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Lee, J.K.; Lee, I., and Kim, J.O., 2017. Analysis on tidal channels based on UAV photogrammetry: Focused on the west coast, South Korea case analysis. In: Lee, J.L.; Griffiths, T.; Lotan, A.; Suh, K.-S., and Lee, J. (eds.), The 2nd International Water Safety Symposium. Journal of Coastal Research, Special Issue No. 79, pp. 199-203. Coconut Creek (Florida), ISSN 0749-0208. In the coastal waters of the Republic of Korea, the incidence of marine vessel accidents has been increasing in recent years, due to increased maritime traffic and complex terrain conditions. With the proliferation of marine leisure activities and the maritime conditions such as tides, rocks, typhoons, tsunamis, there are various types of marine accidents that have not been experienced before. Therefore, it is imperative to establish an information based system (like digital map or 3D distribution map) that can be utilized in marine safety fields such as accident and disaster prevention. In this investigation, it will be discussed the safety mapping for tidal channel connected directly with human life. A tidal channel is a waterway where occurs by the process of ebb tide and flood tide in the tidal flats. Since the shape (included exact depth) of tidal channel cannot be identified when a tide comes in, it must be considered as the main causes of the summer drowning fatalities. A map for tidal channel has been proposed by a 3D distribution map that can be identified the shape and location of tidal channel, and also, this map should be offered to marine tourist and maritime safety authority. A cartography based on image collected by manned aerial Photogrammetry or satellite has the insoluble limitations in terms of economy, time constraint and periodic for measurement. Due to temporary erratic overflow through the tidal amplitude, the information for tidal channel cannot be monitored in real time. Therefore, in the present investigation, a UAV (Unmanned Aerial Vehicle) recently been actively used in the field of spatial information is considered in analyzing the status of tidal channel. First of all, the DEM (Digital Elevation Model) of tidal flats generates through UAV based auto-image, the distribution map for tidal channel expresses different colors by the height of topographic. A tidal channel encoding specific color (normally red) can be provided dangerous signal to the user. It can be identified the sea leveling at the certain time that can be measured whole shape of tidal channels, and also, provided a more realistic and readable information on tidal flats. The information provided through the tidal channel map was verified by comparison with the VRS GPS positioning solution. Since information such as the exact distribution location and shape should be considered as the first priority, the coordinates of the tidal channel was compared with the previously proven method, VRS GPS. As a result, it is determined that the location of attribute information and the 3D shape analysis value analyzed by UAV image can fully provide information within the convergence range. In this investigation, UAV image can be estimated on the location and shape of tidal channel by observing exactly at the time zone for flood tide. It can be fully expected that the UAV is contributed to preventing the marine accident in advance by maximizing the latent properties with regards to periodicity, accuracy, operation convenience and economy. [ABSTRACT FROM AUTHOR]

Kim, J.O. and Lee, J.K., 2021. Urban flood inundation simulation based on high-precision 3D modeling. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 454–458. Coconut Creek (Florida), ISSN 0749-0208. Flooding is a frequently occurring climate-related natural disaster that affects several people worldwide. In recent years, severe natural disasters have occurred due to unusual weather, and the damage caused by such disasters has increased significantly because of high population densities and the presence of large buildings in coastal urban areas. The spatial characteristics of urban floods are becoming more complex due to widespread changes in land use, such as in the construction of buildings, roads, and drainage networks. In particular, factors that affect urban flood modeling include the location and geometry of buildings. Hydrological models can adequately simulate both surface and subsurface processes at the watershed level; however, most models cannot accurately simulate urban flooding without 3D city modeling. A 3D simulation of computation results is thus necessary for practical applications. In recent years, flood simulation technology has been used to build 3D virtual environments based on data such as high definition (HD) maps, LiDAR point clouds, and drone images. The primary objective of this study was to develop and simulate an urban flood based on 3D city modeling. The 3D city model was tested for a coastal city in the Republic of Korea. Results of case studies indicate a reasonable match between the observed and modeled flood spatial extents and highlight the importance of considering 3D city models in urban flood simulations. [ABSTRACT FROM AUTHOR]

Lee, J.K.; Kim, J.O., and, Oh, Y.S. 2021. Development of coastal safety mapping system by vulnerability assessment of tidal creeks. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 459–463. Coconut Creek (Florida), ISSN 0749-0208. Most coastal accidents occur in coastal areas with heavy traffic, or crowded beaches and tidal flats. In Korea, various leisure activities are conducted throughout the year on beaches. A significant increase in the number of coastal area workers has led to a corresponding increase in the risk of accidents; this makes the employment of effective countermeasures a necessity. A coastal safety map integrates spatial information of dangerous areas and hazards to prevent accidents in the ocean. In addition to its use for safe expansion of coastal leisure activities, coastal safety maps can be used for the prevention of disasters caused by sea conditions such as tidal creeks, heavy swells, and rip currents. In this study, a tidal creek map was created using an Unmanned Aerial Vehicle (UAV) to express the shape of a tidal creek in three dimensions. We designed and implemented a mapping system that identifies places with a high potential for human accidents in tidal flats. The system uses computer vision technology to identify the shape and location of the tidal channel and extract areas with a high probability of accidents, contributing to the development and implementation of comprehensive safety measures. [ABSTRACT FROM AUTHOR]