• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.1
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• pp.73-83
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• 2011

The opening status of Saemangeum sluice gate is an important factor to the coastal water qualities near Saemangeum dikes. The sluice gate opening information is important in analysing current velocity and water quality data measured at the Saemanguem observation tower as well as in determining boundary conditions of numerical simulation for coastal environment outside Saemangeum dikes. This study establishes unmanned camera monitoring system on Saemangeum observation tower using mini notebook and digital camera, and extracts information on the opening status from images automatically. Images are analysed using variance difference of images together with edge detection techniques in order to get correct information.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.4
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• pp.259-268
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• 2003

The damage of water quality like red tide occurs every year inspite of the total load regulation of pollutant inflows from land such as COD, phosphorus and so on around Seto inland sea in Japan. It is attributed to the increase of primary production due to eutrophication. and the rising and settling from the sediment containing nutrient salt. Furthermore, the recent research shows that nutrient salt such as nitrogen and phosphorus, flows into Kii channel from land as well as the Pacific ocean. To investigate the distribution of water quality and flow and residual current in Kitan strait, the field observations were carried out. The field data were obtained a time each season from 1999 to 2002. The results of observations and data of other research institution are used to understand the mechanism of pollution in the strait.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.1
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• pp.56-62
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• 2015

The potential impact of water temperature on sea level and air temperature rise in response to recent global warming has been noticed. To predict the effect of temperature change on river water quality and aquatic environment, it is necessary to understand and predict the change of water temperature. Air-water temperature relationship was analyzed using air temperature data at Buan and water temperature data of Shinsi, Garyeok, Mangyeong and Dongjin. Maximum and minimum water temperature was predicted by neural network and the results show a very high correlation between measured and predicted water temperature.

• Journal of Navigation and Port Research
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• v.27 no.3
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• pp.259-266
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• 2003

Due to the growth of population and industrial development at the coastal cities, there has been much increase in necessity to effective control of the wastes into the coastal water and river. The amount of disposal at those waters has been increased rapidly ana it is necessary for us to track of it in order to keep the waterway safe and the water clean. The investigation and research in terms of water quality in these regions have been conducted frequently but the systematic survey of the disposed wastes at the bottom was neglected and/or minor. In this study we surveyed the status of disposed waste distribution at the bottom of coastal water and river from the scanned images. The intensity of sound received by the side scan sonar tow fish from the sea floor provides information as to the general distribution and characteristics of the superficial wastes. The port and starboard side scanned images produced from two arrays of transducers borne on a tow fish connected by tow cable to a tug boat have the area with width of 22m~112m and band of 44m~224m. All data are displayed in real-time on a high-resolution color display ($1280{\times}1024$ pixels) together with position information by DGPS. From the field measurement and analysis of the recorded images, we could draw the location and distribution of bottom disposals. Furthermore, we could make a database system which might be useful for navigation and fundamental for planning the waste reception and process control system.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.3
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• pp.192-197
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• 2014

Water analyses were conducted on 1,525 underground water laid in the western district of Korea's South Gyeongsang Province, from January 2007 until July 2010, according to sections, factors, fountainheads and inter-factor correlativities. The following are the results. 1. As a result of local incongruity rate, 18.2% in inland areas, coastal areas and 24.5% showed a high value comparatively. Costal areas showed high incongruity rate. 2. As a result of local incongruity rate, they were found that the total colony count and general bactria 39.9%, 42.6% showed a high in costal areas. 3. As a result of local factorial inspection, it was found that the turbidity content counted up to 0 to 0.2 NTU in 59.4% in inland areas, 60.2% in costal areas of sections, and in other 12.6%, 14.0%, it exceeded 0.5 NTU. As a result of local factorial inspection, it was found that the nitrate-nitrogen content counted up to 0 to 10 mg/L in 98.2% in inland areas, 97.6% in costal areas of sections, and in other 1.8%, 2.4%, it exceeded 10 mg/L. As regards chloride in coastal areas, water quality standards for chloride 250 mg/L exceeds the 1.4% higher then in inland areas. 4. Hardness in inland areas was closely correlated with total solids (r = 0.910), sulfate ion (r = 0.819). Also, total solids and boron (r = 0.600) showed high correlativities. On the other hand hardness in coastal areas was closely correlated with total solids (r = 0.919), chloride (r = 0.829). Also sulfate ion was closely correlated with hardness (r = 0.599), turbidity and aluminum (r = 0.635) showed high correlativities in this research.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.1
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• pp.30-34
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• 1988

In roastal fish farms the farmers, especialy engaging in dealing with the floating cage culture, going to know about relationships between holding capacity and water quality in cage. Some of water quality managers and specialists studing physiological ecology understand that the key of water quality management concerned fish farming is budget of dissolved oxygen. This paper deals with oxygen budget in floating cage of the yellow tail farms at southern coastal area in Korea. The sampling station is located at Konli-Do fish farm near Chungmu, and the data is collected for 24 hours from 3:00 p.m. 8th September 1987. In result, the needed oxygen coming after the consumption by the rearing fish had been supplied with the tide current exchange, the sum of oxygen produced by phytoplankton photosynthesis and diffused from atmosphere are no more that $43\%$ for the needs of sea water consumption included respiration of planktons and decomposition of organic matters. The optimum holding capacity of cage is possible to compute with the calculation of minimum diurnal water exchange rate $[Qin{\cdot}V^{-1}\;(C-\bar{c})]$ through net mesh of cage.

• 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 Environmental Science International
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• v.11 no.4
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• pp.297-308
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• 2002

Field observations for research of oceanographic characteristics in waters adjacent to fish farm on land and water quality at area where water is supplied to fish farm and area where water is discharged from fish farm are carried out in coastal waters of Pyoson located in the southeastern region of Jeju Island in March, May, August and November of 2000. Semidiurnal tides to the northeast and southwest dominate. The mean velocities of current around neap tides and spring tides are 8.52cmㆍs$^{-1}$, 28.63cmㆍs$^{-1}$, respectively. The difference of temperature between area where water is supplied to fish farm and area where water is discharged from fish farm is about 0.6$^{\circ}C$. Seasonal variation range for temperature and salinity is 13.5$^{\circ}C$ and 3.5psu, individually. Concentrations of nitrate(NO$_3$$^{-}$), phosphate(PO$_4$$^{3-}$ ), silicate(SiO$_2$) and COD(chemical oxygen demand) are high in autumn. Particularly, concentrations of nitrate and COD in winter and spring at station where water is supplied to fish farm are higher than these at station where water is dischared from fish farm. However, concentration of phosphate and silicate at station where is supplied to fish farm in spring, summer and autumn is higher than that at station where water is dischared from fish farm. Water quality in the study area is grade 1 and this level is kept up in the whole year.

• 한국해양학회지
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• v.13 no.2
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• pp.17-25
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• 1978

General water quality parameters were measured, as a base-line study, for possible water pollution problems in the coastal waters of some important harbors and near-sea industrial complexes all around coastal zones of Korea from June 1 to October 15, 1977. The areas surveyed were near Mugho-Samcheog, Ulsan, Jinhae-Masan, Yeosu-Gwangyang, Mogpo, Gunsan and Incheon. Among the surveyed coastal areas, the Ulsan and the Jinhae-Masan areas showed high levels of dissolved oxygen, pH, COD and nutrients. Particularly, the surface waters of the Ulsan inner bay represented COD 15.6mg/l and NO$\sub$2/-N 110$\mu\textrm{g}$/l. The surface layer of the Masan bay displayed pH 8.92 and NO$\sub$3/-N 372$\mu\textrm{g}$/l, while 309$\mu\textrm{g}$/l of PO$\sub$4/-P was recorded in the surface of the Haengam bay. In general it is shown that some coastal areas are presenting signs of pollution from man's activities.

• Journal of the Korean association of regional geographers
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• v.14 no.2
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• pp.114-125
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• 2008

Colored dissolved organic matter(CDOM) is an important component of ocean color that can be used as an invaluable tool in water quality and ocean color studies. With the largest source of coastal CDOM appearing to be from freshwater discharge into the ocean, coastal predictive models will do much to refine our knowledge about major processes that control CDOM distributions in coastal waters and provide a better insight into the global carbon cycle. This study aims at developing a GIS-based watershed-scale predictive model of CDOM distributions in Neponset river watersheds that can be used to appraise our understanding of CDOM sources and distributions in coastal waters and predict the response of CDOM concentration to changes in land use patterns. Weighting factors are developed for CDOM freshwater sources after extensive groundtruthing from various landuse types in the watershed. This model makes use of a publicly available DEM(Digital elevation model) as the base data for analysis. Stream networks, discharge, and land use data are used from public repositories while sub- watershed delineation, pour-points, and land use parcels are generated using Spatial Analysis of ArcGIS 9.2 to estimate the CDOM loading from various sources to the lower tributaries of rivers. The Neponset Watershed in eastern Massachusetts is selected as the site for development of the model.