• Title/Summary/Keyword: 한국연안류

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Understanding the Flow Properties by a Numerical Modeling in the South Sea of Korea (수치모델을 이용한 한국 남해의 유동특성 이해)

  • Bae, Sang-Wan;Kim, Dong-Sun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.18 no.4
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    • pp.295-307
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    • 2012
  • In order to understand the flow properties of the South Sea of Korea, tidal currents, wind-driven currents, density-driven currents and residual flows were investigated by using 3-dimensional numerical model(POM). In offshore regions, tide-induced residual current tends to flow eastward during the spring tide and westward during the neap tide. Total residual flow is irregular due to the bottom topography in the coastal area. The density-driven currents in the coastal area showed to be relatively weak, with little seasonal differences. The special tendency was apparent in the open sea. That is, the flow in the offshore regions showed results similar to that of the Tsushima current. The wind-driven currents in the coastal area showed to be much stronger than in offshore regions. Vertically, the flow of the surface layer was much stronger than that of the bottom layer. Through these results, material transport and diffusion in the south coast, as a basis for predicting the spread of use is expected to be available.

Size-related and Temporal Dietary Variations of Hexagrammos otakii in the Mid-western Coast of Korea (서해 중부 연안에 출현하는 쥐노래미(Hexagrammos otakii)의 성장과 계절에 따른 식성 변화)

  • Choi, Hee Chan;Huh, Sung-Hoi;Park, Joo Myun
    • Korean Journal of Ichthyology
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    • v.29 no.2
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    • pp.117-123
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    • 2017
  • Stomach contents of Hexagrammos otakii collected from mid-western coast of Korea were analysed to determine dietary composition, and ontogenetic and temporal dietary variations. Fish total length (TL) ranged between 5.6 and 32.4 cm. H. otakii primarily consumed amphipods, carid shrimps and teleosts, but also ate various benthic crustaceans and other invertebrates with small amounts. Carid shrimps and teleosts dominated the diet of both immature and mature fishes. Amphipods and polychaetes were secondary, and the former more frequently consumed by smaller specimens, while the latter was more abundant in the diets of larger fishes. DISTLM (distance-based linear modelling) showed diet composition of H. otakii varying significantly with TL, season and water temperature, but did not with maturity.

Characteristics of Wave-induced Currents using the SWASH Model in Haeundae Beach (SWASH 모형을 이용한 해운대 해수욕장의 해빈류 특성)

  • Kang, Min Ho;Kim, Jin Seok;Park, Jung Kyu;Lee, Jong Sup
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.6
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    • pp.382-390
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    • 2015
  • To simulate a complicated hydrodynamic phenomena in the surf zone, the SWASH model is used in Haeundae Beach. The SWASH model is well known as a model competing with the Boussinesq-type model in terms of near shore waves and wave-induced currents modelling. This study is aimed to the detailed analysis of seasonal waves and wave-induced current simulation in Haeundae Beach, where the representative seasonal wave conditions was obtained from hourly measured wave data in 2014 by Korea Hydrographic and Oceanographic Administration( KHOA). Incident wave conditions were given as irregular waves by JONSWAP spectrum. The calculated seasonal wave-induced current patterns were compared with the field observation data. In summer season, a dominant longshore current toward the east of the beach appears due to the effect of incident waves from the South and the bottom bathymetry, then some rip currents occurs at the central part of the beach. In the winter season, ESE incident waves generates a strong westward longshore currents. However, a weak eastward longshore currents appears at the restricted east side areas of the beach.

3D Numerical Simulation of Water Surface Variations and Velocity Fields around Permeable Submerged Breakwaters under Irregular Waves (불규칙파 조건 하에서 투과성잠제 주변의 수면변동 및 유속장에 관한 3차원 수치모의)

  • Lee, Kwang-Ho;Bae, Ju-Hyun;An, Sung-Wook;Kim, Do-Sam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.30 no.4
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    • pp.153-165
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    • 2018
  • In this study, the performance of irregular wave field generation of olaFlow is first verified by comparing the frequency spectrum of the generated waves by the wave-source using olaFlow and the target wave. Based on the wave performance of irregular waves of olaFlow, the characteristics of the velocity field including the average flow velocity, longshore current and turbulent kinetic energy around the three-dimensional permeable submerged breakwaters, which act as the main external forces of the salient formation, are numerically investigated. The numerical results show that as the gap width between breakwaters decreases, the wave height in the center of the gap increases and as the gap width between breakwaters increases, the longshore currents become stronger. As a result, it is possible to understand the formation of the salient formed behind the submerged breakwaters.

Characteristics of Cold Water Appeared in the Southwestern East Sea (동해 남서부해역에 출현하는 냉수 특성)

  • Lee, Moon-Ock;Otake, Shinya;Kim, JongKyu
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.3
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    • pp.455-473
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    • 2014
  • 하계 동해의 남서부해역에 냉수가 왜 그리고 어떠한 해양환경하에 출현하는가를 밝히기 위하여 현장조사, 위성자료의 분석 및 수치실험을 실시하였다. 이 해역에서 냉수는 비정상년의 경우는 정상년에 비해 보다 더 연안 가까이에서 출현하였고, 수온도 낮았다. 이것은 냉수가 비정상년에는 정상년에 비해 크게 발달하여 연안역으로 확장함을 의미하였다. 흐름장의 계산결과는 지형류적인 관점에서 수온의 관측결과를 잘 재현하였다. 한편, 정상년의 경우는, 북한한류(NKCW)가 쓰시마난류(TC)와 균형을 유지하면서 동해의 북서쪽에 머물고 있었다. 이에 반해, 비정상년의 경우는, 북한한류가 점차 남쪽으로 남하하여 동해 서부역의 대부분이 북한한류의 세력하에 놓였다. 그래서, 하계 동해 서부 연안역에서의 냉수 출현은 남쪽으로의 북한한류의 확장에 의한 부산물인 것으로 판단되었다. 울산 연안역에 대한 유동계산결과는 하계 남풍이 불 경우, 표층과 저층 사이에 흐름의 역전현상이 나타났다. 따라서, 하계 동해의 남서부 연안역, 특히 수심의 변화가 급한 방어진 부근에서 냉수의 용승이 일어날 수 있음을 시사하였다.

The changes of fish fauna in and around the artificial reefs (turtle type) placed at the coast of Tongyeong, Korea (경남 통영 연안에 설치된 반구형 어초에서의 월별 어류상 변화)

  • 명정구;박용주;조선형;김종만
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2001.05a
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    • pp.557-558
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    • 2001
  • 인공어초 사업은 어족의 서식환경을 개선하기 위하여 1971년부터 현재까지 약 4000여 억 원을 투자해오고 있으며 앞으로 계속 시설할 예정이다(한국해양수산개발원, 2000). 현재 시설 중인 일반 어초에는 사각형, 원통형, 반구형 등이 있으며(국립수산진흥원,1992) 이중 해조류, 패류를 대상으로 하는 연안 어초 중 반구형어초를 대상으로 어초 설치 유형에 따른 모여든 어종 및 그 규모 차이를 알기 위하여 경남 통영시 산양면 저도 연안에 설치된 반구형 어초에서의 월별 어류상 변화를 조사하였다. (중략)

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Observation of Along-shore Current in the Northern East Sea by SARAL/AltiKa Sea Level Data (SARAL/Altika 해표면 고도 위성에 의한 동해 북부 연안 해류)

  • LEE, DONG-KYU;CHOI, JANG-GEUN
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.24 no.3
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    • pp.429-435
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    • 2019
  • The drifters of the Global Drifter Program were deployed in the northern East Sea for two years from March 2015 to compare and validate currents estimated from sea-level measurements with the SARAL/AltiKa altimetry satellite mission, specially designed to accurately measure sea level in the near-coastal area. The collocated (less than 20 km apart) directly measured current from GPS locations every 30 minutes and the currents normal to the satellite tracks show a similar correlation in the area shallower than 200 m depth as the open ocean and it makes it possible to investigate the time variations of the current along the coast in the northern East sea, where direct observations of current are scarce. The Liman Current along the Siberian coast is found to be southward all year round, but the North Korean Cold Current flows southward only in the summer. The North Korean Cold Current south of the Musudan cape mostly flows to the south, but the current direction depends on the presence of an eddy around the coast of Musudan cape.

A Systematic Study on the Errantiate Polychaeta in Korea (한국산 유영류(다모강)의 분류학적 연구)

  • 노분조;이종위
    • Animal Systematics, Evolution and Diversity
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    • v.3 no.1
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    • pp.74-90
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    • 1987
  • 한국산 유영류(다모강)의 분류학적 연구의 일환으로 1965년부터 1986년까지 우리나라의 삼면연안과 도서지방(36개 지역)에서 채집된 표본을 동정 분류하였다. 그 결과 10과 20속 31종 2 종이 밝혀졌으며 그 중 4아종 1 아종(Amphinome rostrata, Haplosyllis tentaculata, Typosyllis aciculata orientalis, Typosyllis variegata, Glycera subaenea)은 한국미기록종으로 판명되었다. 눈썹참갯지렁이 (Perinereis nuntina)는 총 36개 지역 중 11개 지역에서 채집되었으며 , 총 600여 개체중 232 개체가 채집됨으로써 우리나라에 널리 분포해있는 종으로 나타났다. 동정 분류된 표본 중 한국과 일본 해역에만 분포하는 것은 3 종이었다.

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Numerical Simulation in relation with Coastal Current and Stratification of Water at the Semi-enclosed Estuary (반폐쇄하구에서의 유동 및 성충구조에 관한 시뮬레이션)

  • Lee, Woo-Chul;Lee, Joong-Woo;Park, Dong-Jin
    • Journal of Navigation and Port Research
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    • v.28 no.6
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    • pp.565-572
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    • 2004
  • Residual current plays more important role than the tidal current for long-term material transport in coastal areas. The main component of residual current is tide-induced residual current. Otherwise, wind driven current and buoyancy-driven current are important components which change the residual current. To clarify the characteristic of coastal current, application of a three -dimensional model is necessary. This study focuses on clarifying the stratified systems of coastal water affected by freshwater runoff from a river and analyzes the structure of current at Ulsan bay by applying a three-dimensional buoyancy-driven current model. According to the result of “Ulsan bay” study, it shows that the surface layer in semi-enclosed estuaries, which affected by freshwater runoff. has flows going out, and the bottom layer has flows coming in. Besides when the wind blows toward inside of the bay, the surface layer has flows coming in and the bottom layer has flows going out as compensation flows for the surface circulation. The results of simulation could be applicable to examine vertical upwelling, which might be caused by construction of artificial fishing reef to build aqua farm, submerged breakwater to control coastal sediment, and the formulation of oceanic ridge, or a basic study on application to the usage of deep water.