• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.2
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• pp.92-100
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• 1997

Distribution of bacterial abundance and production was investigated during October, 1995-August, 1996 in Lake Shiwha constructed artificially in 1994. Its water column was distinguished by two layers: the brackish surface layer with salinity ranged from 6 to 20‰ and the saline hypoxic/anoxic bottom layer with salinity of 17 to 27‰ Except for samples collected in March, 1996 (on average 13 ${\mu}g\;l^{-1}$), chlorophyll a concentration ranged from 27.6 to 249.5 ${\mu}g\;l^{-1}$ in the euphotic zone, indicating the hypertrophic condition of Lake Shiwha during most of the studied period. In this study, bacterial productions measured by $^3H$-thymidine incorporation method were similar to those by $^{14}C$-leucine incorporation method. In hypertrophic, surface waters of Lake Shiwha, bacterial abundance and production ranged from 1.4 to $19.5{\times}10^9\;cells\;l^{-1}$ and from 1.6 to $126.5{\times}10^7\;cells\;l^{-1}\;h^{-1}$ respectively; 2 to 4 fold and 2 to 30 fold higher than those in eutrophic coastal waters outside of Lake Shiwha, respectively. Turnover times of bacterial community in the surface layer of Lake Shiwha ranged from 0.2 to 8.9 day, indicating that bacteria in the lake seemed to adapt to the hypertrophic condition. In the hypoxic bottom layer, bacterial abundance and production was up to 3 fold and 20 fold lower than those in the surface layer, and showed slow bacterial growth. Significant correlations between the bacterial abundance, production, and community turnover time with water temperature indicate water temperature was the important factor controlling distribution and growth of bacteria. However, during summer season, bacterial production seemed to be regulated by supply of substrates.

• Journal of Korea Water Resources Association
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• v.33 no.5
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• pp.551-559
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• 2000

In order to diagnose the water environment and assess the water quality restoration, long term trend of water environment has been surveyed at 3-R stations from 1994 to 1999 in Lake Shihwa. Annual mean values of $COD_{Mn}$, Chlorophyll a, total nitrogen, total phosphorus and Secchi depth are ranged in 5.2-15.1 mg/L, 7.3-14R.1 jlg/L, 1.50-4.84 mgN/L, 0.055-0.281 mgP/L and 0.5 -1.4 m, respectively, during the study periods. Carson's trophic state indeies were varied from mesotrophy in 1994 and 1995, hyper-eutrophy in 1996 and 1997, to meso eutrophy in 199R and 1999. After dike construction, water quality were rapidly deteriorated by allochthonous and autochthonous loading of high nutrients and organic carbon. Eutrophication phenomena were characterized by massive phytoplankton blooms and high concentration of COD. However, after onset of restoration program, lake water quality was rapidly restored to the level of just after sea-dike construction. The diversion of waste water inflowing from the Panwol and the Sihwa industrial districts which was started from March, 1997 has contributed to improve water quality in the surface layer. And the tidal mixing (sea water inflowing) through the continuous gate operation was the most effective measure to the whole lake restoration.ration.

• Journal of the Korean Geographical Society
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• v.31 no.4
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• pp.639-647
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• 1996

Raclamaton of tidal flats has been practiced in Korea since the fifteenth century mainly for agiculatural porposes. The total area of reclaimed lands in 1994was estimated to be 400 k$m^2$ which corresponds to 2% of the national farm land. Recently, reclamation has been undertaken extensively, and such a huge projects as Samemankum Development will add over 401k$m^2$ by 2004. The impact of coastal reclamation on the environment is enormous. Most of them are presumably instrumental in causing local changes of coastal ecology. Reclamation is expected to be undertaken continuosly and adverse effects are expected. The authors ineended to identify the impacts of reclamation on the study area, to seek the causes of the environmental prolems of Shiwha-District Reclamation, and to analyze ite Environmental Impact Assessment to for environmentally sound sustained development.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.7
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• pp.690-696
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• 2005

The characteristics of hydrospheric concentration and distribution of polycyclic aromatic hydrocarbons (PAHs) in the Lake of Sihwa were investigated on this study. Sediment and Surface water samples were collected from upstream and downstream in Lake of Sihwa. The total PAHs concentrations of surface water were $21.9{\sim}49.6\;ng/L$ at upstream and $19.4{\sim}99.7\;ng/L$ at downstream, respectively. Most of the PAHs existed in the dissolved phase with average 87%. In the case of sediment samples, total PAHs concentrations were $51.7{\sim}325\;ng/g-dry$ at upstream and $13.4{\sim}72.3\;ng/g-dry$ at downstream, respectively. Low-and-middle molecular weight of PAHs were dominated in dissolved phase of the surface water, while middle-and-high molecular weight compounds were predominantly present in the particular phase of the surface water and sediment. The average slope obtained from the plots of log-log scaled dissolved/solid partition coefficient vs. octanol/water partition coefficient was $0.73{\pm}0.12$ and the slope from the water/sediment partition coefficient was $0.59{\pm}0.10$. These results indicated that distribution of PAHs between the dissolved phase and the solid phase was not at equilibrium as well as between water and sediment.

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.1
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• pp.51-67
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• 2002

In order to understand behaviors of heavy metals around the artificial Lake Shihwa in the vicinity of Kyunggi Bay in Korea in relation with huge environmental changes due to construction of huge artificial lake, water samples were collected from Lake Shihwa and its tributaries from 1996 to 1998 and analyzed. Due to extreme pollutant discharge from various kinds of anthropogenic sources such as the Banweol and Shihwa Industrial Complexes and cities, the Shihwa and its tributaries have been polluted in waters with various heavy metals. The enrichment factors of particulate heavy metals in water of streams and storm sewers were very high. All of the heavy metals observed in the waters showed relatively high temporal and spatial variations. In surface waters of the lake during the desalination after the dike establishment, spatial distributions of heavy metal concentrations were mainly controlled by various biogeochemical factors as well as input of industrial and municipal wastewaters, while, physical mixing was minor factor Pb and Co showed a strong affinity to particle phase, however the affinity to dissolved phase was dominated in Ni, Cu and Cd. Water quality of the artificial Lake Shihwa has been deteriorated by direct discharge of untreated wastewater and heavy metals have been accumulated in the lake system. Therefore, luther environmental improvement plan should be programmed subsequently.

• KCID journal
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• v.9 no.1
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• pp.38-47
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• 2002

The Lake Sihwa gradually changes from freshwater lake to saline lake due to inflow of seawater by sluice gates . The changes of lake water are closely related to characteristic and distribution of turbidity and suspended matter. During the period April-Ma

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.112-114
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• 2006

과거 국내 접지설계는 요구 접지저항값 중심의 설계로 위험전압에 대한 접근은 미흡한 실정이었으나 최근에는 국외에서 중요시하고 있는 접지계의 안전전압에 중점을 둔 접지설계가 이루어지고 있다. 이에 시화호 조력발전소 건설공사의 접지설계를 모델로 하여 최근접지설계 기법을 정리하였다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.294-296
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• 2000

대기에어로졸의 화학적 조성은 대기화학과정 및 에어로졸의 기후변화 (climate forcing)를 이해하는데 필요한 중요한 변수이다 대기에어로졸 군 입자크기가 2.5 $\mu\textrm{m}$보다 작은 미세입자들은 인간의 건강과 사회복지에 악영향을 미치는 것으로 알려져 있다 (U.S. EPA, 1996). 시화지역은 크게 공단지역과 주거지역으로 구분되어 있으며 공단지역에서 발생한 대기오염물질이 대기확산을 통해 주거지역으로 이동하면서 주거지역에 살고있는 주민들에게 많은 악영향을 미치는 것으로 알려져 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.353-355
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• 2003

시화공단에서 악취물질의 원인규명을 위한 공동연구가 실시된바 있다. 이 연구에서 본 연구팀은 주요 악취유발물질인 질소화합물과 카르보닐화합물의 실시간 모니터링 기술을 소개한 바 있다. 이 연구의 후속사업으로 금년 6월부터 3개월에 걸친 장기모니터링을 실시하여 이 기술의 현장 적용성과 악취모니터링의 유용성을 평가한바 있다. 이번 연구에서는 질소화합물, 카르보닐화합물, 유황화합물에 대한 세 분석시스템을 평가하였다. (중략)

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2003.08a
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• pp.315-322
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• 2003

최근 들어 시화호 주변에 연구개발 및 주거를 목적으로 하는 사업지구가 활발하게 계획 또는 시공되고 있는데, 모든 건설공사에서와 마찬가지로 안전하고 경제적인 설계 및 시공을 위해서는 실내 및 현장지반조사를 통하여 지반의 공학적 특성에 대한 정확한 평가가 반드시 선행되어야 한다. (중략)