• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.86.2-86.2
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• 2009

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.2
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• pp.69-83
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• 2018

The South China Sea (SCS) is a typical marginal sea characterized with the deep basin, shelf break, shallow shelf, many straits, and complex bathymetry. This study investigated the tidal characteristics and propagation, and reproduced typhoon-induced storm surge in this region using the regional real-time tide-surge model, which was based on the unstructured grid, resolving in detail the region of interest and forced by tide at the open boundary and by wind and air pressure at the surface. Typhoon Haiyan, which occurred in 2013 and caused great damage in the Philippines, was chosen as a case study to simulate typhoon's impact. Amplitudes and phases of four major constituents were reproduced reasonably in general, and the tidal distributions of four constituents were similar to the previous studies. The modelled tide seemed to be within the acceptable levels, considering it was difficult to reproduce the tide in this region based on the previous studies. The free oscillation experiment results described well the feature of tide that the diurnal tide is prevailing in the SCS. The tidal residual current and total energy dissipation were discussed to understand the tidal and sedimentary environments. The storm-surge caused by typhoon Haiyan was reasonably simulated using this modeling system. This study established the regional real-time barotropic tide/water level prediction system for the South China Sea including the seas around the Philippines through the validation of the model and the understanding of tidal characteristics.

• Journal of Korea Water Resources Association
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• v.38 no.1
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• pp.83-96
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• 2005

Three-dimensional hydrodynamic numerical simulation is carried out to investigate the effects of the coastal land reclamation on the marine hydrodynamics, environment and ecosystem. The changes of tide, tidal currents and residual currents, including tide-induced, wind driven and density driven components due to the construction of the sea dike system are simulated numerically The governing equations transformed into o-coordinates are solved by an implicit finite difference method. The numerical model is calibrated using the tide charts of 4 major tidal constituents, M$_2$, S$_2$, $K_1$ and $O_1$. The numerical solutions show that there are significant changes of residual currents, especially induced by both tidal and wind-driven currents.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.2
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• pp.50-61
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• 2019

The aspects of typhoon-induced surges were classified into three types at the Western coast, and their characteristics were examined. The typhoons OLGA (9907) and KOMPASU (1007) were the representative steep types. As they pass close to the coasts with fast translation velocity, the time of maximum surge is unrelated to tidal phase. However, typhoons PRAPIROON (0012) and BOLAVEN (1215) were the representative mild types, which pass at a long distance to the coasts with slow translation velocity, and were characterized by having maximum surge time is near low tide. Meanwhile, typhoons MUIFA (1109) and WINNIE (9713) can be classified into mild types, but they do not show the characteristics of the mild type. Thus they are classified into propagative type, which are propagated from the outside. Analyzing the annual highest high water level data, the highest water level ever had been recorded when the WINNIE (9713) had attacked. At that time, severe astronomical tide condition overlapped modest surge. Therefore, if severe astronomical tide encounter severe surge in the future, tremendous water level may be formed with very small probability. However, considering that most of the huge typhoons are mild type, time of maximum surge tends to occur at low tide. In case of estimating the extreme water level by a numerical simulation, it is necessary not only to apply various tide conditions and accompanying tide-modulated surge, but also to scrutinize typhoon parameters such as translation velocity and so on.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2006.09a
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• pp.173-176
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• 2006

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.191-191
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• 2017

• Journal of Korean Society of Rural Planning
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• v.7 no.1 s.13
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• pp.61-76
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• 2001

During the performance of large scale tidal land reclamation project along the coast line, the construction of large scale structures such as sea-dikes, closing estuaries will induce big changes of near-shore hydraulic behavior. In this paper, its is aimed to verify the change of tide and currents after the construction of sea-dike of the Saemangeum project along the coast line. Numerical scale model "TRISULA" which development by Delft Hydraulics in the Netherlands was used. "TRISULA" is adopting the finite difference numerical scheme, and mostly using for hydro-dynamic solution along the sea and estuaries. Model boundary is covering $100{\times}170$ Km and constructed with $133{\times}337$ grids. Outer side boundary is divided 48 sections, and input 37 tidal components are gained from another big scale numerical "Yellow Sea" model. Model calibrations & verifications were performed th field tide & current datas which were measured along sea-dike alignment during Aug. $1997{\sim}Apr$. 1999. And then, numerical simulation with the tide condition dated 17 Apr. 1999 was performed with & without sea-dike construction condition for the comparison. Evaluated boundary is 20 km out-side from sea-dike alignment. Four cross lanes were set up, each of lane contains 3 points, for the comparison of sea-dike construction effects. Results showing the tidal amplitude is reducing approximately 20 cm after the construction of sea-dike during spring tide condition, amplitude 6.9m. Currents after construction of sea-dikes along the alignment, the northern part shows 50%(inner), 90%(outer) and the southern part shows 10%(inner) 50%(outer) of the currents before construction.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.6
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• pp.381-389
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• 2012

An EST-based method which is applicable for estimating extreme sea levels from short sea-level records in a tide dominated coastal zone was developed. Via the method, annual maximum tidal level is chosen from the simulated 1-yr tidal data which are constituted by the independent daily high water levels, short term and long term surge heights and typhoon-induced surge heights. The high water levels are generated considering not only spring/neap tides and annual tide but also 18.6-year lunar nodal cycle. Typhoon-induced surges are selected from the training set which is constructed by observed or simulated surge heights. This yearly simulation is repeated many hundred years to yield the extreme tidal levels, and the whole process is carried out many hundred times repeatedly to get robust statistics of the levels. In addition, validation of the method is also shown by comparing the result with other researches with the tidal data of Mokpo Harbor.

• Journal of Environmental Science International
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• v.9 no.5
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• pp.369-374
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• 2000

The estuary of Nakdong river is very influenced by the freshwater contained nutrients and organic materials. The response results of these influences are eutrophication and red tide outbreak in this region. Concentration of chlorophyll a was 0.78~62.55$\mu\textrm{g}$/L in February 1.20~21.29$\mu\textrm{g}$/L in April 1.88~188.35$\mu\textrm{g}$/L in June and 0.78~11.21$\mu\textrm{g}$/L in August respectively. The decrease of chlorophyll a is considered that residence time is shorten by increase of freshwater discharge and unfavorable growth condition of phytoplankton is created by diffusion of low salinity and increase of turbidity. The phytoplankton maximum region located inner side of this estuary during winter season whereas it was moved to outer side when mean discharge of the Nakdong risver was increased, Therefore the variation of phytoplankton maximum region was affected by input discharge from the Nakdong river basin.

• Proceedings of the Korea Water Resources Association Conference
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• 1982.07a
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• pp.91-98
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• 1982

The formulation of depth-averaged two-dimensional mathematical model for the analysis of tide induced circulation in a harbor by the Galerkin finite element techique is presented. In integration of the Galerkin approach in time both explicit and implicit method have been tested for one and two dimentional water bodies, and the two step Lax-Wendroff explicit method is found to be effective than the implicit in reducing computing time. The essential characteristics of the tide induced flow in Busan Harbor with two open boundaries has been foccud to be reproduceable in the numerical model and the simulated results encourage that the model can be used as a predictive tool.