• 환경영향평가
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• 제12권5호
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• pp.341-348
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• 2003

Seasonal characteristics of water quality and effect of the freshwater discharge during open the tide embankment in Haechang Bay were evaluated. In the freshwater, where interior of the tide embankment, COD and Chl-a exceeded about 4mg/L and $10mg/m^3$, respectively, independent of season, while in the seawater they showed high values in April and July in contrast to the other period due to input of freshwater and increase of phytoplankton, respectively. The content of seawater inorganic nitrogen maintained a relatively high level at inner part of the bay, whereas high values of inorganic phosphorus content was distributed at all over the bay. The limiting factor for algal growth was nitrogen with respect to the N/P ratio. The compass of influence by the freshwater discharge in April was quite different with water pollutants. As a result of the salinity variation with time, the freshwater extended strongly to offshore from the surface layer without mixing with depth when open the tide embankment, and reached within about one hour at a station which is 3.5km from the tide embankment. To effective water quality management of Haechang Bay, discharge rate and pollutant loads should be controlled.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2010년 춘계학술발표회 논문집
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• pp.31-34
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• 2010

이중차분을 통한 GPS 측위시 이동국의 위치는 기준국에 대한 상대위치로 결정된다. 단기선의 경우는 조석에 의한 변위량의 상대적인 차이가 거의 없기 때문에 조석보정이 필요하지 않다. 하지만 기선의 길이가 길어지고 망 전체의 크기가 우리나라 전체 면적을 포함하는 경우 조석 변위량의 상대적인 차이로 인해 측위 오차가 발생할 수 있으므로 적절한 조석보정이 수반되어야 한다. 본 연구에서는 우리나라 규모에서 조석영향에 의해 발생할 수 있는 변위량을 분석하였다. 분석결과 GPS를 이용한 정밀측위시 조석영향에 대한 보정이 수행되어야 할 것으로 판단된다.

• 한국수산과학회지
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• 제32권3호
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• pp.368-373
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• 1999

Topex/Poseidon sea surface heights are compared to tide gauge sea levels in the South Indian Ocean in the period of January 1993 to December 1995. A user's handbook (AVISO) for processing sea surface height data was used in this study. Topex/Poseidon sea surface heights were obtained from satellite data at the proximity of tide gauge stations. These data were reproduced by a linear interpolation with the interval of 10 days and were processed by the Gaussian filter with a 60-day window. The tide gauge sea levels were obtained in the same manner as the satellite data. The main results on RMS (Root-Mean-Square) and CORR (CORRelation coefficient) in our study were shown as follows: 1) on the characteristics between two data (in-situ and model data), the results (RMS=2.96 cm & CORR=$92\%$ in the Amsterdam plateau, and RMS=3.45 cm & CORR=$59\%$ in the Crozet plateau) of the comparison of Topex/Poseidon sea surface heights with tide gauge sea levels, which was calculated by in-situ data of obsewed station showed generally low values in RMS and high values in CORR against to the results (RMS=4.69 cm & CORR=$79\%$ in the Amsterdam plateau, and RMS= 6.29 cm & CORR= $49\%$ in the Crozet plateau) of the comparison of Topex/Poseidon sea surface heights with tide gauge sea levels, which was calculated by model data of ECMWF (European Center for Medium-range Weather Forecasting), and 2) on the characteristics between two areas (Kerguelen plateau and island), the results (RMS=3.28 cm & CORR= $54\%$ in the Kerguelen plateau) of open sea area showed low values in RMS and high values in CORR against to the results (RMS= 5.71 cm & CORR=$38\%$ in the Kerguelen island) of coast area, respectively.

• 한국환경과학회지
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• 제26권3호
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• pp.325-334
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• 2017

To understand the changes in physical parameters and phytoplankton size structure caused by tides, a fixed station in the Youngsan River estuary was monitored at 2-h intervals, on April 28, 2012 and August 12, 2012. No clear relationship was observed between the temperature and salinity changes and tidal levels in April. However, in August, temperature decreased during the ebb tide and increased during the flood tide, while salinity showed the opposite trend. In addition, there was no specific change in the phytoplankton biomass corresponding to tidal levels in April. In August, the total chlorophyll a and the biomass of net phytoplankton (>$20{\mu}m$) increased almost 20 times during the ebb tide and decreased during the flood tide. The biomass of nanophytoplankton (<$20{\mu}m$) showed a similar variation in response to tidal level changes. In April, the relationship between percent contributions of phytoplankton size structure and tidal levels was not clear. In August, the net phytoplankton was dominant in the early stage and nanophytoplankton was dominant in the later stage, while contribution of nanophytoplankton and net phytoplankton increased at high tide and low tide, respectively. Therefore, in April, other factors such as freshwater discharge were more important than the tide, whereas in August, when no freshwater discharge was recorded, the changes in semidiurnal tides influenced the physical parameters and phytoplankton dynamics. These results could contribute to the understanding of phytoplankton dynamics in the Youngsan River estuary.

• 한국물환경학회지
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• 제27권4호
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• pp.542-550
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• 2011

Changes of suspended sediment concentration in the Seomjin river estuary located in south sea of the Korea peninsula were investigated during the spring tide in autumn (i.e. 25 hours in October) 2000 and winter (i.e. 25 hours in February) 2001. The changes of temperature and salinity during the spring tide in October 2000 showed larger variations than the those in February 2001. During the spring tide in October 2000, currents at bottom layer were observed to be stronger than during the spring tide in February 2001, showing that both of the two periods had ebb currents-predominant tide asymmetries. The suspended sediment concentrations in October 2000 were larger than the those in February 2001. At the time of the maximum of tide currents or after about one hour of the maximum during the autumn months, the suspended sediment turbidity was observed to be maximum. Another observation station at Hadong upstream from the Seomjin river estuary showed about one hour delay in tide phase, Thereby, the suspended sediment concentration showed high turbidity after two hours at bottom and three hours at surface layer, in particular, in October 2000. This results can be explained by the facts that river discharge increased significantly after the summer rainy season, causing also increase of erosion processes by strong current velocity at bottom layer.

• 물과 미래
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• 제27권4호
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• pp.115-121
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• 1994

감조하천의 수위는 조석파와 상류의 유출량과의 상호작용에 의해 변화하며, 특히 만조상태에서는 홍수위가 증가하여 재해의 원인이 된다. 이러한 감조하천에서 수위는 유량만의 함수라기 보다는 유량과 조석파의 결합에 의한 함수이다. 본 논문은 조위와 하천 유량사이의 관게를 정식화하여 감조하천에서의 수위를 예측할 수 있도록 하는 것이다. 제시된 이론의 검증은 섬진강의 감조하천내에 있는 송정 및 하동수위표에 적용하였다. 적용 결과, 송정수위표에서는 수위에 대한 조위의 상관관계가 0.016으로 조위의 영향이 작으나, 하동 수위표에서는 0.558로 조위의 영향이 크게 나타났다.

• 한국환경과학회지
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• 제11권6호
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• pp.519-528
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• 2002

This study was to evaluate the impact of river runoff and salt intrusion by tide on nutrient balance of estuary during a complete tidal cycle. 24 hours time series survey was carried out during a spring tide July 2001 on a tidal estuary in the Keum river. Three stations(A,B,C) were set along a transect line of about 10km, which linked the lower part of estuary dyke to the subtidal zone. Surface water was sampled simultaneously at each station every hours f3r the determination of nutrients. Water temperature, pH and dissolved oxygen were measured in situ. Riverine input of silicate and nitrate during ebb tide significantly increased the concentration of all stations. Conversely, during high tide, nutrient concentration were lowered by the mixing of fresh water with sea water Ammonium nitrogen concentration were higher at intertidal zone(Stn.B) due to sewage inflow to Kyeongpo stream and ammonium release under anaerobic conditions. Also, these results was discussed as a biological component that influences the processes of nutrient regeneration within the estuary. Best correlations were found at lower part of estuary dyke(Stn.A) for salinity against DIN(Y=0.121 Sal.+4.97, r2=0.956) and silicate(Y=0.040 Sal.+2.62, r2=0.785). But no significant correlation was found between salinity and ammonium. Unbalanced elemental ratio(N/P, Si/N and Si/P) depended significantly on the import of nutrients (silicate & nitrate nitrogen) from river and stream. The effect of the tidal cycle and river runoff is important that in determining the extend of the variations in nutrient concentrations at all station.

• 한국해양학회지:바다
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• 제5권1호
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• pp.27-36
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• 2000

전남 고흥군 나로도 해역은 1995년 이후 해마다 8월부터 10월까지 남해안에서 대규모로 발생되는 유해성 적조 가 가장 먼저 발견되는 곳이다. 이 해역에서의 유해성 적조의 발생에 대한 연구를 하기 위하여, 1997년 6월 20일부터 9월22일까지 모두 5차례에 걸쳐 최대 6개 정점, 5개 깊이에서 시료를 채집한 뒤 적조원인생물과 연관 식물플랑크톤의 분포를 조사하여 본 연구와 동시에 조사, 분석된 수온, 염분, 영양염류 분포 등 환경요인들과의 연관성을 연구하였다. 1997년의 경우 이 해역에서 8월 24일에 적조띠가 처음 발견되었는데 가장 우점했던 유해성적조원인생물은 이제까치 알려진 것과는 다르게 Gyrodinium impudicum이었으며 Cochlodinium polykrikoides의 밀도는 G. impudicum의 밀도보다 훨씬 낮았다. 적조발생직전인 8월 21일에는 G. impudicum의 최대밀도가 90cells $ml^{-1}$로 낮았고 주로 내측(nearshore)에서 밀도가 외측보다 높았으나, 발생직후인 8월 27일에는 G. impudicum의 최대밀도가 30,000 cells $ml^{-1}$까지 이르렀고, 적조띠는 주로 외해(offshore)에 위치한 정점들에서 발견되었다. 이러한 갑작스러운 밀도의 증가는 G. impudicum의 최대성장률을 고려해 볼 때 G. impudicum의 적조띠가 다른 곳에서 이미 형성되었다가 본 조사해역으로 이동해왔거나, 저밀도로 산재해 있던 G. impudicum의 개체들이 물리적인 힘에 의하여 급속히 모여 적조띠를 이루었을 가능성을 제시할 수 있다. 8월 21일과 8월 27일 사이에 내측 정점에서는 G. impudicum의 밀도는 일정한 반면에, Skeleltonema costatum, Chaetoceros pseudocurvisetus, Pseudonitzschia pungens 등 규조류가 대번식하였다. 이는 강우 뒤 육수의 유입이 내측 환경에 상당한 영향을 주었고 이러한 유입수의 고농도의 영양염류가 규조류의 급속한 성장을 야기시켰으며, 규조류의 급증은 오히려 상대적으로 성장률이 훨씬 낮은 G. impudicum 등 와편모류의 성장을 억제했을 가능성이 높다. 그러므로 이 해역에서의 적조발생은 advection, physical aggregation과 같은 물리적인 힘과 적조원인생물과 연관 식물플랑크톤간의 경쟁의 영향을 받았을 것으로 생각된다.

• 한국해안·해양공학회논문집
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• 제20권5호
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• pp.482-490
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• 2008

연안 및 항만구조물의 설계에서 최극 고조위는 매우 중요한 환경인자이다. 특히, 최극 고조위의 분포정보는 최근 부각되고 있는 신뢰성 설계에 필수적인 요소이다. 본 연구에서는 국립해양조사원에서 제시한 한국연안 주요 23개 검조소의 최극조위자료를 이용하여 극치분포 분석을 수행하였다. 특성분석에 사용된 극치분포함수는 Generalized Extreme Value, Gumbel 그리고 Weibull 분포이며, 각 분포함수의 매개변수는 모멘트법, 최우도법 그리고 확률가중모멘트법 등 3가지방법으로 추정하였다. 또한, 극치분포함수의 적합성은 95% 신뢰도 수준으로 $X^2$ 및 K-S 검정을 실시하였다. 그 결과, 23개 검조소의 최극 고조위는 Gumbel 분포형이 가장 적합한 모형으로 파악되었으며, 최적 추정된 매개변수 및 재현기간별 최극 고조위 정보를 제시하였다. 심 등(1992)이 제시한 인천, 제주, 여수, 부산, 묵호에 대한 극치해면값은 본 논문에서 산정한 결과에 비하여 작게 나타났다.

• 한국농공학회지
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• 제31권1호
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• pp.117-130
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• 1989

In this study, an implicit one-dimensional model, DWRM(Dynamic Wave Routing Model) was developed by using the four-point weighted difference method. By applying the developed model to the Keum River, the parameters were calibrated and the model applicability was tested through the comparison between observed and computed water levels. In addition, the effects of the construction of an estuary dam to the flood wave were estimated as a result of the model application. The results of the study can be summarized as follows; 1. The roughness coefficients were evaluated by comparison between observed and computed water level at Jindu, Gyuam and Ganggyeung station in 1985. The Root Mean Squares for water level differences between observed and computed values were 0.10, 0.11, 0. 29m and the differences of peak flood levels were 0.07, 0.02, 0. 07m at each station. Since the evaluated roughness coefficients were within the range of 0.029-0.041 showing the realistic value for the general condition of rivers, it can be concluded that the calibration has been completed. 2. By the application of model using the calibrated roughness coefficients, the R. M. S. for water level differences were 0.16, 0.24, 0. 24m and the differences of peak flood level were 0.17, 0.13,0.08 m at each station. The arrival time of peak flood at each station and the stage-discharge relationship at Gongju station agreed well with the observed values. Therefore, it was concluded that the model could be applied to the Keum River. 3. The model was applied under conditions before and after the construction of the estuary dam. The 50-year frequency flood which had 7, 800m$^3$/sec of peak flood was used as the upstream condition, and the spring tide and the neap tide were used as the downstream condition. As the results of the application, no change of the peak flood level was showed in the upper reaches of 19.2km upstream from the estuary dam. For areas near 9.6km upstream from the estuary dam, the change of the peak flood level under the condition before and after the construction was 0. 2m. However considering the assumptions for the boundary conditions of downstream, the change of peak flood level would be decreased.