• Title/Summary/Keyword: 지형형성작용

Search Result 173, Processing Time 0.029 seconds

The Holocene tidal sedimentary changes in Mosan Bay Estuary, Korea (홀로세 충남 모산만 하구역내 간석지의 퇴적과정)

  • Shin, Young Ho
    • Journal of The Geomorphological Association of Korea
    • /
    • v.18 no.3
    • /
    • pp.37-51
    • /
    • 2011
  • Geomorphic changes and sedimentary changes are investigated by sediment analysis from estuarine tidal flat, Mosan Bay Estuary, which is a tide-dominated and rias estuary. Sediments separatedly deposited during the early Holocene and the late Holocene. There are unconformities between the early Holocene sediment unit and the late Holocene sediment unit. Developments of these unconformities were related with fluctuated sea level change during the mid Holocene. Three deposit zones are spatially classified, which are named "intermittent tide channel deposit zone"(A1, B1, D3), "flood-dominated deposit zone"(A3, B3, C1, C3), and "fluvial sediment deposit zone"(A2, B2). This classification is explained by three main effects; laterally restricted migration of a tidal channel, diffract flood effect and settling lag effect, and fluvial induced reworking. These effects are deserved as main factors which have formed estuarine geomorphology in tidedominated and rias estuary. This study suggests research directions in reconstructing estuarine geomorphic and sedimentary change in west coast of Korea. Furthermore, it gives useful data for making a "land-ocean interaction" model for west coast of Korea.

Tafoni Geomorphic Development in the Western Coast of Dongdo of Dokdo, Korea (독도 동도 서쪽 해안의 타포니 지형 발달)

  • Hwang, Sang-Ill;Park, Kyung-Geun
    • Journal of the Korean association of regional geographers
    • /
    • v.13 no.4
    • /
    • pp.422-437
    • /
    • 2007
  • Dokdo has historical and political meaning in relation to the territorial problems with Japan. The area can be the main factor to explain the formation and development process of East-Sea as exposure volcanic island at East-Sea with Ulreong-island. Accordingly, it also has an important meaning of physical geography aspects In this research, it is perceived the geomorphological development process of slope due to the salt weathering which is considered as the most important factor to understand whole geomorphology of Dokdo. And researched how a geomorphology of this sort affects to animal and plants. The peculiar geomorphology is tafoni which is a weathering geomorphology and one of the remarkable geomorphology in preservation of Dokdo. Tafoni at west part of Dongdo is distributed intensively near shoreline which is composed tuff. The shape of tafoni is mainly massive, circle and oval in Massive tuff breccia layer also is formed toward horizontality bedding direction in Bedded lapilli tuff. Tafoni in Dokdo is constituted after middle of Holocene. This fact can be proved by ranging at surface of sea-cliff which is formed wave erosion after middle of Holocene sea-level reaching to present level. Tafoni is also the most contribute factor of geomorphology dissection of Dokdo as it is eroded the bed rock with salt weathering. In bottom part of tafoni it has an important function for habitat of birds. Herbaceous plants are on it. To procrastinate of bed rock dissection by growth of Tafoni, conservation of vegetation and soil are most important factor.

  • PDF

Soil Compaction of Hiking Trails Induced by Human Trampling in Mt. Halla and Darangshiorum (한라산과 다랑쉬오름 등산로의 답압에 의한 토양 압밀현상)

  • Kim, Tae-Ho
    • Journal of the Korean association of regional geographers
    • /
    • v.9 no.2
    • /
    • pp.169-179
    • /
    • 2003
  • The hardness and physical properties of soils were measured in hiking trails of Mt. Halla and Darangshiorum in Jeju Island to examine the characteristics and formative factors of an aquiclude induced by human trampling. The soil hardness, being generally the highest on trails, decreases outward and shows the lowest on adjacent slopes in a natural condition. The bulk density and solid phase also demonstrates a similar tendency, then implying that the aquiclude occurs in the central part of trails. Although the formation of a hard layer in trails is fundamentally attributed to human trampling, the environmental factors such as landform, lithology, soil and vegetation play a role in the occurrence of the aquiclude. Soil compaction varies with the gradient and location of trails which affects a transport and deposition of soil particles to produce a hard layer. Soil compaction also depends on the physical properties of soils including the soil texture largely affected by lithology. Vegetation is not directly related with the formation of a hard layer, but affects its dimensions through an enlargement rate of bare trails depending on the response and resistance of plants to human trampling.

  • PDF

The studies of the granite landforms in South Korea (한국의 화강암 지형에 대한 연구)

  • KANG, Tay-Gyoon
    • Journal of The Geomorphological Association of Korea
    • /
    • v.18 no.4
    • /
    • pp.1-15
    • /
    • 2011
  • This work is to review the granite landforms studies by Korean geographers. It is verified that geomorphlogical characteristics of granite present landscapes characterized by 1) in case of mountains, are difficultly or irregularly weathered, so as to develop rocky forms such as domes, cliffs, and tors ; 2) in case of stream valley that is inter-massif lowland, low relief hills and flood plains with alluvium. All these facts owe to the difference of weathering mode granite properties. The granite hills and alluvial plains of southwestern coastal parts in Korean peninsula is low undulatory and large owing not only to the existence of highly weathered granitic regolith, but also to frequent flooding. Cultivated brownish field, orchard, meadow and forest are located at granite hills. On the other hand paddy rice field at granite alluvial plains. Korean peninsula have endured erodible geomorphlogical processes since Miocene when warping it up. Therefore many intermontane basins are located on the weathered granite areas which are surrounded by mountains composed of much less Precambrian gneiss complex. In fact, intermontane basin is mainly linear fault-line valley. The landforms of the intermontane basins are characterized by gentle piedmont slopes, alluvial fans, fluvial terraces and alluvial plains.

광양만의 지형변화 및 퇴적환경 발달

  • 최동림;이태희;현상민;최진성
    • Proceedings of the Korea Society of Environmental Biology Conference
    • /
    • 2002.11a
    • /
    • pp.41-45
    • /
    • 2002
  • 광양만의 지형변화 및 퇴적환경발달양상에 대해 표층퇴적물과 지층탐사자료를 이용하여 연구하였다. 광양만 해역은 1970년대이후 광양만 개발에 따라 해안선 및 해저지형이 급격한 변화를 겪어왔다. 광양만의 면적은 개발이전보다 25%정도 감소하였다. 해안선 변형은 공단건설을 위한 해안매립공사로 인해 그리고 해저지형변화는 대형선박들의 안전항로개발을 위한 해저퇴적물의 준설 등에 의해 발생하고 있다. 표층퇴적물는 점토질 퇴적물 묘도서측 및 여수해만의 외해지역에 주로 분포하고, 사질 퇴적물은 섬진강하구와 수로에 분포하고 있다. 표층퇴적물의 유기물 함량은 퇴적물의 특성을 반영하며, 특히 점토질퇴적물에 다량으로 포함하고 있다. 탄성파 단면도상에서 기반암위에 Unit II와 Unit I가 분포하며, 하부 Unit II는 홀로세 이전의 하천환경 퇴적층으로 판단되며, 홀로세 Unit I 퇴적층은 섬진강하구에서 외해를 향해 전진퇴적양상의 쐐기형태를 보인다. 이 층은 섬진강에서 유출된 퇴적물이 델타환경을 이루면서 형성된 퇴적층서로 해석된다. Unit I 퇴적층내에 천부가스층이 광범위하게 분포한다. 천부가스는 광양만의 생태환경에 영향을 미칠 것으로 판단된다. 광양만 주변의 재발에 따른 해안 및 해저지형의 급격한 변형은 퇴적환경 및 해양환경에 변화를 야기할 것으로 예상된다. 특히 섬진강 하구지역의 광양제철소 건설은 섬진강에서 장양만으로 유입되는 퇴적물의 퇴적작용의 커다란 영향을 미칠 것으로 판단된다.

  • PDF

A Geomorphological Classification System to Chatacterize Ecological Processes over the Landscape (생태환경 특성 파악을 위한 지형분류기법의 개발)

  • Park Soo-Jin
    • Journal of the Korean Geographical Society
    • /
    • v.39 no.4
    • /
    • pp.495-513
    • /
    • 2004
  • The shape of land surface work as a cradle for various environmental processes and human activities. As spatially distributed process modelings become increasing important in current research communities, a classification system that delineates land surface into characteristic geomorphological units is a pre-requisite for sustainable land use planning and management. Existing classification systems are either morphometric or generic, which have limitations to characterize continuous ecological processes over the landscape. A new classification system was developed to delineate the land surface into different geomorphological units from Digital Elevation Models(DEMs). This model assumes that there are pedo-geomorphological units in which distinct sets of hydrological, pedological, and consequent ecological processes occur. The classification system first divides the whole landsurface into eight soil-landscape units. Possible energy and material nows over the land surface were interpreted using a continuity equation of mass flow along the hillslope, and subsequently implemented in terrain analysis procedures. The developed models were tested at a 12$\textrm{km}^2$ area in Yangpyeong-gun, Kyeongi-do, Korea. The method proposed effectively delineates land surface into distinct pedo-geomorphological units, which identify the geomorphological characteristics over a large area at a low cost. The delineated landscape units mal provide a basic information for natural resource survey and environmental modeling practices.

$\acute{E}$tude du Processus de Morphogen$\grave{e}$se de l'$\hat{I}$le Rocheuse de Baek dans la Ville de Yeosu en Cor$\acute{e}$edu Sud (여수시 백도의 지형형성과정에 대한 고찰)

  • Lee, Jeong Hun
    • Journal of the Korean association of regional geographers
    • /
    • v.19 no.4
    • /
    • pp.627-640
    • /
    • 2013
  • Cette $\acute{e}$tude a pour objet d'analyser le processus de morphogen$\grave{e}$se de l'$\hat{I}$le rocheuse de Baek. Nous y voyons une cl$\acute{e}$ pour apprendre son relief marin et le processus de morphogen$\grave{e}$se des l'$\hat{I}$les m$\acute{e}$ridionales de Cor$\acute{e}$e du Sud. Le granit porphorique qui compose l'$\hat{I}$le rocheuse de Baek est une roche magmatique qui s'est form$\acute{e}$e il y a 60 million d'ann$\acute{e}$es. La cause principale de formation de l'$\hat{I}$le rocheuse de Baek, est une ligne de d$\acute{e}$lit vers le NE-SO et l'ENE-OSO, un soul$\grave{e}$vement de la plaque tectonique et une $\acute{e}$rosion par les vagues. L'$\hat{I}$le rocheuse de Baek pr$\acute{e}$sente un caract$\grave{e}$re d'$\acute{e}$ruption de magma de calc-alcalin par analyse g$\acute{e}$ochimique de son granit porphorique et fait partie du granit de l'arc volcanique. Il s'agit d'un magma qui s'est form$\acute{e}$ dans la subduction pr$\grave{e}$s du continent. Il est aussi n$\acute{e}$ssaire d'examiner un soul$\grave{e}$vement qui est plus $\acute{e}$lev$\acute{e}$ qu' un mouvement ascendant de la surface de la mer $\grave{a}$ l'$\grave{e}$re quaternaire environ de l'$\hat{I}$le rocheuse de Baek malgr$\acute{e}$ que, selon nous, nous y trouvions une faille et une terrasse marine.

  • PDF

Examination into the Applicability of the River Classification System Based on the Geomorphological Criteria (지형 인자를 이용한 하천분류 체계의 적용성 검토)

  • Lee, Chan-Joo;Lee, Du-Han;Kim, Kyu-Ho;Woo, Hyo-Seop
    • Journal of Korea Water Resources Association
    • /
    • v.37 no.1
    • /
    • pp.1-11
    • /
    • 2004
  • The purpose of this study consists in introducing and examining the previous river classification systems applicable to the river improvement technique including geomorphological considerations, and developing a new system using the geomorphological criteria which represent the morphology of rivers. A newly developed system uses the channel reach as a classifying unit which is delineated by upstream and downstream tributaries. It adopts three basic geomorphological criteria for classification: 1) valley-floor width index(VI) reflecting the confinement of the channel in the valley, 2) sinuosity(P) which expresses the channel planform, and 3) bed material($d_{50}$). The system is composed of 24 stream types. Concerning every stream type, valley forms, principal bed forms and fluvial processes with disturbance elements are briefly presented. Finally, the applicability of this system to the Chungmi Stream and the Imjin River data in comparison with that of Rosgen system is examined.

Mineralogical Changes in the Weathering Profiles of Carnin Gneiss in the Yoogoo Area, Korea (유구지역 화강암질 편마암의 풍화작용에 의한 광물 조성의 변화)

  • 이석훈;김수진
    • Journal of the Mineralogical Society of Korea
    • /
    • v.13 no.3
    • /
    • pp.121-137
    • /
    • 2000
  • Weathering profiles which were developed under a temperate, humid environment and relatively steep geography, show a thick saprolite and soil horiaon in the Precambrian granitic gneiss of the Yoogoo area. In the weathering profiles, secondary minerals such as interstratified biotite/vermiculite, tri- or di-octahedral vermiculite, halloysite, kaolinite, illite, smectite, gibsite and geothite were observed. Kaolinization of biotite is the most prevalent mechanism but vermiculitization is a minor from all ofweathering profiles. Biotite altered to B/V mixed layer-vermiculite, to illite and to halloysite, kaolinite and gibbsite. Halloysite is the most frequently observed weathering product of biotite in these profiles. Goethite is observed at the around or opened fissures of altered biotite. Tubular halloysite aggregates was fDrmed from dissolution-precipitation of plagioclase. The occurrence of halloysite aggregates is divided into a preferentially oriented type and a wrinkled one which were resulted from the dissolved type of plagioclase. Fe-bearing minerals have also been subjected to dissolution leaving the precipitation of geothite along dissolution voids. The profile of granitic gneiss is a typical weathering pattern showing a clay minerals increase toward the surface. Weathering of minerals were controlled by locally acidic and good-drainage environment, and formed a various and complicated secondary minerals in this study area.

  • PDF

A Study on the Cave-microlandscapes of the Saturated Zone in Korea (우리나라 포화수대 성인의 동굴미지형 연구)

  • 홍시환
    • Journal of the Speleological Society of Korea
    • /
    • v.46 no.47
    • /
    • pp.9-18
    • /
    • 1996
  • 우리나라에는 수 많은 석회동굴이 있다. 현재까지 파악된 것만 해도 총 1,000 여개 소에 달하는 것으로 추정되고 있으나 실제로는 이보다 많은 동굴이 있을 것이다. 이들 석회동굴의 용식미형태는 다양하다. 따라서 본 연구에서는 포화수대에서 형성된 동굴 속의 용식작용으로 이루어진 동굴 미지형, 동굴 지물들에 대하여 논하고저 한다. 순환수대에서의 동굴 생성물과 미지형은 단조롭고 뚜렷하다고 하겠지만, 이와 반대로 포화수대 동굴 속의 미지형들은 그 모두가 용식작용으로만 이루어지는 것이다. 이들 미지형은 계속 순환수대 동굴로의 이행 때문에 침식ㆍ삭박작용도 가해지는 경우가 있어 이른바 복합적인 미지형이 남게 되는 것이다. 현재 우리나라에는 수 많은 석회동굴이 있으나 개발되어 공개되고 있는 동굴 중에서는 단양의 고수동굴과 동해시의 천곡동굴에서 이와 같은 용식미지형을 볼 수 있다. 앞으로 이들에 대한 보다 계측적이고 구체적인 학술적 연구가 기대되는 바이다.

  • PDF