• Ocean Science Journal
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• 제43권3호
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• pp.135-146
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• 2008

The monthly distribution of zooplankton communities in Han River estuary was investigated at two stations from July 1998 to June 1999. Monthly mean abundance of total zooplankton varied remarkably, with the range from 20 $indiv.{\cdot}m^{-3}$ to 19,600 $indiv.{\cdot}m^{-3}$. During the study period, dominant species of zooplankton community were dinoflagellate Noctiluca scintillans, copepods Paracalanus indicus, Paracaanus crassirostris, Acartia hongi, Acartia ohtsukai, and meroplanton cirriped larvae. According to tidal states, relative high abundance occurred at high tide without regard to season. The temporal distribution of abundance implied that the reduced salinity probably limited the zooplankton populations and the fluctuations of salinity were an important factor in the variation of abundance. However, the results of salinity tolerance test shows that the variations in salinity do not directly influence the decrease of abundance. This study shows that the relatively high abundance of zooplankton near high tide seems to be related with the expansion of abundant zooplankton inhabiting Incheon coastal waters through tidal currents.

• 한국해양환경ㆍ에너지학회지
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• 제12권3호
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• pp.202-208
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• 2009

갯벌과 주변 연안역 사이의 물질순환, 특히 영양염 순환에 있어서의 갯벌의 역할을 이해하기 위해 서해 남부 해역의 대표적 갯벌인 함평만 입구에서 4차례(2008년 8월 5일과 18일, 2008년 10월 28일, 2009년 2월 9일)에 걸쳐 조위변화에 따른 영양염 변동을 조사하였다. 연구 결과에 의하면 수온은 조위변화에 따라 여름철 간조시 높고 만조시 낮은 반면, 가을과 겨울철은 간조시 낮고 만조시 높아 여름과 대조적인 경향을 보인다. 염분은 조위가 상승함에 따라 외해수가 유입되어 여름/겨울철에 만조시 높고, 간조시 낮은 일반적인 경향을 보이는 반면, 가을철에는 만조시 낮고 간조시 높은 반대의 경향을 보인다. 모든 계절에서 만조와 간조시 염분의 차는 0.3 psu미만이였다. 한편 함평만에서 관측된 모든 영양염은 조위변화에 따라 여름철 만조시 낮고 간조시 높은 반면, 겨울철은 만조시 높고 간조시 낮아 여름철과 반대의 패턴을 보인다. 특징적으로 가을철은 조위변화에 따른 뚜렷한 농도변동을 보이지 않았다. 이러한 결과는 함평만 갯벌이 여름철에는 영양염의 공급원으로 겨울철에는 영양염의 제거원으로 작용하고 있음을 보여준다. 이와 같은 영양염 계절별 조위변동은 외해수와 갯벌에서의 영양염 농도 차이를 반영하는 것으로 갯벌과 외해수 사이의 상호 복합적인 요인에 의해 나타나는 것으로 사료된다.

• 자원환경지질
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• 제33권5호
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• pp.417-424
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• 2000

We applied SP monitoring and resistivity surveys using the pole-pole electrode array to seawater leakage problems in the Youngsan estuary dam and the Eoeun embankment to estimate and detect the zone of seawater leakage. The embankment is generally affected by tidal variation and has low resistivity characteristics due to the high saturation of seawater. For this reason, SP monitoring and the pole-pole array resistivity surveys, which are relatively more effective to the conductive media, were carried out to delineate the leakage zones of sea water through the embankment. We checked out electrical conductivity (EC) and temperature variations along the inner part of Youngsan estuary dam to detect the zone of seawater leakage and found that the measured EC value agreed to that of seawater in the leakage zone and the temperature was lower than that of the vicinity of leakage zone. SP monitoring results were coincided with tidal variations at each embankment. At the leakage zones in the Youngsan estuary dam and the Eoeun embankment, SP anomalies are in the range of -60~-85 mV and -20~-50 mV, respectively, and true resistivity values obtained by 2-D inversion are 3~15 ohm-m and below 0.3 ohm-m, respectively. Both SP monitoring and the pole-pole array resistivity method are found to be quite effective for investigation of seawater leakage zones in the embankment.

• 한국제4기학회지
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• 제18권2호통권23호
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• pp.19-22
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• 2004

Seasonal changes of topograpy, sediment grain size and accumulation rate on the Gomso-Bay tidal flat(Fig. 1), west coast of Korea, have studied in order to understand the seasonal accumulation pattern and preservation potential of tidal-flat sediments. Seasonal levelings across the tidal flat show that the landward movement of both intertidal sand shoals and cheiers accelerates during the winter and typhoon period, but it almost stops in summer when mud deposition is instead predominant on the middle to upper tidal flat. Seasonal variations of mean grain size were largest on the upper part of middle tidal flat where summer mud layers were eroded during the winter and typhoon periods(Fig. 2). Measurements of accululation depths from sea floor to basal plate reveal that accumulation rates were seasonally controlled according to the elevation of tidal-flat surface(Table 1) : the upper flat, where the accumulation rate of summer was generally higher than that of winter, was characterized by a continuous deposition throughout the entire year, whereas on the middle flat, sediment accumulations were concentrated in winter realtive to summer, and were intermittently eroded by typhoons. The lower tidal flat were deposited mostly in winter and eroded during summer typhoons. Cancores taken across the tidal flat reveal that sand-mud interlaers resulting from such seasonal changes of energy regime are preserved only in the upper part of the deposits and generally replaced by storm layers downcore(Fig. 3). Based on above results, it is suggested that the storm deposits formed by winter stors and typhoons would consist of the major part of the Gomso-Bay deposits(Fig. 4).

• 한국습지학회지
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• 제14권3호
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• pp.375-384
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• 2012

강화 갯벌의 퇴적작용은 주변의 대규모 건설로 인하여 지난 20여년 동안 변화되어 왔다. 강화 갯벌 동부와 염하수로 하류에 위치한 동검 갯벌의 퇴적환경은 조류와 하구 순환의 변화에 의하여 영향을 받았다. 그 결과 동검 갯벌에 급격한 퇴적이 일어났다. 두 개의 코어 퇴적물 상부에 나타나는 실트-점토 호층 엽리 실트 퇴적상은 동검 갯벌에서 상대적으로 많은 퇴적이 있었음을 나타냈다. $^{210}Pb$ 분석에 의한 두 개 코어 시료의 퇴적률은 정점3에서 3.25cm/year와 정점 5에서 3.47cm/year 였다. 그러나 2010년부터 2012년까지의 단기 퇴적률은 대부분 1cm/year 미만으로 상대적으로 낮은 비율의 퇴적을 나타내고 있었다. 결과적으로, 동검 갯벌의 퇴적물은 2000년대에 인공구조물 건설에 의하여 급격히 퇴적되었다. 현재 동검 갯벌의 고도 증가는 계절 변화를 가진 상대적으로 낮은 퇴적률을 보여 주고 있다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 INTERNATIONAL SYMPOSIUM ON SOIL & GROUNDWATER ENVIRONMENT
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• pp.150-151
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• 2005

• 한국관개배수논문집
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• 제5권2호
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• pp.41-51
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• 1998

Spatial distributional patterns of temperature in the sediments and the concentration of nutrients in interstitial water were particular interests on the ecological research of tidal flats. It was the aim of this paper to grasp inhabiting environment of t

• Ocean and Polar Research
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• 제28권3호
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• pp.215-224
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• 2006

Spatial variation of heavy metal accumulation was investigated in Manila clam Ruditapes philippinarum collected from several tidal flats. Sediment metal levels varied highly among the sites, which was attributed primarily to differences in Fe and organic carbon contents and in part to gain size. Significant differences in metal concentrations also were found in the clam tissue among the different sampling sites. However, except for a few metals (Mn, Zn, Pb), which showed some elevation, the variations in the clam tissue were not related to the variations in the sediment. This is likely because most metals in filter-feeding herbivores such as R. philippinarum accumulated as a result of feeding on suspended particles such as phytoplankton and organic detritus in the water column, not in bottom sediment. In addition, tissue weight for a specific shell size varied significantly among the sites, and increased tissue mass indicating a good nutritive condition likely caused a subsequent dilution of body metals leading to reduced weight-specific concentrations of some metals (Cd, Zn, Cu, Co).

• Ocean and Polar Research
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• 제30권1호
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• pp.1-10
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• 2008

In order to find the effect of intertidal sediments on nutrient cycle in coastal environment, we measured ammonia, nitrate, phosphate, and silicate concentrations every hour during at least 12 hours in the entrance of Keunso Bay during four seasons. The content of ammonia and silicate do not change considerably with season, but nitrate shows large seasonal variation. In summer, nitrate concentration was much lower than in other seasons, which resulted from large biological uptake and active denitrification in intertidal sediments during summer. Phosphate also exhibit seasonal variations, but not that large like nitrate. N/P and N/Si ratios were lower in summer than in other seasons, which was due to active denitrification in the intertidal sediments during summer. For all seasons, ammonia concentrations were higher at low tide than at high tide, but nitrate concentrations were higher at high tide. Dissolved inorganic nitrogen concentrations measured in spring, summer, and winter were higher at high tide than at low tide, but in fall, they were higher at low tide than at high tide. For spring and winter, phosphate and silicate concentrations were higher at low tide than at high tide, while in summer and fall, they were higher at high tide than at low tide. In Keunso Bay, intertidal sediments affect significantly the nutrient cycle around the coastal areas. The intertidal sediments act as a source for ammonia and silicate, but as a sink for nitrate. However, phosphate is not considerably influenced by intertidal sediments.

• 한국환경과학회지
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• 제32권4호
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• pp.267-276
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• 2023

In this study, we analyzed seasonal variations in carbon dioxide fluxes, concentrations, and soil temperatures over three years in unvegetated tidal flats in the Beolgyo area. We also investigated the correlations between carbon dioxide fluxes and influencing factors. The average carbon dioxide flux was positive in summer and autumn but negative in winter and spring. A positive correlation was observed between carbon dioxide flux and soil temperature in spring whereas a negative correlation was noted in summer. In summer and autumn, as the soil temperature increased, the carbon dioxide flux decreased. In contrast, in spring and winter, as the soil temperature decreased, the carbon dioxide flux increased. Overall, this study reveals the significant influence of soil temperatures on carbon dioxide fluxes between the surface layer of the tidal flat and atmosphere.