• 생태와환경
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• 제36권2호통권103호
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• pp.181-190
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• 2003

옥천천(만)유역을 대상으로 2002년 5월부터 9월까지 총 6회 수환경을 조사하였다. 환경 요인은 하천과 구간에 따라 차이가 컸고, 유수환경과 정수환경에서 더욱 현저하여 대비가 되었다. 수중 영양염은 상류 하천에서 비교적 저농도이었으나, 하수처리수 유입 후부터 고농도로 전환되어 점오염원 영향이 절대적이었다. 특히, 유역에서 SRP와 $NH_4$의 분포는 다른 영양염에 비해 매우 뚜렷하였고, 하수처리수의 영향을 평가함에 있어 가장 중요한 인자가 될 수 있었다. 하수처리수의 유입직 후 정점에서 SRP의 평균 농도는 919.3${\mu}g$ P/l로써 유역에서 가장 영향력이 컸고, P농도에 의해 수중 영양염 비율이 조절됨을 알 수 있었다. 하수처리수의 지속적 공급은 하류의 만입부에서 chl-a 증가를 유도하는 결정적인 요인으로 볼 수 있었다. 남조류가 대발생한 시기에 만입부에서chl-a 농도는 234.5${\sim}$l,692.2 ${\mu}g$/1범위이었고, 8월에 최대 현존량은 ml당 $1.0{\times}10^6$ 세포를 훨씬 초과하여 담수적조 수준보다 200배 이상이었다. 이러한 결과는 다른 환경요인에서 잘 반영되었고, 그 중에서 AFDM/TSS 비는 100%로써 조류에 의한 수질오염이 극심함을 잘 반영하였다. 따라서, 하수처리수에 포함된 P와 N 저감이 선행되어야 하천 수환경 개선 뿐만 아니라 저수지 수질관리에 효과가 있을 것으로 본다.

• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2002년도 학술대회
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• pp.137-140
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• 2002

To determine if fish density, biomass, species richness, and species diversity were greater in ecotone than the stream and littoral zones, I sampled fish monthly in the Ledbetter Creek through Ledbetter Creek Embayment in Kentucky Lake, Kentucky, from April to October 1996 by using throw traps. During the first four months (daytime only) fish density did not vary significantly among zones or among months. However, there were significant differences among zones during the last three months and the stream zone had significantly higher mean fish density than both the littoral zone and the ecotone. Fish biomass also differed significantly among zones during the last three months. The stream zone had the highest mean fish biomass among zones, significantly higher than the ecotone, but not different than the littoral zone. There were no statistically significant differences among zones during the first four months, but mean fish biomass in the stream zone was about eight times higher than the ecotone, The stream zone had the highest fish species richness among zones. Differences were significant among zones during the last three months, and the stream zone (0.98 $\pm$ 0.04) had significantly greater mean fish species richness than the ecotone (0.45 $\pm$ 0.01), but not significantly than the littoral zone (0.56 $\pm$ 0.17). Fish species richness differed significantly among months during the first four months, Monthly species diversities ranged from 0.62 to 1.96 in the stream zone, 0 to a.57 in the ecotone, and 0 to 2.60 in the littoral zone. Combined species diversities in the stream, the ecotone , and the littoral zones were 2.72, 3.58, and 3.10, respectively, There were five families of fishes captured frequently enough for their individual numbers to comprise at least 8 % of the total. Family rankings in the stream zone were opposite of the littoral zone. Percidae was the most abundant family and Clupeidae was absent in the stream zone, whereas Percidae was uncommon and Clupeidae was the most abundant family in the littoral zone. Atherinidae was dominant in the ecotone. Five of the most abundant species comprised 65 % of the total number. The guardian darter occurred only in the stream zone, and it was consistently found in riffles. Longear sunfish and central stoneroller also had significant differences of mean fish densities among zones, and they were found mostly in the stream zone. Threadfin shad and bullhead minnow were almost exclusively caught in the littoral zone. I finally concluded that the ecotone between the stream and the littoral zone in this small-scale freshwater aquatic ecosystem was not as productive as the ones in other ecosystems.

• 한국해안해양공학회지
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• 제13권4호
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• pp.309-318
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• 2001

방조제 최종 체절시 또는 준설토 투기장 공사시 개방구간에서의 유속 및 내외측간 수위차를 예측하기 위한 영차원의 단순 모형이 제시되었다. 일반적으로 내조지에는 조간대가 크게 차지하고 있으므로 수위별 내조지 체적 변화를 수식화하여 조간대가 체절구간의 유속에 미치는 영향을 반영하였다. 그 결과를 다중격자 기법(multigrid method)을 이용하여 상세하게 차분하는 2차원 수심적분 모형 결과와 비교하여 검증하였다. 인천 북항 준설토 투기장에 적용한 결과 두 모형이 투기장에서의 조위변화 및 개구부에서의 조류속 변화를 서로 유사하게 재현하고 있는 것으로 평가된다.

• 한국해양학회지
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• 제29권4호
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• pp.366-375
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• 1994

1991년 8월과 10월, 1992년 1월과 4월에 아산만의 30개 정점에서 채집된 동물플랑 크톤의 분포특성을 조사하였다. 동물플랑크톤의 출현 개체수는 240-1,458개체/m$^3$의 범위를 보였으며 요각류는 채집된 동물플랑크톤의 평균88%를 차지하여 가장 우점하였 다. Acartia bifilosa는 가을부터 봄에 걸쳐 우점 하였고, A. pacifica는 여름, Paracalanus parvus는 가을에 우점하였다. 동물플랑크톤의 수평분포는 식물플랑크톤의 분포와 밀접한 연관을 가져, 특히 식물플랑크톤의 출현개체수가 높은 봄에 높은 상관 관계 ($r^2$=0.66, p<0.01,n=30)를 보였다. 치자어의 출현개체수가 높은 여름에 동물플 랑크톤과 치자어의 수평 분포양상도 밀접한 관계를 가졌다. 동물플랑크톤의 출현개체 수에 의한 정점간 유사도를 집괴분석한 결과 본 해역은 내만과 외만으로 뚜렷이 구분 되었다.

• 한국물환경학회지
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• 제22권6호
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• pp.1060-1067
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• 2006

Water quality in the Daecheong reservoir has been deteriorated by algal bloom due to nutrient supply from the upstream of the Daecheong reservoir after heavy rainfall. Algal bloom is propagated from eutrophicated tributary into the main body of the reservoir according to the hydrological conditions. This study is aimed to estimate the water current and temperature effect by the simulation of dam spill flow control using water quality model, CE-QUAL-W2 in 2003. Water current was resulted in nutrient transport from upstream of main reservoir and nutrients were delivered up to downstream by fast water velocity. Algal blooms occurred in stagnate zone of reservoir downstream as the current of downstream was retarded according to dam outflow control. Consequently water balance in stagnate zone triggered a rise of water temperature in summer. It affected algal bloom in the embayment of the reservoir. The simulation result by outflow control scenarios showed that spill flow augmentation induced in water body instability of stagnate zone so that water temperature declined. It could be suggested that outflow control minimize algal bloom in the downstream in the flooding season as long as water elevation level is maintained properly.

• ALGAE
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• 제25권1호
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• pp.17-26
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• 2010

The effects of salinity on various ecophysiological parameters of Ulva pertusa such as growth, nutrient uptake, photosynthetic performance and internal nutrient composition were tested. U. pertusa was collected from an eelgrass bed in a semi-protected embayment on the southwest coast of Korea. Under salinity regimes from 5 to 40 psu, the specific growth rates $(\mu)$ of U. pertusa ranged from 0.019 to $0.032\;d^{-1}$. Maximum growth rate was observed at 20 psu, and minimum at 40 psu. This species showed various uptake rates for nitrate and phosphate. Nutrient uptake was noticeably higher at intermediate salinity levels, and lower at both extremes. Salinity significantly influenced chlorophyll-$\alpha$ content and effective quantum yield. Tissue nitrogen content ranged from 1.5 to 2.9% N (dry weight), whereas tissue phosphorus ranged from 0.1 to 0.14% P (dry weight). The N : P ratio in the tissue of U. pertusa was considerably higher, ranging from 30 to 50. Increased growth at lower salinity suggests that the initial growth rate of U. pertusa is greater during the rainy season (i.e., late spring and early summer) than any other season during the year. The appearance of an Ulva bloom in eelgrass beds may be triggered by salinity more than by other environmental factors such as light and temperature.

• 한국물환경학회지
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• 제26권1호
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• pp.111-115
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• 2010

Beaches in estuaries, bays, and harbors are frequently contaminated with indicators of human pathogens such as fecal indicator bacteria. Tracking down the sources of contamination at these enclosed beaches is complicated by the many point and non-point sources that could potentially degrade water quality along the shore. A mathematical framework was developed to test quantitative relationships between fecal indicator bacteria concentration in ankle depth water at enclosed beaches, the loading rate of fecal indicator bacteria from non-point sources located along the shore, physical characteristics of the beach that affect the transport of fecal indicator bacteria across the beach boundary layer, and a background concentration of fecal indicator bacteria attributable to point sources of fecal pollution that impact water quality over a large region of the embayment. Field measurements of fecal indicator bacteria concentrations and water turbulence at an enclosed beach were generally consistent with predictions and assumptions of the mathematical model, and demonstrated its utility for assessing waste load of non-point sources, such as runoff, bather shedding, bird droppings, and tidal washing of contaminated sediments.

• 한국패류학회지
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• 제27권1호
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• pp.29-33
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• 2011

남해안 거제도 연안인 장목항에 인공부착판을 투입하여 주요한 부착성 저서동물의 가입양상을 조사한 결과, 3월에는 파래, 4월에는 지중해담치가, 5월에는 지중해담치와 유령멍게가 가입되었고, 6월에는 유령멍게와 다발이끼벌레류가, 8월에는 주걱따개비와 해변말미잘이 가입되었으며, 10월에는 석회관갯지렁이가 가입되었다. 월별로 투입된 부착판 1개월간 가입된 생물의 습중량은 5-6월에서 가장 많았다. 각 종들의 산란시기에 의해서 종 특유의 가입시기를 가지는 것으로 나타났다.

• 한국농공학회지
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• 제36권1호
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• pp.128-140
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• 1994

Coastal areas, especially embayments are apt to be polluted easily and many embayments in Korea are already suffering from pollution problems. To manage such pollution, it is strongly needed to develop technique to trace movements of pollution. Such technique cove- ring the embayment affected by the tidal influence, should take account both of the convection and the diffusion motions which cause lots of problems in numerical calculation. In this study, a Eulerian-Lagrangian Analysis(ELA) model was applied to Young Il bay and tested for its applicablity, which was developed by using the Eulerian-Lagrangian Method that reduce the numerical disperison and oscillation by way of solving convection and diffusion terrns separately. Concentration of Chemical Oxygen Demand(COD) and Suspend Solid(SS) of the embay- ment area were estimated by the model and compared with the observed values and the sound results were obtained. At the same time the diffsion coefficient and decay coefficient for Chemical Oxygen Demand in the Young II Bay were found as Dx = Dy = 20m$^2$/sec, kd=2.5 ${\times}$ 10-5/sec respectively, and for Suspend Solid, Dx =Dy = 30m$^2$/sec, kd=5.0${\times}$ 10-5/sec

• 생태와환경
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• 제42권1호
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• pp.48-57
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• 2009

Primary production of epiphytic and planktonic algae in a shallow reed zone of a lagoon Nishinoko was investigated. Concentrations of nutrients varied widely horizontally and locally in the lagoon. It seems that the reed zone has a heterogeneous environment. The photosynthetic rates of epiphytic and planktonic algae were 7 to 14 mg C surface stem $m^{-2}hr^{-1}$ and 12 to $46mg\;Cm^{-3}hr^{-1}$, respectively. The areal primary production of epiphytic algae was estimated as 4 to $13mg\;Cm^{-2}hr^{-1}$ from the stem density of Phragmites and the water depth at each station. The production of phytoplankton, on the other hand, was 5 to $56mg\;Cm^{-2}hr^{-1}$. The contribution of epiphytic algae to total primary production averaged 53%, although the assimilation number was much lower than that of phytoplankton. The present results indicate that the epiphytic algae are one of the significant primary producers in the reed zone.