• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.173-177
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• 2006

From the viewpoint of coastal hydrodynamics, one of the most important effects of global warming is a sea-level rise in coastal areas. In the present study, impacts on port facilities against sea-level rise were investigated. The sea-level rise causes the increase of the water depth, and it generates variations on the wave height, buoyancy, tidal system and nearshore current system and so on. The increase of water depth gives rise to the decrease of crown height of the structure and it causes increase of wave overtopping quantity. It may flood the port zone and its facilities, and may decrease harbor tranquility. It also leads to difficulties on navigation, mooring and loading/unloading at the port. Increase in water depth also causes increase of wave height in surf zone. This high wave makes structures unstable and may cause them to collapse during storm. In addition, increase in buoyant force due to sea-level rise also makes the gravity type structures unstable. Consequently, theses variations due to sea-level rise will cause functional deterioration of port facilities. In order to protect port facilities from the functional deterioration, reinforcement plan is required such as raising the crown height and increase in block weight and so on. Hence proper estimation method for the protection cost is necessary in order to protect port facilities efficiently. Moreover response strategies and integrated coastal zone management plan is required to maintain the function of port facilities. A simple estimation of cost for breakwaters in Korea was performed in the present study.

• Journal of The Geomorphological Association of Korea
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• v.26 no.2
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• pp.39-54
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• 2019

In this paper, based on evidence of coastal sediment, we show that erosion and sedimentation environments are very sensitive to sea level changes during the Medieval Warm Period (MWP) and the Little Ice Age (LIA). We identified four sedimentary units(4.57-3.07m), which formed in the Dark Age Cool Period (DACP), MWP and LIA were classified based on the lithostratigraphy, grain size distribution, magnetic susceptibility and geochemistry of a drilling core taken from the west coast of Hwaseong City. The unconformity surfaces as boundaries of the units were also identified by the lithostratigraphy shown on the drilling core. We propoese that sedimentation was dominant in the area during the periods of sea level rise, whereas erosion prevailed during the periods of sea level fall. Particularly, extreme events, such as floods and typhoons are believed to have accelerated these processes, and we found the associated evidence in sediments of two units. This study provides an example of estimating the relative sea level variation using coastal sediments and may be useful for studying past sea level changes around the Korean Peninsula.

• Journal of The Geomorphological Association of Korea
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• v.18 no.4
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• pp.235-246
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• 2011

Sea level fluctuations during the Holocene reconstructed by the results of age dating, microfossils researches and sedimentary facies from coastal alluvial plains contain the valuable informations on climatic changes. The sea level during 'maximum phase of transgression' during 6,000~5,000 yr BP was slightly higher than the present by approximately 0.8~1.0 m and the summer temperature conditions seemed to be higher than those of the present by 2~3℃ in the Central Europe when the period of 'Climatic Optimum' might be dominant. The sea level in Korean Peninsula was assumed by 0.8~1.0 m higher at that time compared to the present and climate seemed to be warmer. At 2,000~1,800 yr BP in Korean Peninsula, the sea level reached the higher stand than the present by approximately 1.1~1.3 m and the climatic conditions might be warm similar to the period of 'Climatic Optimum'. Although the temperature in the Central Europe during the period of 'Subboreal' was about 2~3℃ cooler, it is supposed that the sea level in Korean Peninsula was relatively higher than the present. The sea level at 2,300 yr BP might be similar to that of the present, which was the lowest level since the mid-Holocene. From the fact, climatic environment during the cold period might not be reflected exactly in the sea level.

• The Journal of the Korea Contents Association
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• v.16 no.4
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• pp.604-613
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• 2016

The sea level of the Earth is rising approximately 2.0mm per year (global average value) due to thermal expansion of sea water, melting of glaciers and other causes by global warming. However, when it comes to design a river, the standard of design water level is decided by analyzing four largeness tide value and harmonic constant with observed tidal water level. Therefore, it seems the external water level needs to consider an increasing speed of the seawater level which corresponds to a design frequency. In the present study, the hourly observed tidal water level targeting 47 tidal stations operated by Korea Hydrographic and Oceanographic Administration (KHOA) from beginning of observation to 2015 per hour has been collected. The variation of monthly and yearly and increasing ratio have been performed divided 4 seas such as the Southern, East, Western, and Jeju Sea. Also, the external water level existing design for rivers nearby a coast was been reviewed. The current study could be used to figure out the cause of local seawater rise and reflect the external water level as basic data.

• Journal of Environmental Science International
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• v.9 no.1
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• pp.19-25
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• 2000

As the tideland reclamation is done on a large scale these days, construction work is active in the coastal areas. Facilities in the coastal areas must be built with the tide characteristics taken into consideration. Thus the tide characteristics affect the overall reclamation plan. The analysis of the tide data boils down to a harmonic analysis of the hourly changes of long-term tide data and extraction of unharmonic coefficients from the results. Since considerable amount of tide data of the West Coast are available, the existing data can be collected and can be used to obtain the temporal changes of the tide by being fitted into the tide prediction model. The goal of this thesis lies in assessing whether the mean sea level used in the field agrees with the analysis results from the long-term observation data obtained with their homogeneity guaranteed. To achieve this goal, the research was conducted as follows. First the present conditions of the observation stations, the land level standard, and the sea level standard were analyzed to set up a time series model formula for representing them. To secure the homogeneity of the time series, each component was separated. Lastly the mean sea level used in the field was assessed based on the results obtained form the analysis of the time series.

• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.39.3-39.3
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• 2010

Solar-terrestrial links in short-time scales(daily ~monthly) are extensively explored in recent years: such as a response of low cloud amounts to the Forbush decrease, a response of Northern Atlantic oscillation index to sudden increase in electric field intensity of solar wind and so on (e.g., Svensmark et al., 2009; Boberg & Lundstedt, 2002). In this study, we perform the superposed epoch analysis to see any possible response of the sea-level pressure over Korean peninsula to the fast solar wind stream. Data sets are daily values, and zero days are determined to be days when the solar wind velocity exceeds 800km/s. Average profile of superposed sea-level pressure shows a gradual increase during the first 2 days and a decrease afterward below the normal level with a low pressure condition maintained for a few days. This result indicates that the sea-level pressure may respond to the fast solar wind stream. In other words, the average profile of sea-level pressure mimics the average velocity profiles. The correlation coefficient between two average profiles is 0.80, with 2 day lag.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.534-541
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• 1999

This study was undertaken to examine the effect of sea tangle and sea mustard on physiochemical and sensory characteristics of cakes and the possibility commercialization of these functional cakes. The moisture contents of cakes prepared with sea tangle and sea mustard were higher than those of control, and a positive correlation between water holding capacity(WHC) and moisture contents was observed(r=0.836). As addition level of sea tangle and sea mustard was increased, volume of cakes were decreased, whereas hardness was increased slightly and color became deep. Hardness was strongly correlated to the volume of cakes(r= 0.914). Visual observation by photomicrography showed that, as addition level of sea mustard and sea tangle was increased, formation of air cells were prohibited and thus volume of cakes was decreased. The microstructural observation by scanning electron microscopy(SEM) showed that air cells of cakes were well developed up to 5% addition of sea tangle powder. As a result of the sensory evaluation for the cakes prepared with sea tangle and sea mustard, no significant difference was observed between control and those addition levels up to 5%. Flavor was proved to be the most important factor in determining overall acceptability and hedonic hardness score was inversely correlated to the objective hardness value(r= 0.853).

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.3
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• pp.120-130
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• 2014

Change of mean sea level in the western coast of Korean peninsula was estimated with the observed tide data of the KHOA. The cause of the change was investigated. Mean sea levels in the western coast have been changed due to coastal development projects in the coastal zone. The estimated variations, which are significantly different regionally, vary from -6.8 cm in Incheon to 38 cm in Gunsan. The changing rate of mean sea level occurred by natural factors such as global warming varies from 1.1 mm/year in the north to 4.4 mm/year in the south of western coast of Korean peninsula. In Jeju, sea level rise and rise of sea temperature showed a close relationship. Water temperature rise of one degree increases mean sea level to 0.6 mm in Jeju. Rising rate of mean sea level has increased rapidly after the mid-1980s.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.1
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• pp.51-61
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• 2019

Computing the sea level slope at the BM(Bench Mark) in the coast areas around the Korean Peninsula is important for establishing height of BM of the Korean geodetic leveling network. In this study, MSL(Mean Sea Level) was recalculated with the long-term tide observation data based on the IHO(International Hydrographic Organization) standard(18.6 years), and the BM height was reanalyzed by precision leveling. The sea surface topography was analyzed by leveling at Mokpo(Mokpo Starting Point), Busan (09-00-00) and Mukho(20-26-00) BMs, and the sea level slope was computed based on the Korean vertical origin point. As a result of this study, the sea level slope of the west and east coasts between Incheon(-2.27cm) and Mukho(17.56cm) located at $37.5^{\circ}N$ was analyzed as 19.83cm. Domestic geodesists and oceanologists have confronted each other with regard to the issue of latitudinal changes in long term MSL. In the west coast, the Mokpo is 1.12cm higher than Incheon, and the Busan is 2.18cm higher than Mukho. Therefore, the west and east coasts have been analyzed as sea level slope rising to the south. It can be used to solve the reestablishment of the Korean geodetic leveling network and the problem of the elevation discrepancy in the BM.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.1
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• pp.1-8
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• 2013

In this paper, we predicted sea-level rise for RCP 4scenarios(RCP 2.6, RCP 4.5, RCP 6.0, RCP 8.5). To calculate sea-level rise, a semi-empirical method was used and it needs atmospheric temperature rise for each scenario. According to the results, the sea-level has been rising steadily in all scenarios. By 2050 the maximum difference of sea-level rise between the scenarios was within 0.08 m, but its difference was showed more than 0.5 m in 2100. The values of sea-level rise for RCP 2.6, RCP 4.5, RCP 6.0, RCP 8.5 scenarios are 0.87 m, 1.21 m, 1.02 m, 1.36 m, respectively. In the case of RCP 8.5, the slope of atmospheric temperature rise since 2060 was very steep compared to the other scenarios so that the maximum difference of sea-level rise between the scenarios will be much larger after 2100. Estimated by a simple approximation, the maximum difference of sea-level rise can be more than 1.2 m in 2120.