대한환경공학회지 (Journal of Korean Society of Environmental Engineers)

  • 제36권10호
  • /
  • Pages.698-703
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  • 2014
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  • 1225-5025(pISSN)
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  • 2383-7810(eISSN)
대한환경공학회 (Korean Society of Environmental Engineers)
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담수 확산에 미치는 바람과 해저 지형의 영향

Wind and Bathymetry Effects on the Fresh Water Plume Structures

  • 이정우 (한국건설기술연구원 환경연구실) ;
  • 윤상린 (한국건설기술연구원 환경연구실) ;
  • 오혜철 (한국건설기술연구원 환경연구실)
  • Lee, Jungwoo (Environmental Engineering Research Division, Korea Institute of Civil Engineering and Building Technology) ;
  • Yun, Sang-Leen (Environmental Engineering Research Division, Korea Institute of Civil Engineering and Building Technology) ;
  • Oh, Hye-Ceol (Environmental Engineering Research Division, Korea Institute of Civil Engineering and Building Technology)
  • 투고 : 2014.10.08
  • 심사 : 2014.10.30
  • 발행 : 2014.10.30
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초록

강어귀의 기하학적 특징과 바람의 방향(upwelling, onshore, downwelling, and offshore winds)에 의한 담수 확산의 변화에 대하여 3차원 해양 순환 모델인 Regional Ocean Modeling System (ROMS)을 이용하여 연구하였다. 총 4개의 임의의 강어귀를 가정하였으며, 담수가 수심이 깊어지는 바다(sloping shelf)에 진입했을 경우가 편평한 바다(flat shelf)에 진입한 경우에 비해 빠른 x, y 운동량(momentum)의 상실과 상대적으로 강한 Coriolis 효과로 인하여 외해로의 담수 확산이 제한되는 것으로 연구되었다. 바람은 수직혼합을 촉진시켜 성층현상을 파괴한다는 기존 연구에 반해 약용승풍(mild upwelling winds)과 외해풍(offshore winds)의 경우(${\mid}{\tau}_{\omega}{\mid}=0.01Pa$) 성층현상을 촉진시키는 것으로 연구되었다. 이와는 반대로 침강풍(downwelling winds)과 연안풍(onshore winds)의 경우 기존 연구와 같이 성층을 파괴하는 것으로 연구되었다. 해저 물길(submarine channel)은 담수확산에 직접적인 영향을 주며 물길의 방향 또는 폭 등과 같은 해저 물길의 기하학적 특징에 의해 담수의 확산 정도가 달라지는 것으로 연구되었다. 또한 해저 물길은 담수 확산을 해저 물길의 상층부로 강하게 제한하는 것으로 연구되었다.

The structures of fresh water plume depending on estuarine geometries and wind directions (upwelling, onshore, downwelling, and offshore winds) were studied using the Regional Ocean Modeling System (ROMS). Four idealized estuaries, which are different in bathymetry, were considered. The results showed that the fresh water plume was restricted close to the shore line where a river was connected to the sloping shelf rather than the flat shelf due to the fast momentum exchanges from x, y to z momentums on the sloping shelf. Mild upwelling and offshore winds (${\mid}{\tau}_{\omega}{\mid}=0.01Pa$) enhanced stratification on the contrast to previous studies which showed that winds destroyed stratification by enhanced vertical mixing. However, downwelling and onshore winds had similar effects on the vertical structure of the fresh water plume as in previous studies enhancing vertical mixing. The plume was confined above the underneath submarine channel, thus the plume path was directly affected by the direction of the submarine channel on the shelf.

키워드

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