• Journal of the Korean Society of Marine Environment & Safety
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• v.3 no.1
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• pp.99-109
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• 1997

The in situ observations and the seawater analyses were conducted in July and August, 1996 for the purpose of describing the characteristics of organic pollution, dissolved oxygen distributions, and the evaluation of water quality in Mokpo harbour. The vertical density distribution of water column was found to be in stable structure with higher water temperature and lower salinity on surface layer at ebb tide in summer. In July, dissolved oxygen was shown to be oversaturated on surface and bottom layers, while in August, which was shown to be oversaturated on surface layer, and to be unsaturated on bottom layer as 68∼93% of saturation percentage. Dissolved oxygen of bottom layer in August was evaluated to be under the regular grades, based on Korean standards of seawater quality. In view of COD, the seawater quality of Mokpo harbour in summer was evaluated to be deteriorated due to organic wastes and graded to be the third class, and TSS of Mokpo harbour in summer was graded to be the second class, based on Korean standards of seawater quality. In particular, COD of surface layer in August was found to be under the regular grades. It is, therefore, necessary to take measures for the control of pollution loads and the proper management of seawater quality in Mokpo harbour. The distribution patterns of DO, COD, VSS and Chlorophyll-a on surface layer along the downstream center line from inner harbour to harbour entrance were similar to one another at ebb tide in August.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.572-582
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• 1994

To investigate water mass structure and DO(Dissolved Oxygen) distribution in Chinhae Bay, temperature, salinity and DO were observed in the bay in summer and winter from 1990 to 1993, and two-dimensional tidal current and parameter log($H/U^3$) were computed. Shallow water fronts in the bay were formed in summer in Kaduk channel and the central part of the bay having log($H/U^3$) values of $2.0{\sim}2.5$. Oxygen deficiency at the bottom layer in summer occurred in the western and northern part of the bay with weak tidal current, where the value of log($H/U^3$) was more than about 3.5 and $M_2$ tidal current was less than about 20 cm/s. DO concentration at the bottom layer of Kaduk channel and the central channel of the bay having the strong tidal current was more than about 3.5 mg/l. The isolines of DO concentration were nearly parallel to the isovelocity, and the concentrations correlated with the frontal location. The frontal location and DO distribution were influenced by tidal range, river inflow and meteorological conditions, and also correlated with bottom slope characteristics.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.4
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• pp.178-185
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• 2013

We measured salinity and $^{222}Rn$ concentration to explore submarine spring along the coastal areas (Mundongri, Icheon-ri, Jukseong-ri, Daebyeon-ri, Yeonhwa-ri, and Dadae-po) including Ilkwang Bay of Busan Metropolitan City in 2009 and 2010. Before field observation, we selected the potential and possible locations of submarine spring based on the lineament distribution and rose diagram analysis. Salinity and radon concentration were measured within the 1~2 km from the coastal lines. Radon activity decreased gradually from onshore to offshore. Vertical profiles of salinity at some stations showed lateral transport of water mass characterized by low salinity. Vertical profiles of salinity in the Ilkwang Bay, which is a unique bay in the south-eastern coastal area of Busan Metropolitan City, also showed the occurrence of low salinity in the bottom seawater. Our results suggest the possible occurrence of submarine discharge of fresh groundwater in the coastal areas around Busan Metropolitan City. In the future, intensive research should be conducted for the exploration methods of submarine spring as well for the possible utility of submarine groundwater as alternative water resources.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.176-185
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• 1998

For the sustainable production of cultured arkshell Scapharca broughtonii and pre-estimation of the harvest of it, we investigated the relationship between the habitat environmental factors and the physiological conditions of the arkshell in the two experiment sites near the Chinhae Bay, Korea. For the analysis of habitat environmental factors such as temperature, salinity, dissolved oxygen, DIP (dissolved inorganic phosphate), DIN (dissolved inorganic nitrogen), suspended solids and chlorophyll a of bottom water and T-S (total sulfide) and COD (chemical oxygen demand) of surface sediment were measured, To determine physiolosical condition of cultured arkshell, shell length, fatness, glycogen, hemoglobin content and gametogenesis were examined. Water temperature were higher in Woongchon than in Songdo in 1992, and were Higher in Songdo in 1993. Salinity were higher in Songdo than in Woongchon except from January to May in 1992. COD, suspended solids and chlorophyll a content were higher in Songdo than in Woongchon, while the contents of sediment sulfide, DO, DIP and DIN were higher in Woongchon. Based on the environmental assessment, significant factors affecting the growth and physiological condition of arkshell were quantity of food and total sulfide content in the bottom sediment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.157-165
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• 1985

Character of oceanic conditions in the bay is investigated by taking hydrographic data on june in Kamak Bay which has two channels and four submarine topographic parts of its own. This bay has four remarkable water mass influenced greatly by the above topographical factor: inner bay water, Yosu harbor water, the middle water and outer bay water. General characteristics of these four water mass were as fellows: inner bay water has a stagnation character with the influence of inland, Yosu harbor water has a out-sea character with the low salinity caused by run-off of Somjin river, outer bay water has a out-sea character with same values vertically coused by eddy current or bottom turbulunce and the middle water has a middle character among the inner bay water and outer bay water. Outer waters flowed in the bay through both channels during the flood are come upon at a near by Daekyong-do and Hangdae-ri of Dolsan-do. Eddy current or bottom turbulunce in the vincinity of Kunnae-ri which is located at south of the bay are showed sinking of water during the flood flow, while that during the ebb flow shelved up-welling phenomena.

• Proceedings of the KSRS Conference
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• v.1
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• pp.122-125
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• 2006

The distribution of phytoplankton pigments were studied bimonthly at four stations from the mouth of Mahanadi River at Paradip to the 36.7km off coast in Bay of Bengal during April 2001 to December 2002. Bottom depth was shallower than 40m in all stations. The pigment concentration of Chl-a was measured. It increased from surface to bottom in the water column. The water column integrated chlorophyll-a concentration (Chl-a) varied between 6.1 and $48.5mg{\cdot}m-^2$ with peaks during monsoon period (Aug & Oct). Spatial distribution of salinity depended strongly on freshwater runoff. The salinity was 5psu at river mouth and 25.15psu at offshore in monsoon period; however it was 30psu at the river mouth in summer. We found a linear relationship between the amount of river discharge and integrated Chl-a in coastal region from 2 years observations. Extending this result, we analyzed rainfall and coastal Chl-a using satellite data. The relationship between the river discharge and monthly accumulated rainfall estimated from TRMM and others data sources was analyzed in 2001 and 2002 using Giovanni infrastructure provided by NASA. The result depended on the specified area on TRMM images; the river delta area had sharper relationship than wider rain catchments area. Moreover, the relationship between monthly averaged Chl-a derived from SeaWiFS and monthly accumulated rainfall estimated from TRMM was analyzed from 1998 to 2005. It was clear that the broom in monsoon period was strongly controlled by rainfall on river delta.

• Journal of Environmental Science International
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• v.14 no.2
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• pp.167-175
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• 2005

Based on the observation on 20, 23 and 26 July 2004, the distributions of temperature, salinity and stratification was investigated in relation to ebb, turn of tide and flood. The results are as follows: I) The high temperature and low saline water with $23.5\~24.0^{\circ}C\;and\;32.4\~33.0psu$ existed at Naro Island. 2) The cold surface water below $21.0^{\circ}C\;and\;33.0\~33.4psu$ appeared in the area near Gae Island and Geumo Island. 3) The cold and saline water, below $24.0^{\circ}C$ at the surface and $17.0^{\circ}C$ near the bottom, $32.8\~33.8psu$ at the surface and $33.8\~34.0psu$ near the bottom, existed in Sori Island. These waters were more saline compared to the South Sea Coastal Water with about 31.8psu. This suggests that the oceanic saline water intruded into the Bottol Bada through the area near Sori Island. The stratification appeared during all the observation periods due to a high solar radiation of $22MJ/m^2$, and a weak wind speed of 2.9m/s on the average while the mean speed of wind in July is around 3.9 m/s. It qualitatively suggested that the stratification was maintained during the observation periods because of a high solar radiation, a weak wind speed and intrusion of saline oceanic water.

• Journal of Environmental Science International
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• v.11 no.12
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• pp.1205-1215
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• 2002

To evaluate the change for water quality after the water gate operation in Shiwha lake, in situ survey were conducted on september in 2000 and January, march, jane in 2001. Chemical characteristics and eutrophication level was estimated from the survey data. The water quality of the Shihwa lake was greatly affected by pollutant load from rainfall, and formation of stratification in summer and winter was increased to effect on nutrient release from sediment. Especially, high concentration of chlorophyll-a was occurred in autumn, due to increased nutrient, high water temperature and low salinity after rainfall runoff. The mean concentration of DIN, DIP were 0.346mg/L, 0.0217mg/L in surface water and 0.826mg/L, 0.0415mg/L in bottom water, respectively, which were over III grade of seawater standard. Also high percentage of ammonia nitrogen to DIN in bottom water for autumn and winter was affected by released nutrient from sediment. Correlation analysis of chlorophyll-a versus TSS was shown that organic matter was affected by autochthonous organic matter stem from the algae, these factor showed reverse correlation about salinity. Closely correlations among to the water quality constituent in continuity survey was appeared. The results of eutrophication index estimation showed the high potentiality of red tide occurrence in Shiwha lake, particularity in summer or fall. Overall water quality was greatly improve to compared with measuring data during 1997~1998 at the beginning water gate operation, which reported by KORDI. Therefore, to improve of water quality in Shiwha lake, we need to establish of management plan about nutrient release from sediment, rainfall runoff, maximum of seawater exchange.

• Ocean Science Journal
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• v.42 no.2
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• pp.103-116
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• 2007

Seasonal changes of tide signal(s), temperature, salinity and current were studied during the years 2004-2005 in the northernmost Gulf of Aqaba, which is under developmental activities, to obtain scientific bases for best management and sustainability. Spectrum analysis revealed permanent signals of tide measurements during all seasons, which represented semidiurnal and diurnal barotropic tides. The other signal periods of 8.13, 6.10-6.32, 4.16 and 1.02-1.05 h were not detected in all seasons, which were related to shallow water compound and overtides of principle solar and lunar constituent and to seiches generated in the Red Sea and the Gulf of Aqaba. Spatial and temporal distribution of temperature, salinity and density showed significant differences between months in the coastal and offshore region and no significant differences among the coastal sites, between the surface and bottom waters and between coastal and offshore waters. Therefore, the temporal and spatial variation of water properties in the northernmost Gulf of Aqaba behave similarly compared to other parts. The coastal current below 12 m depth was weak $(3-6\;cms^{-1})$ and fluctuated from east-northeastward to west-southwestward (parallel to the shoreline), which may be related to the effect of bottom topography and/or current density due to differential cooling between eastern and western parts in the study area, and wind-induced upwelling and downwelling in the eastern and western side, respectively. The prevailing northerly winds and stratification conditions during summer were the main causes of the southward current at 6 and 12 m depths with average speed of 28 and $12cms^{-1}$ respectively.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.3
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• pp.171-180
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• 2010

Analysis on the temporal variation of the stratification is carried out by using the continuous water temperature and salinity data observed in the coastal monitoring buoy in Mikawa Bay, Japan. The main analysis results are as follows. The stratification pattern have an obvious and dominant 1-year period variation and the occurrence frequency (days) are exponentially decreased as the stratification intensity (SI) defined as the density difference between surface and bottom layers linearly increases. The frequency distribution function of the SI is presumably close to the log-normal function type or exponential function type. From the water temperature and salinity scatter diagram analysis, the line and loop type patterns are shown in the bottom and surface layers, respectively. In addition, the analysis of the SI estimation show that the error bound in case of using the weekly-monitoring data is about 4.45 times greater than that in case of using the continuous (daily) monitoring data.