• Title/Summary/Keyword: sand dune grain analysis

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A Study on the Environment Change of Tidal Flat in the Cheonsu Bay Using Remotely Sensed Data (원격탐사 자료를 이용한 천수만 간석지 환경변화에 관한 연구)

  • Jang, Dong-Ho;Chi, Kwang-Hoon;Lee, Hyoun-Young
    • Journal of Environmental Impact Assessment
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    • v.11 no.1
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    • pp.51-66
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    • 2002
  • The purpose of this study is to analyze the geomorphological environment changes of tidal flat in the Cheonsu Bay. Especially, it centers on the changes in the sedimentary environment using remote sensing data. Multi-temporal Landsat data and topographic maps were used in this study. The results are summarized as follows: the tidal flat of Cheonsu Bay changes in many ways depending on the direction of the tidal current. In the neighborhood of Ganwoldo, the scale of the tidal flat has continuously been expanded due to the superiority of sedimentation after a tide embankment was built. When we analyzed the grain size of sediments and implemented in-situ field survey, it was found that the innermost part of the bay consists of a mud flat, with the midway part mixed flat, and the nearest part to the sea sand flat. On the other hand, in the neighborhood of Seomot isle and its beach, sedimentation is superior in the eastern part whereas erosion is superior in the western part. In other words, the western coast of the beach is contacted with the open seas and under much influence of ocean wave. The eastern coast is placed at the entrance of the bay and has sand bar and tidal flat developed due to submarine deposits that are accumulated on the sea floor by the tidal current. In conclusions, remote sensing methods can be effectively applied for quantitative analysis of geomorphological changes in tidal flat, and it is expected that the proposed schemes can be applied to another geomorphological environments such as beach, sand dune, and sand wave.

Analysis of Shoreline Change Using Multi-temporal Remote Sensed Data on Songjeong Beach, Busan (다중시기 원격탐사 자료를 이용한 부산 송정해수욕장의 해안선 변화 분석)

  • Jang, Dong-Ho;Kim, Jang-Soo;Baek, Seung-Gyun
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.4
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    • pp.59-71
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    • 2012
  • This research was carried out to analyze long-term shoreline change on Busan Songjeong Beach using multi-temporal remote sensed data, GPS survey data and grain size analysis. As a result of multi-temporal satellite imagery analysis, the beach was stable status till early 2000s, but the erosion occurred over whole beach after the construction of shore protection road since 2000. In the result of DEM analysis, the elevation of beach reduced and the slope of berm increased after construction of shore protection road along the coast, this means the erosion environment was dominant on the beach. But the sedimentation was slightly stronger than the erosion in northern region of the beach, then the slope of berm was gentle. In the result of grain size analysis using in-situ samples, the coarsening-trend was found in southeastern region (Line E) of the beach, it is caused by strong wave energy from the outer sea. Consequently, major causes of the beach erosion in the study area were the interception of sand supply from a dune owing to shore protection road construction and scouring phenomenon by strong wave energy in southeastern region of the beach. If the topographic or artificial change will not occur in the future, the erosion in this area will continue. Therefore the prevention measures are required.