• 제목/요약/키워드: Hazard maps

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Recognition of Landslide Activites in Bonggye Area Using Isopleth Mapping Techniques (Isopleth Mapping기법에 의한 봉계지역의 Landslide 활동성 연구)

  • 김윤종;유일현
    • Korean Journal of Remote Sensing
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    • v.5 no.2
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    • pp.123-131
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    • 1989
  • The inventory maps of landslide deposits show where landsliding has occured in the past, and serve as a general guide to slope stability. Isopleth maps derived from those inventory maps, generalized and quantify the areal distribution of landslide deposits in contour form. Isopleth maps can provide an economical means for the recognition of landslide activity and assessing the degree of landslide hazard in a large area, especially rural areas. Isopleth maps of Bonggye area, where the degree of landslide hamedial efforts during the period of 1954-1971.

Fuzzy-based multiple decision method for landslide susceptibility and hazard assessment: A case study of Tabriz, Iran

  • Nanehkaran, Yaser A.;Mao, Yimin;Azarafza, Mohammad;Kockar, Mustafa K.;Zhu, Hong-Hu
    • Geomechanics and Engineering
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    • v.24 no.5
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    • pp.407-418
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    • 2021
  • Due to the complexity of the causes of the sliding mass instabilities, landslide susceptibility and hazard evaluation are difficult, but they can be more carefully considered and regionally evaluated by using new programming technologies to minimize the hazard. This study aims to evaluate the landslide hazard zonation in the Tabriz region, Iran. A fuzzy logic-based multi-criteria decision-making method was proposed for susceptibility analysis and preparing the hazard zonation maps implemented in MATLAB programming language and Geographic Information System (GIS) environment. In this study, five main factors have been identified as triggering including climate (i.e., precipitation, temperature), geomorphology (i.e., slope gradient, slope aspect, land cover), tectonic and seismic parameters (i.e., tectonic lineament congestion, distribution of earthquakes, the unsafe radius of main faults, seismicity), geological and hydrological conditions (i.e., drainage patterns, hydraulic gradient, groundwater table depth, weathered geo-materials), and human activities (i.e., distance to roads, distance to the municipal areas) in the study area. The results of analyses are presented as a landslide hazard map which is classified into 5 different sensitive categories (i.e., insignificant to very high potential). Then, landslide susceptibility maps were prepared for the Tabriz region, which is categorized in a high-sensitive area located in the northern parts of the area. Based on these maps, the Bozgoosh-Sahand mountainous belt, Misho-Miro Mountains and western highlands of Jolfa have been delineated as risk-able zones.

A Case Study for Construction Hazard Zonation Maps and its Application (석회암 지역 재해 등급도 작성 및 응용에 관한 사례 연구)

  • 정의진;윤운상;김중휘;마상준;김정환;이근병
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.165-172
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    • 2002
  • We presents an hazard zonation mapping technique in karst terrain and its assessment. From the detailed engineering geological mapping. Controlling factors of sink hole and limestone cave formation were discussed and 4 main hazard factors affecting hazard potential are identified as follows: prerequisite hazard factor(distributions of pre-existing sink holes and cavities), geomorphological hazard factors(slope gradient, vegetation, and drainage pattern etc.) geological hazard factors(lithology, fracture patterns and geological structures etc.) and hydraulic conditions(hydraulic head, annual fluctuation of ground water table and composition of g/w water). From the construction of hazard zonation map along the Jecheon-Maepo area, and vertical cross-sectional hazard zonations specific tunnel site we suggest hazard zonation rating systems.

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Earthquake risk assessment of seismically isolated extradosed bridges with lead rubber bearings

  • Kim, Dookie;Yi, Jin-Hak;Seo, Hyeong-Yeol;Chang, Chunho
    • Structural Engineering and Mechanics
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    • v.29 no.6
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    • pp.689-707
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    • 2008
  • This study presents a method to evaluate the seismic risk of an extradosed bridge with seismic isolators of lead rubber bearings (LRBs), and also to show the effectiveness of the LRB isolators on the extradosed bridge, which is one of the relatively flexible and lightly damped structures in terms of seismic risk. Initially, the seismic vulnerability of a structure is evaluated, and then the seismic hazard of a specific site is rated using an earthquake data set and seismic hazard maps in Korea. Then, the seismic risk of the structure is assessed. The nonlinear seismic analyses are carried out to consider plastic deformation of bridge columns and the nonlinear characteristics of soil foundation. To describe the nonlinear behaviour of a column, the ductility demand is adopted, and the moment-curvature relation of a column is assumed to be bilinear hysteretic. The fragility curves are represented as a log-normal distribution function for column damage, movement of superstructure, and cable yielding. And the seismic hazard at a specific site is estimated using the available seismic hazard maps. The results show that in seismically-isolated extradosed bridges under earthquakes, the effectiveness of the isolators is much more noticeable in the columns than the cables and girders.

Evaluation on Risk Assessment for Landslide Hazard of Soil Slope Using the Checklists as a Preliminary Investigation Method (점검표를 이용한 토질사면 산사태 예비조사 방법 평가)

  • Kim, Jae Min;Choi, Jung Chan
    • Economic and Environmental Geology
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    • v.48 no.2
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    • pp.177-185
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    • 2015
  • The objective of this study is to evaluate landslide hazard susceptibility and produce the landslide hazard maps for soil slope using checklists as a preliminary investigation method. Tables, proposed by NDMI (National Disaster Management Institute), are applied for slope stability assessment, and are comprised of checklists on soil slopes. Database including engineering properties of soil is constructed through the field survey and results from previous studies for The Mt. Hwangryoeng area at center of Busan. All data related to creating the thematic maps was carried out using ArcGIS 10.0. Results from using this method indicated that soil slope are evaluated from very stable to stable. Moderate stability has been partially presented along the edge of mountain. Results from landslide hazard maps can be used to prevent damage from landslides and facilitate appropriate land use planning.

Computation of Uniform Hazard Spectrum for Wolsong Nuclear Power Plants. (월성 원전 부지의 등재해도 스펙트럼 계산)

  • 신진수
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 1998.10a
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    • pp.297-303
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    • 1998
  • The uniform hazard spectrum of Wolsong Nuclear Power plant Site is computed in order to estimate probabilistically the characteristics of spectral ground response. The spectral hazard values calculated from the seismic zoning maps proposed by eight seismologist are combined with equal weight to produce a uniform hazard spectrum. The uniform hazardd spectra corresponding to reference probabilities of 1.0 $\times$10-4/year and 1.0$\times$10-5/year are presented, which largely depend on the spectral attenuation relation. The computational results of this study contribute to verify the conservatism of the design ground spectrum of Wolsong Nuclear Power Plant.

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THE EFFECTS OF UNCERTAIN TOPOGRAPHIC DATA ON SPATIAL PREDICTION OF LANDSLIDE HAZARD

  • Park, No-Wook;Kyriakidis, Phaedon C.
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.259-261
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    • 2008
  • GIS-based spatial data integration tasks have used exhaustive thematic maps generated from sparsely sampled data or satellite-based exhaustive data. Due to a simplification of reality and error in mapping procedures, such spatial data are usually imperfect and of different accuracy. The objective of this study is to carry out a sensitivity analysis in connection with input topographic data for landslide hazard mapping. Two different types of elevation estimates, elevation spot heights and a DEM from ASTER stereo images are considered. The geostatistical framework of kriging is applied for generating more reliable elevation estimates from both sparse elevation spot heights and exhaustive ASTER-based elevation values. The effects of different accuracy arising from different terrain-related maps on the prediction performance of landslide hazard are illustrated from a case study of Boeun, Korea.

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Development of New Probabilistic Seismic Hazard Analysis and Seismic Coefficients of Korea Part II: Derivation of Probabilistic Site Coefficients (신(新) 확률론적 지진분석 및 지진계수 개발 Part II: 확률론적 지진계수 도출)

  • Kwak, Dong-Yeop;Jeong, Chang-Gyun;Lee, Hyunwoo;Park, Duhee
    • Journal of the Korean GEO-environmental Society
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    • v.10 no.7
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    • pp.111-115
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    • 2009
  • In Korea, the probabilistically developed seismic hazard maps are used with deterministically derived seismic site coefficients in developing the design response spectrum of a specific site. Even though the seismic hazard maps and seismic site coefficients are incompatible, the current design code ignores such incompatibility. If the seismic hazard map and seismic coefficients are both developed in identical probabilistic framework, such problems can be solved. Unfortunately, the available method cannot be use to derive "true" probabilistic site coefficients. This study uses the ground motion time histories, which were developed as the result of a new probabilistic seismic hazard analysis in the companion paper, as input motions in performing one-dimensional equivalent linear site response analyses, from which the uniform hazard response spectra are generated. Another important characteristic of the hazard response spectra are that the uncertainties and randomness of the ground properties are accounted for. The uniform hazard spectra are then used to derive probabilistic site coefficients. Comparison of probabilistic and deterministically site coefficients demonstrate that there is a distinct discrepancy between two coefficients.

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