• Title/Summary/Keyword: tidal variation

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Characteristics of Surface Topography and Sediments before and after the Typhoon Kompasu in the Gochang Open-Coast Intertidal Flat, Korea (태풍 곤파스 전과 후의 고창 개방형 조간대 표층 지형과 퇴적물 특성)

  • Kang, Sol-Ip;Ryang, Woo-Hun;Chun, Seung-Soo
    • Journal of the Korean earth science society
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    • v.40 no.2
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    • pp.149-162
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    • 2019
  • In the macro-tide open coast of the Korean western coast, typhoon effects were investigated in terms of variations on topography, surface sediment, and sedimentary environment, which appeared before and after the typhoon Kompasu of 2010. The Kompasu of small size and strong intensity landed on the southwestern coast of the Korean Peninsula and passed across the inland between September 1st and 2nd in 2010. Topography and surface sediments before and after the typhoon were measured and sampled along the survey line of 22 sites in the Gochang Donghori intertidal flat. The intertidal area was divided into high tidal zone, middle tidal zone, and lower tidal zone on the basis of mean high water level, mean sea level, and mean low water level. Topographic variation before and after the typhoon represented deposition of average 0.03 m in high tidal zone, erosion of average -0.15 m in middle tidal zone, and erosion of average -0.39 m in lower tidal zone, respectively. Surface sediments of the intertidal flat consisted mainly of fine to medium sands, and the ratio of fine sand was the largest both before and after the typhoon. Surface sediments after the typhoon became finer in mean grain size showing well sorting rather than those before the typhoon.

Study on Beach Face Variation Based on Long-term Measurement Data Analysis in Byeonsan Beach (장기관측자료 분석을 통한 변산해수욕장의 해빈변화 고찰)

  • Eo Dae-su;Choi Kang-won;Kang Sang-ki
    • KCID journal
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    • v.6 no.1
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    • pp.39-47
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    • 1999
  • One of the important features of a beach face is the dynamic response to the ever-changing waves and tides imposed from the body of water. Furthermore, human activities at or near the beach can enforce the characteristic changes on tidal motions and wave

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A Taxonomic and Ecological Study of Gloiopeltis furcata J. Agardh (Rhodophyta) in Korea

  • Lee, Jae-Won
    • Journal of Plant Biology
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    • v.38 no.2
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    • pp.165-171
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    • 1995
  • Plants of G. furcata were divided into four variant populations. The habit characteristics, external and internal morphology were analysed quantitatively in order to clarify their morphological variation. Among four variant populations, type I(typical G. furcata type) and type II(G. furcata f. intricata type) may be influenced by the time when the develop from the crustose basal discs and the tidal level. Type III is the immature plants, and type IV (G. furcata f. coliformis type) is a G. furcata population in late spring after the luxuriant season. For the reason, the formas of G. furcata f. intricata and f. coliformis are no more valid in Gloiopeltis furcata.

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A study of sedimentation processes in Dongjin and the Mankyung rivers esturay (만경강과 동진강 하구의 퇴적과정에 관한 연구)

  • 신문섭
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1999.10c
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    • pp.143-148
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    • 1999
  • The purpose of this study is to find sedimentation patterns variation before and after Saemangeum reclamation. Water circulations are calculated diagnostically from the observed water temperature and salinity data and wind data and tidal residual current. Three dimensional movements of injected particles due to currents, turbulence and sinking velocity are tracked by the Euler-lagrange methoed. Calculated sedimentation patterns of riverine material are highly similar to the observed ones.

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Variation of the M2 tide amplitude around the Jeju-Do (제주도 주변 M 2조의 진폭변화)

  • Kim, Kuh;Lee, Sang-Ho
    • 한국해양학회지
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    • v.21 no.3
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    • pp.171-183
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    • 1986
  • The amplitudes of the M2 tide recorded at Seoguipo and Jeju are 77.9cm and 70.1cm respectively, which differ by 7.8cm over a distance of 30km across the Jeju-Do. The difference is an example of the geographical variation of the tidal amplitude around the Jeju-Do, the larger amplitude being along its southern coast compared with that along its northern coast. This variation can be explained in terms of effects of an island on the wave propagation as modelled by Proudman(1914). A numerical experiment of the M2 tide around the Jeju-Do reproduces the basic pattern of the observed variation and results are consistent with the theory. Due to the rotation of the earth larger and smaller amplitudes result along the left-hand and right-hand coasts of an island for an observer facing the direction of the wave propagation in the northern hemisphere.

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A Study on the Telemetry System of Temperature and Salinity (수온 . 염분 원격측정시스템에 관한 연구)

  • 이유원
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.33 no.2
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    • pp.132-140
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    • 1997
  • The basic experiment on the telemetry system of temperature and salinity, which is a study for the effective management of costal fishing-ground nowadays, was carried of 8 days from April 5, 6, 26, 27 , 1996 to May 31 and June 1, 21, 22, 1996 at the fish farm of Yooksam at Samyang-Myun, tongyongkun(34。45.02'N, 128。24.79'E). The results obtained were as follows : 1. The average temperature and salinity of STD of telemetry system was coincided with that of ICTD system calibration precisely. 2. A daily variation of temperature in fish cage which was measured by the telemetry system was influenced mainly by sunrise and sunset. 3. A daily variation of salinity in fish cage which was measured by the telemetry system was influenced mainly by tidal current. 4. The fish school in fish cage was distributed mainly 2~7 m layer during daylight and was arisen to the surface at sunset, was settled down to the bottom at sunrise.

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광도만에 있어서 물질수송과정의 수치예측

  • 이인철;류청로
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2000.10a
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    • pp.159-164
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    • 2000
  • In order to clarify the seasonal variation of residual current and material transportation process in Hiroshima Bay, JAPAN, the real-time simulation of residual current and particle tracking by using Euler-Lagrange model were carried out. The calculated tidal current and water temperature and salinity showed good agreement with the observed ones. The residual currents showed the southward flow pattern at the upper layer, and the northward flow pattern at the lower layer. The flow structure of residual current in Hiroshima Bay is an estuarine circulation affected by density flow and wind driven current. The residual current plays an improtant role of material transportation in th bay.

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Characteristics of Red Tide Blooms in the Lower reaches of Taehwa River (태화강 하류의 적조발생 특성)

  • Cho, Hong-Je;Yoon, Yeong-Bae;Kang, Ho-Seon;Yoon, Sung-Kyu
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.4
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    • pp.453-462
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    • 2011
  • This study was analyzed to determine the cause of red tide at 10 and 30 days antecedental rainfall, stage and discharge in the Taehwa River, tidal data of Ulsan port, also, it was analyzed variation of red tide population, salinity, BOD, COD, T-N, T-P at S1, S2 each point. Most of the red tide in the Taehwa River occurred by provision of proper nutrients with antecedent, the proximity between discharge and low-flow capacity, and stage and discharge of stabilized condition after the sea water was inflowed by maximum tide difference. Red tide population is not nearly related to the change of salinity, the Taehwa River seems specific features of Non-coastal rivers downstream, because red tide was occurred when salinity quite low-end condition.

Pre-Estimation of Soil Diffusion Caused by the Sea Construction (해상공사에 따른 토사확산예측)

  • 신문섭
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.8 no.2
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    • pp.204-214
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    • 1996
  • The purpose of this study is to find a variation in traveling patterns of soil and soil diffusion due to construction of the sea dike in Saemangum coastal sea region. Water circulations are calculated diagnostically from the observed water temperature, salinity and wind data, and tidal residual current. Three-dimensional movements of injected particles due to currents, turbulence and sinking velocity are tracked by the Euler-Lagrangian method. Calculated a variation in traveling patterns of soil and soil diffusion due to construction of the sea dike deposited mostly from estuarine area of the Geum River to Gokunsan coastal sea region. This results are believed to be the combined effect of coastal circulation.

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Seasonal Variation of Coastal Front by Numerical Simulation in the Southern Sea of Korea (수치모델을 이용한 한국 남해안 전선의 계절변동)

  • Bae, Sang-Wan;Kim, Dong-Sun
    • Journal of Environmental Science International
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    • v.20 no.9
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    • pp.1141-1149
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    • 2011
  • The three-dimensional hydrodynamic model was simulated to understand coastal sea front of formation and seasonal variation in the Southern Sea of Korea. In this study, we used to concept of stratification factor, to realize seasonal distribution of stratification coefficient which of seasonal residual flow, considered with, tide, wind and density effect. Tidal current tends to flow westward during the flood and eastward during ebb. The current by the wind stress showed to be much stronger the coastal than the offshore area in the surface layer. And the current by the horizontal gradient of water density showed to be relatively weak in the coastal area, with little seasonal differences. On the other hand, the flow in the offshore area showed results similar to that of the Tsushima Warm Current. The stratification factor (SHv) was calculated by taking into account the total flow of tide, wind and density effect. In summer, the calculated SHv distribution ranged from 2.0 to 2.5, similar to that of the coastal sea front. The horizontal temperature gradient showed to be strong during the winter, when the vertical stratification is weak. On the other hand, the horizontal gradient became weak in summer, during which vertical stratification is strong. Therefore, it is presume that the strength of vertical stratification and the horizontal temperature gradient affect the position of the coastal sea front.