• Title/Summary/Keyword: Coastal boundary

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Boundary Integral Equation Method by Cubic Spline (Cubic Spline을 사용한 경계요소법)

  • 서승남
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.2 no.1
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    • pp.11-17
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    • 1990
  • Dirichlet boundary value problems originated from unsteady deep water wave propagation are transformed to Boundary Intergral Equation Methods by use of a free surface Green's function and the integral equations are discretized by a cubic spline element method. In order to enhance the stability of the numerical model based on the derived Fredholm integral equation of 1 st kind, the method by Hsiao and MacCamy (1973) is employed. The numerical model is tested against exact solutions for two cases and the model shows very good accuracy.

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Estimation of Atmospheric Dispersion Coefficients in A Coastal Area with Complex Topography (복잡한 지형의 임해지역에서 대기 분산계수의 평가)

  • 박옥현;천성남
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.5
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    • pp.411-420
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    • 1998
  • To estimate the dispersion coefficients in a coastal area with complex topography, several schemes using empirical equations expressed with and in lateral and vertical directions, respectively have been examined. Estimation results using these equations and meteorological data obtained from SODAR system were compared' with previously measured dispersion coefficients in other coastal areas. Validations of estimation results have been performed by comparing the measured concentrations with predicted ones empolying in Boryung coastal area. Important conclusions were drawn as follows; (1) Variations of lateral and vertical wind direction revealed different height dependency in upper and lower mixed boundary layer. (2) Because of turbulent constraint effect by large water body in a coastal region, the lateral and the vertical dispersion coefficients were smaller than those of P-G system. (3) As a result of examining the performance measure of these schemes through checking of coincidence between measured and predicted concentrations, vertical dispersion coefficients were smaller than those of P-G system, and the Cramer scheme was found to be more appropriate rather than others in the coastal area surrounding Boryung power plant.

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Characteristics of Ozone Advection in Vertical Observation Analysis Around Complex Coastal Area (연직관측자료를 통한 복잡 연안지역의 오존 이류특성)

  • Lee, Hwa-Woon;Park, Soon-Young;Lee, Soon-Hwan;Leem, Heon-Ho
    • Journal of Korean Society for Atmospheric Environment
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    • v.25 no.1
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    • pp.57-74
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    • 2009
  • In order to clarify the vertical ozone distribution in planetary boundary layer of coastal area with complex terrain, an observation campaign was carried out around Gwangyang Bay with dense pollutant emission sources during two days from June, 4 2007. For this observation are Radiosonde, SODAR(SOnic Detection And Ranging) and Tethered ozone sonde were employed. The surface meteorological and photochemical observation data provided by AWS (Automatic Weather System) and AQMS (Air Quality Monitoring System) were also applied for analysis. Synoptic condition is strongly associated with lower level ozone distribution in complex terrain coastal area. Since mesoscale circulation induced by difference of characteristics of land and sea and orographic forcing is predominant under calm synoptic condition, vertical distribution of ozone is complicate and vertical ozone concentration greatly fluctuated. However in second day when synoptic influence become strong, ozone concentration in lower levels is vertically uniform regardless of observation level. This results in vertical observation indicates that vertical ozone distribution is often determined by synoptic condition and also affects surface ozone concentration.

Prediction of Tidal Changes due to the Development of Incheon Coastal Waters (인천해역 개발에 따른 조석변화 추정)

  • 정신택;소재귀;채장원
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.6 no.3
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    • pp.266-274
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    • 1994
  • Two-dimensional numerical analysis is performed for the simulation of tidal characteristics related to various development projects in Incheon coastal waters along the west coast of Korea. Field observation of tides and currents was made in order to provide the input boundary and validation data set to the numerical modelling. For the simulation of changes of tides and currents a depth-integrated two-dimensional shallow water model of Flather and Heaps (1975) has been used herein. Tidal model is set up with open boundary sea level from observed two major constituents, M$_2$ and S$_2$. Subsequently the established model is utilized to investigate the effect of two development projects in this region. It has been found that in spring tide the changes of tidal amplitude are small, however, those of tidal current are locally significant.

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Coastal Typhoon Deposit in the Hampyung Bay, Southwest Coast of Korea

  • Park, Yong-Ahn
    • Journal of the korean society of oceanography
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    • v.31 no.1
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    • pp.32-36
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    • 1996
  • The oyster shell bed (more than 47 cm thick) atop the Gaipri Point (granite coastal bluff) in the Hampyung Bay, southwest coast of Korea which is a coastal area of southeastern margin of the Yellow Sea basin has been interpreted as unique typhoon deposit formed at about 3610 yr BP or later. The unconformable boundary between the oyster shell bed by typhoon and the granitic soil horizon of the Gaipri Point is 820 cm high above the mean high-tide water level (MHWL). The $^{14}C$ age of the oyster shells is 3610${\pm}$70 yr BP.

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The Evaluation of the Water Quality in Coastal Boundary on Tidal flat (통계분석기법을 이용한 전남 갯벌 해역 수질특성)

  • Jun, Sue-Kyung;Kim, Chong-Ki;Kim, Yun
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.14 no.1
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    • pp.1-10
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    • 2011
  • To understand characteristics of the water quality on the coastal boundary on tidal flat, field observations between 2008 and 2009 were undertaken twice a month at five coastal areas (Muan bay, Tando bay, Hampyeong bay, Shinan Jido and Yeongkwang coastal areas). Yearly water temperature difference was large with the range between $1.3^{\circ}C$ and $31.1^{\circ}C$. Salinity was about 32 but was the lower less than 20 for the heavy rainfall season. DO was high in winter and low in summer according to the variation of water temperature. pH represented the variation similar to DO. Suspended solid was averagely high over 100 mg/l in Yeongkwang coastal area, especially. COD did not revealed large variation with the value of about 1 mg/l. DIN and DIP concentration were high when freshwater was highly input in summer. DIN concentration was low for winter and early spring but DIP concentration did not show the seasonal variation with the continuous increase from July 2009 to December 2009. Chlorophyll a appeared high for spring with approximately $10\;{\mu}g/l$ and was higher for summer in Yeongkwang coastal area than other sites. The results of principal component analysis conducted to compare the characteristics of water quality observed in study areas showed the distinguishable features as follows. The freshwater input fluctuation appeared as the first factor in Muan and Tando bays, and the change of water temperature was the first factor in Shinan Jido and Yeongkwang coastal areas. The influence mixed with the variation of freshwater outflow and the change of water temperature in Hampyeong bay was to be the first factor.

Maritime Boundary Delimitation Regime for the Gulf of Tonkin Dispute and China's Position (해양경계획정제도에 대한 중국의 입장과 통킹만 사례고찰)

  • Yang, Hee-Cheol;Park, Seong-Wook;Kwon, Moon-Sang
    • Ocean and Polar Research
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    • v.26 no.4
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    • pp.669-678
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    • 2004
  • Coastal states are adopting maritime boundary delimitation as their primary maritime policy because maritime jurisdiction directly relates to vast economic interest. This becomes specially important and sensitive when complex maritime boundary issues are involved between neighboring coastal states. China has not actively carried out nor declared maritime boundary delimitation until recently with any country except Agreement between China and Viet Nam on the demarcation of the territorial water, the exclusive economic zones and the continental shelf of China and Vet Nam in the Gulf of Tonkin on 25 December 2000 (hereinafter, the Gulf of Tonkin Agreement). The principles that governs maritime boundary delimitation are to consider primarily an agreement between States concerned, however, if no agreement can be reached, all relevant circumstances are considered to achieve an equity between concerned States. Relevant circumstances are length of coastline, form of coastline, existence and position of island or islands, speciality of geology/topography, and factor of economy and deffnce. Factors which sinologists are considering in regard to continental shelf delimitation of the Yellow Sea are as follows; i) geographical factor, ii) geological factor, iii) topographical factor, iv) environment and ecological (factor, v) historic interest, and vi) social and economic interest. The 'Gulf of Tonkin Agreement' is completed by basically applying the principle of delimitation according to median line which seems that China has adopted the maritime boundary delimitation principle of 'half and half' which was the intention of chinese government. At the same time, China recognized Viet Nam's dominion and sovereign right over the partial exclusive economic zone and the continental shelf of Dao Bach Long Vi in Gulf of Tonkin. This case can be considered as an example of mutual concession or compromise in delimiting maritime boundary for states of concerned.