• Title/Summary/Keyword: Landforms

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Extraction of Lineament and Its Relationship with Fault Activation in the Gaeum Fault System (가음단층계의 선형구조 추출과 선형구조와 단층활동의 관련성)

  • Oh, Jeong-Sik
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.2
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    • pp.69-84
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    • 2019
  • The purpose of this study is to extract lineaments in the southeastern part of the Gaeum Fault System, and to understand their characteristics and a relationship between them and fault activation. The lineaments were extracted using a multi-layered analysis based on a digital elevation model (5 m resolution), aerial photos, and satellite images. First-grade lineaments inferred as an high-activity along them were classified based on the displacement of the Quaternary deposits and the distribution of fault-related landforms. The results of classifying the first-grade lineaments were verified by fieldwork and electrical resistivity survey. In the study area of 510 km2, a total of 222 lineaments was identified, and their total length was 333.4 km. Six grade lineaments were identified, and their total length was 11.2 km. The lineaments showed high-density distribution in the region along the Geumcheon, Gaeum, Ubo fault, and a boundary of the Hwasan cauldron consisting the Gaeum Fault System. They generally have WNW-ESE trend, which is the same direction with the strike of Gaeum Fault System. Electrical resistivity survey was conducted on eight survey lines crossing the first-grade lineament. A low-resistivity zone, which is assumed to be a fault damage zone, has been identified across almost all survey lines (except for only one survey line). The visual (naked eyes) detecting of the lineament was evaluated to be less objectivity than the automatic extraction using the algorithm. However, the results of electrical resistivity survey showed that first-grade lineament extracted by visual detecting was 83% reliable for inferred fault detection. These results showed that objective visual detection results can be derived from multi-layered analysis based on tectonic geomorphology.

Prediction and Verification of Distribution Potential of the Debris Landforms in the Southwest Region of the Korean Peninsula (한반도 서남부 암설사면지형의 분포가능성 예측 및 검증)

  • Lee, Seong-Ho;Jang, Dong-Ho
    • Journal of The Geomorphological Association of Korea
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    • v.27 no.2
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    • pp.1-17
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    • 2020
  • This study evaluated a debris landform distribution potential area map in the southwest region of the Korean peninsula. A GIS spatial integration technique and logistic regression method were used to produce a distribution potential area map. Seven topographic and environmental factors were considered for analysis and 28 different data set were combined and used to get most effective results. Moreover, in an accuracy assessment, the extracted results of the Distribution Potential area were evaluated by conducting a cross-validation module. Block stream showed the highest accuracy in the combination No. 6, and that DEM (digital elevation model) and TWI (topographic wetness index) have relatively high influences on the production of the Block stream Distribution Potential area map. Talus showed the highest accuracy in the combination No. 13. We also found that slope, TWI and geology have relatively high influences on the production of the Talus Distribution Potential area map. In addition, fieldwork confirmed the accuracy of the input data that were used in this study, and the slope and geology were also similar. It was also determined that these input data were relatively accurate. In the case of angularity, the block stream was composed of sub-rounded and sub-angular systems and Talus showed differences according to the terrain formation. Although the results of the rebound strain measurement using a Schmidt's hammer did not shown any difference in topographic conditions, it is determined that the rebound strain results reflected the underlying geological setting.

Geo-educational Values of the Jebudo Geosite in the Hwaseong Geopark, Korea (화성 지질공원 제부도 지질명소의 지질교육적 가치)

  • Ha, Sujin;Chae, Yong-Un;Kang, Hee-Cheol;Kim, Jong-Sun;Park, Jeong-Woong;Shin, Seungwon;Lim, Hyoun Soo;Cho, Hyeongseong
    • Journal of the Korean earth science society
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    • v.42 no.3
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    • pp.311-324
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    • 2021
  • Recently, ten geosites have been considered in Hwaseong for endorsement as national geoparks, including the Jebudo, Gojeongri Dinosaur Egg Fossils, and Ueumdo geosites. The Jebudo geosite in the southern part of the Seoul metropolitan area has great potential for development as a new geoscience educational site because it has geological, geographical (landscape), and ecological significance. In this study, we described the geological characteristics through field surveys in the Jebudo geosite. We evaluated its potential as a geo-education site based on comparative analysis with other geosites in Hwaseong Geopark. In addition, we reviewed the practical effect of field education at geosites on the essential concepts and critical competence-oriented education emphasized in the current 2015 revised science curriculum. The Jebudo Geosite is geologically diverse, with various metamorphic rocks belonging to the Precambrian Seosan Group, such as quartzite, schist, and phyllite. Various geological structures, such as clastic dikes, faults, joints, foliation, and schistosity have also been recorded. Moreover, coastal geological features have been observed, including depositional landforms (gravel and sand beaches, dunes, and mudflats), sedimentary structures (ripples), erosional landforms (sea cliffs, sea caves, and sea stacks), and sea parting. The Jebudo geosite has considerable value as a new geo-education site with geological and geomorphological distinction from the Gojeongri Dinosaur Egg Fossils and Ueumdo geosites. The Jebudo geosite also has opportunities for geo-education and geo-tourism, such as mudflat experiences and infrastructures, such as coastal trails and viewing points. This geosite can help develop diverse geo-education programs that improve key competencies in the science curriculum, such as critical thinking, inquiry, and problem-solving. Furthermore, by conducting optimized geo-education focused on the characteristics of each geosite, the following can be established: (1) the expansion of learning space from school to geopark, (2) the improvement of understanding of specific content elements and linkage between essential concepts, and (3) the extension of the education scope throughout the earth system. There will be positive impacts on communication, participation, and lifelong learning skills through geopark education.

Development of Depositional Landforms in Upstream Reach of Ulsan Sayeon Dam Lake (울산 사연호 상류의 퇴적지형 발달)

  • Chang, Mun-Gi
    • Journal of the Korean association of regional geographers
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    • v.13 no.4
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    • pp.409-421
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    • 2007
  • The purpose of this paper is to consider the formation processes and depositional conditions of bars formed at the upper-stream part of Sayeon Dam since Sayeon Dam construction in 1964. Results of analyzing the shape characteristics of bars and their sediment grain size distribution are as follow: Firstly, bars are able to categorized as subaqueous bars (A, B), mid-channel bars(C, D), and tributary side-bars(E). Secondly, the outline of bars has longish along the flow path, and their height lowers more and more going towards downstream. Also the height of bar surface tend to heighten from flow path to mountain slope. However, the near part of A is comparatively higher than its distant part, A is defined as a subaqueous natural levee and back swamp. Thirdly, the average particle size of A and B become smaller toward mountain slope. In transportation style, ratio of suspended load become higher toward mountain slope. Fourthly, sorting is worse to very worse according with lake's random changable water level. Fifthly, bar A and B were formed by vertical sedimentation of sediments according as sediments transported along flow path in the subaqueous conditions were spreaded out of flow path. C and D were formed by bed load as flood level lowered. And E was formed by vertical sedimentation while stream flow stopped in tributary's mouth areas with the water level heightening.

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Transformation of Discourse on Uses of Computer Technology in Korean Landscape Architecture - Focused on Journal of the Korean Institute of Landscape Architecture and Environmental & Landscape Architecture of Korea - (한국 조경에서 컴퓨터 테크놀로지의 활용에 관한 담론의 변천 - 『한국조경학회지』와 『환경과조경』을 중심으로 -)

  • Lee, Myeong-Jun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.48 no.1
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    • pp.15-24
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    • 2020
  • This work examines discourse on uses of computer technology and its transformation during the last thirty years effecting Korea landscape architecture. First, in the 1990s landscape architects begun to use computers as a new technology for landscape architecture, programming computer software utilities suitable for landscape research, planning, and design. The landscape architects, acting as computer programmers, tried to explore various techniques for landscape analysis and design with a piece of software, and various experts within the field of landscape architecture collaborated with each other. However, landscape architects mainly used computer technology as a tool as a substitute for hands-on cases. Since around the 2000s, the discourse on mapping and diagrammatic techniques as a visualization technique for landscaping processes have begun. Also, realistic representations for perspective drawings using graphic software have been increasingly important. The landscape architects, acting as graphic designers, focused on the specific visualization techniques for landscape planning and design. However, computer technology has been mainly used to produce realistic visuals aids for final presentations instead of creative exploration to generate landforms. Additionally, recent landscape architects have been using landscape performance modeling and parametric modeling for landform and landscape furniture design. The landscape architects as spatial designers are actively using computer modeling as creative form-generating tools during the design process.

Analysis of the Geomorphological Environments of High-Density Residential Zone in Bronze Age around Asan City, Central Korea - A Case Study of Yongdoocheon and Onyangcheon Basin - (충남 아산의 청동기 시대 주거지 밀집 구역의 지형환경 분석 - 용두천과 온양천 유역을 사례로 -)

  • Park, Ji-Hoon;Park, Jong-Chul
    • Journal of the Korean Association of Geographic Information Studies
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    • v.14 no.3
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    • pp.110-125
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    • 2011
  • A number of the Bronze Age dwelling sites have been found and excavated in the Yoodoocheon, Onyangcheon and Baekseokdong basins. Two basins are located near Asan and Onyan in the Chungnam Province of South Korea. Baekseokdong is located in Cheonan, Chungnam. 207 dwelling sites are concentrated around the area of $1.3km^2$ in the Baekseokdong. 177 dwelling sites are sparse and distributed over the area of $1.3km^2$ in the Yongdoocheon and Onyangcheon basins. Most of the Bronze Age dwelling sites in those areas located on the hill. The hills have similar geomorphological environments except for slight differences in geological faces. This study analyzes geomorphological environments of the high-density residential zone of the Bronze Age in the Yoodoocheon and the Onyangcheon basins, and then compares them with the results in Baekseokdong. Study results show that high-density residential zone consists mainly of specific micro-landforms such as the Crest slope, the Crest flat and the Upper side slope, and southeast-facing aspect. A lot of Gentle slope lands were distributed in terms of terrain slope but it is far from specific geomorphological environments. This is not weighted in specific value. Our results show that the geomorphological characteristic derived from this study is major considerations to develop dwelling sites in the Bronze Age. This can be useful to discover the possible dwelling sites over other Chungnam hill regions.

A Study on the Geomorphology and Activity of Jinbu Fault in Pyeongchang-gun, Gangwon Province (강원도 평창군 진부 단층의 지형 및 활동성)

  • Lee, Gwang-Ryul;Cho, Young-Dong;Kim, Dae-Sik
    • Journal of the Korean Geographical Society
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    • v.43 no.6
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    • pp.775-790
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    • 2008
  • This study shows possibility of active fault, throughout analyzing distributional features of tectonic and fluvial geomorphology and mineral composition of fault fracture clay, at Jinbu fault-line system in Pyeongchang-gun, Gangwon Province. Fault-line valley was formed remarkably in the upper reaches of Odae River and upper reaches of Yeongok River according along Jinbu fault-line. Landforms show rectilineal distribution at right shore slopes of Odae River in Ganpyeong-ri, southern zone of Jinbu fault-line system, related to the tectonic processes, such as triangular facet, kernbut, kerncol and alluvial fan. Fault fracture clay zones were developed at 5 outcrops($jbf1{\sim}5$), located in kerncol. Particularly, jbf1 fault outcrop, developed at granite saprolite, has obvious fault plane and fault clay composed of illite and laumontite. The Jinbu Fault-line along jbf4-2-3-5 may be formed by regional compressive stress, and jbf1 fault may be suggested a tributary fault of the Jinbu fault-line formed before the late Pleistocene. The vertical displacement of the east and west blocks of the Jinbu Fault-line is estimated in $0.024{\sim}0.027m/ka$.

Geomorphological Approach in Geological Mapping of the Miocene and Post-Miocene Formations in the Albudeite Area, Spain (동남(東南) Spain Albudeite 지역(地域)의 Miocene및 Post-Miocene Formation에 대한 지질조사(地質調査)에 있어서의 지형학적(地形學的)인 접근(接近))

  • Yun, Suckew
    • Economic and Environmental Geology
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    • v.6 no.3
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    • pp.171-182
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    • 1973
  • Gemorphological and photogeological techniqes are applied to the problem of geological mapping of a semi-arid area, Albudeite, Southeastern Spain. As a result of this, a geological and surface materials map is made which shows the upper Miocene formation, which mainly consists of marl, limestone and sandstone, is further subdivided into three members, i. e. lower, middle and upper, and the post-Miocene deposits were differentiated into seven stratigraphic units, and mapped. The relationships between geology, landforms and land comlexes previously reognized have been reviewed. The methods adopted have proved to be valuable in interpreting and mapping a compex relationship in which highly variable bedrock outcrops and shallow surface materiales produced under sub-aerial conditios.

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The Characteristics and Expression of Landform in Feng-shui Map on Genealogical Table in the Choson Dynasty (조선시대 족보(族譜)에 게재된 산도(山圖)의 특성과 지형표현 - "기계유씨족보(杞溪兪氏族譜)"와 "반남박씨세보(潘南朴氏世譜)"를 중심으로 -)

  • Lee, Hyung-Yun;Sung, Dong-Hwan
    • Journal of the Korean association of regional geographers
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    • v.17 no.1
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    • pp.40-57
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    • 2011
  • A feng-shui map is a kind of map that features such propitious positions as fortune-bringing spots or ideal grave sites. The map is a representation of the most ideal natural terrains in terms of feng-shui perspectives. This study did research on two feng-shui maps registered on some genealogical tables in order to see how the map was drawn up. In addition, the detailed characteristics of landform expressions like the frame of the map, viewpoints, center-oriented mapping, water flow, mountain theories were delved into. The results of the research are as follows: the feng-shui maps for this research used the techniques of double scale and aerial view, described terrains with grave sites in their centers, and enlarged important terrains compared with surroundings for exaggeration purposes. In addition, other vital landforms not observed from grave sites were depicted with viewpoints moved and were represented in fine details. The part of mountain theories had the following points as their main subject matter: geographical locations, overall orientations of mountain ranges, topographical traits, grave seat directions and surrounding terrains.

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Landform Changes of Terminal Area of the Nagdong River Delta, Korea (낙동강 삼각주 말단의 지형 변화)

  • 오건환
    • The Korean Journal of Quaternary Research
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    • v.13 no.1
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    • pp.67-78
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    • 1999
  • In present, the terminal area of the Nagdong River Delta consists of micro-depositional landforms with sand barrier islands, sand bars and tidal flats which are arranged parallel to the present shoreline, and have rapidly shifted toward sea during last 100 years due to human activities such as construction of estuary dam, industrial complex and residential area. To clarify the landform changes of the area, the author traced the morphologic change pattern based on interpretation of air-photos, topographic maps and old Korean traditional map, and the results are as follows ; Based on the Daedongyeojido, one of the old Korean map, published in 1861, the area including upper part of the delta was underlying by sea level except two larger sand barriers, which means the Nagdong River Delta was not completely formed as the present outline of morphology by 1860s. According to the topographic map(1 :50,000) of 1916, the delta resembled to the present morphology pattern was exposed in 1916, and at this time the area was mainly composed of one sand barrier island, four sand bars and tidal flats, which had slowly elongated southwards before construction of the Nagdong River Estuary Dam in 1987. But after 1987, the area has been rapidly and drastically shifted southwards in arrange with one chain of sand barrier islands (Elsugdo -Myeonghodo-Sinhodo ) and four chains of sand bars (first chain ; Jinwoodo -Daemadeung-Maenggeummeorideung, second chain : Jangjado-Baeghabdeung, third chain ; Saedeung-Namusitdeung, fourth : Doyodeung-Dadaedeung) parallel to shoreline. This rapid landform change of the area is now occurring, and is seemed to ascribed firstly, to the construction of the Nagdong River Estuary Dam on Elsugdo in 1987, the Sinho Industrial Complex on Sinhodo and Myeongji Residential Area on Myeonghodo in 1992, secondly, to artificial alteration of drainage channel and consequential breakdown of former energy system between riverflow and tidal-and wave-energy. From these facts, it is inferred that the landform change pattern of the area will continue until a new equilibrium between the factor available to this energy system is accomplished.

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