• Fisheries and Aquatic Sciences
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• v.6 no.3
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• pp.149-154
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• 2003

The characteristics of pollutant loads from the various sources and seawater quality in Kwangyang Bay were evaluated. Total flow rate was estimated to be $10,868,066.8 m^3/day$ with a flow rate of R2l (the Seomjin River) as the highest one. Total COD, TN and TP loads of the input rivers and the ditches were about 27,591.8, 25,029.6 and 586.4 kg/day, respectively. Wastewater discharging loads was the greatest contributors to pollutant loads in the inner part of Kwangyang Bay. COD values in the inner part of the bay was over 3.0 mg/L, which exceeded the seawater quality criteria III of Korea. The average values of DIN and DIP were 8.62 ${\mu}gN/L\;and\;1.26\;{\mu}gP/L$, respectively. The limiting factor for algal growth was DIN. In he total discharging loads of the watershed from unit loading estimations, BOD, TN and TP were 9,132.3, 2,727.2 and 304.2 kg/day, respectively. In addition, municipal sewage by the population as pollution sources and the city of Kwangyang as administrative district had the highest loads. For a appropriate water quality recovery of Kwangyang Bay, it is suggested that it is essential to estimate reduction rate of total pollutant loads by water quality modeling.

• Journal of Environmental Science International
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• v.5 no.1
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• pp.15-23
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• 1996

During the last two decades, many industrial complexes for heavy and chemical industries have been established along the Korean coastline, thereby increasing the pollution materials burden on the coastal environment of seawater. Masan Bay is one of the most polluted coastal areas in Korea and the main soures of pollutants are domestic and industrial wastewater from Masan, Changwon. This study was aimed to evaluate relationships among the physicochemical parameters in the bottom water of Masan bay and to examine environmental factors affecting to pollutions of seawater by factor analysis. 'rife factor loading, 1 is showed higher increasing inclination after 1989 year in station 1. The variance of pollutant materials is showed 43.7% in which the coastal inflow water is indicated external loadings(factor 1 : NO3--N, TN, factor 4 : SiO2-Si) corresponded to domestic sewage, industrial wastewater, and earth-sands in the bottom water of Masan bay And the internal loadings(factor 2 : SS, salinity, factor 3 . W.T., DO) are explained 33.8%'corresponded the phenomena of sedimentary layer and oxygen concentration. Therefore, The external loadings are explained by the higher factor pollutantal variance in Masan bay.

• Journal of the Korean Society of Marine Environment & Safety
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• v.10 no.2 s.21
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• pp.69-79
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• 2004

This study focuses on the relationship between pollution factors around Masan, Changwon and Chinhae city considerd as main pollution sources and marine environment in Masan bay of Korea. Water quality data measured In Jinhae bay and environmental investigation data in Masan, Changwon and Jinhae cities from 1981 to 1998 were used for this study. Annual means and standard deviations of COD, DIN and DIP concentrations from 1981 to 1998 showed that both their concentration and fluctuations were higher in the inner part of Masan bay (region A) than near Somodo (region B). Sediment dredging in Masan bay had been done from 1990 to 1994. After dredging, COD concentration has been decreasing In surface layer. Also water pollution was gradually spreaded from the inner part to the outer part of the bay due to the continuous inflow of domestic sewage and industrial wastewater. In the late of 1990s, the pollution was heavier. DIN and DIP concentrations were found to be increased by establishment of industry complex and decreased by sewage treatment plant near the city adjacent to Jinhae bay, 1993. The correlation between COD, DIN and DIP changes and neighbor cities' pollution sources were calculated From 1981 to 1998, correlation coefficient (r) was over 0.8 except for the bottom of region A From 1981 to 1998, r between the DIP concentration and population was over 0.65 except for the surface of region A, and the r between the DIP and the number of factories was over 0.6 too, in region B.

• Journal of Wetlands Research
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• v.15 no.3
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• pp.329-337
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• 2013

This study was performed to evaluate the temporal and spatial variations of the water quality at stream flowing into the Suncheon bay in Suncheon city from October 2008 to August 2009 and to estimate the pollutant sources from the streams using multivariate analysis. Water qualities from Seo stream, Dong stream, Ok stream were evaluated as I grade(very good) that compared to the Water Quality Standard. But Haeryong stream and inlet site of Suncheon Bay in BOD were evaluated as a little bad and fair. Water quality at the stream flowing into the Suncheon Bay was could be explained up to 92.8% by three factors which were included in loading of nutrients, organic matter and total coliform group by the allochthonous matters(53.7%), Topographic Factors(25.0%), seasonal variation(14.2%). The concentrations of total nitrogen and phosphorus at sewage treatment plant and organic matters at Haeryong stream were higher than that of others, respectively. From principal component analysis and factor analysis, it could be suggested that it is very important to make an effort to reduce the nutrients and organic matters from sewage treatment plant and Haeryong stream to be in good conservation of the Suncheon bay.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.8-14
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• 2007

Water quality in Lake Rotorua, New Zealand, deteriorated since the 1960s because of excessive phytoplankton growths due principally to increasing nitrogen and phosphorus in the lake waters. Nutrient concentrations in eight of the nine major streams feeding Lake Rotorua have increased since 1965. The groundwater system has a key role in the hydrology of the Lake Rotorua catchment and the groundwater system is probably the control on the time delay between intensification of agricultural land use and response of surface water quality. All major, and many minor streams, in the catchment are fed by springs. Two lithological units are most important to groundwater flow in the Lake Rotorua catchment: Mamaku Ignimbrite, erupted in about 200,000 years ago and Huka Formation sediments which filled the caldera left by the Mamaku Ignimbrite eruption. Rainfall recharge to groundwater in the groundwater catchment of Lake Rotorua is estimated as approximately 17300 L/s. A calibrated steady-state groundwater flow model estimates that approximately 11100 L/s of this flow discharges into streams and then into the lake and the balance travels directly to Lake Rotorua as groundwater discharge through the lake bed. Land use has impacted on groundwater quality. Median Total Nitrogen (TN) values for shallow groundwater sites are highest for the dairy land use (5.965 mg/L). Median TN values are also relatively high for shallow sites with urban-road and cropping land uses (4.710 and 3.620 mg/L, respectively). Median TN values for all other uses are in the 1.4 to 1.5 mg/L range. Policy development for Lake Rotorua includes defining regional policies on water and land management and setting an action plan for Lake Rotorua restoration. Aims in the action plan include: definition of the current nutrient budget for Lake Rotorua, identification of nutrient reduction targets and identification of actions to achieve targets. Current actions to restore Lake Rotorua water quality include: treatment of Tikitere geothermal nitrogen inputs to Lake Rotorua, upgrade of Rotorua City sewage plant, new sewage reticulation and alum dosing in selected streams to remove phosphorus.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.217-219
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• 2006

This study focused an water quality response to land-based pollution loads and the appropriate pollutant load reduction in Chinhae Bay using an eco-hydrodynamic model. Land-based discharge foam urban areas, industrial complex and sewage treatment plant was the greatest contributor to cause red-tide blooms and summer hypoxia. Tidal currents velocity af the ebb tide was about 10 cm/s stronger than that of the flood tide. A residual current was simulated to. have a slightly complicated pattern with ranging from 0.1 to. 2.7 cm/s. In Masan Bay, pollutant materials cannot flaw from the inner to the outer bay easily because af residual currents flaw southward at surface and northward at the bottom. The simulation results of COD distribution showedhigh concentrations aver 3 mg/L in the inner part of Masan Bay related pollutant discharge, and charge, and lower levels less than 1.5mg/L in the central part of Chinhae Bay. For improvement water quality in Chinhae Bay, it is necessary to reduce the organic and inorganic loads from paint sources by mare than 50% and ameliorate severe polluted sediment.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.1
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• pp.44-49
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• 2003

Masan Bay is one of the most heavily polluted bay in Korea owing to the large industrial complex and urban area. Water transparency, Secchi depth in meter, was observed 33 times totally at four sites during 1995 through 2002 and analysed statistically. The range was 0.2∼7.2m, mean 204m, and variation coefficient 60% in totally. Roughly speaking, monthly mean showed lower value April or July than other months. Seasonal mean showed lower in spring or summer than other seasons. Yearly mean was lowest in '95 and '98 during 7 years. Each sampling site showed a different patterns by the monthly, seasonal or yearly transparencies. Inner bay area, S1 site, showed lowest transparency and highest variation coefficient owing to the streamlets and urban area. And it was supposed that one of the important factor affecting different transparency distribution of most seaward site, S4 site, among four sites in the Masan Bay may be the underwater effluents of urban sewage water treated.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.460-464
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• 2012

From 1998 to 2008, the bacteriological quality of seawater in Kamak Bay, Korea, was monitored. The total and fecal coliforms in seawater were monitored as bacterial indicators, and the level of fecal coliform contamination was used to evaluate seawater quality. In the southern shellfish growing area of Kamak Bay, the observed fecal coliform geometric mean (GM) and estimated 90th percentile did not exceed the quality standards for fecal coliforms in seawater in Korea and th USA (GM<14 MPN/100 mL, 90th percentile<43 MPN/100 mL). The GM and estimated 90th percentile of the fecal coliform levels in the adjacent northern area of Kamak Bay were higher than in the southern area. Stations near wastewater discharge sites and urban areas in the north had the lowest quality and did not meet the bacteriological seawater quality criteria. The high fecal coliform levels in the Seonso coastal region near wastewater discharges and northern urban areas declined significantly following dredging and operation of a sewage treatment plant.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.1
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• pp.1-8
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• 2007

Environment factors related to the distribution of organic matter in surface seawater and sediments were investigated to estimate main pollution sources and range of their influence in Gwangyang Bay. The main pollution sources for the factors that affect organic matter distribution could be divided into three main sources: fresh water runoffs from Seomjin and Dong River, Gwangyang-si domestic sewage, and Yosu Industrial Complex. Considering the characteristics in horizontal distributions of the environmental factors in water column, sediment, and water current regime, the influencing range of these main sources was likely to be divided into three areas within the bay as follows: Area I receiving lots of fresh water from Seomjin River, Area II receiving lots of domestic sewage from Gwangyang-si and fresh water of Dong River, Area III receiving lots of materials from Yosu Industrial Complex. Area I seems to be characterized as low salinity, high concentration of $NO_3-N,\;and\;SiO_2-Si$, Area II as low salinity, high concentration of $NO_3-N,\;NH_4-N,\;and\;SiO_2-Si$, and Area III as high water temperature, high concentration of $NH_4-N,\;and\;PO_4-P$ in water column, high concentration of $NH_4-N,\;PO_4-P,\;and\;SiO_2-Si$ in surface sediments.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.3
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• pp.41-49
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• 2000

When sewage and industrial wastewater are treated to improve the coastal water quality, we usually consider the reduction of BOD and/or COD. Due to the inflow of untreated nitrogen and phosphorus, however, the coastal water has eutrophicated. Thus, to improve the water qualify, it is necessary to treat and reduce nitrogen and phosphorus which are the factors limiting algal growth. Hence, with regard to the adaption of Ocean Outfall for the treatment of wastewater in Suyoung Bay, we studied the effectiveness and environmental assessment of Ocean Outfall of which cost is lower than that of advanced treatment, The effectiveness of Ocean Outfall of the second treatment effluent in Nambu S.T.P. was simulated, using the eco-hydrodynamic model as far field model the result showed that the water quality of coastal area receiving wastewater on the surface sea has improved. But the concentrations of nitrogen and phosphorus around the diffuser of Ocean Outfall system can cause many problems on estuary, such as red tide, eutrophication and aquatic toxicity.