• Title/Summary/Keyword: Landforms

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A Preliminary Geomorphic Overview of Late Quaternary Glacier Fluctuations in the South Shetland Islands, West Antarctica (서남극 남쉐틀랜드 군도의 제4기 후기 빙하 활동의 지형학적 고찰)

  • Lim, Hyoun-Soo;Yoon, Ho-Il;Lee, Yong-Il;Kim, Yea-Dong;Owen Lewis A.;Seong, Yeong-Bae
    • Journal of the Korean Geographical Society
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    • v.41 no.5 s.116
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    • pp.513-526
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    • 2006
  • The timing and extent of glaciations during the Late Quaternary in the South Shetland Islands, West Antarctica were defined using field mapping, geomorphic analysis and radiocarbon dating. Landforms of glacial erosion and deposition, in particular subglacial meltwater channel erosion, suggest that at least three glaciations occurred during the late Quaternary within the study region. During the global LGM, glacial troughs (such as Maxwell Bay and Admiralty Bay) were overdeepened by an ice stream moving south from $an\sim1000m-thick$ ice cap centered on the present-day continental shelf to the north. This ice was responsible for the subglacial meltwater channel erosion, and glacial polished and striated bedrock on the Fildes Peninsula. The recent local glaciations occurred about 2,000 years ago and during Little Ice Age (LIA). During these glaciations, glaciers were less extensive than the previous one and less erosive as a cold-based ice

Geomorphological Processes of Fluvial Terraces at the River Basins in the East Coast in the Southern Taebaek Mountain Range (태백산맥 남부 동해안 하천 유역의 하안단구 지형 형성)

  • Lee, Gwang-Ryul
    • Journal of the Korean Geographical Society
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    • v.49 no.1
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    • pp.1-17
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    • 2014
  • This study estimates geomorphological processes of fluvial terraces by uplifts and bedrock features, by the analyses of topography, distribution, formation age and incision rate of fluvial terraces using Gwang-cheon River in Uljin, Namdae-cheon River in Pyeonghae and Osip-cheon River in Yeongdeok located in the southern Taebaek Mountain Range. The tectonic and climatic terraces I in the upper reaches of Gwang-cheon River with an altitude from riverbed of 9~12m indicate the formation age of MIS 2 with a incision rate of 0.40m/ka. However, the tectonic and climatic terraces I in the upper reaches of Osip-cheon River with an altitude from riverbed of 7~10m show the formation age of MIS 3 with an incision rate of 0.10m/ka. These results suggest that the uplift rate in the Gwang-cheon River basin is likely to be higher than that in the Osip-cheon River basin. Unlike the lower reaches of Osip-cheon River, the thalassostatic terraces are not found in the lower reaches of Gwang-cheon River, because the basin has low maintainable ability of landforms in river valley due to high uplift rate and bedrock properties resistant to weathering and erosion. On the other hand, the lowest tectonic and climatic terraces in the study areas indicate different formative ages and the terraces during the cooling stage in interglacial as well as during interstadial are also found. Therefore, this study suggests that chronological method for fluvial terrace by the previous developmental model of climatic terrace should be reconsidered.

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Geomorphic Processes of the Terraces at Lower Reach of Yeongpyeong River in Chugaryeong Rift Valley, Central Korea (추가령 열곡 영평천 하류 단구지형의 형성과정)

  • Lee, Min-Boo;Lee, Gwang-Ryul;Kim, Nam-Shin
    • Journal of the Korean Geographical Society
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    • v.40 no.6 s.111
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    • pp.716-729
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    • 2005
  • In the Yeongpyeong River, one of the branches of Hantan River, there 4 fluvial terraces are identified. During the Quaternary, lava flow from Hantan River had gone 4.5km into upstream Part of the Yeongpyeong River and damed its entrance, and resultantly its lower basin had become a lava-damed paleolake. This study deals with fluvial terrace surface classification, stratigraphic analysis, deposits analysis, and OSL age dating in from Gungpyeongri to Seongdongri in lower reach of Yeongpyeong River, in order to identify Seomorphological Process of the terrace landforms relating to duration of lava-damed paleolake. Terrace surface T4, named Baekeuiri Formation, has been located under Jeongok lava layer to indicate pre-lava river bed. Terrace surfaces T3 and T2 are supposed to be formed during paleolake time, based on $3{\~}4m$ thick sand deposits including pebble and cobble layers, and clay and silt layers intersected with sand ones in nearly horizontal bedding. Terrace T1 is estimated to be formed as post-lake fluvial terrace after dissection of lava dam, based on the more fresh phase of deposits and very low height from present riverbed. The results of the OSL age dating for the T3 deposit layers indicate approximately $33{\~}40ka$, and still lake phase at that time.

Prospect Behavior in the Analysis of Kyumjae Chung Sun's One Hundred Scenes from the Real Landscape Painting (겸재 정선의 진경산수화에 나타난 조망행동 - 진경산수화 100엽을 대상으로 -)

  • 강영조;배미경
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.5
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    • pp.1-15
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    • 2002
  • The purpose of this study is to consider the relationship between point of view and prospect behavior occurring in the experience of a painted landscape. This study analyzes one hundred scenes from the 'real landscape painting' by Kyumjae, one of the most famous landscape painters in 18th century Korea. The results of the study are as follows: 1. It clarified that Kyumjae's real landscape painting's 100 scenes have many view points such as roads, bridges, pavilions, mansions, towers, terraces, hillsides, bases of mountains, broad flat roots, brooksides, and ferries that are apt to occur in the experience of a landscape. The spatial characteristics of view points are expanded fields of vision, evening and night scenes, edges of landforms and structures from which to improve ones vantage point. 2. It showed that 99 out of real landscape painting's 100 scenes depict a view point'to look'and 79 of 'to look through', 73 of 'look around'and 24 of 'to look over'. 3. It showed that real landscape painting's 100 scenes depict that the view point 'to look' is mainly upon a road from which people are looking over an elevated landscape such as the top of a mountain or rockwall. The view behaviors of looking down are depict 15 pavilions, 14 mansions, 2 broad rocks and 10 mountain tops on which people experience landscapes such as fields, rural communities and streams. The view behaviors to look depict 33 ships, 24 roads, 24 pavilions, 19 mansions and 12 terraces on which people experience landscapes such as distant views of mountains, rivers and landscapes. The view behaviors to look around to obtain orientation of landscape are depict 16 pavilions, 10 mountaintops. To glimpse on the way of journey depict 33 ships and 29 roads. To look over depict 11 mansions and 6 pavilions on which experience borrows the landscape. To look through landscapes such as rivers, mountains and rockwalls depict 15 roads, 14 pavilions and 11 mansions. To exchange looks depict 30 ships, 14 roads, 12 pavilions and 12 mansions. We expect that these results might give clues toward the experience of landscapes and the practice of landscape design methods which select viewpoints, and in the design of view points suitable to prospect behaviors.

Analysis of Fluvial Terraces at Kohyun River in Youngcheon City (경북 영천시 고현천의 하안단구 지형 분석)

  • Cho, Young-Dong;Lee, Gwang-Ryul
    • Journal of the Korean Geographical Society
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    • v.44 no.4
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    • pp.447-462
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    • 2009
  • Kohyun River basin is located at southern parts of Taebaek Mountains and most of river basins consists of sedimentary rock. The aims of this study are to investigate the distribution characteristics and processes of fluvial terraces at Kohyun River, using scientific methods such as classification of fluvial landforms, analysis of geomorphological deposits, XRD and OSL age dating. In Kohyun River basin are three levels terraces from T1 to T3. Fluvial terraces are assumed to be erosional terraces according to deposited situation of alurium and existences of bedrock riverbed. From the result of OSL age dating, formation age of fluvial terrace 1(T1) is calculated about 37,000 yr.B.P.(MIS 3), and fluvial terrace 2(T2) is calculated about 113,000 yr.B.P.(MIS 5). Therefore, fluvial terraces at Kohyun River are assumed to be formed at warmer period in the glacial stages or cooler period in the interglacial stages. The incision rate of fluvial terrace 1 at Kohyun River is calculated to be 0.054m/ka, and the incision rate of fluvial terrace 2 is calculated to be 0.115m/ka. This results suggest to lower incision rate than other rivers in Korea because of low uplift rates and little discharge.

Formation processes of low river terraces in Korea (우리나라 저위하안단구(低位河岸段丘)의 형성요인)

  • Son, Myoung-Won
    • Journal of the Korean association of regional geographers
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    • v.7 no.2
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    • pp.71-81
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    • 2001
  • According to the change of stream power/resisting power relationship due to the crustal movement or the climatic change, most channel landforms which reflect the equilibrium state of fluvial system are eroded and a part of them is remained as a river terrace. In many rivers in Korea are extensively distributed the relatively younger low river terraces. But their accurate formation mechanism is not known. In this paper, the formation processes and the dating of low river terraces distributed in Nakdong River basin will be investigated. Stream power of the downward erosion was revived because the sea level fell down. So stream power was superior to the resisting power under the cool-wet climatic condition during the last glacial period. Thus the river bed was excavated deeply, so that low river terraces were built up. And many incised meander loops were cut during this period. But, when fluvial system did not have equilibrium over all reaches, the last glacial period ended and the sea level initiated to rise rapidly. The headward erosion from the fall of sea level during the last glacial period had kept up to Hagye Fall because of the cutting of incised meander loops. Deeply excavated valleys and abandoned channel of cut-meander in lower reaches of a stream were filled with sediments. Thus the longitudinal profile of the uppermost reaches reflect the last interglacial, the upper reaches the last glacial, and the middle/1ower reaches recent fluvial system. Therefore low river terraces have been formed since the last glacial period.

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The Changes of Depositional Landforms in the Downstream Reach of Cha-Cheon (차천(車川) 하류 구간의 퇴적지형 변화)

  • Yu, Tai-Il
    • Journal of the Korean association of regional geographers
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    • v.12 no.3
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    • pp.352-363
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    • 2006
  • The purpose of this paper is to analyze changes in the depositional landform in the channel of Cha-cheon, a branch stream of Nakdong river(main stream) since the artificial straight channel has been constructed in 1973. The results of analyses are as follow. First, the Cha-cheon has flooded over one time in a year, and flowed backward over three times annually, according to analyze the data of the Hyeonpoong Gauging Station of rainfall and water level during a decade(1993$\sim$2002). Second, the flood plain within the artificial straightened channel has a nearly plain profile between the small dike and last riffle(point A). Deposits thickness of flood plain reduce gradually toward upstream. Third, grain size distribution of the flood plain deposits(0$\sim$20cm) within the artificial straightened channel has a coarsening trend in downstream reach of C point. It implies that the backward flow of Nakdong river(the main stream of Cha-cheon) make effect on the depositional mechanism of lowest reach in Cha-cheon. Finally, the result of analyzing grain size distribution of the flood plain deposits(0$\sim$20cm) within the artificial straightened channel implies that the c-point is the boundary between the vertical deposition of suspended load due to the backward flow of Nakdong river and the deposition of bed load supplied from hillslope of Cha-cheon basin.

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The Geomorphic Development of Angyae Basin (안계분지(安溪盆地)의 지형발달)

  • Bak, Byeong-Su;Son, Myoung-Won
    • Journal of the Korean association of regional geographers
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    • v.3 no.1
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    • pp.51-62
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    • 1997
  • In various places of drainage basins of major rivers in South Korea are distributed intermontane basins. Basin floor covered with fluvial deposits carried from the surrounding mountane area becomes alluvial plain. Its productivity is comparatively higher than anywhere else. Thus basin is a local administrative, economic, and cultural core area. Intermontane basin consists of backward mountane area, gentle hills, and alluvial lowland. The purpose of this paper is to elucidate the morpogenetic processes and development age of Angae Basin located in the sedimentary rock region. Hills with the height of a.s.l. $80{\sim}100m$ distributed in Angae Basin are residual landforms, which are the remnants of dissection of the etchplain that results from the denudation of bedrock deeply weathered along tectolineaments under the warm and moist climate, and reflect lithological differentiation of bedrock. Those hills have been comparatively higher ridges since the initial stage of the original etchplain, and they have been immune from fluvial processes. The etchplain appeared as $80{\sim}100m$ hills. the high terrace distributed in upstream reach of Nakdong River drainage basin and the old meander-cut at Seoburi in Wicheon drainage basin, are formed at the same stage when riverbed of Wicheon Stream functioned as a local base level according as the fluvial system of Wichoen arrived at dynamic equilibrium.

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Classification of Unit Ecosystems in Damyang Riverine Wetland (담양 하천습지 내 단위 생태계의 분류)

  • Son, Myoung Won;Chang, Mun Gi;Yoon, Kwang Sung;Choi, Tae Bong
    • Journal of the Korean association of regional geographers
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    • v.19 no.1
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    • pp.1-13
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    • 2013
  • Damyang Wetland Reserve with $980,575m^2$ area is located in Damyang-gun, Jeonlanam-do and Buk-gu, Gwangju Metropolitan City. The purpose of this paper is to divide Damyang riverine wetland into several geomorphic units, to analyze their sediments, and to categorize small ecosystem units composing riverine wetland. Riverine wetlands are classified into three types such as riverbed-, floodplain-, and abandoned-channel-wetland, and Damyang riverine wetland belongs to riverbed-wetland type. In this paper to categorize small geomorphic units of riverine wetland, we divide small geomorphic units from aircraft images analysis, and modify and supplement them following field survey results. Damyang Wetland Reserve is categorized into 22 ecosystem units. That physical and chemical properties of their sediments are different spatially, implicate that inorganic environment of Damyang riverine wetland ecosystem is very extensive. On the basis of the results of this study, policymakers will be able to design a strategy which manage Damyang Riverine Wetland Reserve more effectively, and for them interdisciplinary researches on relationships between various fluvial landforms and various lifeforms inhabiting them in Damyang Riverine Wetland Reserve are required.

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The Value and Application of The Mt. Palgong in Daegu (대구 팔공산의 가치와 활용방안)

  • JEON, Young-Gweon
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.2
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    • pp.51-68
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    • 2012
  • This paper aims to investigate the value in culture, history and ecology of the Mt. Palgong. It attempts to build the strategy for making use of The Mt. Palgong by literature survey, interview, and field survey. The main results are as follows: 1) The boundary of physical geography of the Mt. Palgong is classified into two. The boundary of the Mt. Palgong limits to granite mass block in a narrow sense, while in a broad sense, the boundary of the Mt. Palgong includes a contact aureole to be bordered on the Mt. Palgong granite mass block. The boundary from a cultural viewpoint limits to Daegu city(excluding Dalseong county) and Gyeongsan city, Yeongcheon city, Gunwi county and Chilgok (Dongmyeong-myeon, Giseong-myeon) in Gyeongbuk province. 2) In the geological boundary, one of the south-west slope is clearer than that of the north-east slope of the Mt. Palgong. The landforms such as tor, sheeting joint and gutter are well developed as a whole. Mountain landform such as boulder stream, polygonal cracking is relatively well developed on the south-west slope, while river landform is relatively well developed on the north-east slope of the Mt. Palgong. 3) It is necessary to develope various masterpiece of interesting stories related to Mt. Palgong in order to make the Mt. Palgong excellent tour complex. 4) It is desirable to designate the Mt. Palgong as a national park for systematic management. A master plan should be ultimately designed to raise brand value of Daegu city, and make good identity of the city by restoring 'The Mt. Palgong Jecheondan' and registering 'Gatbawi' as world heritage. 5) It is reasonable that the method of development in The Mt. Palgong should be based on the pattern of 'slow life town'. 'The Mt. Palgong museum' will then be designed to give visitors all the informations on The Mt. Palgong.