• Title/Summary/Keyword: geomorphic development

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Geomorphic Variables Influential to Develop Erosional Characteristics (산지사면의 침식에 영향을 주는 지형인자에 관한 연구)

  • Yoo-Jeong Hwang
    • Journal of the Korean Geographical Society
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    • v.33 no.3
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    • pp.365-376
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    • 1998
  • The goal of this study is to find the geomorphic variables contolling gully development on hillslopes following deforestation. Two possible geomorphic processes, surface erosion and mass movement were reviewed to compare the characteristics and geomorphic variables involved. The research objective in this paper is to find the variables and the statistical model which can explain gully density in the study area. Gully density was selected as a response variable. For log gully density, the best subset regression was found to have the variables such as area, surface length, and surface width. Log area is the most significant predictor. Even with several outliers, the normal probability plot of the residuals from this regression looks straight. So, area, surface length, and surface width explain half of the variance in gully density.

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The Expansion of Urbanized Area and Geomorphic Environments in Seoul (서울의 시가지 확대와 지형적 배경)

  • Kim, Dong-Sil
    • Journal of the Korean association of regional geographers
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    • v.12 no.1
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    • pp.1-15
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    • 2006
  • This study is to review the site of Seoul and its urbanized area expansion in relation with a geomorphic environments. Surveying on the urbanized area of Seoul by period and related geomorphic conditions found the following conclusions. Seoul urbanized area had been expanded from the cheonggyecheon drainage basin to its surrounding hills and marshland. The marshland development began during the Japanese period from around the tributaries of the Hangang river and expanded to the areas by the main stream of the river. The extensive marshland at the point where the main stream and its tributaries of the river join has been developed relatively new. The marshland development, which took advanced engineering skills and a huge investment, is comparatively later and also involves large additional expenses to keep the areas from food damages. Judging from the above findings, this study concluded that the urbanized area expansions in a big metropolitan city such as Seoul, are greatly influenced by geomorphic environments and the importance of geomorphic conditions still hold true even today when scientific and technological developments have reached unprecedented heights.

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The Environmental Change and Geomorphic Development of Unsan Alluvial Plain in Kangreung City during the Late Holocene (강릉 운산충적평야의 홀로세 후기의 환경변화와 지형발달)

  • 윤순옥
    • Journal of the Korean Geographical Society
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    • v.33 no.2
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    • pp.127-142
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    • 1998
  • Unsan alluvial plain is the backmarsh of Seomseokcheon which is a river originated from Chilseongdae(954m) on Mts Taeback, flowing into Donghae in southern Kangreung City, Kangwon Province. The vegetation change, geomorphic develoopment and depositional environment during the late Holocene have been investigated, using the methods such as boring, pollen analysis and radiocarbon dating. Because the deposits fo the study area are mainly consisted of peat and paety sand, they contained many pollen fossils. The peat layer has been sedimented since the high sea-level periods, 3,200 y. BP, and the records of vegetation change until now has well preserved here. According to archeological researches and the results of pollen analysis in east coast of Korea, it is supposed that the prehistoric rice farming in this area has begun since ca. 1,800 y. BP.

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Geomorphic Resources of Mt. Palgong, in Daegu (대구 팔공산의 지형자원)

  • JEON, Young-Gweon
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.4
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    • pp.247-259
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    • 2011
  • This research aimed to analyse geomorphic resources of Mt. palgong(in Daegu city and Gyeongbuk province) through some field surveys, and then to clarify geomorphic features. The main results are as follows. 1) The geological boundary of the south slope(granite) is more clear than one of the north slope(granite bedrock and metamorphic sedimentary rock). Small basins are along with fault line between granite bedrock and metamorphic sedimentary rock. 2) It is estimated that relatively big valleys on the north slope are due to local climate, geomorphic and geological features. 3) Tor, sheeting joint, gutter are well developed both on the south slope and on the north slope, however the development of polygonal cracking and boulder stream are more dominant on the south slope; river cliff, pool, waterfall are more dominant on the north slope with valleys that well developed. 4) Scenic geomorphic landscapes are mainly developed in Dongsan valley and Chisan valley on the north slope. 5) There are many interesting geomorphic resources in the viewpoint of storytelling in Mt. Palgong. So the specific design to utilize such resources is required

The Geomorphic Development of Alluvial Fans in the Cyeongju City and Cheonbuk area, Southeastern Korea (경주 및 천북 지역의 선상지 지형발달)

  • 윤순옥;황상일
    • Journal of the Korean Geographical Society
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    • v.39 no.1
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    • pp.56-69
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    • 2004
  • We investigated the distribution and geomorphic development of alluvial fan in Gyeongju City including Cheonbuk area. According to a relative height to a river bed, alluvial fans of this area are divided into Higher surface, Middle surface, and Lower surface. As alluvial fans of Bulguk temple∼Ulsan bay area, the confluent fans in Cheonbuk and Gyeongju areas were formed by the Quaternary climatic change alternating glacial and interglacial stages, and the development of N-S and NW-SE fault lines. The Gyeongju alluvial fan, the largest in Korea, has been provided as the significant space for human activity since the prehistoric age. Bukcheon river formed the Gyeongju alluvial fan had not flowed over during the prehistoric and the ancient times. In contrast with general geomorphic characteristics, many springs in the Gyeongju alluvial fan are located in the middle part of the fan because ground water reaches to the surface. It is supposed that sedimental materials were not sufficiently piled up at lower reach of Bukcheon river due to the large deposits at upper and middle reach of the basin.

Types and Geomorphic Development of Large Landslides in the Kokomeren River Basin, Kyrgyzstan (키르기스스탄 코코메렌강 유역의 대규모 산사태 유형과 지형 발달)

  • Oh, Jeong-Sik
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.1
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    • pp.1-14
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    • 2019
  • Large landslide is a type of mass movement that causes drastic landform changesin a short period, and it causes huge human and property damage over a large area. The purpose of this study is to categorize the types and characteristics of large landslides around the Kokomeren River basin, Kyrgyzstan and to discuss the geomorphic development after the large landslides. The topographic analysis about a total of 20 landslides documented collapsed volumes of 0.01 to 1.10 km3, height drops of 180 to 1,770 m, and runout distances of 1,200 to 5,400 m. Rock avalanche and rockslide are identified as major types of large-scale landslides in the study area. Rock avalanches can be divided into P-type, J-type, and S-type based on the features of slope failure and kinematic characteristics of rock debris. Landslide synchronistic landforms such as trimlines, transverse ridges, longitudinal ridges, levees, and hummocks are well developed in the rock avalanche. The pieces of evidence of landslide dam, landslide-dammed lake, and remnant outburst flood deposits are observed in the upstream and downstream where the rockslides occurred. The Ak-Kiol landslide dam is the best example of a geomorphic development due to lake spillover and the large landslides were likely to be triggered by huge paleo-seismic events.

Development of the GIS Method for Extracting a Specific Geomorphic Surface of Coastal Terrace at Gampo Area, Southeastern Coast in Korea (GIS를 이용한 해안단구 지형면 분류 기법 연구 - 감포지역을 사례로 -)

  • 박한산;윤순옥;황상일
    • Journal of the Korean Geographical Society
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    • v.36 no.4
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    • pp.458-473
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    • 2001
  • The classified map of geomorphic surfaces is the most basic data for the geomorphological research. Up to recent days, the traditional methods extracting specific geomorphic surfaces are accomplished by analyzing the aerial photographs and topographical maps, and field works. Also it needs a lot of time and expertness. Furthermore it is difficult to gain the aerial photographs in Korea. Since digital maps in Korean Peninsula are almost completed recently, we tried to extract specific surfaces by analyzing the characteristics of marine terraces based on the level of paleoshoreline and slope analysis on the terrace surface using GIS. However, research used GIS was hardly found up to date, therefore many problems are not be solved yet. The aim of this study is to develop the more efficient and objective method for the extraction and classification of specific geomorphic surfaces by using GIS in Gampo-eup, Gyeongju city, Southeastem Coast in Korea, where a lot of traditional research has already accomplished. For this aim, we have designed the process of extracting specific geomorphic surfaces, chosen the factors that was Gyeongiu city, Southeastem Coast in Korea, where a lot of traditional research has already accomplished. For this aim, we have designed the process of extracting specific geomorphic surfaces, chosen the factors that was suitable for classification of specific geomorphic surface, and presented method of setting up optimum criteria of extraction. As last, effectiveness and problems of these methods were investigated through conincidence rate and error rate.

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Geomorphic Development of the Kajo Basin (加祚盆地의 地形發達)

  • Jo, Wha-Ryong;Chang, Ho;Lee, Jong-Nam
    • The Korean Journal of Quaternary Research
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    • v.1 no.1
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    • pp.35-45
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    • 1987
  • Several fluvial terraces were developed in the Kajo Basin located in Kochang-gun, Kyongsangnam-do, Korea. The peat layers are formed on a fluvial terrace of them. To clarify the geomorphic development of this basin, a detailed classification of geomorphic surfaces, a soil profile study, grain size analysis, pollen analysis of the peat layers and C-14 dating were made. The main findings are as follows: 1) The Kajo Basin was formed by a differential erosion of granic rocks. The surrounding mountains are contact-metamorphosed gneiss and sedimentary rocks. 2) Seven geomorphic surfaces were recognized. They are named the H1, H2, M1, M2, T, L1 and L2 surfaces, from older to younger. 3) C-14 dating and the pollen analysis indicate that the L1 surface was formed during the Early Wurm Glacial. 4) The formation periods of the L2, M and H surfaces are supposed to be the Late Wurm, Riss and Mindel glacial, respectively, on the basis of the color of soil horizons (with or without the Red Soil) and the weathering degree of gravels. 5) Betula and Pices were dominant in the pollen of the Kajo Basin around 30,000 years B.P.

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