• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.2
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• pp.124-128
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• 2005

Marine reservoir correction $({\Delta}R)$ values are measured using two species of mollusk tests collected by NFRDI in 1942 before nuclear bomb testing to convert the radiocarbon age to calendar age in Korean coastal waters more accurately. The ${\Delta}R$ values are calculated to be $-117\pm45\;^{14}C\;yr$ in the southwestern coast of Korea and $-160\pm35\;^{14}C\;yr$ in southeastern coast. These values are similar to those in Chinese coast of the Yellow Sea $(-81\pm60\~-178\pm50\;^{14}C\;yr$, indicating that regional reservoir $^{14}C$ ages of these areas are lower than mean global reservoir $^{14}C$ age. The lower ${\Delta}R$ values in these areas are presumed to be mainly caused by influence of fresh-water inflow. The ${\Delta}R$ values presented In this study enhance the accuracy in converting radiocarbon age to calendar age in Korean coastal waters.

• Journal of Wetlands Research
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• v.12 no.3
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• pp.107-127
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• 2010

This research is about the monitoring of people's consciousness on ecosystem change after coastal restoration project in Gangjin Bay. Tidal flat ecosystem of Ganjin Bay was major producing district of short-necked clam in Jeonnam Province. Owing to coastal restoration project (sand gathering and dredging) during 5 years, however, ecosystem was disturbed and harvesting of fish was decreased. Although a few of ark shell and oyster are harvested but drastically decreased. Even aging and depopulation is general situation like other rural regions, life pattern of villages and depopulation in Gangjin Bay was influenced by drastic decreasing of income. As the results of social monitoring, drastic decreasing of fish and shell in Gangjin Bay is significantly concerned with coastal restoration project (sand gathering and dredging) and also with difficulty of fresh-water inflow to coastal bay because of Jangheung Dam. In order to get the detail information on the cause and consequence of ecosystem change in tidal flat, it is necessary to apply the long-term socio-economic monitoring as well as biological and ecosystem monitoring.

• ALGAE
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• v.23 no.4
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• pp.317-326
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• 2008

Marine algal flora and community structure were investigated seasonally at three sites in Ilkwang Bay on the southern east coast of Korea from May 2007 to February 2008. Total 103 species including 10 of green algae, 17 of brown algae, 76 of red algae were collected and identified. Among these species, 21 species were found throughout the year. Ulva pertusa, Enteromorpha linza, Grateloupia lanceolata, Chondracanthus intermedia and Caulacanthus ustulatus were distributed dominantly in upper intertidal zone. By contrast, crustose coralline algae, Grateloupia spp., Chondracanthus tenellus, Prionitis cornea and Sargassum spp. occurred predominantly in middle intertidal zone. Grateloupia spp., Sargassum spp., Ecklonia cava and Ulva pertusa were dominant in lower intertidal zone. Annual mean biomass in wet weight was 478.3 g m$^{-2}$. Maximum biomass was recorded in site 1 (731.8 g m$^{-2}$), and minimum was recorded in site 3 (78.5 g m$^{-2}$). The R/P, C/P and (R + C)/P value reflecting flora characteristics were 4.47, 0.59 and 5.06, respectively. Two groups produced by cluster analysis, one including sites 1, 2 and the other including site 3, showed meaningful difference in similarity, each other. Site 3 showed the limited species composition due to inflow of fresh water and absence of solid substratum. However, there was no significant difference between site 1 and site 2. In conclusion, the number of marine algae species and biomass in Ilkwang Bay were markedly reduced comparing with the previous studies. These suggest that a solution for reconstruction of the poor marine algal vegetation is considerably demanded.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.2
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• pp.81-93
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• 2015

The comprehensive master plan in November 2010 on Saemangeum internal development has been released, and there is a need for complementary measures related to in-situ monitoring methods in order to acquire water temperature (T) and salinity (S) data. Thus, these data are monitored and analyzed by Korea Rural Community Corporation continuously. The purposes of current study are to evaluate the distributions of seasonal T and S, sigma-t, and stratification parameter and to compare annual stratification system in 2011 and 2012. To achieve these objectives, monthly vertical changes of T, S, and sigma-t, which are reproduced by a kriging technique, have been analyzed. In summer, the temperature difference between surface and bottom layers varies from 2 to $3^{\circ}C$, and the stratification of T is considerably weak. The stratification of S occurs abruptly within depth of EL. (-)5 to EL. (-)10 m. Therefore, stratification is induced by sudden increasing of water inflow amount due to a localized downpour during the rainy season, and these stratification processes are strongly influenced by inflowing a fresh water from watersheds in estuary environment.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.3
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• pp.15-30
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• 2019

Changpo Lake was created as a part of a land reclamation for refugee self-helping projects. It shows characteristics of a fresh water lake, and still retains the early appearance of reclamation that surrounding regions have not been developed into farm lands. Shallow wetland has formed around the lake, which provides great conditions for diverse lives, and surrounding earthiness is favorable for growth of vegetation and restoration of the ecosystem. However, as facilities of the Muan International Airport nearby Changpo Lake are expanding and barns are being constructed, artificialness is gradually increasing. Particularly, since pollution sources such as sport facilities, farm lands and barns are scattered around Changpo Lake, pollutants are flowing in constantly. Accordingly, the results for setting up management areas according to the spatial characteristics and creating natural ecological spaces near Changpo Lake, Taebongcheon stream and Hakgyecheon stream are as follows. First, the creation of a natural eco-friendly waterfront space should be promoted by securing the health of the aquatic ecosystem and restoring species and the ecosystem. In addition, a consultative body needs to be formed to lead local residents to participating in river investigation and monitoring, maintenance, and management through role sharing. Second, the basic direction of the spatial management plan is to keep the unique charm of Changpo Lake, maintain harmony with nature, create diverse waterfront areas, and secure the continuity of Changpo Lake and inflow streams. Moreover, the area should be divided into three zones such as a conservation zone, a restoration zone and a waterfront zone, and for each zone, the preservation of vegetation, the creation of ecological wetlands and restoration of the ecotone and ecological nature need to be promoted. Third, facilities and activity programs for each space of Changpo Lake should be operated for efficient management of protected areas. In order to suit the status of each space, biological habitats, water purification spaces, experiential and learning spaces, and convenience and rest spaces should be organized and designated as research, monitoring, education, and tourism areas. Accordingly, points of interest should be set up within the corresponding area. In this study, there are many parts that need to be supplemented for immediate implementation since the detailed plans and project costs for the promotion of programs by area are not calculated. Therefore, it is necessary to make detailed project plans and consider related projects such as water quality, restoration of habitats, nature learning and observation, and experience of ecological environments based on the categories such as research, monitoring, education and tourism in the future.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.4
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• pp.259-268
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• 2005

There has been a growing interest in the elimination of anoxic layer in the Youngsan River Estuarybecause the anoxic water mass caused mainly by the inflow of fresh water from the sea wall might cause the mass reduction of benthos during summer. An ocean outfall system to discharge treated wastewater into sea water may be used as one of the effective and economical ways to eliminate the anoxic layer. The suitable ocean outfall design is generally proposed for the prediction of the buoyant jet behavior in the near field. The parameters including CTD and current data are taken into account f3r more reliable buoyant jet behavior calculation. One of the numerical models, CORMIX 1, approved by EPA is used herein for the prediction of the trajectorial variation of the cross-sectional salinity and DO concentration distribution on the calculated buoyant jet boundary according to the tidal periods. On the basis of the results, it is suggested that the single port outfall is a useful system to eliminate the anoxic layer. Proper strategies are also proposed for achieving desirable ambient conditions.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.2
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• pp.318-331
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• 2019

In this study, comparative analysis is performed on the long-term persisted warm eddies that were generated in 2003 (WE03) and in 2014 (WE14) over the East Sea using the HYCOM reanalysis data. The overshooting of the East Korea Warm Current (EKWC) was appeared during the formation period of those warm eddies. The warm eddies were produced in the shallow Korea Plateau region through the interaction of the EKWC and the sub-polar front. In the interior of the both warm eddies, a homogeneous water mass of about $13^{\circ}C$ and 34.1 psu were generated over the upper 150 m depth by the winter mixing. In 2004, the next year of the generation of the WE03, the amount of the inflow through the western channel of the Korea Strait was larger, while the inflow was lesser than its climatology during 2015 corresponding to the development period of the WE14. The above results suggest that the heat and salt are supplied in the warm eddies through the Tsushima Warm Current (TWC), however the amount of the inflow through the Korea Strait has negligible impact on the long-term persistency of the warm eddies. Both of the warm eddies were maintained more than 18 months near Ulleung island, while they have no common feature on the pathways. In the vicinity of the Ulleung basin, large and small eddies are continuously created due to the meandering of the EKWC. The long-term persisted warm eddies in the Ulleung Island seem to be the results of the interaction between the pre-existed eddies located south of the sub-polar front and fresh eddies induced by the meanderings of the EKWC. The conclusion is also in line with the fact that the long-term persisted warm eddies were not always created when the overshooting of the EKWC was appeared.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.2
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• pp.111-117
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• 2008

We estirmted the yearly and monthly variation in discharge from the Nakdong River Barrage. We studied the total monthly discharge, the mean daily discharge, and the maximum daily discharge based on the observational discharge data for the 11-year period 1996-2006. We also examined the correlation between the discharge and the meteorologiml factors that influence the river inflow. The results from this study are as follows. (1) The total monthly discharge for 11 years at the Nakdong River Barrage was $224,576.8{\times}10^6\;m^3$: The daily maximum was in 2003, with $56,292.3{\times}10^6\;m^3$. The largest daily mean release discharges occurred in August with $52,634.2{\times}10^6\;m^3$ (23.4% of the year), followed by July and September in that order with 23.1 and 17%, respectively. (2) The monthly pattern of discharge could be divided into the flood season for the period July-September (discharge =$1000{\times}10^6\;m^3$/day), the normal season from April to June and October (discharge=$300{\times}10^6\;m^3$/day), and the drought season from December to March (discharge < $300{\times}10^6\;m^3$/day). (3) Periods of high temperature, low evaporation loss, and short sunshine duration produced a much higher discharge in general. Conditions of low rainfall and high evaporation loss, as was the rose in 2003, tended to reduce the discharge, but high rainfall and low evaporation loss tended to increase the discharge as it did in 200l. (4) The dominant wind directions during periods of high discharge were NNE (15.5%), SW and SSW (13.1%), S(12.1%), and NE (10.8%) This results show that it run bring on accumulation of fresh water when northern winds are dominant, and it run flow out fresh water toward offslwre when southern winds are dominant.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.1
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• pp.1-8
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• 2005

We estimated the loadings of nitrogen and phosphorus flowing into Gwangyang Bay front river for monthly interval from April to December of 2003. We analyzed the concentrations of nitrogen and phosphorus in water and estimated the flowing rates of fresh water in 34 rivers. The amounts of water flowing into the Gwdngyang Bay from Sum-Jin River was 51-76％ in the total inflow of the river. The river water over 96％ of discharge was from Sumjin River, Dong River, Ju-Kyo River, Seo River and Shinkyum River. The flowing patterns of nitrogen and phosphorus into Gwangyang Bay were similar to the flowing of river. The nitrogen and phosphorus loadings into the Bay were higher in July and August than in dry seasons. In particular, the concentrations of phosphorus were high in Namshu River, Deukyang River and Kilho River sewage during in dry seasons. The range of DIN and TN loadings from Sumjim River were 46-66％ and 36-64％, respectively. The loading of DIP and TP from Sumjim River were 2-55％ and 12-67％, respectively. These results show that the most efficient control of N. p flow into Gwangyang Bay is to restrain the inflows of N, p from Namshu River, Deukyang River and Kilho River and to restrain the flows of N, p from Dong River, Ju-Kyo River and industrial plant. The DIN/DIP atom ratio in river water was about 18 in July and August, while the ratio was more higher in dry seasons than July and August of rainy seasons. The TN/TP atom ratio in river water was about 7 in rainy seasons, while the ratios were higher than 100 in the other months of dry seasons.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.2
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• pp.53-64
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• 2013

This study analyzed the ADCP records along with wind by KMA and discharge records at Seosan A-, B-district tide embankment by KRC for 33 days obtained in the Chunsu Bay, Yellow Sea, Korea spanning from July 29 to August 30, 2010. Various analyses include descriptive statistics, harmonic analysis of tidal constituents, spectra and coherence, complex correlation, progressive vector diagram and cumulative curves to understand the tidal and sub-tidal current characteristics caused by local wind and discharge effect. Observed current speed ranges from -30 to 40 (cm/sec), with standard deviation from 1.7 (cm/sec) at bottom to 18.7 (cm/sec) at surface. According to the harmonic analysis results, the tidal current direction show NNW-SSE. The magnitudes of semi-major axes range from 9.4 to 14.8 (cm/sec) for M2 harmonic constituent and from 4.4 to 7.0 (cm/sec) for S2, respectively. And the magnitudes of semi-minor axes range from 0.1 to 0.5 (cm/sec) for M2 and from 0.4 to 1.4 (cm/sec) for S2, respectively. In the spectral analysis results in the frequency domain, we found 3~6 significant spectral peaks for band-passed wind and residual current of all depth. These peak periods represent various periodicities ranging from 2 to 8 (days). In the coherency analysis results between band-passed wind and residual current of all depth, several significant coherencies could be resolved in 3~5 periodicities within 2.8 (days). Highest coherency peak occurred at 4.6 (day) with 1.2-day phase lag of discharge to band-passed residual current. The progressive vector of wind and residual current travelled to northward at all layers, and the travel distance at middle layer was greater than surface layer distance. The Northward residual current was caused by a seasonal southern wind, and the density-driven current formed by fresh water input effected southward residual current. The sub-tidal current characteristics is determined by seasonal wind force and fresh water inflow in the Chunsu Bay, Yellow Sea, Korea.