• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.2
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• pp.124-136
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• 2006

The change pattern of the sediment grain size distribution information (median grain size(D50)) due to some gridding method and sampling density is analyzed with reference to the grid information estimated by the 90 sediment samples which was collected in the coastal water off the Baengnyeongdo Island, in June 2004. The standard deviation of absolute deviation (AD) estimated the selected gridding method shows 8.0 ${\mu}m$ at June, 2004 and 10 ${\mu}m$ November, 2004. The estimated statistical information of absolute deviation in comparison with the grid information of reference and changed sampling density shows that the AD mean error trends increase as the number of samples decrease. The AD mean error is below 10% in the case of the information estimation using 50-sample with reference to the 90-sample information. In this case, the sampling density is suggested as about 9 sediment samples per $km^2$, at coastal zone in Yoggipo port in the condition of the study area is 5.9 $km^2$.

• The Korean Journal of Quaternary Research
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• v.3 no.1
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• pp.1-15
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• 1989

The Holocene marine surficial sediments and submarine morphology of the continental shelf of the Korea South Sea have been investigated to understand the evolutionary history of tile continental shelf sedimentation in relation to Holocelle sea level fluctuations. It is considered that along 120m $\pm$ $\alpha$ water depth of so-called Pusan Trough between the Tsushima Island and Pusan, Korea the lowest stand of Holocene sea level seems to be existed.

• 한국해양학회지
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• v.20 no.3
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• pp.55-61
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• 1985

Two hundred suspended-matter samples were collected from the continental shelf off the southeast coast of Korea during September, 1981, March, 1982 and April 1983. Superficial bottom sediments on the shelf were also taken. Based on the alalyses of TSM distribution and concentration patterns, it is considered that finegrained suspended matters are restricted to nearshore-inner shelf showing a band or zone paralleling with coastal morphology. This fact suggests a limitation of "modern" fine grained sediments to a nearshore and inner shelf band. The sand deposits with the lower value of mud content (<5%) adjacent to the shelf break and on the outer shelf would probably be "relict" sediments (old beach sediments) deposited in response to a lower stand of sea level during the Pleistocene ice age. The transgression did little to alter the distribution of sand on the outer shelf in this particular study area. The progress of shore line was so rapid that a given locality was in the beach zone and subject to rapid longshore drift and extensive reworking only for a few years. Probably the most pronounced effect of the transgression was sorting of the sand, and at least partial winnowing out of the finer fractions.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.481-482
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• 2001

연안 이용을 목적으로 건설되는 방파제 혹은 호안의 건설은 해류의 자연적인 흐름을 인위적으로 방해함으로서 해역의 수력학적 조건을 변화시키고, 그에 따른 저질 퇴적물 조성 및 대기노출 시간의 변화는 결과적으로 갯벌에 서식하는 해양저서동물의 번식과 섭식, 그리고 사망에 영향을 미친다 (hummel et al., 1994). 시화호는 1994년 1월 물막이 공사가 완료된 이후 1996년까지 완전히 폐쇄된 해역으로 유지되면서 내부에 분포하는 갯벌이 상당부분 훼손되었다. (중략)

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.101-110
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• 2013

In order to classify the trophic state and environmental quality of marine coastal system, an approach using the characteristics and biochemical composition in the sediments can be available. This research, including 25 coastal bay, belong to 131 stations, was carried out along the south coasts of Korea in February 2007. Type of sediment, total ogranic carbon, total nitrogen, phytopigments and biochemical composition(proteins, lipids, carbohydrates) were analyzed. Result from Multi-dimensional Scaling(MDS) ordination indicates that four group can be identified. The result of ANOVA with tukey test shows that the concentrations of proteins, carbohydrates and biopolymeric carbon were significantly different to four groups. We propose the trophic state classification for these groups using the biochemical composition of sediment organic matter. I group(Masan, Jinhae, Haengam) has been defined as hypertrophic state, II group(Tongyeong, Goseong；Jaran, Geoje et al.), as eutrophic; III group(Gamak, Deungnyang, Yeoja et al.), as mesotrophic and IV group(Sinan, Jindo, Muan), as oligotrophic. On the basis of results reported in this study, the biochemical composition of sediment organic matter could be considered an useful and sensitive tool for the classification of the trophic state of marine coastal systems.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.11a
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• pp.255-260
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• 2006

천수만의 수리 역학 및 수질 모델을 위하여 3차원 수리역학 모델(EFDC)과 21개 수질 변수에 대한 수질 모델이 접합된 3차원 수리역학-부영양화 모델(HEM-3D)을 이용하였다. 관측 자료에 대한 모델 검증 결과, 조위는 관측치에 비해 5% 정도, 유속은 10% 정도 작은 값을 보였으며, 지각은 모델 결과치가 고정항에서 늦고 간월도에서 빠르게 나타났다. 수질 항목, 특히 용존산소의 관측치에 나타난 전반적인 분포 양상을 잘 재현하고 있었으며, 항목별 기여도 분석에서는 수질 모델이 퇴적물에 의한 산소 소비에 민감하게 반응하고 있으며, 용존산소 변화에 있어서 퇴적물에 의한 영향이 중요한 역할을 하고 있음을 보여주었다. 본 모델 결과는 기존의 모델들과 비교하여 천수만 해역의 해수 유동 특성을 잘 재현하고 있으며, 본 모델과 연계된 수질 모델의 오염물 확산과 수질 항목들의 거동을 이해할 수 있는 정보를 제공하였다. 그럼에도 불구하고 본 연구를 통하여 나타난 문제점은, 수질 예측 모델에 필요한 수질 변수들의 관측 자료와 양식장에 의한 오염 부하량 자료가 충분하지 못하며, 퇴적물에 의한 수질 변화를 정량화할 수 있는 모델의 개발이 시급하다는 것이다. 특히 퇴적물에 의한 산소 요구량은 유기퇴적물이 미생물 등에 의해 분해되는 과정에서 요구되는 산소량으로서, 해수 유동 조건의 변화와 오염부하에 의한 유기퇴적물의 집적이 주된 요인이다. 방조제 건설 이후 해수유동 조건의 변화와 더불어 지속적으로 오염물이 유입되고, 담수 및 천수만의 수질이 점점 악화되고 있다. 따라서 이러한 오염부하와 퇴적물에 대한 관리대책이 시급한 것으로 판단되며, 향후 정확한 수질 예측을 위해서는 본 연구에서 나타난 문제점들에 대한 재고가 필요할 것으로 사료된다.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1203-1211
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• 2010

In order to study geology and sediment characteristics in Danghang Bay area, surface geological survey, SBP (sub-bottom profiler) survey, and sediment analysis were conducted. Danghang Bay area has a closing coast surrounded by land, and surface layer are covered by mud and sandy mud. Sedimentary facies of the surface layer consists of Mm and Mms facies. A SBP seismic survey shows that gas bearing sediments might be spread throughout the sediment layers, so that it seems to be hard to find acoustic basement and gas seeps are easily found throughout the survey lines. The gas trapped in the sediments may be related to the high organic contents of the sediment, and the thick mud layer may restrain the gas from releasing.

• 한국해양학회지
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• v.28 no.4
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• pp.272-280
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• 1993

The seasonal variations of water salinity and the concentration of suspended particulate matter (SPM value) have been monitored in the Keum Estuary and its adjacent coastal area. the concentrations of suspended matters show great seasonal variations with low concentrations during summer season and high concentrations during winter season. During the flood season of summer, water salinities are less than 5% in the Keum estuary, and the brackish water (salinity<28%) prevails seaward covering the entire coastal area. The concentrations decreased abruptly to the seaward from higher than 100mg/l in the Keum estuary to less than 5 mg/l in the offshore. These phenomena probably results from the rapid e\deposition of riverine suspended matters within the Keum Estuary. The seasonal variations of suspended matter concentrations in the Keum Estuary and its adjacent coastal area are interpreted as the cyclic (seasonal) sedimentation processes in the west coast of Korea, that is, replenishment and deposition of fine sediments in summer, and resuspension and seaward transport in winter.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.1
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• pp.16-24
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• 2012

To study the seasonal pattern of sediment distribution and the transport tendency in Haeundae nearshore area; i) the grain size texture of surface sediment was examined in June, October, and December of 2007, and March and June of 2008, and secondary, ii) the transport tendency was studied by using a two-dimensional sediment transport model of Gao and Collins (1992), and finally, iii) the bathymetric changes were analyzed by using the data collected in February, May, August, and December of 2007 by Haeundae District Office. Spatial distribution of sediment texture, the tendency of sediment transport as well as the bathymetric change showed significant seasonal variations. From June to December of 2007, the eastern part of the Haeundae area, off Dalmaji Hill showed the coarsening of mean grain size with a prominent transport tendency toward the Haeundae beach. On the contrary, the western part of the area, off Dongbaek Island showed a fining trend of mean grain size, and the transport tendency toward the beach was relatively weakened. From December of 2007 to June of 2008, the mean grain size of Mipo Harbor became finer, and the transport tendency toward the central beach decreased. The mean grain size of Dongbaek Island became coarser, while the tendency increased in the direction of the beach. The areas of significant net accumulation and erosion were depicted based on the bathymetric changes between observation periods. During the period of February to May of 2007, net accumulation was observed on the eastern part of the study area, in front of Mipo Harbor. Erosion was generally occurred throughout the area from May to August of 2007. From August to December of 2007, erosion and accumulation was observed off Mipo Harbor and Dongbaek Island, respectively. The change of sediment facies also suggests the accumulation on the eastern coast during the spring, erosion around the entire coast during the summer, and accumulation on the western coast during the winter. The changes in the accumulation and erosion were most apparent during the summer when several typhoons have passed by, while unnoticeable during the spring.

• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.441-450
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• 2016

A pilot scale biostimulation experiment was performed under field conditions to degrade organic pollutants and PAHs (Polycyclic Aromatic Compounds) in contaminated coastal sediment. During the experiment, the seawater temperature around the sediment varied from $16.5^{\circ}C$ to $21^{\circ}C$, while the sediment pH was stable at 8.4-8.5. The experiment was conducted over a one year period with a control group and a sample group with a applied biostimulant composed of acetate, sulfate, and nitrate. Chemical oxygen demand decreased 39% in the control group and 79% in the sample group. Volatile solids were reduced from 15 to 7 g/kg in the control group and 2.5 g/kg in the sample group. Out of the 2-, 3- ,4- ,5-, and 6-rings of the 16 vital PAHs, the compound including naphthalene (2-ring), took 2 months to degrade completely, while the degradation efficiency was 55.6% in the control group during the same period. In the case of the 3-ring and 4-ring PAHs, complete degradation in the sample and 46% - 100% degradation in control was observed after one year of the experiment. The 5-ring and 6-ring PAHs were degraded to about 77%-100% in the sample group and 26%-87% in the control group during the one year of the experiment. The study results show that biostimulation is a very effective method to improve the degradation rate of organic pollutants and PAHs (Polycyclic Aromatic Compounds) in contaminated coastal sediment.