• Korean Journal of Microbiology
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• v.40 no.4
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• pp.302-306
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• 2004

A total of forty strains of pigment-producing halophilic bacteria were isolated from the solar saltern and coastal seawater in Korea. The diversity of those bacteria were determined on the basis of PCR-RFLP and 16S rDNA sequences. The isolated strains were clssified into nine genera: Pseudoalteromonas, Photobacterium, Vibrio, Halobacillus, Bacillus, Paracoccus, Salinicoccus, Tenacilbaculum, and Flavobacterium. While more than $80\%$ of the pigment-producing halophilic bacteria isolated from the coastal seawater were classified as gram-negative Pseudolateromonas, most of the strains isolated from the solar saltern were classified into gram-positive Halo­bacillus. The other strain was KK7, which may be identified as novel species belonging to the genus, Salini­coccus.

• Journal of Soil and Groundwater Environment
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• v.8 no.1
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• pp.68-74
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• 2003

SHARP numerical model was used to estimate the interface, ranges and seasonal variations of seawater intrusion. The interface obtained from the SHARP model represented more sensitive to seasonal variations than that estimated from the monitoring wells. When TDS and groundwater velocity vector distributions generated by SUTRA simulations are compared to the interfaces obtained from SHARP simulation, the difference of the range on seawater intrusion is less than 50 m, and the range of seawater intrusion from seasonal variations has the difference of about 12 m. These differences are small for the numerical simulation of the coastal aquifer at regional scale. Therefore, the model with sharp interface is very useful to estimate the interface at this study site, where is regional aquifer system in the scale of seawater infusion. However the SHARP model have some limitations in simulating the range of seawater intrusion, when the hydrodynamic dispersion is significant for seawater intrusion at local aquifer system.

• Journal of the Korean GEO-environmental Society
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• v.2 no.1
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• pp.81-89
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• 2001

Soil-bentonite mixture is often used for barrier wall to prevent seawater intrusion. In this study, the effect of seawater on the permeability of soil-bentonite mixture is examined, and the effect of permeability change on the seawater intrusion is investigated. Seawater intrusion in coastal areas was modeled using a finite element method. Seawater intrusion in the seawater-contaminated zone was determined by considering the hydraulic conductivity changes using the residual flow procedure (RFP) in the simulation model. Steady state and unsteady state conditions with variations in ground water levels in an inland area were investigated. The interface between fresh water and seawater, found by the proposed method, was located lower at the seawater side and the level at the fresh water side is higher than those by conventional methods.

• Ocean and Polar Research
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• v.40 no.2
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• pp.77-85
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• 2018

We observed the concentrations of Dissolved Organic Carbon (DOC) and Colored Dissolved Organic Matter (CDOM) in coastal seawater and groundwater around a volcanic island, Jeju, Korea. The sampling of surface seawater and coastal groundwater was conducted in Woljeongri, Pyoseon, and Kwakgi beaches, in three sampling campaigns (June, July, and October 2016). The concentrations of DOC in groundwater were relatively higher in June and October than in July. Salinity and DOC concentrations in the coastal groundwater of Woljeongri and Pyoseon beaches did not show a marked relationship, whereas those in Kwakgi beach showed a good positive correlation (July: $R^2=0.64$, P < 0.01; October: $R^2=0.95$, P < 0.01). In addition, the concentrations of CDOM (C and M peaks) in the groundwater of Woljeongri and Pyoseon beaches, where saline groundwater discharge dominates, were relatively higher than those of Kwakgi beach, where fresh groundwater discharge dominates. The relatively higher DOC concentrations in the coastal groundwater of Woljeongri and Pyoseon, with higher CDOM concentrations, seem to be mainly from anthropogenic sources such as local pollution sources (i.e., aquaculture wastewater or domestic sewage). In order to understand the behavior of DOC in the coastal groundwater of a volcanic island, extensive studies are necessary in the future over a larger-area and greater time-scales using various isotopic tracers.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.4
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• pp.193-200
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• 2007

The purpose of this study is investigate to water quality, pH, turbidity, salinity, nutrients, SS, DO, COD, ${NH_4}^+$-N, ${NO_2}^-+{NO_3}^-$-N, TN, TP, ${PO_4}^{3-}$-P in ditches and seawater of the Hwawon, southwestern coastal area of Korea. Two stations of the ditch, one station at outfall from reservoir of the coastal development and 15 stations of seawater were measured in August just after a 96.5 mm rainfall and in dry season of November 2006. The sampling time were divided into a rainy and dry season based on turbidity, SS, salinity and nutrients difference of distributions that was evidence as a inflow of pollutants from the developing coastal land area. The pH, turbidity, salinity and SS were high and showed different from between surface and bottom in near the developing of coastal land than the other stations after a strong rainfall over 90 mm while it were not varied in vertical and horizontal concentration profile in dry season. The other nutrients were showed the same concentrations gradient patterns. In opposition to expectations, the SS in dry season was higher than in the rainy season due to upwelling by the wind and strong current. It appears that the researched coastal seawater qualities were mainly effected by the inflow of freshwater from the ditches and drain from the reservoir of the developing land area during strong rainfall while the seawater qualities were mainly effected by the wind and strong current in dry season.

• Microbiology and Biotechnology Letters
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• v.27 no.1
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• pp.70-74
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• 1999

Vibrio vulnificus, a normal bacterial inhabitant of estuaries, is of concern because it can be a potent human pathogen, a causing septicemia, wound infections and gastrointestinal disease in susceptible host. In this survey, total 431 samples were obtained from different sites of the Chonman coastal area during the periods from Mar. 1997 to Feb. 1998. Vibrio vulnificus was isolated from the middle of May to the begining of November of 1997 in Chonman coastal area, as the seawater temperature was at 20$^{\circ}C$ and 15$^{\circ}C$, respectively and was rapidly increased to above 40% from July to September. The isolation rates of V. vulnificus from sediment, seawater, raw seafoods and aquarium water were 52.1%, 49.1%, 32.5%, and 27.3%, respectively and isolation rate was highest in oyster among various collected samples. V.vulnificus was also isolated from 73.1%(38/52) of sampling sites of Chonman coastal area.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.116-117
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• 2017

The most important factor when designing coastal and offshore concrete structures is durability. However, concrete in marine environment is exposed to physical and chemical deterioration of seawater, which might easily lead to low quality. The purpose of the present study is to understand advantages of adding ground solidificaton materials by comparatively analyze the seawater resistance of general concrete and environmental-friendly ground solidification materials.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.3
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• pp.48-54
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• 1998

Korea becomes one of the countries which suffer from water shortage. It is expected that its water shortage in the early 2000's will be more than 10% of the annual demand. The shortage problem is more serious in the coastal areas where many industry complex locate. To solve the shortage problem, seawater desalination gets more attention as an alternative water supply source since Korea is surrounded by sea on its three sides. For potential application of seawater desalination in Korea, an economic analysis was conducted using cost data for the plants in the Middle Ease areas, The United states and others. The study is to provide a basis for the government to establish a strategy for promoting seawater desalination in Korea. It is discussed that the Reverse Osmosis (RO) process gets cheaper over times than the thermal processes of Multi-stage Flash Distillation (MSF) and Multi Effect Distillation (ME), especially in case where the capacity is less than about 50,000 ton/day. The unit cost of RO seawater is analyzed about US$1.35/ton in 1990 price. Since the Desalination plant can be operated regardless of weather conditions, industries in Korea's coastal areas which suffer from frequent droughts and water shortages are recommended to look into this option with more attention.

• Ocean and Polar Research
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• v.25 no.spc3
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• pp.423-426
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• 2003

The seawater exchange breakwater equipped with an oscillating water channel and water transmitting pipes has a very spectacular function that seawater supply can be greatly increased due to the upsurge of the water surface inside the channel at resonance condition which can be reached when the incident wave period becomes close to the natural period of the channel. The variations of the water level and period inside the channel are very important factors in enhancing the efficiency of sea water exchange, especially when designing the breakwater cross-section in shallow water zone which requires longer resonance period with the elongated horizontal projection of the channel. In the present study, a hydraulic experiment was performed varying the length of the oscillating channel, and the resonance periods and water surface variations are analyzed in terms of water transmission through the pipes.

• Journal of the Korean Society for Marine Environment & Energy
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• v.4 no.4
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• pp.3-11
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• 2001

To know the seawater infiltration into tidal flat sediment in coastal area is very important, because it is significantly correlated with the infiltration and transportation of pollutants in soil, the supply of dissolved oxygen, nutrients and organic matter to benthic organisms for survival of benthic organisms and the seawater purification. So, we set up purpose to clarify the infiltration behavior of seawater by wave action in tidal flat, to clear the effects of slope of tidal flat and breaking wave height on seawater infiltration and to quantify the infiltration volume of seawater. For purpose, the seawater infiltration was studied with visualization method by using coloring tracer and transparent glass beads replaced as natural sediment in model tidal flat. Specific conclusions derived from this study are as follows. The semi-circular type infiltration of seawater by wave action into saturated sediment was a new infiltration behavior that was not considered in previous studies. The infiltration rate of seawater was increased with increasing of breaking wave height and slope of tidal flat. However, the effects of the slope was bigger than that of breaking wave height on seawater infiltration into tidal flat sediments. It was possible to calculate the infiltration volume of seawater by wave action in natural tidal flat sediment and in fields. Therefore, we can point out that wave action play an important role in the supply of dissolved oxygen, nutrients and organic matter to benthic organisms, transportation or diffusion of pollutants and seawater purification. So, we hope to be studied the supply of food to benthic organism, pollutant transport and seawater purification on the base of these results.