Hazard Mapping (GIS 기반 산사태 예측모형의 적용성 평가)

  • Oh, Kyoung-Doo;Hong, Il-Pyo;Jun, Byong-Ho;Ahn, Won-Sik;Lee, Mee-Young
    • Journal of Korea Water Resources Association
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    • v.39 no.1 s.162
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    • pp.23-33
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    • 2006
  • In this study, application potential of SINMAP, a GIS-based landslide hazard mapping tool, is evaluated through a case study. Through the application to the severe landslide events occurred during a heavy storm in 1991 on the Mt. Dalbong area about 78 kilometers south from Seoul, SINMAP successfully spotted most landslide sites. The effects and proper ranges of three calibration parameters of SINMAP, i.e. the soil internal friction angle, the combined cohesion of tree roots and soil, and T/R, were examined through comparison of predicted landslides with the landslide inventory data. From the findings of this study, it seems that SINMAP could be used as an effective screening tool for landslide hazard mapping especially for mountain areas with fairly steep slopes and relatively thin soil layers.

Analysis on Visibility Range of Forest Fire Detection Facilities for Forest Fire Prevention (산불예방을 위한 감시시설 가시범위 분석에 관한 연구)

  • Lee, Si-Young;An, Sang-Hyun
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.157-160
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    • 2008
  • This study analyzed on the area of Samcheok, Kangwondo about forest fire alarming area and enlargement of the area. Then, visible area by unattended watching camera and watchtower for forest fire which were run by Samcheok was cross-checked with geographic information system, and it could be whether effective on watching the area where the forest fire risk was high enough and also it could be expanded to larger forest fire. The result of study, the visible area by watching facilities only holds for 13.4% of the whole forest fire alarming area, but the forest fire can be observed even though it is occurred in small valley because of smoke and all the forest fire have been occurred in daytime. Therefore, it can be determined that watching area will be extended around 50.3% while the observation radii of watching facilities raise by 4km. However, Samcheok has much greater area of mountain area in compared to any other cities or counties, watching facilities should be installed and run additionally for extinguishing the forest fire from the beginning.

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Analysis of Mountain Trail Hazard areas Based on Watershed Scale (유역단위 산지탐방로 위험지역 분석)

  • Oh, Chae Yeon;Jun, Kye Won
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.280-280
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    • 2015
  • 최근 봄철을 맞아 산을 찾는 등산객의 수가 증가하고 있으며 그에 따른 안전사고 발생 위험도 높아지고 있다. 산지재해 중 가장 많이 발생하고 있는 산사태나 토석류는 산을 찾는 등산객에게도 많은 안전사고를 발생시키고 있으나 아직까지 탐방로의 위험성과 안전에 대한 연구는 미흡한 실정이다. 본 연구에서는 설악산 국립공원 탐방로를 중심으로 재해발생 이력조사 및 현장조사를 실시하고 분석에 필요한 공간 데이터를 구축하였으며 설악산 전체 탐방로를 유역단위로 분할하여 위험성 분석을 실시하였다. 전체 탐방로를 대상으로 GIS기반의 확률론적 분석과 SINMAP을 이용하여 위험성 평가를 수행하였으며 그 결과 일부 탐방로 구간에서 위험성이 높게 나타났다. 탐방로 위험구간을 유역별로 나누어 분석함으로써 탐방로 전체에서 유역단위로 위험요소를 판단하는 자료로 활용될 수 있을 것으로 판단된다.

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Disaster risk predicted by the Topographic Position and Landforms Analysis of Mountainous Watersheds (산지유역의 지형위치 및 지형분석을 통한 재해 위험도 예측)

  • Oh, Chae-Yeon;Jun, Kye-Won
    • Journal of Korean Society of Disaster and Security
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    • v.11 no.2
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    • pp.1-8
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    • 2018
  • Extreme climate phenomena are occurring around the world caused by global climate change. The heavy rains exceeds the previous record of highest rainfall. In particular, as flash floods generate heavy rainfall on the mountains over a relatively a short period of time, the likelihood of landslides increases. Gangwon region is especially suffered by landslide damages, because the most of the part is mountainous, steep, and having shallow soil. Therefore, in this study, is to predict the risk of disasters by applying topographic classification techniques and landslide risk prediction techniques to mountain watersheds. Classify the hazardous area by calculating the topographic position index (TPI) as a topographic classification technique. The SINMAP method, one of the earth rock predictors, was used to predict possible areas of a landslide. Using the SINMAP method, we predicted the area where the mountainous disaster can occur. As a result, the topographic classification technique classified more than 63% of the total watershed into open slope and upper slope. In the SINMAP analysis, about 58% of the total watershed was analyzed as a hazard area. Due to recent developments, measures to reduce mountain disasters are urgently needed. Stability measures should be established for hazard zone.

Development in Geomorphology and Soil Geography: Focusing on the Journal of the Korean Geomorphological Association (한국지형학회지를 중심으로 본 지형학과 토양지리학의 발달)

  • Park, Kyeong
    • Journal of the Korean Geographical Society
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    • v.47 no.4
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    • pp.474-489
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    • 2012
  • Last review papers on Korean geomorphology and physical geography had been published in 1997 and 2000 respectively. A proposal to publish a book on Korean geomorphologists' achievement resulted in series of review papers in Journal of the Korean Geomorphological Association. This article aims to summarize these papers and introduce their findings to foreign scholars. On remarkable achievement is a fierce debate on the effectiveness of traditional mountain concept to explain the shape of Korean peninsula, which made the public's understanding of geomorphology widen to the general public. Reflecting public demands, concerns for the effects of coastal facilities on coastal erosion and conservation mind and scientific researches for the coastal sand dunes have increased so much. Geomorphological hazards such as debris flow attracted many concerned scientists, and geotourism-related papers in scientific journals increased thanks to the designation of first geopark in Korea. Research papers submitted to the famous foreign academic journals are increasing in numbers these days.

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Structure and Management Devices of Vegetation at Weolmi Urban Nature Park, Incheon (도시자연공원의 식생구조에 따른 관리방안 - 인천광역시 월미공원의 사례 -)

  • Cho, Woo
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.1
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    • pp.61-74
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    • 2002
  • The purpose of this study is to propose vegetation management devices through analyzing the actual vegetation, flora, plant community structure and soil chemical concentrations in Weolmi urban nature park, Incheon. The actual vegetation of Weolmi Park in various areas is composed of urbanization area(2 types, 25.9%), landscape planting area(4 types, 16.1%), grass and marsh area(5 types, 7.6%) and mountain forest areal(14 types, 50.4%). The flora is composed of 295 taxa with 80 families, 253 species, 35 varieties and 7 formas, and among them there are 16 naturalized plant families, 39 species, 3 varieties. In reflection of size, the number of the species seems high but most of the them are under influence of human disturbance. Nine survey plots of plant community structure are classified into two groups. One is the semi-natural plant community(Prunus sargentii-Acer palmatum, Quercus accutissma-Prunus sargentii, Quercus serrata-Quercus accutissma-Prunus sargentii, Prunus sargentii, and Zelkova serrata-Prunus sargentii) that migrated finn the planting forest to the natural forest and the other is planting forest(Pinus koraienssis-Pinus thunbergii-Abies holophylla-Chamaectparis obtusa, Prunus sargentii, Pinus thunbergii-Alnus firma, Zelkova serrata). The average pH is 4.65 which means the soil acidity is quite high. The concentration of K, Ca, Mg and base saturation is very low. It seems that the environmental pollutants from Incheon Port and industrial plants near by survey site and long-distance transport of air pollutants from China made the soil condition worse. On the basis of the results above, six vegetation management devices are suggested: 1) removing the hazard plants(Pueraia thunbergiana and Humulus japonica), 2) natural landscape management of the middle and long term, 3) increasing species diversity, 4) Robinia pseudoacacia management, 5) keeping the naturalized plants from being distributed any further inside the mountain forest, 6) improving soil acidification.

Effect of Land Slope on Propagation due to Debris Flow Behavior (전파면의 경사에 따른 토석류 흐름양상에 대한 연구)

  • Lee, Jun Seon;Song, Chang Geun;Kim, Hong Teak;Lee, Seung Oh
    • Journal of the Korean Society of Safety
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    • v.30 no.3
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    • pp.52-58
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    • 2015
  • As sudden rainfall has happened, the debris flow has occurred in the mountain area. Recently sudden rainfall occurred so frequently caused by abnormal climate. Thus debris flow hazard had consecutively increased damage because of debris flow. Recently, Enormous damage due to debris flow have occurred in Korea. Various studies have been conducted to prevent search debris flow hazard. This study was carried out for debris flow behavior according to the land slope on propagation. It is the important one among factors that are related to the propagation over the city with respect to debris flow discharge and depth. For the numerical simulations in this study, the land slope was varied of 5, 0, $-5^{\circ}$ to investigate the debris flow behavior with the FLO-2D, often recommended by FEMA to simulate debris flow. To verify the performance of FLO-2D, comparison with the USGS experiments (Iverson et al, 2010) was conducted. From numerical results the propagation length of the debris flow was found the most sensitive one. Maximum of debris flow thickness and velocity and structural vulnerabilities were investigated to the effect of land slope. They was became smaller according to land slope of 5, -5, $0^{\circ}$ in the order. As a result, debris flow behavior analysis about the effect of the land slope could contribute to understand the vulnerability of city for debris flow hazards.

Fragility Assessment of Agricultural Facilities Subjected to Volcanic Ash Fall Hazards (농업시설물에 대한 화산재 취약도 평가)

  • Ham, Hee Jung;Choi, Seung Hun;Lee, Sungsu;Kim, Ho-Jeong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.6
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    • pp.493-500
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    • 2014
  • This paper presents findings from the assessment of the volcanic ash fragility for multi-hazard resisting vinyl greenhouse and livestock shed among the agricultural facilities. The volcanic ash fragility was evaluated by using a combination of the FOSM (first-order second-moment) method, available statistics of volcanic load, facility specifications, and building code. In this study, the evaluated volcanic ash fragilities represent the conditional probability of failure of the agricultural facilities over the full range of volcanic ash loads. For the evaluation, 6 types(ie., 2 single span, 2 tree crop, and 2 double span types) of multi-hazard resisting vinyl greenhouses and 3 types(ie., standard, coast, and mountain types) of livestock sheds are considered. All volcanic ash fragilities estimated in this study were fitted by using parameters of the GEV(generalized extreme value) distribution function, and the obtained parameters were complied into a database to be used in future. The volcanic ash fragilities obtained in this study are planning to be used to evaluate risk by volcanic ash when Mt. Baekdu erupts.