• Journal of Korea Water Resources Association
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• v.31 no.2
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• pp.209-219
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• 1998

Sea water volume intruded from the lock gated was compted by a one-dimensional numerical model and the extent of diffusion of sea water was evaluated for that. The volume of intruded sea water, in the exchange processes of salt and fresh waters, was computed by the conceptual model considering the tidal level, volume of chamber, volume of canal, and operation period only, It was divided into some cases according to whether ships enter or leave the canal and whether the level of tide is lower or higher than that of water level in canal. The model, developed in this work, assumed that intruded sea water is well mixed in the canal; and complete is the exchange of waters between sea and canal. The simulation case was divided into two categories according to whether the water was added from the Han River or not.

• Journal of Wetlands Research
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• v.8 no.1
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• pp.83-96
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• 2006

In this study, hydraulic flood routing is performed by 1-Di. unsteady flow model, FLDWAV on the downstream of Nakdong river. For input information, KOWACO Rainfall-Runoff Model is used and resonable boundary condition is constructed. As the result of the application about the past flood event, good agreement of comparison with observed and calculated values are show in the interesting sites, Jindong and Samrangjin. Additionally, estuary barrage's WSL evaluation procedure is enhanced to accurate calculation, and it is defined by downstream boundary condition in Nakdiong river. The new regressive equation to calculate the predicted tide value is developed by considering the astronomical tide and past observed tide value at Nakdong estuary barrage. The guideline's construction of the new application and flood forecasing system of other river basins is possible by using this studied results.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.62-62
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• 2011

한강하구지역의 강화해협은 한강, 임진강과 예성강의 강물이 흘러들어오는 하구형 수로로서 폭이 좁고, 유속이 매우 빠른 특성을 갖는다. 또한 조류(潮流)의 영향을 강하게 받아 상당량의 유량을 경기만으로 내보내고, 한강의 상류로부터 유입되는 상당량의 물질이 하구로 운반되어 침전하여 쌓이거나 하류의 외해로 배출하는 역할을 한다. 본 연구에서는 한강하류부에 위치한 강화해협의 유 무에 따른 한강과 임진강의 흐름특성 변화를 분석하였다. 수치모의를 위해 복잡한 하구지역의 물의 흐름해석이 가능한 일차원적인 모델링 도구인 MIKE 11 모형을 이용하여 정류 및 부정류 해석을 실시하였다. 상류경계조건은 홍수 시 방류량이 크게 증가하는 홍수기 유량과 조위의 영향을 많이 받는 평수기 시 유량으로 설정하였고, 하류경계조건은 평수기를 비롯하여 홍수기에도 임진강과 한강의 유량에 영향을 미치는 서해 조위로 설정하였다. 강화해협의 폐쇄에 따른 수위 변화의 영향은 홍수기 시 실제 강우 사상을 모의 하였을 때 최대 8.21% 수위가 상승하였으며, 200년 빈도 계획홍수량을 모의한 결과로는 정류 해석의 경우 최대 8.25%의 변화율을 보였고, 부정류 해석의 경우 최대 13.08%의 변화율을 보였다. 평수기는 창조기에 수위 변화가 적었던 반면 낙조기에는 창조기에 비해 수위 변동이 심하게 일어나는 것으로 나타났다. 추후 강화해협 뿐만 아니라 해양생태계의 중요한 가치를 지니고 있는 한강하구의 다른 수로에 의한 영향을 분석함으로써 수로의 중요성을 평가하고, 2차원 수치해석 등을 통한 다양한 분석을 실행하여, 홍수 및 해양환경 훼손으로부터 하구 환경을 보호하는 보다 정량적인 대응체계가 정립되어야할 것으로 사료된다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.5
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• pp.333-343
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• 2010

In Mokpo coastal zone, the characteristics showing ebb-dominant tidal flow was confirmed by analysis of observed tide and tidal currents, Physical factors occurring ebb-dominant flow were reviewed. Influence of critical depth for drying, bottom shear stress, coastal reclamation, tidal amplitude, nonlinear tide, and eddy viscosity on the change of ebb-dominant flow was investigated by applying a two-dimensional circulation model. The simulation results for a variety of conditions showed that eddy viscosity and critical depth for drying does little or no impact on the generation of asymmetric flow. Strong bottom friction stress makes ebb-dominant flow clearly. Change of tidal flat into land swells ebb- dominant flow, and change of tidal flat into sea disappears ebb-dominant flow. Nonlinear tides play a decisive role in the generation of asymmetrical tidal flow. Non-linear tides should be included in the open boundary conditions of hydrodynamic modeling in the Mokpo coastal zone.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.12 no.4
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• pp.203-209
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• 2000

Mokpo coastal zone suffers from increase of tidal amplitude by the reclamation projects of Youngsan River Scadike, Youngam and Keumho Seawalls, resulting inundation oflower lands. Tidal records at Mokpo harbor show jumps just after each construction not only in the mcan high water level but also in extreme one. Thus the design water levels must be newly estimated by a frequency analysis with the data of period after the last construction. But this period is at most 6 years yet, which restrains the normal frequency analysis. In this paper, new approach of converting the past data to the present one by a numerical model is proposed. Converted 32 years and observed 6 years data enables normal frequency analysis.

• 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.

• Journal of Environmental Impact Assessment
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• v.26 no.6
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• pp.445-456
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• 2017

For impact assessment of inundation in coastal area due to sea level rise (SLR), model for estimating future peak water level was constructed using observed mean sea level (MSL), storm surge level (SSL) data and calculated tide level (TL) data. Based on time series analysis and quadratic polynomial model for SLR and Monte-Carlo simulation for IC, SSL and TL, 100-year return peak water level is expected to be 2.3, 2.6, 2.8m, respectively (each corresponding to year 2050, 2080, 2100). Further analysis on future potential inundation area showed U-dong, Yongho-dong, Songjeong-dong, Jaesong-dong to be at high risk.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.2 no.2
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• pp.104-111
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• 1990

The water level variation due to the Typhoon around the coast of Pusan in the southern sea of Korea is investigated from the observed tidal record. Water level variations at six stations along the coast are discussed in association with the meteorological data. The characteristics of storm surge at Pusan during Typhoon Thelma in 1987 is analysed using the observed data, and it is performed the numerical simulation of storm surge which includes a inverse barometric effect due to the horizontal distribution of sea sur-face pressure. From the calculation results, the peak value of storm surge in the coast of Pusan was occur-red around the 01：00 July 16th, which is well coincident with the observed water level variation at the Kadukdo. However, the calculated value at the Pusan TBM is inconsistent with the observed one, which is regarded due to a reason that the Tidal Bench Mark (TBM) locates in the channel. In the computation results, the maximum surge occurs at the coast of Nakdong estuary, which is considered primarily due to a topographic effect, and water level variation exceeded 2.5 meter in these areas while only about 60 cm in another coasts.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.2
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• pp.188-195
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• 2018

Time series analysis was conducted to identify the factors affecting short-term variation of water temperature in Wando. Spectrum analysis showed that air temperature peaks at diurnal period, while water temperature and tide level peak at both semi-diurnal and diurnal periods. Coherence between water temperature and the tide level presented 0.92 at semi-diurnal period. Numerical experiment were carried out to understand the spatio-temporal distribution of water temperature in the study area. Average water temperature difference between maximum ebb and flood was $0.3^{\circ}C$ in spring tide, but $0.13^{\circ}C$ in neap tide. The reason for the large difference in spring tide is that relatively cold water entered with strong tidal currents at flood tide and flowed out at ebb tide. Water temperature on coasts was higher than out at sea. This is because the depth in the coast is shallower than at sea, and water temperature increases rapidly due to solar radiation.

• Journal of Wetlands Research
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• v.9 no.3
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• pp.13-24
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• 2007

This study was conducted to confirm if spatial distribution of macrobenthic fauna were related with sedimentary characteristics. Sedimentary characteristics were compared in each community after carrying of community analysis based upon species composition. Macrobenthic animals were distinguished with 4 communities based on the tidal level, of which 3 communities were divided into two groups on the sediment composition. Common species which were presented in all communities, Nephtys californiensis Hartman 1938, Haploscoloplos elongatus Johnson 1901, Glycera sp., Heteromastus sp. Notomastus sp. Timarete amtarctica Mono 1930, Glysinde sp., Lumbrineris japonica Marenzeller 1879 were having different appearance densities at each community area caused by different sedimentary characteristics. But only two species among the common species have a correlation significantly. Temporal variation of common species could not be recognised because of 4 times of seasonal investigation was not enough know their life cycles. So, in the future more frequently sampling method should be required.