• 제목/요약/키워드: Well waters

검색결과 470건 처리시간 0.025초

Wave-Induced Impulsive forces in Tension Cables of a Floating Silt Curtain

  • Aoki, Shin-ichi
    • 한국해안해양공학회:학술대회논문집
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    • 한국해안해양공학회 1993년도 정기학술강연회 발표논문 초록집
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    • pp.124-124
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    • 1993
  • Recently silt curtains have been increasingly used at a dredging or reclaiming site in a sea for the purpose of preventing the neighbouring waters from becoming turbid. However, the hydrodynamic forces acting on such a flexible structure have not been investigated well and the design criteria have not been established. The floating silt cur-tain treated in this study consists of floats, tension cables and curtain canvases. (omitted)

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Nutrients and Phytoplankton Blooms in the Southern Coastal Waters of Korea: I. The Elemental Composition of C, N, and P in Particulate Matter in the Coastal Bay Systems

  • Kang, Chang-Keun;Kim, Pyoung-Joong;Lee, Won-Chan;Lee, Pil-Yong
    • Journal of the korean society of oceanography
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    • 제34권2호
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    • pp.86-94
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    • 1999
  • An investigation was conducted to determine limiting nutrients in the bay systems of the southern coastal area of Korea. The elemental composition of C, N, and P in suspended particulate matter was monitored nearly monthly in Chinhae and Koje Bays and seasonally in Deukryang Bay for 2 years. Atomic C:N ratio in particulate matter ranges from 4.3 to 9.6, typical of marine phytoplankton. C:P and N:P ratios vary from the Redfield ratio to 229 (C:P) and 37 (N:P). A constant C:N ratio of 6.87 from regression of particulate C and N concentrations demonstrates that the particulate matter in the systems originates from primary production. C:P and N:P ratios from regression of C on P and N on P are well associated with changes in salinity. The low N:P ratio of 13.1 implies N limitation in the environments of the systems. This seems to result from the low N:P ratio of nutrients released across sediment-water interface. Phytoplankton response, expressed here as the increase of chlorophyll a, to N addition also verifies N limitation for phytoplankton communities. In heavy rainfall season (from June to September), the addition of excessive N via streams into the stratified coastal water proliferates phytoplankton greatly. During the phytoplankton blooms, C:P and N:P ratios are much higher than the Redfield ratio, implying P limitation. This results from the high N:P ratio in nutrients supplied from stream waters. Strong stratification during the blooms also interrupts the supply of nutrients, particularly p, from bottom waters. Dependent upon precipitation, this tendency shows great inter-annual variation.

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한국진(韓國塵) 참복아목(亞目) 어류(魚類) (Synopsis of the Suborder Tetraodontoidei (Pisces ; Tetraodontiformes) from Korea)

  • 김익수;이완옥
    • 한국어류학회지
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    • 제2권1호
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    • pp.1-27
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    • 1990
  • 한국산(韓國産) 참복아목(亞目) 어류(魚類)를 4과(科) 10속(屬) 24종(種)으로 분류(分類)하여 과(科), 속(屬) 및 종(種) 검색표(檢索表)를 작성(作成)하고, 1986년부터 1990년 까지 채집한 17종에 대하여 계수(計數), 계측형질(計測形質), 외부형태(外部形態), 체색(體色) 그리고 채집지성(採集地成) 등을 기록하였다. 이중 Lagocephalus gloveri Abe et Tabeta 1983, 와 L. whheeleri Abe, Tabeta et Kitahama 1984, 를 한국 미기록종으로 기재(記載)하면서, 국명(國名)을 "흑밀복"과 "은빌복"으로 각각 명명한다. Takifugu chinensis(Abe)는 1949년 Abe가 부산표본을 paratype으로 사용하여 기채 보고 하였으나, 최근의 한국산 목록에 포함되어 있지 않아 본 연구에서 이 종을 추가하고, 한국명으로 "참복"으로 제안한다. 우리나라에 분포하는 참복아목(亞目)에 해당하는 종의 대부분은 일본(日本)과 중국(中國)에도 분포하고 있지만, 그 가운데 황복 T. obscurus, 황점복 T. flavidus와 바실복 T. basileusskianus 3종은 한국의 황해(黃海)와 중국의 해역(海域)에만 출현하고 있어 주목되었다.

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고리해역에 있어서의 표류병 및 염료확산시험 (Some Physical Oceanographic Survey in the Sea Off Kori)

  • 장지원;박시열;서두옥
    • 수산해양기술연구
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    • 제7권1호
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    • pp.1-8
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    • 1971
  • The forth dye diffusion experiment, which was authorized by the Office of Atomic Energy, and some physical aspect of oceanographic observations were carried out in the sea off Kori in September 29-October 1, 1971. In a series of drift bottle experiments the 337 bottles were released. And bottom topography by echo soundings in the survey was well approached to the chart No. 433, Kori and Approaches, published by Hydrographic Office in October 1970. Results deduced from this survey were as follows: 1. A small ridge extends from Kori-Mal tip in southwestward over 1300 meters, and eastside of which is plain and a little sloping while westside of which cliffy and very steeper sloping. 2. A gyre was formed in the waters from Kori-Mal to Mat-dum in cum sole definitely at flood tide and in contra solem less definitely at ebb tide. And that the gyre rose and decayed with the turn of the tide. 3. Diffusion coefficients of 2.5% Rhodamine B solution of 200 liters were 9. 3 ${\times}{10^2}$ c$m^2$/sec in the waters Kori-Mal to Mat-dum and 28.6${\times}{10^2}$ c$m^2$/sec in the waters eastside of Mat-dum at the time after 26 minutes from releasing of the dye solution. 4. According to the above results the eastside of Mat-dum is rather recommendable to settle as the point for the outlet of drainage or waste of atomic power plant to be constructed.

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Seasonal Variation of Phytoplankton and Zooplankton Communities in the Coastal Waters off Tongyeong in Korea

  • Lee, Jin-Hwan;Chae, Jin-Ho;Kim, Won-Rok;Jung, Seung-Won;Kim, Jong-Man
    • Ocean and Polar Research
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    • 제23권3호
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    • pp.245-253
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    • 2001
  • To investigate the community structures and the their seasonal variation of phytoplankton and zooplankton, a study was conducted at 6 selected stations during the period from April 1999 to October 2000 in the marine ranching ground off Tongyeong. One hundred ninety species of phytoplankton were identified, including 146 diatoms, 38 dinoflagellates, 4 silicoflagellates and 2 euglenophytes. Phytoplankton standing crops varied extensively by months and stations, ranging from $3.0{\times}10^4\;cells/l\;to\;1.0{\times}10^6\;cells/l.$. The dominant species varied from the vertical distribution as well as seasonal changes. In April and July 1999, Skeletonema costatum and Ceratium fusus were predominant in both the surface and the bottom water columns. Leptocylindrus danicus was the dominant species in April and June 2000, and Thalassiosira spp. were also predominant in bottom waters in June 2000. Pseudonitzschia pungens and Chaetoceros spp. were the dominant species at both surface and near bottom waters in August and October 2000, respectively. Zooplankton abundance was comparatively high in April and July in 1999, and April, June, and October in 2000, but extremely low in November 1999. The density of dominant zooplankton was higher in 2000 than in 1999. Copepods were the most predominant group except for July 1999 when the bivalve larvae showed extremely high abundance. Acartia omorii and Oithona similis were the dominant or subdominant copepod species mainly in April 2000, and June/July, while O. davisae and O. plumifera had peaks in August and October 2000. Corycaeus affinis and Paracalanus sp. also showed higher peaks in April and June (or July), even though they occurred in all sampling time. Centropages abdominalis occurred abundantly only in April 1999. Oikopleura dioica, a gelatinous zooplankton, was another important zooplankton, showing high density in all samples except in July 1999.

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천수용 다기능 해양폐기물 수거시스템 개발(PART II : 시스템 구성 및 성능시험) (Development of Multi-purpose Marine Wastes Cleaning Systems for the Shallow Waters(PART II : System Development and Performance Evaluation))

  • 조용진;문일성;신명수;유정석;강창구
    • 한국해양환경ㆍ에너지학회지
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    • 제5권2호
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    • pp.62-67
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    • 2002
  • 본 연구는 '천수용 다기능 해양폐기물 수거시스템 개발(PART I 초기 개념설계)'의 후속연구로서, 천수용 다기능 해양폐기물 수거시스템의 시스템 구성 및 성능시험 결과에 대하여 논한다(조[2003]). 수거깊이 15미터 이내의 항내 침적폐기물의 수거를 위한 다관절 수거시스템과 100미터 이내의 예인식 수거시스템이 개발되었다(해양수산부[2001]). 다관절 수거시스템은 부유폐기물, 침적 잔여폐기물의 수거, 작업의 고효율화를 위한 스틸와이어커터 시스템도 포함이 되어 다기능화 되어있다. 이 시스템의 시제품을 제작하여 수심이 낮은 해역에서 실해역 시운전을 수행, 시스템의 성능검증을 수행하였다. 결과로서, 개발된 시스템은 안전하고 원활하게 작동되어 시스템의 타당성을 입증하였다.

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Variations in the downwelling diffuse attenuation coefficients in the northern South China Sea

  • Wang, Guifen;Cao, Wenxi;Yang, Dingtian;Xu, Dazhi
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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    • pp.905-908
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    • 2006
  • The diffuse attenuation coefficient for downwelling irradiance $(K_d({\lambda}))$ is an important parameter for ocean studies. Based on the optical profile data measured during three cruises in the northern South China Sea in autumn from 2003 to 2005, variations in the $K_d({\lambda})spectra$ were analyzed. The variability of $K_d({\lambda})$ shows much distinct features both in magnitude and spectra shape. The $K_d({\lambda})value$ are much higher in costal waters than that of open oceanic waters and the blue-to-green(443/555) ratios of $K_d({\lambda})$ tends to increases with the chlorophyll a concentration ([Chl a]) from open ocean to coastal waters. These characteristics can be explained primarily by the increasing of $a_{w+p}(433)/a_{w+p}(555)$ with [Chl a]. In the short waveband, the relation between $K_d({\lambda})-K_w({\lambda})$ and [Chl a] can be well described by a power law function, suggesting the large contribution of phytoplankton to the variations in $K_d({\lambda})$. As for the spectral model of the diffuse attenuation coefficient, there are good linear relationships between $K_d(490)$ and $K_d({\lambda})$ at other wavelengths, with the slope parameter and the intercept following linear functions within the spectral range $412{\sim}555$ nm. These variabilities of $K_d({\lambda})$ provided much useful information for us to study the bio-optical properties in the northern South China Sea.

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수위변화와 흐름효과를 고려한 파랑모델링 (Wave Modeling considering Water Level Changes and Currents Effects)

  • 엄호식;강태순;남수용;정원무
    • 한국해안·해양공학회논문집
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    • 제28권6호
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    • pp.383-396
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    • 2016
  • 본 연구에서는 파랑과 흐름이 공존하는 해역에서 수위변화 및 흐름효과 고려 유무에 대하여 파랑모델을 수행하여 그 결과를 비교하였다. 해수유동장은 RIAMOM 모델 결과를 적용하였으며 파랑모델은 SWAN모델을 적용하였다. 바람자료는 ECMWF, NCEP 및 JMA의 3가지에 대하여 관측자료를 비교적 잘 재현하는 JMA 자료를 적용하였다. 수치모의는 2016년 1월~8월까지 8개월간 수행하였으며, 각 경우에 대하여 관측자료와의 비교를 위하여 2.5 m이상의 고파랑 기간에 대해 파고변화를 검토하였다. 분석결과, 수심이 깊은 파랑관측부이 정점에서는 수위/흐름효과를 고려할 경우 파고변화가 크지 않게 나타났으나, 수심이 얕은 비교 정점에서는 수위/흐름효과의 고려 여부에 따라 5~10%의 유의미한 파고변화가 나타났다.

CORDEX-EA 지역기후모형이 모사한 한반도 주변해 기후평균 표층 바람 평가 (Evaluation of Climatological Mean Surface Winds over Korean Waters Simulated by CORDEX-EA Regional Climate Models)

  • 최원근;신호정;장찬주
    • 대기
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    • 제29권2호
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    • pp.115-129
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    • 2019
  • Surface winds over the ocean influence not only the climate change through air-sea interactions but the coastal erosion through the changes in wave height and direction. Thus, demands on a reliable projection of future changes in surface winds have been increasing in various fields. For the future projections, climate models have been widely used and, as a priori, their simulations of surface wind are required to be evaluated. In this study, we evaluate the climatological mean surface winds over the Korean Waters simulated by five regional climate models participating in Coordinated Regional Climate Downscaling Experiment (CORDEX) for East Asia (EA), an international regional climate model inter-comparison project. Compared with the ERA-interim reanalysis data, the CORDEX-EA models, except for HadGEM3-RA, produce stronger wind both in summer and winter. The HadGEM3-RA underestimates the wind speed and inadequately simulate the spatial distribution especially in summer. This summer wind error appears to be coincident with mean sea-level pressure in the North Pacific. For wind direction, all of the CORDEX-EA models simulate the well-known seasonal reversal of surface wind similar to the ERA-interim. Our results suggest that especially in summer, large-scale atmospheric circulation, downscaled by regional models with spectral nudging, significantly affect the regional surface wind on its pattern and strength.

인공어초어장의 어류 군집상과 어획량 변동 (Variations of Fish Community and Fish Density on Artificial Reefs)

  • 이정우;강영실
    • 한국수산과학회지
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    • 제27권5호
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    • pp.535-548
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    • 1994
  • 각 해역에 시설된 사각형, 반구형, 원통형 인공어초어장의 어류 군집상 및 어획량 변동을 조사하여 인공어초 모형에 대한 어종 친화성과 해역별 최대효과를 가져 올 수 있는 적정 어초모형에 대해 논의하였다. 1988년 5, 7, 9, 11월에 각 1회씩 삼중자망으로 어획조사를 실시하였으며, 어획된 어류는 종별로 분류하여 계수하였다. 인공어초어장에서 출현한 총 어종수는 45종이며 볼락류, 쥐노래미, 가자미류, 쥐치 및 말쥐치의 출현빈도가 높았다. 사각형 인공어초어장에서는 총 38종이, 원통형 인공어초어장에서는 총 31종이, 그리고 반구형 인공어초어장에서는 총 18종이 출현하였다. 해역별 주요 우점종은 대부분이 가자미류, 가오리류, 쥐치, 말쥐치, 쥐노래미, 볼락류와 같은 연안정착성 혹은 저서성, 암초성어류였으며 남해 외양만이 회유성 어종인 고등어가 최우점종이었다. 인공어초모형에 따라 저서성, 암초성, 회유성 어류의 조성률이 다르게 나타났다. 사각형 인공어초어장에서는 회유성어류의 조성률이 높은 반면 반구형 인공어초어장에서는 저서성 어류 및 부착생물을 주로 먹이로 하는 어류의 조성률이 높았다. 동해 중부연안을 제외한 전 해역의 인공어초어장중 사각형 인공어초어장에서 어획량이 가장 높았으며, 동해 중부연안은 원통형 인공어초어장에서 어획량이 가장 높았다. 인공어초모형별 어류 군집상은 사각형 인공어초어장과 반구형 인공어초어장은 서로 차이가 있으며, 원통형 인공어초어장은 이 두 인공어초어장의 중간적인 성격을 띤 군집상을 나타내었다. 또한 해역별로 보면 남해연안과 서해 남${\cdot}$중부연안의 군집상이 유사했고, 남해외양과 동해 남${\cdot}$중부연안의 군집상이 유사하였다./TEX>인 점을 고려하여 볼 때 수은 오염에 주의할 필요가 있음을 알 수 있었다. 6. 카드뮴의 어종별 96hr-LC50은 넙치 28.4mg/l, 숭어 2.55mg/l, 조피볼락 28.7mg/l으로 나타났다. 7. LAS의 96hr-LC50은 0.79mg/l이었고, 숭어에 대한 96hr-LC50은 0.06mg/l, 조피볼락 1.08mg/l으로 기수성 어류인 숭어의 내성이 매우 낮은 점이 특이하였다.치사하지 않으므로, 본 실험의 결과를 기초로 하여서 무수 수송 장치를 만들면 충분히 실용화가 가능할 것으로 생각된다.X>로 상당히 높게 나타났고, EPA, DHA 등 w3 계의 장쇄(長鎖)고도불포화지방산의 조성비가 $22.13\%$로 높게 나타났으며, 양적으로 많은 지방산은 포화산 중에는 palmitic acid($C_{16:0}$), monoene산 중에서는 palmitoleic acid($C_{16:1}$), polyene산 중에서는 hexadecatetraenoic acid($C_{16:4}$), eicosapentaenoic acid ($C_{20:5}$), docosahexaenoic acid($C_{22:6}$) 등이 함량이 많았다. Carotenoprotein으로부터 분리한 총 caroteoid 함량은 $8.80mg\%$였고, 주 carotenoid는 mytiloxanthin($74.79\%$), 3,4,3'-trihydroxy-7',8'-didehydro-${\beta}$-carotene($18.26\%$)였다

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