• 한국조경학회지
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• 제23권2호
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• pp.167-181
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• 1995

An Ecocomplex is proposed for ecological design of the estuarine environment of Han River, which is designed upon an alternative mamagement concept of estuarine environment. The concept reveals interrelationships among estuary, delta region and urban inland with inputs/outputs and feedbacks among them. The Ecocomplex emphasizes an integration of wastewater treatment with aquaculture, agriculture and recreation, and carries out ecological treatment, recycling, and harvest processes. A module of wastewater treatment pond system is employed in the Ecocomplex, which treats a flow of 3,786 ㎥/day and is composed of a four-facultative-pond series. Treatment ponds stabilize wastewater discharged from the urban area, and concurrently produce algae for commercial or recreational fish farming. Effluent from treatment and fish ponds is reused for agricultural production. Through the waste-algae-fish-vegetable-recreation processes, wastewater from the urban settlement is recycled back to the urban ecosystem. This resource-conserving design approach can maintain a sustainable urban ecosystem, managing an estuarine environment more naturally, healthly, and economically.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.276-276
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• 2022

Estuarine dams are constructed for securing freshwater resources, flood control, and improving upstream navigability. However, their impact on estuarine currents, stratification, and sediment fluxes is not well understood. To develop a general understanding, an idealized modeling study was carried out. Tide and river forcing were varied to produce strongly stratified, partially mixed, periodically stratified, and well-mixed estuaries. Each model ran for one year. Next, the models were subject to the construction of an estuarine dam and run for another year. Then, the pre- and post-dam conditions were compared. Results showed that estuarine dams can amplify the tidal range and reduce the tidal currents. The post-dam estuaries tended to be a salt wedge during freshwater discharge and a bay during no freshwater discharge. For all estuaries, the estuarine turbidity maximum moved seaward, and the suspended sediment concentrations tended to decrease. In terms of sediment flux mechanisms, the estuarine dam increased the seaward river runoff for cases with strong river, and increased the landward tidal pumping for cases with strong tides.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.519-519
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• 2023

Estuarine dams are a recent and global phenomenon. While estuarine dams can provide the benefit of improved freshwater resources, they can also alter estuarine processes. Due to the wide range of estuarine types and estuarine dam configurations, the effect of estuarine dams on estuaries is not well understood in general. To develop a systematic understanding of the effect of estuarine dam location and freshwater discharge interval on a range of estuarine types (strongly stratified, partially mixed, periodically stratified, and well-mixed), this study used a coupled hydrodynamic-sediment dynamic numerical model (COAWST) and compared flow, sediment transport, and morphological conditions in the pre- and post-dam estuaries. For each estuarine type, scenarios with dam locations at 20, 55 and 90 km from the mouth and discharge intervals of a discharge every 0.5, 3, and 7 days were investigated. The results were analyzed in terms of change in tide, river discharge, estuarine classification, and sediment flux mechanism. The estuarine dam location primarily affected the tide-dominated estuaries, and the resonance length was an important length scale affecting the tidal currents and Stokes return flow. When the location was less than the resonance length, the tidal currents and Stokes return flow were most reduced due to the loss of tidal prism, the dead-end channel, and the shift from mixed to standing tides. The discharge interval primarily affected the river-dominated estuaries, and the tidal cycle period was an important time scale. When the interval was greater than the tidal cycle period, notable seaward discharge pulses and freshwater fronts occurred. Dams located near the mouth with large discharge interval differed the most from their pre-dam condition based on the estuarine classification. Greater discharge intervals, associated with large discharge magnitudes, resulted in scour and seaward sediment flux in the river-dominated estuaries, and the dam located near the resonance length resulted in the greatest landward tidal pumping sediment flux and deposition in the tide-dominated estuaries.

• 물과 미래
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• 제55권2호
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• pp.18-29
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• 2022

• 대한지리학회지
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• 제42권3호
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• pp.344-354
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• 2007

본 연구는 한강하구역에 위치한 33개 표준유역을 대상으로 1910년대, 1970년대, 2000년대 지형도를 이용하여 하구습지를 추출하여 공간적 분포특성과 시기별 변동추이를 분석한 것이다. 또한 하계밀도, 유역의 위치 및 크기, 경사도, 평균표고 등 유역특성이 하구습지 분포와 어떤 관계를 갖고 있는지 살펴보고, 개발사업 등 인위적 교란이 하구습지 훼손에 미치는 영향을 파악하였다. 지형도 분석결과, 하구습지는 1910년대부터 1970년대까지 완만하게 감소하였으며, 수도권이 팽창하기 시작한 1970년대 이후 한강하구의 습지는 급속하게 훼손되었다. 표준유역의 위치에 따라 하구습지를 구성하는 퇴적물 구성비율도 다르게 나타났는데, 해안에 인접한 유역에서는 갯벌(펄)의 구성비율이 높고 한강본류 및 지류에 인접한 유역에서는 사구나 습지(식생군락)가 우세한 것으로 나타났다. 또한 유역면적이 넓고 경사가 급하며 평균표고가 낮은 지역에서 하구습지는 광범위하게 분포하였다. 1970년대 이후 하구습지는 인위적 교란이 높은 한강서울, 한강서해, 한강고양 권역에서 크게 훼손된 반면 군사적 이유로 민간인의 출입이 제한된 임진강하류 및 한강하류 권역에서는 감소폭이 낮았다. 특히 지난 30여년 동안 인구증가율이 높으며 인공적인 토지피복 구성비율이 높아진 유역에서 하구습지의 훼손이 높게 나타났다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(2)
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• pp.1189-1192
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• 2005

Due to their slow degradation properties, hydrophobic organic contaminants in estuarine sediment have been a concern for risks to human health and aquatic organisms. Studies of fate and transport of these contaminants in estuaries are further complicated by the fact that hydrodynamics and sediment transport processes in these regions are complex, involving processes with various temporal and spatial scales. In order to simulate and quantify long-term attenuation of Polycyclic Aromatic Hydrocarbons (PAH) in the Elizabeth River, VA, we develop a modeling approach, which employs the U.S. Environmental Protection Agency's water quality model, WASP, and encompasses key physical and chemical processes that govern long-term fate and transport of PAHs in the river. In this box-model configuration, freshwater inflows mix with ocean saline water and tidally averaged dispersion coefficients are obtained by calibration using measured salinity data. Sediment core field data is used to estimate the net deposition/erosion rate, treating only either the gross resuspension or deposition rate as the calibration parameter. Once calibrated, the model simulates fate and transport PAHs following the loading input to the river in 1967, nearly 4 decades ago. Sediment PAH concentrations are simulated over 1967-2022 and model results for Year 2002 are compared with field data measured at various locations of the river during that year. Sediment concentrations for Year 2012 and 2022 are also projected for various remedial actions. Since all the model parameters are based on empirical field data, model predictions should reflect responses based on the assumptions that have been governing the fate and sediment transport for the past decades.

• 한국해양학회지:바다
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• 제8권2호
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• pp.151-163
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• 2003

본 논문은 섬진강 담수가 해양으로 유입하는 남해의 여수해협 -소리도 연안 해역에서 홍수기 (일평균 강우량 50 mm 이상이 10일간 지속)동안 형성된 염하구 환경의 물리-화학적 특성(공간분포 및 조절인자)에 관하여 조사 . 연구한 결과이다. 섬진강 담수는 해수와 비교하여 수온, 염분, pH가 낮고 COD와 영양염(특히 질산염 ) 농도가 높은 특성을 갖는다. 겨울철 갈수기와 달리 여름철 홍수기에는 이러한 특성의 담수가 섬진강 하구에서 약 20~60 km떨어진 전 연구해역으로 유입ㆍ확산되어 광범위한 염하구 환경을 형성하는 것으로 밝혀졌다. 본 연구에서는 여름철 홍수기 동안 일시적으로 형성되는 염하구를 일반적인 강 하구의 염하구(river estuary)와 구분하여 “연안 염하구(coastal pseudo-estuary)"로 정의 하고자 한다. 한편, DIN/DIP비는 겨울철 갈수기보다 여름철 홍수기에 훨씬 더 높으며, 이는 일반적으로 논에서 사용되는 질소 화학비료 때문인 것으로 해석된다. 이러한 연안 염하구 환경의 해수중에서 물리-화학적 인자들의 공간 분포와 거동 특성은 일차적으로 섬진강이 공급하는 담수와 해수의 물리적 혼합과 이 과정에서 일어나는 탈착 및 기타 생지화학적 요인 등에 의해 조절되는 것으로 해석된다. 본 연구에서 제시된 연안 염하구 환경 특성은 전반적으로 강 하구의 염하구 환경 특성과 크게 다르지 않은 것으로 판단된다.판단된다.

• Ocean and Polar Research
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• 제30권4호
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• pp.475-484
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• 2008

The word 'Saemangeum' indicates an estuarine tidal flat in the southwestern part of the Korean peninsula. The Saemangeum Reclamation Project was launched as a national project in 1991 to reclaim a large coastal area of $401\;km^2$ by constructing a 33-km long dyke. The final dyke enclosure in April 2006 has transformed the tidal flat into lake and land. An integrated oceanographic study has been conducted since 2002 as a part of the Government Action Plan to monitor and assess changes in the marine environment. Prior to the dyke enclosure, the coastal environment in the Saemangeum was a complex system governed by tidal motion, estuarine processes, and coastal circulation of the Yellow Sea. The dyke construction has radically changed not only the estuarine tidal system inside the dyke, but also the coastal marine environment outside the dyke. Post to the dyke enclosure, subsequent changes such as red tide, hypoxia, and coastal erosion/deposition occur successively. Red tides appear almost the year round in the inner area. Even under the condition that the sluice gates are fully open, the water quality does not improve as much as the developers would expect, mainly due to the critical reduction of the hydrodynamic stirring power. We will introduce details of our monitoring program and significant changes in the Saemangeum marine environment, based on observations and model results.

• 한국해양학회지:바다
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• 제9권4호
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• pp.153-163
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• 2004

In order to estimate the nutrient flux of the Seomjin River into the coastal waters of South Sea, and to understand the estuarine reactions during mixing between river water and seawater, we collected surface water along the salinity gradient in the Seomjin River estuary from Mar. 1999 to Apr. 2001. We found that nitrate and silicate were delivered by fluvial input, while phosphate was, supplied from disposed wastes in the Gwangyang Bay. Mean annual flux of dissolved inorganic nitrogen (DIN), phosphate and silicate into the Gwangyang Bay was estimated 10.9 molesㆍsec$^{-1}$(4,820 tonnesㆍyr$^{-1}$), 0.07 molesㆍsec$^{-1}$(68 tonnesㆍyr$^{-1}$), 13.3 molesㆍsec$^{-1}$(11,747 tonnesㆍy$^{-1}$), respectively. An evident removal of phosphate, silicate and ammonium at the mid-salinity zone during the dry season was attributed to the active uptake of phytoplankton, and consequently nutrient flux into the Gwangyang Bay was low. Whereas, during the flood season in summer, conservative or additional distribution of the nutrients was observed in the estuary. As a rsult nutrient flux into the Gwangyang Bay was maintained high. High concentrations of chlorophyll a and the active removal of nutrient during the dry season at the mid-salinity zone suggest that nutrient distribution in the Seomjin River estuary was mainly controlled by biological processes and nutrient fluxes into the Gwangyang Bay might be significantly modified of by the primary production.

• 한국수산과학회지
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• 제27권6호
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• pp.754-770
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• 1994

미국 북캐롤라이나의 동해안에 위치하는 뉴우스강 하구를 대상으로 1988년 2월부터 1989년 2월까지 매월 부유퇴적물의 분포와 유속 및 염분을 조사하여, 최대혼탁수의 형성과 물리적 환경요인(담수유출량, 풍향 및 풍속, 조석 등)에 따른 시간적, 공간적 변화를 조사하였다. 대부분의 조사기간동안, 염하구 순환과 관련된 미약한 최대혼탁수의 형성이 염수 침입한계 근처에서 관측되었으며, 염수 침입한계의 연중 이동과 수반하여 강 상류의 약 20 km 지역에 걸쳐 이동하면서 분포하였다. 이 지역 계절풍의 주된 풍향(북동-남서)과 Pamlico Sound의 지형적 방향성의 일치로 인하여, 염분 성충구조와 염하구 순환의 발달정도는 바람의 영향을 크게 받으며, 따라서 최대혼탁수의 형성과 변동 양상도 조석의 영향보다는 담수유출량과 바람의 영향을 뚜렷이 나타내었다.