• Journal of Korean Port Research
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• v.15 no.1
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• pp.57-74
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• 2001

In the past, the predictions of beach processes and harbor sedimentation were mainly relied on the hydraulic model tests and empirical methods. In recent years, however, as computers have come into wide use, more accurate models have gradually been developed and thus replaced those conventional methods. For prediction of topographical change near the coastal area, we need informations of wave and current conditions in the numerical model which should be calculated in advance. Numerical model introduced in this study combines wave refraction-diffraction, breaking, bottom friction, lateral mixing, and critical shear stress and three sub-models for simulating waves, currents, and bottom change were briefly discussed. Simulations of beach processes and harbor sedimentation were also described at the coast neighboring Bangpo Harbor, Anmyundo, Chungnam, where the area has suffered accumulation of drifting sand in a small fishing harbor with a wide tidal range. We also made model test for the new layout of the harbor and planned south breakwater for preventing intrusion of sand. Although the model study gave reasonable description of beach processes and harbor sedimentation mechanism, it is necessary to collect lots of field observation data, including waves, tides and bottom materials, etc. for better prediction.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.257-262
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• 2002

Numerical model introduced in this study combines wave refraction-diffraction, breaking, bottom friction, lateral mixing, and critical shear stress and three sub-models for simulating waves, currents, and bottom change were briefly discussed. Simulations of beach processes and harbor sedimentation were also described at the coast neighboring Bangpo Harbor, Anmyundo, Chungnam, where the area has suffered from accumulation of drifting sand in a small fishing harbor with a wide tidal range. We also made model test for the case of a narrow tidal range at Nakdong river's estuary area to understand the effect of water level variation on the littoral drift. Simulations are conducted in terms of incident wave direction and tidal level. Characteristics of wave transformation, nearshore current, sediment transport, and bottom change are shown and analyzed. We found from the simulation that the tidal level impact to the sediment transport is very important and we should apply the numerical model with different water level to analyze sediment transport mechanism correctly. Although the model study gave reasonable description of beach processes and harbor sedimentation mechanism, it is necessary to collect lots of field observation data, including waves, tides and bottom materials, etc. for better prediction.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.179-183
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• 2006

As there are many human activities in the coastal regions, various facilities and coastal engineering structures for protecting beach have been built. Dredging work, reclamation and harbor construction have caused the topography of sea floor to change rapidly. So sedimentation in the vicinity of the groins has get dull and the serious aspects sometimes turn up. Analyzing the surface sediments with transport vector model is one of the good methods to understand the sedimentation in the vicinity of the groins. I analyzed the transport vector of the surface sediments in the vicinity of the groins at the region where serious beach erosion happens near Pohang harbor.

• Journal of Environmental Science International
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• v.20 no.5
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• pp.655-665
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• 2011

Contamination of butyltin compounds (BTs), namely tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT), was evaluated in sediments collected inside Jeju Harbor in 2001. The concentrations of BTs in surface sediments were comparable to those in other sites of domestic and foreign countries. The high correlations between BTs in surface ($r^2$ = 0.83~0.91) and core ($r^2$ = 0.70~0.79) sediments and the significant correlations between BTs concentrations and the number of incoming and outgoing vessels indicated that DBT and MBT were mainly degraded from TBT based on antifouling paints of vessels etc. and other sources, such as DBT and MBT, could be ignored. The butyltin degradation indices ([DBT] + [MBT]/[TBT]) in surface sediments were in the range of 2.2~3.6 (mean 2.7), indicating that the parent compound, TBT, was inflowed into the surface sediments a long ago, degraded and deposited. The sedimentation age of BTs contaminated core sediments could not estimated because the content of $^{210}Pb$ activity was nearly all the same and so the sedimentation rate could not obtained.

• Journal of Environmental Science International
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• v.14 no.12
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• pp.1141-1153
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• 2005

Butyltin compounds (BTs), namely tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT), were measured in surface and core sediments collected in 2001 inside Seogwipo Harbor, in order to evaluate their distribution characteristics. Seogwipo Harbor is one of major harbors of Jeju Island where a lot of shipping occurs and is designated as a trade port by the Korea Maritime and Port Law. BTs were detected in surface and core sediments of all stations and their concentrations in surface sediments were low, compared with to those in other sites of domestic and foreign countries. The main species among BTs was MBT, although there was a little difference with a survey site in surface sediments and in core sediments with depth. No or low correlations were obtained between organic matter or particles size of surface and core sediments and total BTs, indicating that these factors did not affect the distribution of BTs. It was estimated that more complex factors including BTs loads and surrounding sedimentary environments, affect the distribution of BTs. The high correlations between BTs indicated that DBT and MBT were mainly degraded from TBT based on antifouling paints of vessel etc. and other sources, such as DBT and MBT, could be ignored. The butyltin degradation indices ([DBT]+[MBT]/[TBT]) in surface sediments were in the range of $2.0\~3.8$ (mean 3.0), indicating that the parent compound, TBT, were inflowed into the surface sediments a long years ago, degraded and deposited. The sedimentation age of BTs contaminated core sediments could not estimated because the content of $^{210}pb$ activity were nearly all the same and so the sedimentation rate could not obtained.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.3
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• pp.133-142
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• 2010

We calculated using siltation model to know the influnce of the tidal current, the tidal level, the sediment transport of seabed around sea area due to the construction of the Song do New city. We calculated the tidal current and based on this we estimated scour, sedimentation using the advection-diffusion equation and accessed the sediment transport of seabed before and after the construction of the New city. Sedimentation was increased in the east coast of Young jong Do, and Scour was increased according to the direction from the front route of north harbor to Ho do. Tidal level was increased overall.

• Korean Journal of Veterinary Research
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• v.10 no.1
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• pp.25-31
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• 1970

The techniques which have been used for the fecal examination of ruminant infected with the pancreatic flukes, Eurytrema Pancreaticum, were reviewer in their efficiency to detect the ova. One of modified fecal examination: H.F.E. (hydrochloric acid-formalin-ether) sedimentation method was devised in this study. Efficiency in the detecting ability of the fluke eggs with H.F.E. sedimentation method was determined by a series of repeat tests. Among 20 head of cattle known to harbor 1-5 adult worms of the pancreatic fluke, 75% of the infected cattle were detected, and among 60 head of cattle known to harbor more than 6 adult worms, 95% of the infected cattle were detected with H.F.E. sedimentation method. The procedures of the H.F.E. sedimentation method are as follows; 1) Take the sample 5-10 gm., emulsify throughly with 20 ml. of 50% hydrochloric acid in a cup. 2) Strain this mixture through one or two layers of wet surgical gauze into 15ml. centrifuge tube. 3) Washing the cup with 5ml. of 50% hydrochloric acid and strain again. 4) Centrifuge at 2,300 rpm. for 2 minutes. 5) Pour off the supernatant fluid. 6) After the sediment mixed with 10% formalin, stand for 5 minutes. 7) Add 2-3ml. of ether, shake vigorously up and down, after the top of the tube covered with thumb. 8) Centrifuge at 2,300 rpm. for 2 minutes. 9) Loosen the fecal plug in the tube by ringing with an applicator stick. 10) Quickly, but carefully, pour of all, but the bottom layer of sediment. 11) Thoroughly mix the sediment, pour on a slide (or pick up it with a pipett), mount with a cover glass. 12) Examine carefully.

• Journal of Navigation and Port Research
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• v.32 no.4
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• pp.305-313
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• 2008

Recently it was known that the problems of nearshore processes and damage of berth and counter facilities frequently had appeared at the small fishery port, such as Daebang near Samcheonpo city, Korea. Here we try to analyze the impact of the rearrangement of counter facilities and berth layout adopted for tranquility of its inner harbor. Because this harbor is being connected to Daebang channel, the rearrangement of the structures might affect to the current speed and direction and wave height, so do to the sea bottom undulation. Therefore, we made model test for the several layouts of the berth and breakwater in this area. Numerical model result shows that the bottom was eroded by 1m by tidal currents and the speed of flow did not shrink, even after the construction work was completed. The direction of the sand movement was downdrift. Although the model study gave reasonable description of beach processes and approach channel sedimentation mechanism, it is necessary to compare with the field history, including the records of waves, tides and bottom materials, etc. for better prediction.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1993.07a
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• pp.122-123
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• 1993

Bangkok Bar Channel is a unique approach channel to Bangkok(on Toi)Harbor that is the representative river port constructed along the river mouth of Chao Praya River. Various facilities are scattered along the both sides of the river between the river mouth and the bridge located about 50km upward. The construction of the channel began in 1951 and was completed in 1954. (omitted)

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.4
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• pp.196-203
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• 2005

To describe dinoflagellate cyst distribution from Busan Harbor, eleven surface sediment samples and a vertical sediment sample were collected in 2003. Dinoflagellate cysts were identified 12 genera 22 species, and the total cyst concentrations varied from $210\~869\;cysts/g$. The proportion of heterotrophic dinoflagellate cysts was higher in inner parts than in outer parts of the harbor, which reflects that water quality is worse in inner harborthan that in outer harbor. On the basis of the sedimentation rate of 2.0 mm/yr, total depth of the vertical core reflects marine environment far the past 260 years, where dinoflagellate cysts were identified 9 genera 18 species and the total cyst concentrations were $79\~446\;cysts/g$. The cyst concentrations were low and the proportion of heterotrophic dinoflagellate cysts were incerased in the upper part from $14\~15cm$ depth$(1928\~1933)$, which shows industrialization and urbanization in this study area.