• 한국해양학회지
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• v.17 no.1
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• pp.12-18
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• 1982

Tidal exchanges of sea water are studied by using drogue experiments and tidal current measurement data in Gamag Bay which has two channels. At the spring tide, the volume of tidal transport in the bay was estimated to be 46∼52% of the total volume of sea water in Gamag Bay, 7.1 10$\^$8/㎥. The tidal transport through the wide channel occupies 87% of the total tide transport of the bay. Residual current was deduced to flow north-northeastward at the rate of 3.254 10$\^$5/㎥ per tidal cycle. the tidal exchange of the sea water during the flood flow was estimated to be approximately 26% of the tidal transport, while that during the ebb flow was 41%. The tidal exchange through the wide channel during the flood flow occupies 77% of total tidal exchange of the bay through both channels, whereas that during the ebb flow does 88%. The diffusion coefficient of 2.08∼ 2.30 10$\^$7/$\textrm{cm}^2$/sec at the narrow channel was greater than that at the wide channel which was 1.2∼2.8 10$\^$6/$\textrm{cm}^2$/sec.

• Journal of Fisheries and Marine Sciences Education
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• v.13 no.2
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• pp.168-177
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• 2001

The flow pattern and water mass structure in the Chungmu channel were investigated using the field observations during June and July, 2001. The currents in the channel may be regarded as a hydraulic current decided by difference of tide levels between two sides in the channel. The strongest current in the channel occurs around in high water and low water. The coefficient C to be determined the characteristics of velocity in the channel was obtained from an equation, $u=C{\sqrt{2gh}}$ and ranges from 0.37 to 0.65 in the Chungmu Channel at the spring tide and from 0.23 to 0.37 at the neap tide. Eastward tidal transport is usually larger than that of westward transport in Chungmu the Channel. Sea water exchange rates are 39.2% in spring tide and 20.5% in neap tide respectively. The water mass structure in the channel is changed by the speed of the tidal current. The water mass is well mixed at the high water when the current is strong and is stratified at slack water when the current is weak.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.4
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• pp.503-512
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• 2012

In Yongwon channel, its natural flow of seawater is blocked by the construction of Busan New Port including the container berth. The channel was transformed into a narrow and long one, where it is possible that ships are only allowed to pass through the north-side channel of Gyeonmado located at the point of river mouth to Songjeongcheon. In addition, Yongwon channel is approximately 100 m wide on average and 3,600 m long, and has the highest slenderness ratio (length/width = 36). So it is considered that the changes in the terrain characteristics of Yongwon channel is likely to alter the circulation of sea water, thereby changing its water quality. In this study, the bottom sediment were collected from the 48 points of the Yongwon channel and the long-term leaching characteristics were analyzed. Thus, changes in sediment and water quality were analyzed through the sediment release test to investigate the degree of contamination. The sediment release from the inside region was higher than the outer region, which is due to the pollutant that comes form the downtown area. The results of this study can be used to predict the water quality in the future and prepare the economically optimized countermeasures to improve the water quality of Yongwon channel, Busan New Port.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.28 no.2
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• pp.117-131
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• 1992

A studies on the pattern of sea water circulation was carried out by using drogue experiments, tidal current measurement and hydrographic data in Kamak Bay which has two channels. At the flood, the water inflowed from the northern narrow channel flows mostly to the southward then the westward because Daekyung-island located at the flow path, at the same time the water from the southern channel of bay directed strongly to the north with a spine centered at around Gunnaeri. And these waters converged at the area between eng-Island and Deakyung-Island in the bigining of the flow, and placed at less southern part than the area at the late. The water of the north west inner bay having concave bottom topography inflows to Najin inlet with a spin of anti-clockwise. At the ebb, those waters in the bay turn back to two channels respectively, but most of waters directed to the southern channel of the bay. The directions of residual current of two channels are the southward mainly, and the current of inner area are influenced by the prevailing wind. The north-west inner bay which has the weak tidal current less than 10 cm/sec shows a similar upwelling by off-shore wind in winter, and the stratification in summer, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.19 no.1
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• pp.33-39
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• 1983

Tidal exchange of sea water was studied by using drogue experiments and tidal current measurement data in Yeoja Bay which has a narrow channel. At the spring tide, the volume of tidal transport in the bay was estimated to be 43% of the mean volume of the sea water in Yeoja Bay, 1.96km super(3). Residual current was deduced to flow southward at the rate of 3,658$\times$10 super(4) m super(3) per tidal cycle. The mean tidal exchange of sea water during the flood flow was estimated to be approximately 5.0% of the volume of sea water at the mean high water level in the bay, 2.33km super(3), while that during the ebb flow was 6.3%. One dimensional diffusion coefficient of 1.69-1.97$\times$10 super(6) cm super(2)/sec was obtained at the channel in the bay.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.574-578
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• 2006

Tidal amplification by construction of the sea-dike and sea-walls had been detected not only near Mokpo Harbor but also at Chungkye Bay which is connected with Mokpo Harbor by a narrow channel. This brings about increase of tidal flat area and in particular increase of surge-wave combined runup during storms. The purpose of this study is to examine an efficient operational model that can be used by civil defense agencies for real-time prediction and fast warnings on wind waves and storm surges. Instead of using commercialized wave models such as WAM, SWAN, the wind waves are simulated by using a new concept of wavelength modulation to enhance broader application of the hyperbolic wave model of the mild-slope equation type. Furthermore, The predicting system is composed of easy and economical tools for inputting depth data of complex bathymetry and enormous tidal flats such as Mokpo coastal zone. The method is applied to Chungkye Bay, and possible inundation features at Mokpo Harbor are analyzed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3B
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• pp.307-313
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• 2008

Tidal amplification by construction of sea-dike and sea-walls had been detected not only near Mokpo North Harbor but also at Chungkye Bay which is connected with Mokpo North Harbor by a narrow channel. This brings about increase of tidal flat area and in particular increase of runup height and inundation area during storms. In this study, a simulation process is composed of wind wave generation model for large area and wave inundation model for small coastal zone. The nonlinear version of mild-slope equation is modified for simulating wind-driven surge and wave inundation at a small area. The models are applied to Chungkye Bay, and possible inundation features at Mokpo North Harbor are investigated.

• Journal of Navigation and Port Research
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• v.34 no.7
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• pp.525-532
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• 2010

Mobile Harbor (MH) is a new transportation platform that can load and unload containers onto and from very large container ships at sea. It could navigate near harbors where several vessels run, or it could navigate through very narrow channels. In the conceptual design phase when the candidate design changes frequently according to the various performance requirements, it is very expensive and time-consuming to carry out model tests using a large model in a large towing tank and a free-running model test in a large maneuvering basin. In this paper, a new Planar Motion Mechanism(PMM) test in a Circulating Water Channel (CWC) was conducted in order to determine the hydrodynamic coefficients of the MH. To do this, PMM devices including three-component load cells and inertia tare device were designed and manufactured, and various tests of the MH such as static drift test, pure sway test, pure yaw test, and drift-and-yaw combined test were carried out. Using those coefficients, course-keeping stability was analyzed. In addition, the PMM tests results carried out for the same KCS (KRISO container ship) were compared with our results in order to confirm the test validity.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.21 no.4
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• pp.125-133
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• 2016

We investigated the distribution of organic matter and trace metals in surface sediment from Tonyeong coast. To determine the status of trace metal pollution, we also conducted an ecological risk assessment. Relatively high concentration of TN (total nitrogen), TOC (total organic carbon), and AVS (acid volatile sulfide) was found in surface sediment located in the narrow channel (site 35-38). Spatial distribution of Cd, Cr, Ni, Co, Hg, and Zn in surface sediment was similar and high Cu concentrations were found in narrow channel. The assessment of heavy metal pollution was derived using the Enrichment factors (EF). The enrichment factor indicated that Cd was no enrichment (EF<1), Pb, Cr, Ni, Co, Zn, and Hg were minor enrichment (1

• Journal of Environmental Science International
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• v.14 no.4
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• pp.397-404
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• 2005

In order to study the temporal variations of nutrients and chlorophyll-a in the Bottol Bada, three field observations were carried out on 20, 23 and 26 July, 2004. The low N:P values exhibit nitrogen deficiency during the periods of observation. This result is not representative of typical summer environment in the southern coast of Korea. The possible mechanisms are as follows: 1) The freshwater inflow was not sufficient for the supply of nitrogen because the total precipitation was 11.9 mm in July, 2004. This amount is no more than $5\%$ in normal precipitation in July. 2) There was an inflow of oceanic water under the subsurface into the Bottol Bada. Even though the oceanic water comprises more nutrients, it produces the stratification between the surface and the subsurface water and seems to prevent the supply of nutrinets to the surface layer. 3) The high chlorophyll-a concentration of $1.2 {\cal}ug/L$ was shown near the narrow channel between Gae-do and Geumo-do. This seems to be resulted from the inflow of water from Gamak Bay.