• Journal of Wetlands Research
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• v.20 no.2
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• pp.181-189
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• 2018

This study was performed to analyze the dynamics and distributional condition of biological community and to support the basic information about the estuarine ecosystem management by using the intensively surveyed results by each taxon experts around Tamjin river. We analyzed the biological diversity, abundance, correlation among species, and ecological characteristics about 11 taxa groups including vegetation, fish, birds, mammals, etc. in the Tamjin river estuarine ecosystem. We classified vegetation types into 7 physiognomic types and 18 communities according to habitat conditions with the physical environments and salinity. In total, 1125 species including 9 species of endangered species were identified in research area. The species composition and distributional characteristics of each taxon were corresponded to the environmental characteristics of the estuarine ecosystem. Especially, the species diversity and distribution were clearly distinguished in the river according to the difference of the environmental factors such as flow rate, salinity, and soil. Despite the disturbance factors such as barrage and levees, the biodiversity and its distribution were evaluated to be high level under the current environmental conditions. However, loss or reduction of wildlife habitat due to reclamation, embankment, barrage installation and expansion of farmland has been identified as a major threat to the diversity and health of the local ecosystem. The results of this study can be used as a basic data to cope with various development pressure and damage crisis of the whole estuaries including Tamjin river.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.2
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• pp.138-150
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• 2003

In the mid-west coast of Korea where Mankyung and Dongjin rivers discharge fresh water, Saemangeum tidal dyke of 33 km long is under construction to reclaim the very shallow estuary region of 41,000ha. Main source of freshwater in this coastal area is Keum River locating closely north of the dyke. At present, the dyke connected with Gogunsan-Gundo separates this area into three regions; northwestern, southwestern and eastern (Saemangeum) region of the dyke, and the water in Saemangeum region is exchanged through one gap in the northern dyke and two gaps in the southern dyke. We have observed distributions and structures of temperature and salinity to examine the summer circulation related with low-salinity water in this coastal area in 1998 and 1999. In the surface layer off the northern dyke a tongue-like distribution of low-salinity extends 60 km long from Keum River estuary mouth to the northwest, forming plume front bounded by offshore water. In the inner region of Saemangeum dykes salinity distributions show that two river waters are merged together and the low salinity water is deflected toward northern gap of the dyke. In the surface layer off the southern dyke we observed small tongue-like distribution of another low-salinity water extending to the north from Gomso Bay. Based on the analysis of distributions of low-salinity water and frontal structures, we can suggest an anticlockwise circulation of coastal water around the dyke, composed by the estuarine water outgoing from the inner region of the dyke through the northern dyke's gap and the inflow through two gaps of southern dyke from offshore. After completing the dyke construction, this coastal circulation around the dyke will be, however, changed because fresh water discharge of Mankyung and Dongjin rivers will be routed artificially and directly into the area offshore of the southern dyke.

• Journal of the Korean GEO-environmental Society
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• v.2 no.3
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• pp.5-15
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• 2001

The purpose of this study is to find sedimentation patterns variation before and after the Saemangeum reclamation. Water circulations before and after the Saemangeum reclamation are calculated diagnostically and prognostically from the water temperature, salinity data, wind data and tidal residual current. Three dimensional movements of injected particles due to currents, turbulence and sinking velocity are tracked by the Euler-lagrange method. The dispersion range of soil grain for one and three day after releasing in the Geum river indicates that the soil grain was sedimented coastal area of Janghang and outer harbor of Kunsan. The soil grain moves a quite distance from the release point when size of soil grain is a small. These results indicate that size of soil grain and residual current is greatly influenced on the dispersion range of soil grain.

• 한국해양학회지
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• v.14 no.2
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• pp.71-77
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• 1979

Tidal waves and the fluctuation of current are studied by use of observed data on tidal level, flow velocity and river discharge in the estuarine region of the Nakdong River. Observed data on the tidal level at five stations are used to obtain the fluctuation of amplitude and phase of tides, and the change of the wave speed versus distance from the river mouth. Comnining these tidal data with the vertical distribution of horizontal velocity data, some characteristics of the periodic tidal flow are deduced: (1)Diminishing rates of the tidal amplitude ratio η / η$\_$0/ at high tide were 0.058η$\_$0H/ /Km at neap tides. The constant of phase change, K, was 0.035rad/km. (2)While proceeding landward, the shape of the tidal wave changes from symmetrical to asymmetrical. The traveling speed of the tidal wave crest was estimated to be 3.6∼5.2m/sec, while that of the tidal wave trough was 2.4∼ 3.5m/sec. (3)The flowing speed of the water varies periodically in accordance with the tidal period. The maximum speed of landward flow appeared approximately at two hours before the high tide, while that of seaward flow at two hours before the low tide. (4)The upstream boundary is deduced approximately to be 50km at spring tide and 44km at neap tide from the tidal velocity decreasing. the tidal influence area is estimated approximately to be 65km from the tidal amplitude damping.

• 한국해양학회지
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• v.25 no.4
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• pp.205-216
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• 1990

This study was carried out to investigate the composition and the distribution of the polychaete community in Kwangyang Bay during 1987-1988, and to deduce causal factors of temporal changes in community by the comparison with the results of 1982 (Choi, 1984). In the present study, the Polychaetes comprised a total of 79 species, and had a mean density of 520 ind. $.$m/SUP -2/. They showed high abundance and species diversity in the main tidal channel and the north channel of Myodo. The most abundant polychaete was Lumbrineris longifolia (28.2%), and followed by Nephtys polybranchia (16.3%) and Stermaspis scutata (8.3%). Comparing the polychaete community in summer of 1987 with that in summer of 1982, Lagis bocki and Chone teres, the most dominant species in 1982, disappeared in 1987, while Lumbrineris longifolia, Nephtys polybranchia, Terebellides horikoshii, and Sternapis scutata experienced above twice increases in densities. the community in the north channel was distinguished from those in other regions by the high abundance of L. bocki in 1982, but was similar to that of the main channel by the disappearance of L. bocki in 1987. The community in the western inner bay was similar to that of the main channel in 1982, but became to be distinguished by the disappearance of l. longifolia and the high densities of S. scutata and Tharyx sp. in 1987. The temporal change in species composition and regional difference might be induced by the combined effects in the changes of hydrologic and sedimentary environments owing to the reclamation on the delta of Seomjing River and the dredging of the north chnnel.L.bocki in the north chnnel vanished after the habitat disturbance by the reclamation and dredging.S.scutata and Tharyxsp.dominated in the western inner bay because of the accumulationfo fine sediments through weakenend durrent flow by the obstruction of a new bank constructed on the delta.

• 한국해양학회지
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• v.13 no.1
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• pp.29-34
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• 1978

Simultaneous tidal current observation at five or seven stations on the channel near Incheon Habour was conducted at neap, mean and spring tides during the period of August 16 to August 27, 1976 and the characteristic of tidal currents with each tide was studied by the analysis of these data. Times of slack refer to the times of high and low waters at neap, mean and spring tides seem to be small. Times of maximum current refer to the times of high and low waters at the mean tide tends to appear earlier than that of the neap tide and later than that of the spring tide. The velocity ratio of maximum ebb current to maximum flood current at the mean tide has larger value than that of neap tide and has smaller value than that of spring tide. The current velocity ratio of spring tide to neap tide and to mean tide are approximately 1.8 and 1.3, respectively.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.9 no.1
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• pp.1-8
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• 1997

A horizontal 2-D model which includes the wetting-drying treatment technique in the intertidal zone is established for the prediction of tidal changes and contaminant transport due to the development of Incheon coastal zone. The flow model is verified by the measurement data at Jeong-Do, and then the computed values are closely matched to the observed water elevations and velocities of main-flow direction. And then, the tidal change patterns are simulated using this model before and after the construction of the Youngjongdo New Airport and Shihwa Seadike. In the spring tide condition, pollutants transport pattern is also simulated for the arbitrary pollutants loads. By the analysis of this numerical simulation results, the velocities after development are decreased, and discharged pollutants are mainly transported by the advection along a narrow deep trough. Thus, this model can be used as the compatible prediction model for the tidal change and pollutant transport due to the development plan of Incheon coastal zone.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2007.05a
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• pp.308-311
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• 2007

황해의 25개 조사정점의 표층수에 대한 해양환경요인 및 식물플랑크톤 현존량의 월별 조사결과를 종합하여 주성분분석(PCA)을 실시한 결과 주성분 I에서는 변화를 26.6% 설명할 수 있으며, 이중 질산질소가 가장 많이 기여하였고, 이어서 용존무기질소, 규산규소, 수온, 용존산소, 암모니아질소 순으로 기여 하고 있었다. 주성분 II에서는 20.3%를 설명 할 수 있으며, 이중 용존산소가 가장 많이 기여하였고 그 외 엽록소 a, 수온, 염분, 규산규소, 식물플랑크톤 현존량 순으로 기여 하였다. 주성분 III에서는 15.1%를 설명 할 수 있으며, 이중 인산인이 가장 많이 기여하였고 그 외 염분, 아질산질소, 수온, 용존산소, 질산질소, 용존무기질소 순으로 기여하였다. PCA에 이용된 항목 중 부유물질은 제외한 모든 항목은 주성분 I, II, III에 5%이하 유의수준에서 의미 있는 상관성이 있었다. 주성분 I은 질산성질소, 용존무기질소, 규산규소, 인산인과는 긍정적인 상관성(p<0.0001)을 갖고, 수온, 암모니아질소와는 부정적인 상관성을 보였다(p<0.001). 주성분 II에서는 용존산소, 엽록소 a, 식물플랑크톤 현존량은 긍정적 상관성을 나타내었고, 수온, 염분, 규산규소와는 부정적인 상관성을 보였으며(p<0.0001), 주성분 III에서는 염분, 수온, 질산질소, 용존무기질소, 식물플랑크톤 현존량과는 긍정적인 상관성(P<0.0001)을 나타내었고 인산인, 아질산질소, 용존산소는 부정적인 상관성을 나타내었다 (p<0.01). 공간적인 분포특성은 조사정점에 따라 항목별 결과에 대한 분산이 커서 일정한 특성을 도출하기가 어려운 상태이나 대체로 PCA II축을 기준으로 상부인 $1/4{\sim}2/4$분면에 북부와 중부의 조사정점이 위치하고 음의 방향인 $3/4{\sim}4/4$분면에 중부와 남부의 조사정점이 위치하고 있어 북측의 307선과 308선 및 중부의 309선과 310선 그리고 남측의 311선과 312선으로 구분되어지는데 그 중에서 태안반도의 연안역인 307선의 03점은 계절에 변화가 가장 커서 분산의 폭이 심한 상태로서 다른 조사정점들과 구분되어진다. 전반적으로 북측해역에서는 용존산소, 엽록소 a, 식물플랑크톤 현존량이 남측해역에 비해 상대적으로 많은 반면, 남측해역은 수온과 염분 및 규산규소가 높은 상태이었다. 북쪽인 307선과 308선은 연안역과 외해에서 상대적으로 영양염류가 높았으며, 중부인 309선과 310선은 연안역과 준 외해역인 07점과 09점에서 영양염류가 높았었고, 남부 해역인 311선과 312선에서는 연안역에서 영양염류가 상대적으로 높은 경향을 나타내었다. 즉 황해 동부는 연안역에서는 조석간만의 차가 심하고, 새만금 및 시호호등과 같은 대규모의 간척 매립으로 육상의 오염원이 자정작용을 거치지 못하고 직접 연안으로 유입되고 있는 실정이다. 또한 10여 년 전부터 육지의 모래부족으로 다량의 바다 모래가 채취되어 왔고 그 량이 점차 증가추세이며, 중부외해역에서는 각종 폐기물 투기로 점차 영양염류의 부하량이 증가되고 있어 특히 질소계와 인의 영양염류 농도가 높아지고 있는 추세이다. 시간적 변동특성은 전반적으로 순환하는 형태를 유지하고 있다. 2005년 2월에는 질산질소, 용존무기질소, 규산규소, 인산인, 용존산소가 높았었으며 4월로 접어들면서 항목 간에 분산되는 경향을 보이면서 수온, 엽록소 a 및 식물플랑크톤이 증가 하면서 해역에 따라 좌우로 분산되는 경향을 나타내었고 6월에는 아질산질소를 제외한 영양염류가 감소하는 경향을 보였다. 8월에는 6월에 비해 수온이 높아지고 규산규소, 질산질소, 용존무기질소 등이 약간 증가추세이었으며 10월로 접어들면서 증가추세가 더 높아졌었고 12월에는 질산질소, 용존무기질소, 규산규소, 인산인, 용존산소가 높아졌었다. 2006년 4월에는 2005년 4월에 비해 수온, 엽록소 a, 식물플랑크톤의 현존량이 높아져서 전년 동시기와 약간 다른 양상을 보이고 있었다. 즉 동계인 2월을 시작으로 반 시계 또는 시계 방향으로 순환하는 형태를 유지하고 있으며, 4월은 2개년 비교해 보았을 때 해마다 해양환경에 따라 그 순환 정도 및 형태가 다를 것으로 추정된다.

• 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.

• Journal of Science and Technology Studies
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• v.4 no.1 s.7
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• pp.1-30
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• 2004

In this paper, I have attempted to show how the environmental controversy surrounding the Saemangeurn Reclamation Project in Korea has been framed as narrow scientific debates. First of all, science, or specifically the Expert Review Pane, has played dual roles in the controversy. On the one hand, it has contributed to illuminating the future environmental impacts of reclamation, by so doing, to providing a momentum to reconsider the project. This has significant meaning that environmental concerns successfully checked the symbolic national project of developmental era through adopting a joint-investigation scheme that guaranteed participation of environmental groups on an equal footing with the government. On the other hand, by limiting the scope and participants of discussion, it fundamentally blocked the possibilities of public debates and deliberative decision-making with full considerations of the political, social, and cultural aspects of the controversy. I have shown that this is due to the realist belief shared by both the developers and the environmentalists in Korea that 'proper' science would disclose the truth. Environmental groups, in particular, were naive in evaluating the role of scientific expertise in the controversy and neglected the political role of the Expert Review Pane as a ritual. In opposition to the realist argument, I have shown through the analysis of the water quality debates concerning the future fresh water lakes that scientific 'facts' were not discovered but constructed through complex negotiations, conflicts, and compromises among related actors. The framing of the controversy as an experts' debate has resulted in the exclusion of an important actor from the discussion. Little attention has been paid throughout the controversy to the very people who have lived in the Saemangeum area for generations and will lose their livelihood all together soon. About 20,000 fishermen are living on the Saemangeum tidal flats.