• Proceedings of the Korean Information Science Society Conference
• /
• 2008.06b
• /
• pp.246-249
• /
• 2008

최근 지구온난화로 인한 기후변화 및 해양온난화로 태풍의 강도가 높아지고 빈도가 증가함에 따라 연안 지역의 침수범람과 같은 자연재해로 인한 인명 재산 피해가 심각해지고 있다. 이에 폭풍해일로 인한 연안 재해저감을 위한 해양 관측 및 수치 모델을 통한 정확한 폭풍해일 예측에 대한 연구가 활발히 진행되고 있다. 따라서 본 논문에서는 Web-GIS 기반 실시간 폭풍해일 예측 결과의 시각화 기법에 대한 연구를 통하여 자연재해 저감을 위한 효과적 정보전달 통한 의사결정에 도움을 주고자한다.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.5 no.3
• /
• pp.173-181
• /
• 1993

An improved two-dimensional Eulerian-Lagrangian convection-dispersion model was established after comparing several models. To simulate long term release of discontinuous suspended solid source from coastal dike construction, source was represented by Fourier transformation. It was concluded that this model can effectively simulate long term coastal dispersion problems.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.11 no.1
• /
• pp.31-36
• /
• 2006

A study on estimation of the datum level is carried out by combining observed and simulated harmonic constants of 4 major tides ($M_2$tide, $S_2$tide, $K_2$tide, and $O_1$tide). In the coastal zone, the datum level can be estimated by using observed tide harmonic constants at tide station. The observed tide harmonic constants, however, cannot be used to calculate the datum level of the sea because of the lack of tide station. In order to estimate the datum level of the sea, it is necessary to adopt the simulated harmonic constants instead of the observed ones. In this study, the datum level is calculated by using the simulated harmonic constants which is modified by tuning coefficient based on relationship between observed and simulated harmonic constants at tide station. Tuning coefficient of sea is interpolated on TIN (Triangulated Irregular Network) which has node points at tide stations.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.31 no.6
• /
• pp.458-467
• /
• 2019

The purpose of this study is the suggestion of optimized parameters in OI (Optimal Interpolation) by experimental study. The observation of applying optimal interpolation is ADCP (Acoustic Doppler Current Profiler) data at the southwestern sea of Korea. FVCOM (Finite Volume Coastal Ocean Model) is used for the barotropic model. OI is to the estimation of the gain matrix by a minimum value between the background error covariance and the observation error covariance using the least square method. The scaling factor and correlation radius are very important parameters for OI. It is used to calculate the weight between observation data and model data in the model domain. The optimized parameters from the experiments were found by the Taylor diagram. Constantly each observation point requires optimizing each parameter for the best assimilation. Also, a high accuracy of numerical model means background error covariance is low and then it can decrease all of the parameters in OI. In conclusion, it is expected to have prepared the foundation for research for the selection of ocean observation points and the construction of ocean prediction systems in the future.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.22 no.6
• /
• pp.361-373
• /
• 2010

Analysis has been made on the tide/storm surges characteristics near the Korean marginal seas in the 2008 and 2009 years using operational ocean prediction model of the Korea Meteorological Administration(KMA). In order to evaluate its performance, its results were compared with the observed data by tidal stations around Korean Peninsula. The model used in this study predicts very well the characteristics of tide/storm surges near the Korean Peninsula. Simulated storm surges show the evident effects of Typhoons in summer season. The averaged root mean square error(RMSE) of 48 hr forecasting between the modeled and observed storm surges are 0.272 and 0.420 m in 2008 and 2009, respectively. Due to strong sea winds, the highest storm surges heights was found in summer season of 2008, however, in 2009, the high storm surges heights was also found in other seasons. When Typhoon Kalmaegi(2008) and Morokot(2009) approached to Korean Peninsular, the accuracy of model predictions is almost same as annual mean value but the precision accuracy for Typhoon Morakot is lower than of Typhoon Kalmaegi similar to annual results.

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

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.16 no.4
• /
• pp.155-168
• /
• 2011

Coastal boundary current flows along the eastern boundary of the Yellow Sea and its speed was about 0.l m/s during the summer 2007. In order to find major factors that affect the coastal boundary current in the eastern Yellow Sea, three-dimensional numerical model experiments were performed. The model simulation results were validated against hydrographic and current meter data in the eastern Yellow Sea. The eastern boundary current flows along the bottom front over the upper part of slopping bottom. Strength and position of the current were affected by tides, winds, local river discharge, and solar radiation. Tidal stirring and surface wind mixing were major factors that control the summertime boundary currents along the bottom front. Tidal stirring was essential to generate the bottom temperature front and boundary current. Wind mixing made the boundary current wider and augmented its north-ward transport. Buoyancy forcing from the freshwater input and solar radiation also affected the boundary current but their contributions were minor. Strong (weak) tidal mixing during spring (neap) tides made the northward transport larger (smaller) in the numerical simulations. But offshore position of the eastern boundary current's major axis was not apparently changed by the spring-neap cycle in the mid-eastern Yellow Sea due to strong summer stratification. The mean position of coastal boundary current varied due to variations in the level of wind mixing.

• Journal of Ocean Engineering and Technology
• /
• v.12 no.3 s.29
• /
• pp.75-85
• /
• 1998

A finite difference model for predicting time-dependent, wave-induced nearshore current is studied. The model includes wave refraction, wave-current interaction, bottom friction and wind effect. This model iteratively solved the linear the linear set of conservation of both mass and momentum, which were time averaged (over one wave period) and depth integrated, for mean velocities and free surface displacement. Numerical simulations of nearshore current under oblique wave attack, and for wave and wind induced current on a longshore periodic beach are carried out. Longshore velocities tend to zero in some distances outside the breaker line. And the peak velocity is shifted shoreward at the breaker line. The results represent the general characteristics of the nearshore current induced by wave.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.5 no.4
• /
• pp.307-317
• /
• 1993

The problem of sea wave transformation in the coastal zone taking into account effects of nonlinearity and disperison has been studied. Mathematical model for description of regular wave transformation is based on the method of nonlinear ray theory. The equations for rays and wave field have been produced. Nonlinear wave field is described by the modified Korteweg-de Vries equation. Some analytical solutions of this equation are obtained. Caustic transformation and dissipation effects are included in the mathematical model. Numerical algorithm of solution of the Korteweg-de Vries equation and its stability criterion are described. Results of nonlinear transformation of sea waves in the coastal zone are demonstrated.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
• /
• 2008.06a
• /
• pp.461-464
• /
• 2008

연안에서의 태풍 해일에 의한 침수범람 지역 예측을 위하여 GIS를 통한 정밀 육도-해도 접합 및 분석을 만리포 해변을 대상으로 시범 수행하였다. 만리포 해변의 정밀 육도-해도 접합을 위하여 고해상도 지상 LIDAR 시스템의 시범 측량 자료와 국토지리정보원의 수치지형도, 국립해양조사원의 수치해도 수심자료 및 한국 주변해역의 30초격자 수심자료를 사용하였다. 또한 평균해수면 산정을 위하여 만리포에 설치된 수압식파고계 조위자료와 해변의 표척을 통한 목측 관측을 통한 조위자료를 활용하였다. 다양한 자료의 GIS 기반 육도-해도 접합 및 분석을 통한 정밀 지형도 구축 기술은 태풍 해일에 의한 침수범람 예측을 위한 정밀 격자 수치모델의 입력 자료로 활용되어 침수 범람 예측 결과의 재해도(Hazard Map) 작성이 가능하고, 나아가 침식 퇴적 등의 지속적인 해안선 변화 모니터링에 활용될 수 있다.