• Title/Summary/Keyword: geological hazards

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Physical Properties of Old Fluvial Aggregates in the Southeastern of Jeonnam Province, Korea (전남 동남부 지역에 부존하는 육상골재의 물성특성에 관한 연구)

  • Kim Ju Yong;Oh Keun Chang;Yang Dong Yoon;Hong Sei Sun;Chang Soo Bum;Lee Jin Young;Rim Hyun Soo
    • Economic and Environmental Geology
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    • v.38 no.3 s.172
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    • pp.319-334
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    • 2005
  • Some of old fluvial sediments are originally composed of fine and silty-clay grains with sands or some of them have been segregated by weathering as a result of the influence of groundwater fluctuations. For this reason, some of old fluvial sediments are not suitable for using as fine aggregates. Furthermore, the old fluvial aggregates with comparatively good quality have been exploited for a long time and quality of most remainders have been significantly poor. Though many old fluvial aggregates do not satisfy the quality controls(QC) standards such as KS F2526 and KS F 2527, they must be utilized to various usage suitable far different quality categories. Thus, we try to make constant efforts to utilize aggregates of all qualities. This study shows that physical properties of old fluvial aggregates are both controlled by source rocks and also related to old fluvial environment.

Soil Properties regarding Geological Conditions in Landslides area (산사태 발생지역에서의 지질조건별 토질특성)

  • Song, Young-Suk;Kim, Won-Young;Chae, Byung-Gon;Kim, Kyeong-Su
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.884-889
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    • 2005
  • A lot of landslides were occurred in Gangnung, Macheon and Geochang areas by Typhoons such as RUSA(2002) and MEAMI(2003). Soil properties of these areas are investigated regarding geological conditions in this study. The shallow plane failure were occurred in Gangnung and Geochang areas, whereas the deep circle failure were occurred in Macheon area. The matrix in Gangnung and Geochang areas was composed of Granite, and the matrix in Macheon area was composed of Gabbro. The disturbed and undisturbed soils were sampled in these areas. As the results of laboratory tests using sampled soils, the coefficient of permeability in Granite region is lower than that in Gabbro region. In the cases that the silt and clay contents are included less than 4% for the soils of Granite region and less than 7% for the soils of Gabbro region, the coefficients of permeability are rapidly increased for both soils. In addition, the simple equations for predicting the coefficients of permeability are proposed using the effective particle size and the silt and clay contents according to geological condition.

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Consideration for the Highest Temperature Point Movement of the Dongrae Thermal Water in the Pusan Area. (Poster)

  • Kim Tong-Kwon;Lee Jin-Soo;Lee Seung-Gu;Song Yoon-Ho;Kim Tack-Hyun
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2005.10a
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    • pp.158-159
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    • 2005
  • This study showed that the highest temperature point of the Dongrae thermal spring in Pusan was moved to the north direction of the Dongrae fault as times goes by. The Br concentration(1.5mg/L) in Dongrae thermal waters indicated the influence of 2% seawater mixing. If the simple mixing without hydrochemical reaction occurs between seawater and thermal water, the concentration of Mg will be about 20mg/L. But the low concentration(0.1 mg/L) of Mg, contrary to high concentration(10 mg/L) of surrounding groundwater not affected by thermal water, suggested the thermal water, seawater and rock interactions. The calculation of saturation index(SI) by using the geochemical code of EQ3NR showed that the Mg in thermal groundwater, which was introduced by seawater, was removed by the precipitation of Antigorite (SI: log Q/K =71.753, $Mg_{48}Si_{24}O_{85}(OH)_{62}$) and Tremolite (SI: 8.463, $Ca_2Mg_5Si_8O_{22}(OH)_2$), Talc (SI: 6.409, $Mg_3Si_4O_{10}(OH)_2$), Dolomite (SI: 2.014, $CaMg(CO_3)_2$), Chrysotile (SI: 3.698, $Mg_3Si_2O_5(OH)_4$) in the crack of fault zone. The highest temperature point in the study area will move to north direction and stop in the Jangjun area without the input of seawater.

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Slope Management Program of Available to an Urban Area (대도시지역에 적합한 사면관리프로그램)

  • Kim, Kyeong-Su;Cho, Yong-Chan;Chae, Byung-Gon;Song, Young-Suk;Lee, Choon-Oh
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.644-651
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    • 2006
  • In general, a damage that occurs due to landslide or slope failure in urban areas is larger than that in rural areas. In order to reduce the damage, a program is necessary to categorize slopes based on properties and to manage them systematically. Based on the above necessity, a slope management program which is applicable to slope management in an urban area has been developed at Hwangryung mountain in Busan as a target area. The program has a function of systematic slope information constructed by slope ID number of each slope or sub-region of a mountain, making a slope data sheet, analysis and grouping of slope stability, and establishment of a data base. It can also be utilized practically by end users due to the convenient input, edition, printing, management and operation of slope data. For practical utilization of the developed program, a research related to construction of the slope management system for a regional area is demanded to be performed continuously. The supply and utilization of a web based slope management system would contribute to damage reduction.

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Urban geology of Tabriz City: Environmental and geological constraints

  • Azarafza, Mohammad;Ghazifard, Akbar
    • Advances in environmental research
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    • v.5 no.2
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    • pp.95-108
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    • 2016
  • Urban geology is the study of urban geologic environments to provide a scientific basis for rational land use planning and urban development and provides information on geologic environments as a basis for city planners. Based on AEG recommendations, urban geological studies covered the urbanism and historical backgrounds, geological setting, engineering geological constraints and environmental assessments of understudied cities. The aim of this study is to provide a good view of urban geology of Tabriz city the capital of East Azerbaijan province in Iran. The topics of discussions about Tabriz city urban geology are included geologic (geomorphology, geology, climatology and hydrogeology), engineering geological (earthquake, landslide and geotechnical hazards investigations) and environmental characteristics (air, soil and water hazards assessment).The results of the urban geologic studies indicated that Tabriz city in terms of engineering geological and environmental constraints is at high risk potential and in terms of seismic activity and landslide instability is highly potential. In terms of air, soil and water pollution there are many important environmental concern in this city.

Geometric Characteristics of Landslides on Natural Terrain according to the Geological Condition (지질조건에 따른 자연사면 산사태의 기하학적 특성)

  • Kim, Kyeong-Su;Song, Young-Suk;Chae, Byung-Gon;Cho, Yong-Chan;Lee, Choon-Oh
    • The Journal of Engineering Geology
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    • v.17 no.1 s.50
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    • pp.75-87
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    • 2007
  • The recognitions of geometrical characteristics and occurrence conditions are very important to evaluate the land-slides in natural terrains. In this paper, the geometrical characteristics of landslides are analyzed according to a geo-logical condition in three landslides areas. The three landslides areas are classified to the geological condition. The three landslides areas are Jangheung, Sangju and Pohang. The geology of Jangheung area, Sangju area and Pohang area is gneiss, granite, and the tertiary sedimentary rock, respectively. During a heavy rainfall of $150{\sim}588mm$ in these areas, 1,582 landslides have occurred in 1998. The geometrical characteristics according to the geological condition analyzed from the investigation of these landslides. The frequency of landslide is high exceedingly above 90% of a slope attitude, while the frequency is very low below 70%. The frequency of landslide is high exceedingly between $26^{\circ}$ and $30^{\circ}$ of slope angle, while the frequency is very low below $20^{\circ}$. The size of the landslides is ranged from several tens to several hundreds The length is ranged from 5 m to 300 m, and the width is ranged from 3 m to 50 m. Also, the depth is less than 1 m. Therefore, the landslides in these areas have small width, long length and shallow depth. The type of the landslides is changed from transitional slide at the scarp to debris flow at the low part of slope.

Analysis of Landslide Hazard Probability for Cultural Heritage Site using Landslide Prediction Map (산사태예측도에 의한 석조문화재 주변의 산사태재해 가능성 분석)

  • Kim, Kyeong-Su;Lee, Choon-Oh;Song, Yeung-Suk;Cho, Yong-Chan;Kim, Man-Il;Chae, Byung-Gon
    • The Journal of Engineering Geology
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    • v.17 no.3
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    • pp.411-418
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    • 2007
  • It is a very difficult thing to estimate an occurrence possibility location and hazard expectation area by landslide. The prediction difficulty of landslide occurrence has relativity in factor of various geological physical factors and contributions. However, estimation of landslide occurrence possibility and classification of hazard area became available correlation mechanism through analysis of landslide occurrence through landslide data analysis and statistical analysis. This study analyzed a damage possibility of a cultual heritage area due to landslide occurrence by a heavy rainfall. We make a landslide prediction map and tried to analysis of landslide occurrence possibility for the cultural heritage site. The study area chooses a temple of Silsang-Sa Baekjang-Am site and made a landslide prediction map. In landslide prediction map, landslide hazard possibility area expressed by occurrence probability and divided by each of probability degrees. This degree used to evaluate occurrence possibility for existence and nonexistence of landslide in the study site. For the prediction and evaluation of landslide hazard for the cultural heritage site, investigation and analysis technique which is introduced in this study may contribute an efficient management and investigation in the cultural heritage site, Korea.

Online preconcentration and preelutioin for the ion chromatographic determination of trace anions in high-sulfate wastewater

  • Song, Kyung-Sun;Kim, Sang-Yeon;Cheong, Young-Wook
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2005.05a
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    • pp.327-328
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    • 2005
  • Trace anions in high-sulfate wastewater from mainly derelict mines were determined by ion chromatography with on-line preconcentration and preelution technique. As the sample was preconcentrated and more strongly held ions were preeluted to the principal separation system, this approach was highly effective in removing large concentration of sulfate in high-sulfate wastewater. With this practical on-line preelution treatment, the peaks of fluoride and chloride showed good resolution even when the sulfate concentration was as high as 2000 mg/L and the analyzed total metal concentration was above 500 mg/L.

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Significance of biogenic silica on paleoenvironmental studies in South Korea

  • Orkhonselenge, A.;Yang, D.Y.;Nahm, W.H.
    • The Korean Journal of Quaternary Research
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    • v.22 no.1
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    • pp.23-27
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    • 2008
  • Paleoenvironmental evolution in South Korea is investigated on the basis of fluctuations in biogenic silica content in sediments from Cheollipo coast on western shore. The biogenic silica measurement was done by alkaline extraction technique. The concentration of the biogenic silica in the Cheollipo coastal sediments is generally low, with an average of 1.2 %. The proxy of biogenic silica records in Cheollipo sediments implies the significant difference of bio-productivity on Korean Peninsula in comparison with those in lacustrine sediments in interior terrestrial continent of the Eurasia.

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Evaluating comparisons of geological hazards in landslides using fuzzy logic methods and hierarchical analysis

  • Shasha Yang;Maryam Shokravi;H. Tabatabay
    • Steel and Composite Structures
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    • v.48 no.5
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    • pp.499-505
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    • 2023
  • Geological hazards in landslide is one of the most extensive and destructive phenomena are among natural disasters. According to the topography high mountains, tectonic activity, high seismicity, diverse conditions Geology and climate, basically China to create a wide spectrum of landslides have natural conditions and these landslides are annual. They cause a lot of financial losses to the country. It is very difficult to predict the time of the landslide, hence the identification landslide sensitive areas and zoning of these areas based on the potential risk is very important. Therefore, it should be susceptible areas landslides should be identified in order to reduce damages caused by landslides find. the main purpose of landslide sensitivity analysis is identification high-risk areas and as a result, reducing damages caused by landslides It is the way of appropriate actions.