• Title/Summary/Keyword: tides

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Sea Level Change due to Nonlinear Tides in Coastal Region (연안해역에서 비선형 조석으로 인한 해수면 변화)

  • Jung, Tae Sung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.29 no.5
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    • pp.228-238
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    • 2017
  • In coastal region, tidal harmonic constants of semi-diurnal tides and nonlinear tides were collected. The observed tide data of KHOA were analyzed by a tide harmonic analysis method. In the southwestern coasts and Han river estuary, nonlinear tides are clearly generated. The generation of tide non-linearity and tide asymmetry is closely related with tide form factor in Korean coastal zone. Tide non-linearity and asymmetry in Mokpo harbour have increased by a series of coastal development projects. The increase has caused rise of high water level and drop of low water level, and increase of tidal range. In Kunsan Outport, tidal range has been declined due to inter-annual change of nonlinear tides after completion of Samangeum sea-dyke.

Seawater Quality And Red Tides In Jinhae Bay:I. Relationships Between Water Quality Parameters And Red Tides

  • Lee, Kwang Woo;Hong, Gi-Hoon;Yang, Dong-Beom;Lee, Soo-Hyung
    • 한국해양학회지
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    • v.16 no.2
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    • pp.43-48
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    • 1981
  • To carry out baseline studies on monitoring systems for red tides in Jinhae bay, measurements and analyses were made on seawater samples from 15 sampling stations during 15 months from July, 1979. Water quality parameters studied are temperature, pH, DO, salinity, COD, SS, NO$\sub$3/, NO$\sub$2/, PO$\sub$4/, SiO$\sub$2/, Ca, Mg, Cd, Cu, Pb, Zn, Chlorophyll ${\alpha}$, diatoms and dinoflagellates. Multiple regression analyses were undertaken with chlorophyll ${\alpha}$, cell numbers of diatoms and dinoflagellates as the dependent variables and water quality parameters as the independent variables. The results showed that biomass, expressed as total cell numbers of diatoms and dinoflagellates, was largely influenced by COD, salinity and nutrients.

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Nutrients And Chlorophyll $\alpha$ Variations At A Fixed Station During The Red Tides In The Jinhae Bay

  • Yang, Dong-Beom;Hong, Gi-Hoon
    • 한국해양학회지
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    • v.17 no.1
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    • pp.19-26
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    • 1982
  • 12 or 25 hours continuous observations were made for the variations of nutrients and chlorophyll ${\alpha}$ with tidal cycle at a fixed station located at a mid-channel of the Masan Bay. High nitrate concentrations were observed at the time of low tides whereas high phosphate concentrations at the time of high tides. It is suggested that anoxic bottom waters could also be the possible source of high phosphates in the outer bay. Chlorophyll ${\alpha}$ concentrations were related to the nitrates in April and to the phosphates in June and August. The possible role of growth stimulators in causing the extensive blooms of red tide organisms is suggested.

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Rapid Tidal Predictions for the Inchon Bay (인천항 조석의 신속 예보)

  • 최병호
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.7 no.4
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    • pp.355-367
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    • 1995
  • Tidal prediction at a given location has been conventionally made by harmonic method. Another means of tidal prediction is through numerical modeling of tides. Present research focussed on whether prediction of tides and tidal currents can be made everywhere in the Inchon Bay using the numerical model directly or by harmonic constants of tides and tidal currents of the whole Bay derived from the extended model run.

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The Effect of Typhoons on Red Tide (태풍이 적조에 미치는 영향)

  • Hong, Chul-Hoon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.50 no.2
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    • pp.222-226
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    • 2017
  • It is well known that typhoons strongly influence marine ecosystems. For example, red tides nearly disappear after the passage of typhoons, although the physical or biological mechanism underlying this has not been elucidated. Here, a particle tracking model is executed in a three-dimensional primitive equation model to understand the process of red tide extinction after the passage of a typhoon. Red tide organisms may be regarded as tracers because they have limited mobility and thus their behavior is governed entirely by currents. Initially, tracers are randomly scattered within a limited area, and their spatial and temporal behavior is tracked during and after the passage of a typhoon. This model suggests that the extinction of red tides is significantly influenced by momentum disturbances caused by the typhoon.

Application of A Depth-Averaged Two-Dimensional Mathematical Model to Tidal Computations in the Estuary near Gunsan Port (수심평균 2차원 수학적 모형(TIFS)을 이용한 금강하구 및 연해의 조석계산)

  • 박창언;박승우
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.28 no.1
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    • pp.60-67
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    • 1986
  • A depth-averaged two dimensional model TIFS was developed from simplified basic flow equations. The model was applied to tidal computations for the Biin Bay area near the Gunsan port. Vertical tides and tidal velocities for the tested was simulated for neap and spring tides. The simulation results were in good agreement with the obserbed data. This paper also attempts to evaluate model sensitivity from different initial conditions, roughness coefficient, time increments, and water depths. Among the selected input parameters, water depth and roughness coefficient were found to significantly affect vertical and horizontal tides.

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Tidal Computations for the Southwestern Sea of Korea (한국 남서해역의 조사 산정)

  • 최병호;정홍화;조양기
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.7 no.2
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    • pp.163-169
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    • 1995
  • A two-dimensional numerical tidal model is formulated to reproduce tides in the Southwestern Sea of Korea. Tidal charts and ellipses of eight major tidal constituents (M$_2$, S$_2$, K$_1$, O$_1$, N$_2$, K$_2$, P$_1$, Q$_1$) are presented. Model results show that the semi-diurnal tides are dominant in this area. Maximum transport by tides in the Cheju Strait is about 4.2${\times}$10$\^$6/ ㎥/sec which is greater by eight times than that by residual current.

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Additive Materials to Reduce the Amount of Loess Being Applied for Red Tide Removal on Coastal Water (적조방제용 황토살포의 양을 줄일 수 있는 첨가제에 대한 연구)

  • Park, Chi-Hyun;Lee, Byoung-Ho
    • Journal of Environmental Science International
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    • v.16 no.6
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    • pp.745-750
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    • 2007
  • Large scale of loess has been applied on the south - sea shore of the Korean peninsula to treat red tides, due to many fishery's devastation by red tides every year. However, coastal ecosystem is ruined by the huge amount of loess applied every year. Almost all creatures, living under water such as sea weeds, clams, and fishes, where loess was applied, are disappearing. In this paper, alternative methods of the loess application are investigated. The amount of loess could be reduced by the alternative methods, Especially, loess mixed with calcium oxide has excellent effects to reduce Cochlodinium polykrikoides numbers. It was found that when loess is used with calcium oxide(CaO), removal efficiency of red tides is highly increased. Moreover, the amount of loess could be reduced dramatically.

Detection of Red Tides by IRS/OCM Imagery

  • Kang, Y.Q.;Suh, Y.S.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.697-699
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    • 2003
  • We present a simple algorithm for detection of red patches by remote sensing in coastal waters of Korea. The red tide patches can by identified by the relative intensity of red band signal with respect to the blue-green background signal, provided the radiometric signals only in the sea area are properly stretched. We tested our algorithm by Ocean COlor Monitor(OCM) data of Indian Satellite IRS-P4, which has been received from 2001 by National Fisheries Research and Development Institute of Korea. A comparison of our results with observation shows that the locations of red tides derived from remote sending imagery by our algorithm are in accordance with observations.

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Disaster Characteristics Analysis at Busan Coastal Areas by Typhoon Maemi in 2003 (2003년 태풍 매미로 인한 부산 연안지역의 재해특성 분석)

  • 서규우
    • Journal of Ocean Engineering and Technology
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    • v.18 no.2
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    • pp.25-32
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    • 2004
  • We surveyed the coastal structure damage created by typhoon ‘Maemi’, which heavily struck the Korean peninsula on September 12, 2003. The survey revealed that high tides and strong winds induced by the typhoon were the main causes of the coastal damage, especially in the Busan areas. Though some experimental real-time coastal monitoring stations captured the typhoon movements at the critical time, more systematic and complete system should be implemented to save human lives and property from huge typhoon disasters.