• Title/Summary/Keyword: Terrace

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Numerical Model for Predicting Sand Bar Formation around River Mouth (하구역의 사주 형성 예측을 위한 수치 모델)

  • Kuroiwa, Masamitsu;Matsubara, Yuhei;Suzuki, Yoko;Kuchiishi, Takayuki
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.26 no.2
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    • pp.96-102
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    • 2014
  • A three-dimensional beach evolution model was presented to predict morphodynamics around a river mouth. The presented model was based on the depth-averaged (2DH) and quasi three-dimensional (Q-3D) nearshore current modules, and the model took into account shoreline changes, the effect of advection diffusion of suspended load and discharged sediments from the river. First, the 3D beach evolution model was applied to the formation of sand spits and terrace at the river mouth in order to investigate the performance of the model. Secondly, the model was applied to the river mouth at the Ara River, facing the Sea of Japan. The formation of sand spit at the Ara River in winter season was reproduced. The computed result showed qualitatively agreement with field site observation.

Hwasan Wetland Vegetation in Gunwi, South Korea: with a Phytosociological Focus on Alder (Alnus japonica (Thunb.) Steud.) Forests (군위군 화산습지의 식생: 오리나무림을 중심으로)

  • Kim, Jong-Won;Lee, Seung-eun;Lee, Jung-a
    • Korean Journal of Ecology and Environment
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    • v.50 no.1
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    • pp.70-78
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    • 2017
  • The Hwasan wetland vegetation is observed at mountain basin (644~780 m a.s.l.) where had become a potential land for indigenous people since prehistoric period. We phytosociologically investigated old-growth alder (Alnus japonica) forests using the $Z\ddot{u}rich$-Montpellier School's method and analyzed their spatial distribution pattern by actual vegetation map. Species performance was determined by using coverage and r-NCD. Viburnum opulus var. calvescens-Alnus japonica community syntaxonomically belonging to the Alnetea japonicae was first described and composed of three subunits: Salix koreensis subcommunity, typical subcommunity, and Pyrus ussuriensis subcommunity. Present plant community was compared with vicariant syntaxa such as Molinia japonica-Alnus japonica community, Rhamno nipponicae-Alnetum japonicae, and Aceri-Salicetum koreensis. Hwasan's alder forest, an alluvial terrace vegetation type on valley fan in the montane zone, is evaluated as vegetation class [I], which is a sort of benchmark plant community potentially on mountain wetlands in southeastern part of the Korean Peninsula. Simultaneously we suggested an establishment of the national strategy for habitat conservation free from hydrologically radical transform due to military utilization.

A Study On the Classification and Characteristics of Wetlands - Cases on the Watershed of Tumen River downstream in China - (중국 두만강 하류 유역의 습지 분류 특성에 관한 연구)

  • Zhu, Wei-Hong;Kim, Kwi-Gon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.5 no.1
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    • pp.35-50
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    • 2002
  • This study aims to understand wetland distribution and type-specific classification features with a focus on Tumen River downstream in China by adjusting and improving the classification system used in Korea with a reference to international wetland classification systems and their criteria & methods. In this study, wetland types were determined based on hydrology, vegetation, and soil conditions, which are the most basic elements of wetlands. Also, topography analytical map, vegetation analytical map, and soil analytical map for wetland classification were developed and used based on currently available topography map, vegetation map, and soil map. In addition, codes were defined based on topography, location, hydrology, and vegetation. The result shows that, in the Tumen River downstream, wetlands are often found near natural revetment and terrace land & river-bed lakes. In the discovered wetlands, riverine, lacustrine, and inland wetlands were mostly found at system level. Riparian and human-made wetlands were also identified. At a sub-system level, perennial and seasonal wetlands were found to a similar degree. At a class level, perennial open water, herbal plants, and shrubs were mostly found and sandy plain, hydrophytes, and forest tree types were also observed. An overall detailed classification shows that a total of 17 wetland types were found and a large distribution of sand dunes and river-bed lakes, which are scarce in Northeast Asia, indicates that other rare wetland types such as palustrine seasonal sand plain wetland and lacustrine seasonal sand plain wetland may be discovered.

A Preliminary Study on Application of Alluvial Deposit in the Han River for Planting Soil (한강 퇴적토의 식재 토양 활용에 관한 기초연구)

  • Cho, Yong-Hyeon;Kim, Kap-Su
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.3 no.4
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    • pp.60-73
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    • 2000
  • The purpose of the study was to analyze the feasibility of the alluvial deposit deposited on upper terrace in Han River as a substitute for conventional plant soil. For this purpose, the soil characteristics were analyzed, and germination and growth rate of pansy and marigold for 75 days were investigated. Soil contamination level of all the samples, except mineral oil, was analysed under the legal contamination level, while some mineral oil was detected in almost samples at 2.0~32mg/kg. The measures of the soil texture (sandy loam or loam), organic matter (2.5~5.5%), available phosphate (22~98mg/kg), exchangeable cation of K (0.5~1.1cmol/kg), Ca (0.9~9.6cmol/kg), Mg (0.1~0.7cmol/kg), Na (0.7~3.1cmol/kg), CEC (3.1~24.3cmol/kg) were identified as not worse than those of conventional planting soil. But the pH (5.1~5.3) was detected slightly lower than the range (5.5~6.9) of average domestic field soil. The germination rate of pansy in alluvial deposit was lower than that of fertile field or paddy field soil, while the growth rate of pansy for 75 days in alluvial deposit was as good as that of the compared fertile soils. But the germination rate and growth rate of marigold in alluvial deposit were much poorer than those of marigold in compared fertile soils. Consequently, the feasibility of alluvial deposit as a substitute for planting soil was evaluated to be high.

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The Geomorphic Development of River Terraces along the Middle and the Lower Parts of the Osip-cheon River in Samchok City (三陟 五十川 중.하류부의 河岸段丘 지형발달)

  • 윤순옥;황상일;정석교
    • Journal of the Korean Geographical Society
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    • v.37 no.3
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    • pp.222-236
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    • 2002
  • The Osip-cheon river flowing on the east side of the Taeback mts. has formed river terraces on the several heights along the middle- and downstream. The river terraces are classified into 5 climatic ones and 7 thalassostatic ones. The thalassostatic ones are found to the height of 145-l50m level at 20-30m intervals. These vertical distribution is caused by the continuous uplift and periodical rise and fall of the sea-level. The high higher surfaces among the thalassostatic ones are the highest among those of Korea. The chronologies of the terraces are correlated to the marine oxygen isotope stages : The thalassostatic terraces on the level of 40 m.a.s.l. are to the stage 7, 70 m.a.s.l.. to the stage 9, 90 m.a.s.l. to the stage 9, 110 m.a.s.1. to the stage 11 and those of 150 m.a.s.1. to the stage 15 among the Interglacial Ages. The landuses and geomorphic landscapes of the Samchok area are chracteristic, because the karst landforms, such as doline and uvala, are developed on the surfaces of the middle-, the higher- and the high higher surfaces of river terrace.

Classification and Forming Processes of Low Relief Landforms in the Korean Peninsula (한반도 평탄지의 유형분류와 형성과정)

  • Park, Soo-Jin
    • Journal of the Korean Geographical Society
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    • v.44 no.1
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    • pp.31-55
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    • 2009
  • This research aims 1) to characterize the spatial distribution of low relief landforms (plains) via analyses of a Digital Elevation Model (DEM), 2) to classify plains according to morphological and genetic similarity, and 3) to develop a model to explain forming processes of plains in the Korean peninsula. Plains can easily be separated from high relief mountaneous areas by analyzing the DEM. The overall morphological and locational characteristics of plains can be categorized into lava plains, fluvial-marine plains, erosional plains, intermontane basins, and higher ground plains. It is concluded that the characteristic of each plain type is decided by base-level changes caused by tectonic uplift and sea-level changes, and topological relationship of different rock types. Different plain types do not exist independently, but connected with each others along stream networks. The model developed is able to combine the morphological characteristics of plains with the channel network to conceptualize characteristics and development pathways of plains in the Korean Peninsula.

Preparation of Atomically Flat Si(111)-H Surfaces in Aqueous Ammonium Fluoride Solutions Investigated by Using Electrochemical, In Situ EC-STM and ATR-FTIR Spectroscopic Methods

  • Bae, Sang-Eun;Oh, Mi-Kyung;Min, Nam-Ki;Paek, Se-Hwan;Hong, Suk-In;Lee, Chi-Woo J.
    • Bulletin of the Korean Chemical Society
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    • v.25 no.12
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    • pp.1822-1828
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    • 2004
  • Electrochemical, in situ electrochemical scanning tunneling microscope (EC-STM), and attenuated total reflectance-FTIR (ATR-FTIR) spectroscopic methods were employed to investigate the preparation of atomically flat Si(111)-H surface in ammonium fluoride solutions. Electrochemical properties of atomically flat Si(111)-H surface were characterized by anodic oxidation and cathodic hydrogen evolution with the open circuit potential (OCP) of ca. -0.4 V in concentrated ammonium fluoride solutions. As soon as the natural oxide-covered Si(111) electrode was immersed in fluoride solutions, OCP quickly shifted to near -1 V, which was more negative than the flat band potential of silicon surface, indicating that the surface silicon oxide had to be dissolved into the solution. OCP changed to become less negative as the oxide layer was being removed from the silicon surface. In situ EC-STM data showed that the surface was changed from the initial oxidecovered silicon to atomically rough hydrogen-terminated surface and then to atomically flat hydrogenterminated surface as the OCP moved toward less negative potentials. The atomically flat Si(111)-H structure was confirmed by in situ EC-STM and ATR-FTIR data. The dependence of atomically flat Si(111)-H terrace on mis-cut angle was investigated by STM, and the results agreed with those anticipated by calculation. Further, the stability of Si(111)-H was checked by STM in ambient laboratory conditions.

A Study on the Information of Landforms in the vicinity of the Hantan River (한탄강(漢灘江) 일대(一帶)의 지표기복(地表起伏)에 관한 정보(情報))

  • Kim, Joo-Hwan
    • Journal of the Speleological Society of Korea
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    • no.72
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    • pp.19-30
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    • 2006
  • The purpose of this study is to clarified the geology and geomorphic characteristics of the Hantan River Basin. In this area, some kind of landforms are developed such as pre-land forms, lava plateau, and present landforms etc. Some river terraces are peculiar features in the area. Some conclusions are as follows : The vicinity of the Hantan River is lava plateau formed from the volcanic activity. Some steptoes are located in the lava plateau. Baekeuiri formation means the river bed boulder beneath the lava formation. The development of drainage patterns are unstable and the bifurcation ratio, the ratio of mean length of the river are lower than the other rivers. The relative height of the terraces is about $5{\sim}25m$ and the terraces are alluvial terraces. In the Jiktang Fall area, bedrock is granite and basalt plateau covered the bedrock. In that point, the old erosion surface is relatively steeper than the horizontal-basalt plateau. Vertical columnar joints are developed and weathering materials creep on the valley wall. The cross section of the landform of the Kosukjung vicinities are somewhat different from the landforms of Jiktang Fall. The bedrock near the Kosukjung is granite that is the same with the Jiktang Fall. But the cross section shows a asymmetrical curve from each side.

A Study on Jean-Renaudie's Design Philosophy and Method for Urban Housing Project - Focusing on the City of Ivry-sur-Seine - (쟝 르노디의 도시 집합주거에 관한 디자인 철학과 방법에 대한 연구 - 이브리 쒸르쎈느 시의 집합주거를 중심으로 -)

  • Bae, Dae-Seung
    • Journal of architectural history
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    • v.21 no.4
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    • pp.93-106
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    • 2012
  • Jean Renaudie was an French architect who designed many urban social housing in France, especially in the city of Ivry-sur-Seine, near Paris, with Renee Gailhoustet, co-responsible as the architect of this city, communist city from long time. He was formed as an architect by the influence of Auguste Perret and Marcel Lods, two french architects, great specialist of the structure of concrete. He formed the Atelier Montrouge with Pierre Riboulet, Gerard Thurnauer, Jean-Louis Verret, and proposed many innovative projects, based on geometrically pure forms and masses. After he joined Renee Gailhoustet, the architect of the City of Ivry-sur-Seine, as a co-responsible for the redevelopment of this ideologically communist city. His urban housing concept approached to take the function as a space to welcome the urban life of the resident, not to offer the physical provision of housing repeating the simple housing unity. He accentuated the social role of Housing project not only as the level of a personal home but also as that of an urbanism. He offered divers choice opportunity to the citizen by the urban functional complex through his efforts to make characteristic complex of urban housing, and by the consequence, the innovative result was done which ameliorated the quality of life for resident. This is an exceptional example, not only in France but even in whole over the world. But the maintenance of building against the oldness and the closing shop of inside commercial zone of Jeanne Hachette became a problem, not only that of physical amelioration but also that of spiritual conservation of the works of Jean Renaudie.

A study on the building site excavated in the Oeseonmi-ri, Uljin (울진 외선미리 발굴 건물지에 관한 연구)

  • Kim, Chan-Yeung
    • Journal of architectural history
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    • v.16 no.2
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    • pp.79-98
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    • 2007
  • The building site was presumed as the Howonjeokwon or the Dasiwonji established at the traffic route among western inland areas in old Pyeonghaegun. The groundwork was composed inclination terrace of two steps. The upper step was the territory of the main house of ceremony symbolic+lodging function and the down step was divided in the territory of both Ikrang-chae of boarding and lodging management function and the territory of Haengrang-chae pavilion of rest reception management. The building composition by each territory formed space differentiation with the line of flow according to the thorough rule of court rank. The arrangement composition set the strong center axis in tandem, and it was the building arrangement interpreting the territory and the rule of court rank by function as the relationship of master and servant and was the building type emphasizing on the whole unity with the geometric symmetry structure. The Dasiwonji and the Hyeeumwonji had the common point which is the traffic architecture of semi governmental management reinforcing the boarding lodging function in the place which a visitor stayed. The Haeeumwonji and Dasiwonji had the difference in the size, but was the same in the composition system of construction. The external space and the system of the line of flow decided from the functional territory separation and the hierarchical rank as thorough as the geometric arrangement focusing on the whole unity. Namely, it was the strict and unusual system of the line of flow depended on the thorough rule of court rank than the efficient approach or arrangement of the line of flow. After being established to be the Howonjeokwon at the end of Koryeo, it disappeared at the time of the invasion of Japanese pirates when it was the time of the King Woo in Koryeo. It is presumed that it was continued until both wars, Imjin Byeongja, ago after changing its name to the Dasiwon, being restored to the small size at the end of Koryeo at the early of Choseon.

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