• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.3
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• pp.227-235
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• 2016

This paper emphasized the necessity of the marine spatial planning (MSP) through the analysis of the major developmental projects which could make a contradiction based on the adequacy of the site selection and environmental impacts. The conflicting affairs between space utilization and management plan happen in the following ways: marine renewable energy development, sand mining, reclamation, construction of golf course in coastal area, thermal effluent and waste heat, erosion causing port development. The conflict of stakeholder continues caused by the accumulated environmental impact. For the reasons mentioned above, we found two things. First, it is necessary to comprehend the fact of developmental planning and MSP. Second, it is still unsatisfactory to connect the relevance of laws related to the spatial planning. For the reinforcement of marine environmental policy management, it is necessary to consolidate the property of site selection and assessment of developmental scale. Especially, while the strategic environmental assessment is in progress based on site selection and property of scale, consistent diagnosis is needed in the following concerns: the fact of the marine spatial planning, the relevance between national developmental plan and regional developmental plan, fisheries regulation, marine protected animals. For the environmentally sound and sustainable development (ESSD), MSP should have to be prepared based in a way of top-down including coastal and EEZ plan, relevance of ocean-use zoning and sector planning, 3-D spatial information. And also integrated information system have to be prepared through high-tech marine spatial information. In conclusion, consistent and relevant strategy for MSP should have to include the whole information related to the maritime affairs such as harbor, fishing port, fishing ground, coastal management, marine ecosystem generally.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.5
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• pp.423-432
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• 2004

In coastal area of Inchon, dredging and the disposal of dredged material for sea-wall construction and reclamation have increased in recent years. These activities may impact the benthic environment and result in changes in benthic communities, but little information is available on the extent and direction of these changes. We investigated whether there have been changes in the dominant macrobenthic species and benthic community over the last decade, and explored the relationship between environmental variables and spatial patterns of macrobenthic community structure. We sampled macrobenthos and recorded environmental variables in the coastal habitats of Inchon in March and June 2004. In total, 212 macrobenthic species were recorded during this study, predominately crustaceans $(34{\%})$, mollusks $(32{\%})$ and polychaetes $(21{\%})$. The mean density of macrobenthos was $1,393\;ind./m^{2}$.The most abundant species was Amphioplus japonicus $(20.5{\%})$, followed by Heteromastus filiformis $(14.4{\%})$, Theora fragilis $(8.2{\%})$ and Ampharete sp. $(4.0{\%})$. Over the past decade the dominant macrobenthic species in this area shifted. Multivariate analysis (multidimensional scaling) revealed significant differences in community structure among three regions: the middle part of the sampling area (B), site 8 (C) and other sites (A). Mean density varied significantly among the three regions, but no differences in the number of species and diversity (H') were observed. The distribution of the macrobenthic community was affected by environmental variables such as percentage sand content and sediment kurtosis. Species that were important in different areas included A. japonicus in region A, Raeta puchella in region B and T. fragilis in region C. The important species in regions B and C were filter-feeding bivalves, and the abundance of these species may be related to the increase in percentage sand content. We suggest that the sediment composition (percentage sand content) may be an important factor in determining the dominant species and structure of the macrobenthic communities in coastal Inchon. Long-term monitoring programs are necessary to understand ongoing changes in the benthic communities of this area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.1
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• pp.25-31
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• 2012

The frequency and abundance of jellyfish, presumably related with climate change, fisheries overexploitation, marine pollution including land reclamation and dyke construction, are increasing worldwide. This feature has attracted interest and concerns from general public and public officials, and government is seeking how the damages could be prevented or reduced down. Korean government, having recent huge blooms of jellyfish, engaged in reducing and/or countermeasuring jellyfish damages. Korean research themes include ecology and physiology of blooming jellyfish species, understanding of the blooming mechanism, and focus on the eradication of blooming jellyfish, without governmental integrative management plan. EU is undertaking scientific projects focused on understanding of the mechanism and control of jellyfish blooms, and establishment of an integrative management. In USA, government has established the code on jellyfish management for conserving and protecting the fish and shellfish resources and one of its department is specially assigned to monitor jellyfish appearance, undertake research, and prepare management plan. Japan also assigned a department and research institute for jellyfish research. Their main interest is to predict jellyfish drifting and mass bloom. Compared to Korea, USA, EU and Japan emphasize integrative management that includes ecological understanding, public education and outreaches, communication and control, if possible, of jellyfish blooms, based on scientific data. We suggest then, 1) establishment of an integrative scientific system consisting of policy and scientific experts to prepare inter-ministrial integrative management plan to effectively combat jellyfish blooms and to maximize the scientific result; 2) concept change from harmful to exploitable marine animal in policy making and research; and 3) active education and information service for people. We expect that these suggestions can be useful for jellyfish management and policy making on another harmful marine organisms.

• Geomechanics and Engineering
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• v.22 no.2
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• pp.173-185
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• 2020

Calcareous soil is originated from marine biogenic sediments and weathering of carbonate rocks. The formation history for calcareous sediment includes complex physical, biological and chemical processes. It is preferably selected as the major fill materials for hydraulic reclamation and artificial island construction. Calcareous sands possess inter pores and complex shape are liable to be damaged at normal working stress level due to its fragile nature. Thus, the engineering properties of calcareous soil are greatly affected by its high compressibility and crushability. A series of triaxial shear tests were performed on calcareous sands derived from South China Sea under different test conditions. The effects of confining pressure, particle size, grading, compactness, drainage condition, and water content on the total amount of particle breakage for calcareous soil were symmetrically investigated. The test results showed that the crushing extent of calcareous sand with full gradation was smaller than that a single particle group under the same test condition. Large grains are cushioned by surrounding small particles and such micro-structure reduces the probability of breakage for well-graded sands. The increasing tendency of particle crushing for calcareous sand with a rise in confining pressure and compactness is confirmed. It is also evident that a rise in water content enhances the amount of particle breakage for calcareous sand. However, varying tendency of particle breakage with grain size is still controversial and requires further examination.

• Journal of the Korean earth science society
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• v.28 no.3
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• pp.357-366
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• 2007

In Gomso Bay, on the west coast of Korea, the surface sediments sampled in 1991 and 2006 were analysed to identify the long-term variations of tidal flat sediments. Silt and clay contents have decreased in the bay-mouth tidal flats whereas sand and clay contents have decreased on the inner-bay and bay-head tidal flats over the last 15 year period. In particular, the clay contents of the tidal flats in 2006 were relatively low when compared to those of both tidal flats adjacent to other semi-enclosed bays and those of the tidal flats in 1991. The variations of textural compositions in the tidal flat sediments have led to changes of the sedimentary facies. It indicates that the changes must have been made by the changes of hydrodynamic conditions impacted by human activities, such as the construction of sea-walls, land reclamation, structures of farms constructed compactly near the low water line, and the Saemangeum dyke constructed in the northern part of the area where this research was conducted.

• Journal of Ocean Engineering and Technology
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• v.21 no.2 s.75
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• pp.42-49
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• 2007

It has been known that shallow-water regions, such as tidal flats, sea grass and sea weed beds have water purification capability, and they also serve as nursery grounds for many fishes. On the other hand, tidal flat areas are economically attractive sites for reclamation, to be used for developing industries. When developing shallow-water areas, we have to propose a plan to mitigate the environmental impact associated with such a development plan. However, it is difficult to estimate the affects on the ecosystem and water purification, and the literature related to this matter is insufficient. In order to evaluate the ability of coastal tidal flat and to predict the future changes, it is necessary to develop a reliable prediction technique and construction of data by using a field investigation. In this study, we carried out a numerical model test for the tidal flat ecosystem, using the pelagic system and the benthic system, simultaneously, in order to show a change in the tidal flat ecosystem. The flow of nitrogen, phosphorus and carbon has been identified as a primary consideration of marine ecosystem components, and the capability of water purification and the change of the tidal flat were predicted using this flow. In order to make a more reliable prediction, a field investigation to determine tide, current and creatures of the object coastal area has been done. The purification capability of this shallow-water region is estimated from the model results. According to the results of experiments, the tidal flat has a capability of water purification (Sink) of 11mgN/m2/day, but the other area has a load (Source) of 20mgN/m2/day. As a result, we could confirm that the tidal flat of an object coastal area plays an important role in water purification.

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.221-228
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• 2003

In land reclamation construction using marine clay, a measure of material function, that is, the relation between void ratio-effective stress and permeability, is very important aspect for the prediction of self-weight consolidation behavior. But reclaimed ground has very high water content, so there are many difficulties in the laboratory test for measuring material function. For this reason, some researches are carried out using slurry cconsolidometr to measure material function. In this study, material function was measured using slurry consolidometer, and to overcome the shortcoming of researches using slurry cosolidometer, an equation for the prediction of material function was proposed on the basis of column test's parameter. Material function was determined through low stress consolidation test and permeability test, and it also was calculated with the equation using column test parameter. The continuity of material function could be confirmed through these tests. Material function is easily determined with the equation proposed in this study, and can be used for the prediction of self-weight consolidation behavior.

• Ocean and Polar Research
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• v.36 no.2
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• pp.87-101
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• 2014

Recently, more attention has been paid to the geomorphological changes in the Nakdong River Estuary, because those changes are caused by artificial activities including weirs, reclamation and construction. In order to analyze quantitatively the recent geomorphological variability in the Nakdong River Estuary, we surveyed the depth and elevation of submarine topography near Jinwoodo and Sinjado from March 2007 to February 2012. A statistical method (based on Digital Shoreline Analysis System) and an Empirical Orthogonal Functions method were used to evaluate the morphological changes. According to the statistical variables (DCE, NDC, EPR, LRR), the highest amount and rate of accumulation were recorded around the Gadeokdo whereas the greatest amount of erosion appeared around the coast off the eastern part of Sinjado. In particular, a dynamic variation of morphology was clearly observed in the vicinity of the sub-tidal channel located between Jinwoodo and Sinjado, which seems to be attributable to channel migration. As a result of the EOF method, the first mode (48.7%) is most closely related to the pattern of morphological variability that might be associated with the westerly movement of sediment by longshore current. The spatial variability of the second mode (16.6%) was high in the shoreface of Sinjado, showing a 4-year periodicity of temporal variability. The strong correlation (coefficient 0.73) between the time coefficient and suspended sediment discharge from Nakdong River emphasizes the role of sediment discharge to deposition in this area. The spatial variability of the third mode (11.3%) was distributed mainly around the coast off the eastern part of Sinjado, which is related to the movement of the coastline of Sinjado. Based on the last 5 year's data, our results suggest that the study area is characterized on the whole by a depositional pattern, but the extent of sedimentation is different locally.

• Journal of the Korean Geotechnical Society
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• v.21 no.8
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• pp.63-72
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• 2005

Rocks are dumped to soft marine ground in order to improve trafficability and construction conditions in the tideland reclamation construction sites. Though this rock layer under earth fill has caused in a serious seepage problems after construction, seepage behaviors of this embankment structure is not correctly investigated. Water flow through rock layers is, in general, known as Non-Darcy's flow. However, the embedded rock layer under earth fill is not known whether its flow is governed by Darcy's or Non-Darcy's law. Therefore, a numerical analysis, laboratory model test and filed investigations were performed for analyzing the those seepage characteristics in this research. Results show that there is significance of $95\%$ of confidence between observed heads and seepage rates, and the calculated ones by SAMTLE which is developed under the assumption that the water flows through the two-layer system obey the Darcy's flow. And after operating the hydraulic gradient(i) of $0.10\~0.55$ upon laboratory model, these seepage characteristics of the embedded rock layer show that Reynolds Numbers are less than 10 and the relationship between these velocities of rock layer(v) and hydraulic gradients(i) is linearly proportional with more than 0.79 of the coefficient of correlation $(R^2)$. And the Reynolds Number of the velocity calculated by the relation of v=ki in the embedded rock layer of OO sea dike is $1\~6$. It shows also laminar flow. Based on these results, it is concluded that the seepage characteristics of embedded rock layer under earth fill can be laminar and Darcy's flow.

• Korean Journal of Remote Sensing
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• v.25 no.4
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• pp.339-357
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• 2009

The Saemangeum Reclamation Project was launched as a national project in 1991 to reclaim a large coastal area of 401 km$^2$ by constructing a 33-km long dyke. The final dyke enclosure in April 2006 has transformed the tidal flat into lake and land. The dyke construction has abruptly changed not only the estuarine tidal system inside the dyke, but also the coastal marine environment outside the dyke. In this study, we investigated the spatial change of SST distribution using the Landsat-5/7 and NOAA data before and after the dyke completion in the Saemangeum area. Satellite-induced SST was verified by compared with the various in situ measurements such as tower, buoy, and water sample. The correlation coefficient resulted in above 0.96 and RMSE was about 1$^{\circ}C$ in all data. 38 Landsat satellite images from 1985 to 2007 were analyzed to estimate the temporal and spatial change of SST distribution from the beginning to the completion of the Samangeum dyke's construction. The seasonal change in detailed spatial distribution of SST was measured, however, the estimation of change during the Saemangeum dyke's construction was hard to figure out owing to the various environmental conditions. Monthly averaged SST induced from NOAA data from 1998 to 2007 has been analyzed for a complement of Landsat's temporal resolution. At the inside of the dyke, the change of SST from summer to winter was large due to the relatively high temperature in summer. In this study, multi-sensor thermal remote sensing is an efficient tool for monitoring the temporal and spatial distribution of SST in coastal area.