해양과학기지 원격 파랑 관측 자료의 품질 향상을 위한 응용기술 개발

도기덕,민용침,심재철,Do, Gi-Deok,Min, Yong-Chim,Sim, Jae-Cheol 한국수자원학회 2020 물과 미래(한국수자원학회지) Vol.53 No.1

유한한 깊이를 가진 투수층 위에서의 파의 감쇠율

도기덕(Do Ki Deok),서경덕(Suh Kyung Duck) 대한토목학회 2007 대한토목학회 학술대회 Vol.2007 No.10

기상청 현업 예보 바람자료를 이용한 동해안 동계 파랑 예측 재현도 연구

도기덕(Kideok Do),김진아(Jinah Kim) 한국해안해양공학회 2018 한국해안해양공학회 논문집 Vol.30 No.5

본 연구에서는 동해안의 너울성 고파랑 예측하기 위해 기상청 현업 예보 바람자료를 입력장으로 하여 파랑수치모델(SWAN)을 수립 및 최적화하고 동해안 동계 파랑의 예측 재현도를 평가하였다. 파랑 모델은 연안역에서의 파랑 변형을 모의하기 위해 네스팅 기법을 적용하였으며, 백파 에너지 소산항을 개선하여 너울성 파랑을 모의하였다. 수치실험을 위한 입력 바람장으로는 기상청 현업 기상예보모델인 RDAPS 및 LDAPS 자료를 사용하였다. 모의된 파랑에 대한 정확도 비교 · 평가를 위해 ECMWF 재분석 바람자료와 KIOST 운용해양시스템의 WRF 예측바람자료를 이용한 파랑모델링 및 기상청 현업 파랑예보모델 결과와 연안 및 외해 4개 관측정점의 파랑 관측자료를 이용하였다. 기상청 현업 기상예보모델을 입력바람장으로 이용한 경우 연안에서는 유의파고, 첨두주기 및 평균파향이 모두 가장 낮은 RMSE와 가장 높은 상관계수를 가졌으며, 외해에서는 모든 수치실험 결과가 관측자료와 전반적으로 잘 일치하였다. 백파항을 수정한 SWAN 모델과 기상청 현업 기상예보모델을 사용할 경우 급격하게 발생하는 고파랑 재현은 개선이 필요하지만 비교적 겨울철 폭풍파를 잘 재현하고 있다. The predictability of winter storm waves using KMA’s operational wind forecasts has been studied to predict wind waves and swells in the East coast of Korea using SWAN. The nested model were employed along the East coast of Korea to simulate the wave transformation in the coastal area and wave dissipation term of whitecapping is optimized to improve swell prediction accuracy. In this study, KMA’s operational meteorological models (RDAPS and LDAPS) are used as input wind fields. In order to evaluate model accuracy, we also simulate wind waves and swells using ECMWF reanalysis and KIOST WRF wind and they are compared with the KMA’s operational wave model and the wave measurement data on the offshore and onshore stations. As a result, it has the lowest RMSE and the highest correlation coefficient in the onshore when the input wind fields are KMA’s operational meteorological forecasts. In the offshore, all of the simulate results shows good agreements with similar error statistics. It means that it is very feasible to use SWAN model with the modified whitecapping factor and KMA’s operational meteorological forecasts for predicting the wind waves and swells in the East coast of Korea.

양빈 후 미국 델라웨어의 Bethany Beach에서 발생한 해안침식

도기덕(Ki-Deok Do),Nobuhisa Kobayashi,서경덕(Kyung-Duck Suh),심재설(Jae-Seol Shim) 한국해양환경·에너지학회 2012 한국해양환경·에너지학회 학술대회논문집 Vol.2012 No.5

해운대의 파랑 및 흐름 구조의 특성파악을 위한 현장 관측실험

도기덕(Kideok Do),유제선(Jeseon Yoo),이희준(Hee Jun Lee),도종대(Jong-Dae Do),진재율(Jae-Youll Jin) 한국해안해양공학회 2015 한국해안해양공학회 논문집 Vol.27 No.4

본 연구에서는 사질 해안인 해운대 해수욕장을 대상으로 수리·퇴적 작용의 동적구조 규명에 필요한 현장 관측실험을 수행하였다. 연안에서 발생하는 계절별 파랑 및 수리 현상을 정량적으로 파악하기 위하여, 동계 및 하계 집중 관측기간 중 해안선의 법선 방향으로 3개 정점 및 해안선 방향으로 3개 정점 등 공간적으로 여러 정점에 파랑 및 층별 유속 관측장비를 설치하였다. 파랑 관측자료의 분석결과, 동계에는 동해안으로부터 입사하는 E계열 파랑이 대부분이며, 하계에는 S계열과 ESE 계열이 공존하는 분포를 가지고 있다. 대상 해역에서 유속의 공간적 분포는 전체적으로 주 흐름방향이 동계와 하계에 조석운동의 영향으로 동서방향으로 형성되어 있다. 심해역에서 천해역로 갈수록 연안지형의 영향으로, 유속의 세기는 약해지며 유속의 방향은 해안선 및 등수심선과 나란하게 변형되어 나타나고 있다. 본 연구를 통하여 제시된 파랑 및 흐름 등 수리특성에 관한 기초 분석자료는 동 기간에서 측정된 모래이동량 및 지형변화 관측자료와 연계하여, 대상 해역의 침퇴적 정도를 정량적으로 산출하는데 활용될 수 있다. Field observations were conducted to collect hydrodynamic and morphological data, which are needed to account for mechanisms of bathymetry changes caused by physical forcings, in Haeundae beach. In order to quantitatively describe characteristics of wave transformations and current patterns in space in winter and summer, in-situ sensors for measuring waves and current profiles were installed at three locations in the cross-shore direction and also three locations in the along-shore direction. As for the results of wave measurements, waves with main direction from the east dominate in winter while waves are incident from the S and the ESE in summer. Analysis of current data reveals that currents over the study domain are considerably influenced by a pattern of tidal motions, thereby, mainly oscillating in the direction of tidal currents, i.e., east-west directions, in both winter and summer. Currents tend to be influenced by local bathymetry in the shallow water region, with the direction changed along the depth contours and the magnitude reduced as they approach the shoreline. The results analysed from the hydrodynamic data through this study can be further combined with the morphological and bathymetry data, leading to the quantification of seasonal sediment transport rates and sand budget changes.

양빈 후 미국 델라웨어의 Bethany Beach에서 발생한 해안침식

도기덕(Ki-Deok Do),Nobuhisa Kobayashi,서경덕(Kyung-Duck Suh),심재설(Jae-Seol Shim) 대한조선학회 2012 대한조선학회 학술대회자료집 Vol.2012 No.5

GCP Placement Methods for Improving the Accuracy of Shoreline Extraction in Coastal Video Monitoring

이창율,도기덕,김인호,장성열 한국해양공학회 2024 韓國海洋工學會誌 Vol.38 No.4

In coastal video monitoring, the direct linear transform (DLT) method with ground control points (GCPs) is commonly used for geo-rectification. However, current practices often overlook the impact of GCP quantity, arrangement, and the geographical characteristics of beaches. To address this, we designed scenarios at Chuam Beach to evaluate how factors such as the distance from the camera to GCPs, the number of GCPs, and the height of each point affect the DLT method. Accuracy was assessed by calculating the root mean square error of the distance errors between the actual GCP coordinates and the image coordinates for each setting. This analysis aims to propose an optimal GCP placement method. Our results show that placing GCPs within 200 m of the camera ensures high accuracy with few points, whereas positioning them at strategic heights enhances shoreline extraction. However, since only fixed cameras were used in this study, factors like varying heights, orientations, and resolutions could not be considered. Based on data from a single location, we propose an optimal method for GCP placement that takes into account distance, number, and height using the DLT method.

Quality Enhancement of MIROS Wave Radar Data at Ieodo Ocean Research Station Using ANN

박동현,도기덕,윤미영,정진용 한국해양공학회 2024 韓國海洋工學會誌 Vol.38 No.3

Remote sensing wave observation data are crucial when analyzing ocean waves, the main external force of coastal disasters. Nevertheless, it has limitations in accuracy when used in low-wind environments. Therefore, this study collected the raw data from MIROS Wave and Current Radar (MWR) and wave radar at the Ieodo Ocean Research Station (IORS) and applied the optimal filter by combining filters provided by MIROS software. The data were validated by a comparison with South Jeju ocean buoy data. The results showed it maintained accuracy for significant wave height, but errors were observed in significant wave periods and extreme waves. Hence, this study used an artificial neural network (ANN) to improve these errors. The ANN was generalized by separating the data into training and test datasets through stratified sampling, and the optimal model structure was derived by adjusting the hyperparameters. The application of ANN effectively improved the accuracy in significant wave periods and high wave conditions. Consequently, this study reproduced past wave data by enhancing the reliability of the MWR, contributing to understanding wave generation and propagation in storm conditions, and improving the accuracy of wave prediction. On the other hand, errors persisted under high wave conditions because of wave shadow effects, necessitating more data collection and future research.

해양과학기지 RangeFinder 파랑 시계열 자료의 특성 분석 및 품질개선을 위한 알고리즘 개발

황예진,도기덕,정진용,이은주,신성원 (사)한국연안방재학회 2022 한국연안방재학회지 Vol.9 No.3

Ocean Research Station is a comprehensive ocean research infrastructure built to collect and provide real-time data with state- of-the-art observation systems. This station operates various research facilities, and the data is actively used for research in each field. In particular, since wave data is produced through the remote-sensing observation method, they are valuable as observation data. Unlike the direct observation method, they can stably collect data and store long-term observation data on severe weather. However, there is a limitation that outlier may occur due to the process of measuring and collecting data or the effects of temporary environmental changes. This study improves the remote wave data quality of MIROS RangeFinder installed at the Socheongcho Ocean Research Station using an algorithm and confirms the reliability by comparing it with the wave buoy observation data operated by the Korea Meteorological Administration. The algorithm used is a Spike removal median filter, which is applied after adjusting the conditions and variables according to the characteristics of the Socheongcho wave data. Also, we developed a new filter using a variable threshold to increase the outlier detection rate. As a result, the final algorithm shows a high outlier detection rate, but some outliers are still not removed, so improvements are required to enhance the algorithm’s performance. In addition, continuous research on the remote-sensing wave observation method is required to compensate for the limitation that the accuracy is slightly lower than that of the direct observation method.

Field Observation and Quasi-3D Numerical Modeling of Coastal Hydrodynamic Response to Submerged Structures

황예진,도기덕,김인호,장성열 한국해양공학회 2023 韓國海洋工學會誌 Vol.37 No.2

Even though submerged breakwater reduces incident wave energy, it redistributes the coastal area's wave-induced current, sediment transport, and morphological change. This study examines the coastal hydrodynamics and the morphological response of a wave-dominated beach with submerged breakwaters installed through field observation and quasi-3D numerical modeling. The pre-and post-storm bathymetry, water level, and offshore wave under storm forcing were collected in Bongpo Beach on the East coast of Korea and used to analyze the coastal hydrodynamic response. Four vertically equidistant layers were used in the numerical simulation, and the wave-induced current was examined using quasi-3D numerical modeling. The shore normal incident wave (east-northeast) generated strong cross-shore and longshore currents toward the hinterland of the submerged breakwater. However, the oblique incident wave (east-southeast) induced the southeastward longshore current and the sedimentation in the northeast area of the beach. The results suggested that the incident wave direction is a significant factor in determining the current and sediment transport patterns in the presence of the submerged breakwaters. Moreover, the quasi-3D numerical modeling is more appropriate for estimating the wave transformation, current, and sediment transport pattern in the coastal area with the submerged breakwater.