• Title/Summary/Keyword: Geomorphological Change

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Basic Research of the Paleo-Environmental Change and Possibility of Ancient Port Location Through Geomorphological Survey and Sediment Analysisin Hwaseong City (화성 당성 유적 일대의 지형 조사 및 퇴적물 분석을 통한 고환경 변화 및 고대 포구 입지 가능성 기초 연구)

  • Han, Min;Yang, Dong-Yoon;Lim, Jaesoo
    • Journal of The Geomorphological Association of Korea
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    • v.24 no.4
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    • pp.27-41
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    • 2017
  • In this study, geomorphological and geological research has been carried out to estimate the possibility of ancient port location near Hwaseong Dangseong. Geomorphological characteristics around Eunsupo were analyzed through comparison of past and present topographic maps and field survey. Grain size, age dating, and geochemical analysis on surface sediments and borehole sediments were performed. Through the geomorphological characteristics analysis, it was interpreted that Eunsupo area was submerged in seawater especially at high tide in the past, and that ships could approach to the inside of the area through the tidal channel which were developed in the area. It is also assumed that ships were anchored at a low elevation point in the area. The paleo-environmental change in the area was analyzed based on the classification of sedimentary environment using grain size distribution of surface and borehole sediments and geochemical analysis. It was confirmed that the geomorphological interpretation for the possibility of ancient port location coincided well with the paleo-environmental change interpreted through sediment analysis. This study is a basic study for estimating ancient port location, and it is expected that more accurate paleo-environmental changes will be restored through detailed geomorphological survey and additional borehole analysis in the future research.

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.

Did Fluvial Terrace of Mountain Streams in Korea Form in Each Glacial Stage? (우리나라 산지 하천의 하안단구는 매 빙기마다 형성되었는가?)

  • Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.3
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    • pp.19-30
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    • 2019
  • This study summarizes domestic and foreign previous works on fluvial terrace with absolute ages to discuss formative process of climatic terrace in Korea. Different from traditional climatic terrace model, approximately three quarters from foreign works have argued that formation of climatic terrace can be attributed to medium- and short-term climatic change or other environmental factors, rather than long-term climatic change of glacial and interglacial cycles. Based on previous works on fluvial terrace in Korea, it can be suggested that fluvial terrace in Korea formed not due to long-term climatic change of 100,000-year cycles related to glacial and interglacial cycles, but due to medium- and short-term climatic change or climatic event of tens of thousands of years related to intensity change in summer monsoon, one of the important factors affecting precipitation in Korea.

The Change of Vegetation Environment since middle-late Holocene in the lower reaches of Taehwa River, Taehwa-dong, Ulsan-si, Korea (울산 태화강 하류 태화동 홀로세 중·후기 식생환경 변화)

  • Kim, HyeRyung;Yoon, Soon-Ock;Hwang, Sangill
    • Journal of The Geomorphological Association of Korea
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    • v.23 no.2
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    • pp.1-13
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    • 2016
  • This study analyzed pollen compositions in archaeological site on alluvial plain of Taehwa River, Taehwa-dong, Ulsan-si vegetational and environmental change during 6,200~3,000 yr BP. The results consist upward of Pollen Zone I (Inner Bay environment), Pollen Zone II (Quercus-Alnus stage) and Pollen Zone III (Alnus stage). The pollen grains of Fagopyrum and reddish gray silty horizon including artifacts of the Bronze Age suggest that there was cultivation on dry-field around the study site, although it is not sure that there was paddy-field cultivation.

Holocene Sea Level Change and Geomorphic Process of the Uihang Coast in Taean (태안 의항 해안의 홀로세 해수면 변화와 지형 형성과정)

  • Lee, Gwang-Ryul
    • Journal of The Geomorphological Association of Korea
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    • v.28 no.4
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    • pp.31-39
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    • 2021
  • Gaemok, the place name of Uihang-ri, Sowon-myeon, Taean-gun, Chungnam, indicates a tombolo. This study estimated the Holocene sea level change and development process of the coastal landforms of the Gaemok and Hwanyeong Tombolos in the Uihang coast. The tombolos seemed to form at approximately 3.4 ka and the average sea level at that time was estimated to be higher than that of the present by ca. 1 m. The Gaemok area was a separated island from the Taean peninsula during the Holocene Climatic Optimum. At approximately 3.4 ka when the sea level rose again after the fall, the Gaemok area was tied to the land by formation of the Gaemok and Hwanyeong Tombolos. The falling or fluctuating sea levels after 3.4 ka have shaped the present coastal landforms.

The design load factor of road structure considering long-term coastal geographic change (해안지형의 장기적 변화에 따른 도로 구조물 설계하중 고려 요소에 관한 연구)

  • Bae, Sun-Hak;Kang, Sang Hyeok
    • Journal of The Geomorphological Association of Korea
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    • v.20 no.1
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    • pp.75-83
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    • 2013
  • Human-induced modifications in coastal area may cause strong geomorphic responses by disturbing sediment supply, transport and deposition regimes. Morever, engineering structure have been built to stabilize coastal change, these effort impact on other morphologic change. In case of coastal area, there are lack of sediment yield data. This study focus on the tendency of long-term shoreline change, estimate method od sediment discharge which is a major factor of coastal change and adduced to way for considering design load influenced to coastal road.

Landsat 자료를 이용한 금강하류의 충적주 환경변화에 관한 연구

  • 장동호;지광훈;이봉주
    • Korean Journal of Remote Sensing
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    • v.11 no.2
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    • pp.59-73
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    • 1995
  • The study is focused on the analysis of geomorphological environment changes of alluvial bar in lower Kum river using satellite-based multitemporal/multisensor data. Landsat datas for environment changes analysis consists of Landset MSS(2 scenes) and Landset TM(7 scenes) acquired from 1979 to 1994. This study is to develop the analysis techniques for the environment change detection of using ratio, classification, false color composite etc, of Landsat data especially useful to the geomorphological study of tidal flats and river channels. The results of this study can be summarized as follows : 1. The lower Kum River alluvial bar have had rapid geomorphological changes after the construction of the temporary dam to block the river flowing in 1983. The most alluvial bar located in the river has both bankway growth, especially the allurival bar in the Lower Kum River had grown between 1983 to 1990. 2. After construction of the estuarine barrage, no remarkable geomorphological changes have been found in Kum River area but the growth and formation of new underwater bar has continued. The enormous materials was needed for the growth and formations of new underwater barrier oslands and bar would be supplied from the sea bottom and river sediment to diminish of stream velocity after construction of the estuarine barrage.

Sea level change and paleogeomorphological change since the middle Holocene in the lowerreaches of Taehwa River, Ulsan-si, South Korea (울산시 태화강 하류부의 Holocene 중기 이래 해수면변동과 고지형변화)

  • Kim, Jeong-Yun;Hwang, Sangill;Yoon, Soon-Ock
    • Journal of The Geomorphological Association of Korea
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    • v.23 no.1
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    • pp.61-75
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    • 2016
  • This study aims to reconstruct sea level change and paleogeomorphology since the middle Holocene by diatom analysis and 14C-dating from the sedimentary facies of three trenches on alluvial plain of Taehwa River, Taehwa-dong, Ulsan-si, South Korea. The Taewha-dong area was a narrow bay located between Bangeojin and eatuary of Taehwa River was a narrow bay which has been detached from the open sea during middle Holocene. Taewa-dong area at bay area was developed into alluvial plain by the sediments had been come from the Taewa river basin. The sea level change during the middle Holocene effected on the development of Taewha-dong alluvial plain and its information is included in the sediment facies.

The sediment runoff and geographic change around coastal structure using Korean modern map (근세 지도를 이용한 토사유출 및 항만구조물 주변의 지형변화 분석)

  • BAE, Sun-Hak;KANG, Sang Hyeok
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.3
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    • pp.135-142
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    • 2012
  • The map drawn on a scale of 1 to 50,000, modern Korea map drawn on a scale of 1 to 50,000 made by Japanese colonial era in 1910s, is the first topographical map using modern technical method. The map has been mainly used in human activities and geographic viewpoint, recently it is available on various field with recognizing high accuracy. It is especially expected that the map will provide us with lots of information on long-term change of topography in field of coastal area which is built on coastal structure. This study presents a method for analyzing before and after geographic change of coastal structure in independent drift sand system. The reference point to analyze long-term coastal geographic change was selected the map of 1910s.

Spatial-temporal Analysis of Topographical Change at the Malipo Beach (만리포 사빈의 시계열 3차원 지형 변화 분석)

  • PARK, Han San
    • Journal of The Geomorphological Association of Korea
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    • v.20 no.1
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    • pp.97-109
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    • 2013
  • This study introduces an analysis of the quantitative characteristics of topography and topographical changes based on precise 3D topography through 6 times surveys from December 2008 to January 2010 using Terrestrial LIDAR on the Malipo beach. The Malipo sand beach is mostly located between 0m to 1.5m MSL. The area of the beach above 2.25m, the Mean High Water, is very small. It have characteristics of topographical change of erosion and deposition along the entire coast line which more apparently appear in the northern beach than the southern part of the beach. Erosion prevails from spring to autumn, while during winter both erosion and deposition largely occur. Volumes from first and last survey were almost equal.