• Title/Summary/Keyword: 기후지형학

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Spatial pattern and surface exposure ages of cryoplanation surface at Mt. Moodeung (무등산 평활사면(cryoplanation surface)의 형성시기와 분포특성)

  • OH, Jong Joo;PARK, Seoung-Phil;SEONG, Yeong Bae
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.1
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    • pp.83-97
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    • 2012
  • Slopes of Seoseokdea~ Jangbuljae, at Mt. Moodeung, appears repeatedly the cliffs are mostly greater than $70^{\circ}$, and the planations maintain around $5^{\circ}$ in general. They studied the creation of development environments, cryoplanation are mainly facing the southwest. It is assumed that rock falling had been wostly occurred under a periglacial environment through jointing due to repeated freezing and thawing. Planation at the bottom of Columnar joint are described structural benches. Movement precesses of planation matrix are solifluction or jelifluction. The result of age determination of the slopes in Jangbuljae tells that the upper part of Ibseokdae has been remaining exposed to the land surface from 110,000 year ago. The blocks in the bottom part has been exposed to the surface around 10,000 year ago while Jangbuljae has been exposed to the surface about 50,000 year ago. It was assumed that they moved to the current location since being separated from columnar joint after exposure to the surface.

Morpho-climatic Milieu and Morphogenetic Succession of Coastal Terrace in Suncheon Bay (순천만 일대 해안단구의 형성 및 기후지형환경)

  • YANG, Jae-Hyuk;KEE, Keun-Doh;KIM, Young-Rae
    • Journal of The Geomorphological Association of Korea
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    • v.20 no.1
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    • pp.57-74
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    • 2013
  • Coastal terrace was developed at 8.3m height near Waon village in Suncheon-si. Due to the sandgravel layer deposited in a different today's environments, rounded gravel(4.3m, 5.8m, 6.3m) sequentially in a cross-section of coastal terrace, so it provides a good example which understand Holocene sea level changes to determine the effect on the various climatic-environments traits. For the purpose of identifying the morphogenetic process, Profile description, Grain size, XRD, Thin section analysis was attempted. As a result, coastal terrace are more likely to have been formed by the more recent period rather than the last interglacial(MIS 5 period), and at that time, various pedological features are considered to be formed.

Mass-Movement of Slope Material Since the Last Glacial Period at Angol Basin within Downstream Area of Gurongcheon in Cheonan, Choongnam Province (충남 천안 구룡천 하류부 안골유역의 최종빙기 이후 사면물질이동)

  • PARK, Ji-Hoon;PARK, Kyeong
    • Journal of The Geomorphological Association of Korea
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    • v.17 no.3
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    • pp.31-47
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    • 2010
  • The history of mass movement has been reconstructed from the Angol basin in Guryongcheon drainage basin. Sedimentary facies study, radiocarbon dating, particle size analysis, magnetic susceptibility and geomorphological analysis have been performed to reconstruct the paleo-environmental history of Angol basin. From 40,480 to 9,850yrBP there were five periods of slope instability and from 9,850yrBP to present there were at least four periods of slope instability. Magnetic susceptibility curves match well with the sedimentary facies data. This study may help reconstruct the denudational history of the small basins in Cheonan area and could be the cornerstone of the paleo-climatological study of the Korean Peninsula.

Analysis of changes in the Naesung stream channel and vegetation under hydrological fluctuations since 2010 using the ece-morphodynamic model (수문식생지형 모델링을 활용한 2010년 이후 수문 변동 조건에서의 내성천 하도 및 식생 변화 분석)

  • Choi, Hun;Lee, Chanjoo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.54-54
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    • 2022
  • 수변식생(riparian vegetation)은 하천 지형학적 프로세스에 영향을 미치는 요인 중 하나로, 최근 기후변화와 더불어 중요성이 커지고 있다. 내성천은 사질 곡류 하천으로, 2014년과 2015년 유량 감소에 의해 급격한 식생의 정착이 나타났다. 내성천 수변식생의 정착 및 활착은 수문-지형학적 프로세스에 영향을 미쳤고, 결과적으로 하도와 범람원의 형태를 변화시켰다. 이와 같은 변화를 예측하고 분석하는 것은 이수, 치수 및 방재 정책과 생태계 사이의 균형 및 조화를 추구하는 정책결정에 필수적이다. 그러나 식생을 고려하지 않은 기존의 수문-지형 모델링에서는 이와 같은 변화를 재현할 수 없다. 본 연구의 목적은 흐름, 식생, 지형의 상호작용이 하천 지형에 미치는 영향을 시각화 및 분석하고, 식생을 고려하지 않은 기존의 모델들의 결과와 비교하고자 한다. 본 초록은 이를 위해 수문-지형학 모델인 D-Flow-FM을 수변 식생 모델과 결합한 커플링 모델(Van Oorschot et al., 2016)을 활용하여 내성천에서 2013년부터 2019년까지의 발생한 지형학적 프로세스와 식생 사이의 상호작용을 재현한 예비결과이다. 식생 모델 결과는 내성천 현장조사 자료와 원격탐사 자료를 이용해 검보정하였다. 식생을 고려한 모델의 하천 형태는 식생을 고려하지 않은 모델의 결과에 비해 좁고 깊은 형태로 나타났으며, 지형학적 변동성이 적게 나타났다. 이는 유량 변화와 관련하여 생태-지형학적 프로세스로 인한 수변 식생 변동성이 강의 형태에 영향을 미쳤다는 것을 보여준다. 모의된 하천의 형태학적 특성이나 식생의 분포 특성은 항공사진과 비교했을 때 준수한 수준이다. 본 모델은 기후변화에 따른 식생의 변동성이 하천에 미치는 영향을 연구하는 데에 활용할 수 있으며, 수문-생태-지형학적 프로세스에 의한 하천의 변화를 예측하고 분석하는 데에 유용하게 활용할 수 있을 것이다.

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A Time-Series Analysis of the Erosion and Deposition around Halmi-island, Baramarae (안면도 바람아래 할미섬 주변의 시계열적 침식·퇴적환경 변화 분석)

  • Yu, Jae Jin;Kim, Jang-soo;JANG, Dong-Ho
    • Journal of The Geomorphological Association of Korea
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    • v.23 no.1
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    • pp.47-60
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    • 2016
  • In this study, datum points measurement have been collected and then weather data have been analyzed to figure out erosion and deposition environmental change around Halmi-island, Baramarae. First of all, it was difficult to analyze geomorphological change which is caused by climate change because of quite short term of collection period of data. However, differences in spatial distribution of erosion and deposition have locally been shown. In all season, the wind is blowing in north and north-west direction mostly except in summer which is shifted to south direction. However, since its ratio which are above 5m/s is much lower than the north and north-west wind, its effect on geomorphological process is very tiny. In order to look at a tendency of erosion and deposition environmental change around Baramarae Halmi-island, the periphery of Halmi-island was classified to east and west part, then accumulated erosion and deposition values have been calculated. As a result, generally, the datum points are located in the west part which are mostly depositional sites. On the other hand, the datum points are located in east part showed the dominant erosion patterns.

Morphology and Ecological Milieu of Keum-gae River basin in Andong Province (안동 금계천 유역의 지형과 생태 환경)

  • KEE, Keun-Doh
    • Journal of The Geomorphological Association of Korea
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    • v.17 no.4
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    • pp.99-110
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    • 2010
  • This study elucidates the interrelationship between climatic, morpological, and hydraulic milieu in the drainage basins of Keum-gae river from the viewpoint of ecogeography. The region of this basin is located at low-relief hills. Because hills are made up of granitic regolith by deep weathering, the rate of permeability is very high. And, the speed of drainage is very fast, and the deficit of water easily revealed and BOD is very high. Therefore a great deals of efforts are needed for the maintenance of stable milieu.

Chemical Weathering Trend of Granitic Rock by evaluated with CIA in Southern Korea (화학적 풍화지수(CIA)로 본 한반도 중남부 화강암류의 화학적 풍화 경향성)

  • KIM, Young-Rae
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.3
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    • pp.53-64
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    • 2011
  • Grus weathering mantles are widely distributed in Southern Korean Peninsula and are considered to be results of chemical weathering related to palaeoclimate milieu. This paper attempts to address this issue by CIA(chemical index of alteration). The climatic approach to the formation of grus mantles offers limited explanation of field occurrences, as these materials are widespread across climatic zones, from the humid tropics to cool temperate areas, although rates of grusification are likely to be influenced by climatic parameters. CIA values for granitoid weathering mantles in S. Korea are 50, which is the same of unweathered granitic rocks. Grus mantles in Korean peninsula show very low level in chemical alteration by CIA.

Discussion of the Origin and the Properties of Granitic Red Regolith Profile in Goseong, Southern Korea (경남 고성의 화강암 적색 풍화층의 특색과 성인에 관한 논의)

  • KIM, Young-Rae
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.1
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    • pp.57-71
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    • 2011
  • Granitic regolith profile in Goseong, southern Korea, reveals various types of corestones from unweathered round fresh rocks to decomposed rock cores with unweathered spheroidal rock-layers on outer surface, deep weathering profile with 10m in depth, and red saprolite usually cited as related to high temperature climatic environment. In respect of this optical features such as the depth and the color of the profile, Goseong granitic profile may be regarded as products of paleoclimate with more high temperature and humidity than the present. But it is revealed that halloysite is a predominant clay mineral in upper part as well as lower part by XRD analysis. Halloysite is dominant mineral in hydrothermal alteration milieu. The leaching rate of chemical components is up to 97%, very high compared to common granite profiles with 60~70% in Korean peninsula. So, it is assumed that granitic red regolith in Goseong is a product of hydrothermal alteration, not meteoric weathering.

Pollen analysis of alpine wetlands on Mt. Jeombong in Gangwon-do, South Korea and climate change during the late Holocene (점봉산 고산습지의 화분분석과 홀로세 후기 기후변화)

  • Yoon, Soon-Ock;Kim, Minji;Hwang, Sangill
    • Journal of The Geomorphological Association of Korea
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    • v.20 no.4
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    • pp.101-115
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    • 2013
  • 11 alpine wetlands at the upper reaches of Bangtae River on a high flat summit around Mt. Jeombong were found. Two core samples(JB-1 and JB-2) among them were collected in order to reconstruct paleovegetation history and climate change using pollen analysis. Pinus and Quercus dominated at the wetland of JB-2 with a deep water depth were developed from 1,700 yr BP to 1,000 yr BP of the pollen zone I. Subsequently Quercus dominated in the pollen zone II from 1,000 to 400 yr BP, and it is supposed that warm weather prevailed with oak climax forest corresponding to the Medieval Warm Period. Moreover, sphagnum grew densely in the alpine wetlands and the wetlands were extended widely on the summit around Mt. Jeombong with the beginning of subzoneIIc at JB-2. The pollen zone III from 400 yr BP to the present with an increase in Pinus and a decrease in Quercus suggests cold climates under the Little Ice Age. Moreover, human disturbances at JB-2 were more significant than those at JB-1, based on the increase in Pinus.

The Climatic Change during the Historical Age inferred from Vegetation Environment in Alpine Moorsin the Korean Peninsula (한반도 고산습지의 식생환경과 역사시대 기후변화)

  • Yoon, Soon-Ock;Kim, Minji;Hwang, Sangill
    • Journal of The Geomorphological Association of Korea
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    • v.21 no.4
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    • pp.69-83
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    • 2014
  • This study examines vegetation and climate changes from pollen compositions of alpine moors in the Korean Peninsula such as Mujechineup at Mt. Jeongjok, Yongneup at Mt. Daeam, Jilmoineup at Mt. Odae and Wangdeungjaeneup at Mt. Jiri including moors at Mt. Jeombong. It can be found that the alpine moors were less interfered by human than low moors during the past 2,000 years of the historical age. Based on dominant periods of Pinus and Quercus, pollen compositions of the alpine wetlands, climatic environments of vegetation and historical records, vegetation and climate changes during three periods such as approximately 2,000~1,000 yr BP, 1,000~400 yr BP and 400 yr BP~present are examined. It was warmer during the period of 1,000~400 yr BP than 2,000~1,000 yr BP. The period of approximately 400 yr BP indicate the coldest climate of Little Ice Age. This study finds dominances of Quercus, low NAP/AP ratios, obvious divisions of pollen zones and human interference after 400 yr BP from pollen compositions of the alpine moors during the historical age. Human interference in the high moors becomes obvious after approximately 400 yr BP, indicating that there is a time lack of approximately 1,500~2,000 years between the alpine and low moors.