• 제목/요약/키워드: Geomorphological characteristics

검색결과 229건 처리시간 0.023초

전남 완도군 신지면 일대의 고해안퇴적층과 최종간빙기 고해수면 증거 (The Evidence for the High Sea Level of MIS 5e and the Paleo-coastal Sediments from Sinji-myen, Wando-gun, Jeollanam-do, Korea)

  • 신원정;이재호;변종민;김종연
    • 한국지형학회지
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    • 제26권1호
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    • pp.59-78
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    • 2019
  • The physical and chemical characteristics of more than 5 m sandy deposits behind the beach in Sinji-do Island are investigated and its burial ages are estimated using Optically Stimulated Luminescence. By the estimated burial ages of the sandy deposits, this section is divided into four sub-units: Unit I (6.2 ka), Unit II (23.2 ka), Unit III (115.9 ka), and Unit IV (115.9 to 127.5 ka). It can be proposed that the Unit I of a coarse sand deposited during the Holocene Climatic Optimum. Unit II, supposed to be the aeolian sediments, formed during the Last Glacial Maximum (LGM). It can be supposed that the study area was not affected by the marine processes during the LGM, directly. Unit III is more consolidated deposits of coarse silt to fine sand and deposited during the Last Interglacial Period. Unit IV mainly consist of beach gravels with sandy matrix deposited during the Marine Isotope Stage 5e (MIS 5e), and thus indicates that the sea level of the southwest sea had risen 3 to 5 m above present sea level during the MIS 5e.

조선시대(1392-1910) 해일 발생의 시공간적 분포 특성 (Spatio-temporal Distribution of Surges and Tsunamis in the Korean Peninsula from 1392 to 1910)

  • 김다해;홍성찬;최광희
    • 한국지형학회지
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    • 제28권3호
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    • pp.37-49
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    • 2021
  • Analysis and prediction of storm surges are very important because the global warming has raised sea levels and increased the frequency of massive typhoons, accelerating damage of coastal flooding. However, the data for storm surge prediction is lacking due to the short history of observation in South Korea. The purpose of this study is to investigate the spatial and temporal characteristics of the previous surges and tsunamis based on the historical documents published during the Joseon Dynasty. In addition, we tried to evaluate the damage and spatial extent of such disasters, using the expressions about surge records including heights and number of administrative divisions. As a result, a total of 175 records of surges and tsunamis were compiled from 1392 to 1910: 145 events were extracted through the analysis of the ancient documents, and 30 events were from the previous research. Most of the strorm surges occurred along the west coast during summer season. More than half of the total surges were concentrated for 120 years from the mid 1600s to the mid 1700s, which was estimated to be highly relevant to the climate conditions in East Asia during the Little Ice Age. Hazardous areas by storm and tidal surges were also extracted, including Asan, Ganghwa, and Siheung during the Joseon Dyanisity period.

지형요소를 활용한 전라도 논매기소리의 공간분포와 전파에 관한 연구: 아리시고나 류, 산아지 곡, 방게 류를 사례로 (A Study on the Spatial Distribution and Diffusion of Rice-paddy Weeding Songs Using the Geomorphic Elements in Jeolla-do: A Case of Arishigona, Sanaji and Bang-gae)

  • 윤혜연;장동호
    • 한국지형학회지
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    • 제28권2호
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    • pp.71-85
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    • 2021
  • In this study, the effect on the spatial distribution and diffusion of Arishigona, Sanaji and Bang-gae appearing in Jeolla-do was analyzed using geomorphic elements. Based on result, the AriShigona is distributed in the western plains of the Yeongsan River basin and around from the Noryeong mountain range to Mudeung mountain range, the Sanaji is mainly diffused in the middle and upper parts of the Seomjin River and the lower parts of the Mangyeong River, Dongjin River and the Boseong River basin, and the Bang-gae is found to be distributed in the Seomjin River and the upper part of the Yeongsan River basin. Although the cultural centers of these Rice-paddy Weeding Songs are different but they appear to have a similar distribution pattern in Jeolla-do. This is used as a diffusion path of cultural elements by crossing lineaments in various directions and serving bridge role at the same time. However, in the region where the lineaments do not intersect, the continuity of Rice-paddy Weeding Songs are relatively low, which are considered to be reflected in the spatial distribution and propagation of the sound due to the influence of the drain network rather than the lineament. The results of this study can provide basic data for spatial distribution of Rice-paddy Weeding Songs, and regionality and cultural division by diffusion characteristics.

한라산의 지형 특성을 활용한 자연해설 탐방 프로그램의 개발 (Development of Trip Programs with Nature Interpretation Using Geomorphic Characteristics of Mt. Halla)

  • 김태호
    • 한국지형학회지
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    • 제19권2호
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    • pp.17-29
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    • 2012
  • 정상 등반만 지향하는 한라산에서의 탐방 문화를 개선하고, 한라산의 자연 보존과 탐방객의 질적 만족도 향상을 위하여 한반도 산지와는 구별되는 한라산의 지형 특성을 활용한 자연해설 탐방 프로그램을 개발하였다. 윗세오름 대피소부터 장구목오름 사이의 1.5km 구간에서 진행되는 아고산대 탐방 프로그램은 아고산 생태계에 관한 전문 지식의 습득뿐 아니라 아고산 생태계의 취약성을 이해시킴으로써 소중한 자연 자원으로서 한라산 아고산대의 보존 필요성을 인식시키는 교육적 효과를 올릴 수 있다. 관음사 탐방로 입구부터 구린굴 상류 협곡 지대 사이의 1.5km 구간에서 탐방로를 따라 흐르는 병문천에서 진행되는 산지하천 탐방 프로그램은 병문천의 지형 및 수문학적 특성을 바탕으로 한반도 하천과는 상이한 제주도 하천의 지역성을 효과적으로 소개할 수 있다. 두 자연해설 탐방 프로그램에서 다루고 있는 한라산의 아고산 초지대와 건천은 한반도에서는 체험하기 어려운 탐방 장소로서, 탐방 활동을 통하여 한라산 더 나아가 제주도 고유의 지역성을 탐방객에게 알리는 계기가 될 수 있다.

입도분포 특성을 기반으로 한 고창 연안의 과거 퇴적환경 분석 (Analysis of Paleo Sedimentary Environment of Gochang Coast Using Grain Size Distribution Characteristics)

  • 한민;양동윤;박찬혁
    • 한국지형학회지
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    • 제25권3호
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    • pp.43-55
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    • 2018
  • This study aimed to identify different sedimentary environments of Gochang coast according to geomorphic conditions of each bore hole. To achieve the aim, this study utilized the classification of sedimentary environmental conditions of surface sediment, which was based on grain size distribution characteristics.In other words, three sedimentary environmental conditions ofsandy flat + sand beach, coastal sand dune and weathered bedrock soil, which were distinguished based on grain size distribution characteristics of mean-sorting for surface sediments, were applied to the sediments of bore holes. Four sedimentary environments could be identified in Gochang coast. First, the lake sedimentary environment originated from terrestrial sediments seems to have been dominated by weathered bedrock soil that the surface flow has deposited in a coastal wetland or a boundary, which is affected by the sea. Second, the lake sedimentary environment that is little affected by coastal sand dunes is located at the center of a valley, which is connected to the land, and the dune slack of Saban-ri. The surface flow of weather bedrock soil is the main source of deposits. However, there seems to have been a temporary influence of the sea. Third, the lake sedimentary environment that is strongly affected by coastal sand dunes is located at the dune slack of Yeongjeong-ri. This environment shows traces of a change from a coastal sand dune into the dune slack. Finally, the coastalsand dune sedimentary environment, which wasinvestigated by boring the current coastal sand dune, shows a temporary influence of the land but seems to have maintained the overall stability. Consequently, this study demonstrated that the grain size distribution characteristics of the present surface sediments could be effectively applied to identify the sedimentary environments of the paleo bore hole sediments. In addition, the paleo change of sedimentary environment could also be identified in many places of Gochang coast. If the results of this study are combined with the age dating and geochemical analysis in future works, the paleo environmental change in Gochang coast will be restored more precisely.

화순천의 퇴적환경 및 퇴적물과 하천수의 지구화학적 특성 (Sedimentary Environments, Geochemical Characteristics of Sediments and River waters, Hwasun-cheon)

  • 오강호;고영구;김주용;김해경
    • 한국환경과학회지
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    • 제11권9호
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    • pp.881-895
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    • 2002
  • Sediments and river waters form the channel of Hwasun-cheon were studied in sedimentological size and geochemical analyses of metallic elements for the purposes of identification of depositional environments and geochemical characteristics. The sizes of sediments are assigned to pebble to coarse sand in mean size and polymodal in distribution. And the sediments are poorly to very poorly sorted and positively skewed. According to the grain size distributions of the sediments, the Hwasun-cheon belongs to gravel-bed river on the basis of the grain size distribution of the sediments. The behaviors of metallic elements in the sediments mainly depend on not grain size distribution but the geology connected with geomorphological reliefs near the stream. Contamination indices(CI) of Zn, Cu and Pb are 2.83 to 6.96 with average 4.31 in the sediments. Hwasun-cheon is assigned to general stream type in accordance with water quality of physical factors and chemical characteristics by Piper's diagram. Though meaningful values of BOD, T-N, T-P were locally depicted near Masan-ri, Hwasun-eup and Jiseok-cheon areas, artificial metal concentration do not represent in the most area of the stream. Sediments and river water are considered that the relatively more or less high metallic contents in the stream are originated from coal mine and urban area.

기반암별 산지와 곡지의 지형 기복 특성과 유형 (Characteristics and classification of landform relieves on mountains and valleys with bedrock types)

  • 이광률
    • 한국지형학회지
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    • 제21권4호
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    • pp.1-17
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    • 2014
  • 본 연구는 우리나라의 12개 기반암 지역과 24개 산지와 곡지를 대상으로 지형 기복 특성을 분석하고, 이를 토대로 기반암과 지형 기복 간의 특성 및 관계를 다음의 4가지로 유형화하였다. 1) 편마암-고 산지와 화강암-고의 전체, 산지, 곡지는 지반 융기로 인하여 하천의 하각 작용은 활발하지만, 삭박의 영향이 사면 전체에 전달되지 못하여, 매우 높은 해발고도에 비해 기복과 경사는 상대적으로 크지 않다. 2) 편마암-고 전체, 곡지, 편마암-중 산지, 편암-산지, 화강암-중 산지, 화산암 전체, 산지, 퇴적암-고(역암) 전체, 산지, 곡지, 퇴적암-중(사암, 셰일) 산지, 석회암 전체, 산지 지역은 하천 침식과 사면 운반 작용이 활발하지만, 풍화 침식에 대한 저항력이 강한 기반암이나 지질 구조를 가져서 지형 기복이 큰 편이다. 3) 편마암-중 전체, 곡지, 편암-전체, 곡지, 화강암-중 전체, 곡지, 화산암 곡지, 퇴적암-중 전체, 곡지, 퇴적암-저(셰일) 산지, 석회암 곡지 지역은 풍화 침식에 대한 저항력이 약하며, 사면과 하곡에서 풍화, 사면 운반, 하천의 침식, 운반, 퇴적 작용이 진행되어, 지형 기복이 작은 편이다. 4) 편마암-저 전체, 산지, 곡지, 화강암-저 전체, 산지, 곡지, 퇴적암-저 전체, 곡지 지역은 고도가 낮은 해안에 위치하여, 하천의 침식 작용과 활발한 사면 운반작용은 거의 발생하지 않아, 지형 기복이 매우 작다.

계곡형 토석류가 발생한 급경사 신기 계곡의 특성 (Characteristics of Steep Shingi Gully with Channelized Debris Flows)

  • 박상덕;김용현;함광현;손상진;나락스메이;김남진
    • 한국지형학회지
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    • 제28권3호
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    • pp.13-26
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    • 2021
  • In mountain gully, channelized debris flow is an important phenomenon in the process of topographical change. Social infrastructure as roads may be damaged by channelized debris flows, but there has been little information about their occurrence and movement to prepare for the risk of the debris flow. Most of the channelized debris flows occur during heavy rains in mountainous valleys that are difficult to access, so there are not many field data. In this study, the topographical characteristics of the catchment, the rainfall and runoff related to the debris flow, the sedimentary pattern and the cross-sectional change of the channel bed, and the underflow velocity of the gravel bed have been investigated and analyzed in the Singi gully where the channelized debris flows occurred. In the catchment, there was almost no sediment runoff because the vegetation combine with the debris landforms and covered the surface. Therefore, the obvious cause of the channelized debris flows is the collapse of the slope and bed of the gully. Even if the gravel, cobbles, and boulders of the channel bed were lost by debris flow, the thalweg change due to debris flow may not be significant because they are supplied from the gully side slope normally. After the gabion structures were installed, the debris flow increased the thalweg change, bed erosion and side slope of the gully. Various sedimentary structures in the gully were classified according to the factors supporting the sedimentation. The hypsometric curve of the gully reflects the debris landforms and vegetation characteristics of the watershed and the sediment runoff due to debris flow, etc. The relationship between the flow velocity and the hydraulic gradient was non-linear under the condition that the porous medium with gully bed gravels is saturated with water. These results may be used as basic data for channelized debris flow research.

GIS 기법을 이용한 금강 유역의 지형학적 특성 분석 (Analysis of Geomorphological Characteristics of Gum River Basin using GIS)

  • 이미선;박근애;김성준
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2006년도 학술발표회 논문집
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    • pp.858-863
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    • 2006
  • 본 연구에서는 금강유역을 대상으로 GIS기법에 의해 1:5,000 NGIS자료로부터 DEM과 하천망을 생성하였고, 이를 이용하여 하천차수별 하천수, 하천연장과 평균하천연장의 하천특성인자와 유역면적, 유역평균폭, 최원유로연장, 하천총수, 총하천연장, 수계밀도, 수계빈도, 형상인자, 평균표고, 평균경사, 최대하천차수, 유역내 최고표고, 기복비 등의 유역특성인자들을 추출함으로써 수자원단위지도 기반의 단위유역별 지형학적 특성을 파악하였다. 또한 대상유역을 금강권역상류, 금강권역중류, 금강권역하류유역으로 구분하여 지형학적 인자를 추출하고 그 특성을 분석하였으며, 선형 및 비선형 회귀곡선을 이용하여 인자들 간의 상관관계를 분석함으로써 각 유역을 특징짓는 주요 인자들을 추출하였다.

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비점오염 취약지역을 고려한 관리우선순위 설정 (Prioritization of Control Areas using Vulnerable Areas by Non-point Source Pollution)

  • 김홍태;신동석;김용석
    • 한국농공학회논문집
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    • 제56권6호
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    • pp.11-18
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    • 2014
  • Vulnerable areas by non-point source pollution and prioritizing control areas were researched using hydrological and geomorphological data, non-point source loads, and water quality data. Using overlay analysis, vulnerable areas were graded with various scenarios. Vulnerable areas were selected near the metro city with impermeable landuse because non-point source loads and water quality data had influence on overlay analysis to rank vulnerable area. Analysis scenarios and weighted values can be changed under regional characteristics and given conditions.