• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.21-24
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• 2001

As one of the phil-environmental alternative plan of Saemankeum project, gradual development is recommended. The procedure of the Saemankeum project start with the completion of 32 km long sea-dikes which contains two discharge gates until the year 2004. Second step is pre-development of Mangyoung area permitting temporary intrusion of sea water, i.e. tides, by the opening of discharge gate until the environmental evaluation on the water quality of this area secures permanent meet to government's water quality standard. Therefore this study is to predict the future condition of this tidal flat with the point of view tidal environments, salt, water quality, soil mechanics, etc. of Mangyoung area when the sea water still passed in the inland reservoir through the discharge gate.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.685-688
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• 2004

Fresh water discharge from the sea floor strongly affects a coastal ecology and the diffusion of contaminants. Much fresh water discharge has been found in the edge of Kurobe alluvial fan, in which annual rainfall is over 4000mm and there is abundant groundwater. However, it is difficult to find the groundwater discharge, thus the search of possible areas with some remote sensing tools is required. Because the temperature of the discharge point is relatively low compared with the surrounding sea water surfaces, there is a possibility to detect the area as an irregular zone of thermal infrared images. Two anomalous temperature zones, which have no surface streams from rivers, are detected by ASTER thermal-infrared images. One of them was verified as the groundwater discharge point by dives. In addition, the distribution of water table under the land side of the two areas is also detected as irregular zones by a ground-penetrating radar

• Journal of the korean society of oceanography
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• v.39 no.1
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• pp.14-19
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• 2004

Difference of Dissolved Inorganic Phosphorus (DIP), Dissolved Inorganic Nitrogen (DIN) and Dissolved Silicate (DSi) budgets in the Bohai Sea between 1982 and 1992 related the decrease of the Yellow River discharge is discussed on the basis of observed data. The estuarine circulation in the Bohai Sea had been weakened from 1982 to 1992 due to the decrease of the Yellow River discharge and the average residence time of fresh water had become longer. DIN concentration increased but DIP and DSi concentrations decreased from 1982 to 1992 in the Bohai Sea. Primary production was regulated mainly by water temperature and DIN concentration in 1982 but it was regulated mainly by DIP concentration in 1992. Primary production was larger than decomposition plus bottom release and nitrogen fixation was larger than denitrification in 1982. However, decomposition plus bottom release was larger than primary production and denitrification was larger than nitrogen fixation in 1992 in the Bohai Sea.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.711-716
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• 2010

This study selected the promising area of submarine groundwater discharge(SGD) that flows into the sea following unconfined physical aquifer through the electrical resistivity survey of the land and sea. The submarine groundwater discharge(SGD) mostly flows into the sea following fracture zones, and the detection of the fault zone becomes the important guideline of groundwater discharge. Electrical sounding of the land assessed the groundwater flow and integration possibility according to the location of a fault that is a water path between underground reservoir and surface water as well as a rock fracture. In addition, the study conducted sea electrical resistivity to expand the area with high potential and selected the expected water potential groundwater area. The areas of the study were Busan and coastal areas, and for the terrain analysis, the candidates of the ground exploration were selected after analyzing lineaments that is expanded to coast direction.

• Proceedings of the KSRS Conference
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• v.2
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• pp.688-691
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• 2006

The current system of the East China Sea, a marginal sea in the northwest Pacific, has a seasonal variation. The Changjiang Diluted Water, Chinese coastal water in the East China Sea, has different seasonal paths. It flows southward along the Chinese coast within a narrow band in winter and does northeastward the Korea/Tsushima Strait in summer, which has been a subject to many researchers. In particular, low salinity in the South Sea of Korea in 1996 and 1998 was in discord with the Changjiang River discharge and the Changjiang Diluted Water seems to play an important role in occurrence of red tide in the South Sea of Korea in 1997 and on the contrary, disappearance in the next year. These facts suggested that the Changjiang Diluted Water does not flow along the same path in every summer. According to the analyses for path of the Changjiang Diluted Water using ocean color images by SeaWiFS and salinity observations by shipboard CTD in August for recent years, the Changjiang Diluted Water in summer flowed within the range of direction from southeastward to north-northeastward anticlockwise. However, the Changjiang Diluted Water flowed northeastward toward Jeju Island of Korea for the most part. It is necessary to examine the influence of major factors on path variability of the CDW in summer such as surface wind, the Changjiang River discharge and background current.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.800-807
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• 2006

Sea dyke construction is simply defined that the cutting procedure of sea water flow. Sea dyke construction is more difficult than in-land construction because it’s placed on deep seabed and exposed sea wave attack. Especially, the final closure of sea dyke is most dangerous due to the fast velocity of tidal flow. The final closure section is consisted with vast rubble and heavy stone gabion, therefore the discharge velocity at land side of final close section is irregularly and sometime occur the fast discharge velocity. In this study, the seepage model test performed to evaluate seepage behavior with tidal variation of final closure and continuous sea dyke section such as discharge velocity, hydraulic gradient, and phreatic line. Based on the seepage model test results, the maximum discharge velocity of final closure section is 1.7m/sec. Also the local discharge velocity increment and vortex is occurred.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_3
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• pp.97-106
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• 2001

To improve the water quality, particularly for sea bathers, the behaviour of wastewater from sewage outfalls in water adjacent to Swansea, UK, was studied using a mathematical model. The water quality in the sewage receiving basin was determined using factors like the outfall diffuser location(distance from land boundary), sewage treatment scheme, discharge time, and bacteria decay rate, etc. With respect to these factors, an optimal strategy for sewage discharge was then investigated to minimize bacteria levels along the bathing beaches. As water quality criteria, predicted faecal coliform levels were monitored along the coast adjacent to the outfall locations. The resultant values were compared with EC Mandatory(<2000, 95 % of 20 samples) and Guideline Standards(< 100, 80 % of 20 samples). For the advective-diffusion equation, the non linear advective terms were represented using the ULTIMATE algorithm and the third-order accurate QUICKEST scheme to avoid numerical diffusion. Details of the simulation results are then presented as an optimal policy for sewage discharge in the region.

• Journal of the korean society of oceanography
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• v.39 no.1
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• pp.72-95
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• 2004

The Yellow Sea is characterized by relatively shallow water depth, varying range of tidal action and very complex coastal geometry such as islands, bays, peninsulas, tidal flats, shoals etc. The dynamic system is controlled by tides, regional winds, river discharge, and interaction with the Kuroshio. The circulation, water mass properties and their variability in the Yellow Sea are very complicated and still far from clear understanding. In this study, an effort to improve our understanding the dynamic feature of the Yellow Sea system was conducted using numerical simulation with the ROMS model, applying climatologic forcing such as winds, heat flux and fresh water precipitation. The inter-annual variability of general circulation and thermohaline structure throughout the year has been obtained, which has been compared with observational data sets. The simulated horizontal distribution and vertical cross-sectional structures of temperature and salinity show a good agreement with the observational data indicating significantly the water masses such as Yellow Sea Warm Water, Yellow Sea Bottom Cold Water, Changjiang River Diluted Water and other sporadically observed coastal waters around the Yellow Sea. The tidal effects on circulation and dynamic features such as coastal tidal fronts and coastal mixing are predominant in the Yellow Sea. Hence the tidal effects on those dynamic features are dealt in the accompanying paper (Kim et at., 2004). The ROMS model adopts curvilinear grid with horizontal resolution of 35 km and 20 vertical grid spacing confirming to relatively realistic bottom topography. The model was initialized with the LEVITUS climatologic data and forced by the monthly mean air-sea fluxes of momentum, heat and fresh water derived from COADS. On the open boundaries, climatological temperature and salinity are nudged every 20 days for data assimilation to stabilize the modeling implementation. This study demonstrates a Yellow Sea version of Atlantic Basin experiment conducted by Haidvogel et al. (2000) experiment that the ROMS simulates the dynamic variability of temperature, salinity, and velocity fields in the ocean. However the present study has been improved to deal with the large river system, open boundary nudging process and further with combination of the tidal forcing that is a significant feature in the Yellow Sea.

• Journal of Korean Port Research
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• v.13 no.1
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• pp.133-146
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• 1999

Mokpo coastal area is connected to the adjacent a long river and two large basins. It is essential for port planning coastal zone management and environmental impact study to analyze the data related to the ship operation and variation of current and water quality due to the development of water area including dredging reclamation and estuary barrage. The Yongsan river estuary weir and Yongam-Kumho basins discharge much of water through water gates for the purpose of flood control and prohibit salt intrusion at the inland fresh water area. To meet this purpose discharge through the gates have been done at the period of maximum water level difference between inner river and sea level. This discharged water may cause the changes of current pattern and other environmental influences in the vicinity and inner area of semi-closed Mokpo harbor. In this study ADI method is applied to the governing equation for the analysis of the changes on current pattern due to discharged water. As the results of this study it is known that the discharging operation causes many changes including the increase of current velocity at the front water area at piers approaching passage and anchorages. Discussion made on the point of problems such as restricted maneuverability and the safety of morred vessels at pier and anchorage. To minimize this influence the linked gate operation discharging warning system and laternative mooring system are recommended.

• Maritime Security
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• v.2 no.1
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• pp.125-149
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• 2021

Even 10 years after the Fukushima nuclear disaster, Japan has yet to solve the problems emerging from generating contaminated water every day. Japan has unilaterally decided to release nuclear wastewater in the sea despite Korea's concerns about safety as their radioactive water storage tanks reach the limits. Despite Korea's response, Japan is still preparing to discharge nuclear wastewater without fulfilling its obligations under the United Nations Convention on the Law of the Sea. There are concerns about marine pollution caused by the radioactive materials from nuclear wastewater and invading Korea's maritime sovereignty. In particular, it is impossible to reverse the effects of environmental pollution, so plans to discharge radioactive water must be prevented unless immediate safety is guaranteed. This study proposes Korea's response strategy to resolve the conflict between the two countries due to plans to release contaminated water. Korea should respond to Japan's release of nuclear wastewater in the sea in various ways through cooperation with Japan, provisional measures, and cooperation with neighboring countries.