• Title/Summary/Keyword: Sea-water

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Oceanographic Conditions in the Neighboring Seas of Cheju Island and the Appearance of Low Salinity Surface Water in May 2000 (2000년 5월 제주도 주변해역의 해황 및 표층 저염분수의 출현)

  • KIM Sang Hyun;RHO Hong Kil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.37 no.2
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    • pp.148-158
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    • 2004
  • In the adjacent seas of Cheju Island, the oceanographic conditions show low salinity surface waters starting in May. This water flows from the southeast part of the China Coastal Water, which flows southeastward along the Great Yangtze Sand Bank until April, with the help of southeasterly winds and flows from the adjacent sea off Cheju Island. In May, the Tsushima Warm Current and the low salinity surface water fluctuate in short and long-term periods as influenced by Yellow Sea Cold Water, which flows to the bottom layer at the western entrance of Cheju Strait. Temperature and salinity fronts in the northeastern sea area of U Island are formed in the boundary area between the Tsushima Warm Current, which expands towards Cheju Island from the southeastern sea area of Cheju Island and Hows out from the eastern entrance of the strait. Seasonally, additional oceanographic conditions, such as coastal counter-currents, which flow southward, appears within limited areas in the adjacent eastern and western seas of Cheju Island.

Characteristics of the Visco-elastic Grout Material in Fresh and Sea Water (해수와 담수에서 점탄성을 갖는 그라우트재의 공학적 특성 평가)

  • Kim, Ukgie;Cho, Samdeok;Park, Bonggeun;Song, Byeongdeok;Kim, Juhyong
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.6
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    • pp.41-50
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    • 2012
  • In general, it is critical that grout consistency permit the complete filling of void space without segregation of ingredients. Recently, the antiwashout agent is used on underwater grout materials for preventing the grout from the segregation in water. This study introduces a new type of antiwashout underwater and flowable grout material using viscous modifiers and its characteristics comparing with conventional grout materials in fresh and sea water. It is found that the antiwashout underwater grout both in fresh and sea water has enough strength and good resistance to segregation.

Verification for applied water management technology of Global Seasonal forecasting system version 5 (확률장기예보GloSea5의 물관리 활용을 위한 검증)

  • Moon, Soojin;Hwang, Jin;Suh, Aesook;Eum, Hyungil
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.236-236
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    • 2016
  • 현재 댐운영 계획 수립 시 매월 유지해야 하는 저수량의 범위를 나타낸 기준수위가 사용되고 있으며 매년 홍수기 말에 현재의 수문 상황과 장래의 전망을 통한 시기별 연간, 월간 댐운영 계획을 수립하고 있다. 물관리의 이수측면에서 댐수위 운영계획 수립과 홍수기 운영목표 수위를 결정하는데 활용하기 위해서는 계절단위, 연단위의 기상정보가 필요하다. 본 연구에서는 기상청에서 운영하고 제공하는 전지구 계절예측시스템 GloSea5(Global Seasonal forecasting system version 5)자료를 활용하여 금강유역에 적용하고자 하였다. GloSea5는 전지구계절예측시스템으로 대기(UM), 지면(JULES), 해양(NEMO), 해빙(CICE)모델이 서로 결합되어 하나의 시스템으로 구성되어 있으며 공간 수평해상도는 N216($0.83^{\circ}{\times}0.56^{\circ}$)으로 중위도에서 약60km이다. Hindcast자료는 유럽중기예보센터(ECMWF)에서 생산된 ERA-Interim 재분석장을 대기 모델의 초기장으로 사용하며 기간은 1996~2009년의 총 14년이다. 예보자료의 검증은 예보의 질을 결정하는 과정으로 Brier Skill Score (BSS), Reliability Diagrams, Relative Operating, Characteristics (ROC)등을 통해 정확성과 오차에 의한 예보의 성능을 검증하였다. 또한 Glosea5의 통계적 상세화를 수행하여 다양한 변수가 갖는 계통적인 지역 오차를 보정함으로써 자료의 신뢰도를 향상시키고자 하였으며 이는 이후 수문모델과의 연계 시 보다 정확하고 효율적인 댐운영에 활용할 수 있는 기후예측정보를 제공할 수 있을 것으로 판단된다.

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A Study on the New Method for Water-Purification in a Semi-enclosed Bay (폐쇄성해역에 있어서의 새로운 수질개선책에 관한 연구)

  • Gug, S.G.
    • Journal of Korean Port Research
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    • v.12 no.1
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    • pp.95-104
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    • 1998
  • Water pollution in a semi-enclosed sea area such as a bay due to stagnancy of water has been a serious water environmental problem. Recently, some kinds of new methods to activate the tidal exchange between an inner bay and an outer sea area by control of a tidal residual current have been proposed. However, these methods have several problems, that is, I). deterioration in a natural view due to building of huge structures, II). increase of risk of navigation in case of a submerged structure, III). limition of sea area where a tidal current can be controlled and IV). difficulty in removing those structures in case of occurrence of an unexpected impact on water environment. In this paper, a new method is proposed, which can solve all the above problems, to purify water quality in a semi-enclosed bay by creation and control of a pattern of a tidal residual current. The tidal residual current is controlled by unsymmetric structures, which change the properties of resistance according to the direction of flow, arranged on the sea bottom. In this study, several numerical and hydraulic experiments of tidal current and particle-tracking for various arrangements of bottom roughness in a semi-enclosed model bay were carried out. As a result of experiments, it becomes clear that it is possible to generate a new tidal residual current and to activate a tidal exchange by only operation of bottom roughness arrangement.

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Usefullness of Mask Pack Sheets Including Marine Materials: Skin Regeneration Effect (해양소재를 이용한 마스크팩의 유용성 : 피부재생효과)

  • Park, Dae-Hwan;Park, Sang-Uk;Choi, Sung-Gon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.45 no.2
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    • pp.167-172
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    • 2012
  • Minerals from marine materials such as deep ocean water and Dead Sea water have been used since ancient times. We made a mask pack sheet including deep ocean water and salt from the Dead Sea and evaluated the function of the mask pack sheet through animal study. Three full-thickness skin defects were made on the backs of Sprague-Dawley rats. The wounds were left untreated in group Con, and mask pack sheets including deep ocean water or deep ocean water and Dead Sea water were used as treatment for 20 min on the skin of animals in groups DP and DDP, respectively. We analyzed the gross, histological and biochemical findings. Groups DDP and DP showed decreases in wound size, as compared to group Con at 7 days after wound infliction. The histological findings revealed that wound healing had progressed further in groups DP and DDP than in group Con, with more rapid collagen deposition and regression of neutrophils. Also, the expression of vascular endothelial growth factor and transforming growth factor ${\beta}1$ were increased in groups DDP and DP compared with those in group Con at 3 days after wound infliction. Mask sheet packs including deep ocean water and Dead Sea salt affected wound healing by reducing the inflammatory phase and stimulated wound contracture by facilitating the deposition of collagen.

The Seasonal Distribution Characteristics of Watermass and Fishery Creatures in the Adjacent Sea of Naro Island (나로도 주변해역의 수괴 및 어업생물의 계절별 분포특성)

  • PARK, Ju-Sam
    • Journal of Fisheries and Marine Sciences Education
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    • v.17 no.1
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    • pp.132-143
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    • 2005
  • In order to investigate the seasonal variation of watermass and fishery creatures in the adjacent sea of Naro Island, an oceanographic observation was carried out seasonally on the fishing grounds, and the sales performance data of the fisheries cooperative's joint market of Naro Island was examined by using a principal component analysis. The temperature and salinity ranged from 8.1 $^{\circ}C$ to 13.7 $^{\circ}C$ and from 33.1 psu to 34.3 psu in spring, from 14.5 $^{\circ}C$ to 24.2 $^{\circ}C$ and from 30.5 psu to 34.1 psu in summer, from 14.8 $^{\circ}C$ to 18.6 $^{\circ}C$ and from 30.1 psu to 34.0 psu in autumn, and from 4.3 $^{\circ}C$ to 10.1 $^{\circ}C$ and from 33.1 psu to 34.9 psu in winter, respectively. In winter and spring, the offshore water spread out to all sea areas of all water layers. In summer, the mixed waters covered the entire sea surface whereas the mixed water and offshore water covered the bottom. In autumn, the coastal water and mixed water appeared on the surface, but the mixed water was distributed widely on the bottom and the offshore water began to appear in the open sea. For two years from 2002 to 2003, 58 fishery creature species in total were sold in the fisheries cooperative's joint market of Naro Island. In general, the total of 50% fish were sold, and crustacea and mollusc by each 25%. Medium shrimp, whiparm octopus, blue crab, and octopus predominated. A number of species and biomass of fishery creatures were sold mostly in April and May, while they were sold the least in January and February. The seasonal sales results showed that mullet, angler, short necked clam, large shrimp, and webfoot octopus were sold mainly in spring, tonguefish, flathead, pomfret, glass eel, blue crab, whiparm octopus, and squid were sold mainly in summer, and octopus, medium shrimp, and spanish mackerel were sold mainly in autumn.

Long-term Variation and Characteristics of Water Quality in the Garolim Coastal Areas of Yellow Sea, Korea (가로림연안 수질환경의 특성과 장기변동)

  • Park, Soung-Yun;Kim, Hyung-Chul;Kim, Pyoung-Joong;Park, Gyung-Soo;Ko, Joen-Young;Jeon, Sang-Baek;Lee, Seung-Min;Park, Jong-Soo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.15 no.4
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    • pp.315-328
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    • 2009
  • Long-term trends and distribution patterns of water quality were investigated in the Garolim coastal areas of Yellow Sea, Korea from 1998 to 2007. Water samples were collected at 3 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids(SS), chemical oxygen demand(COD), dissolved oxygen(DO) and nutrients. Spatial distribution patterns were not clear among stations but the seasonal variations were distinct except pH and ammonia. The trend analysis by principal component analysis(PCA) during twenty years revealed the significant variations in water quality in the study area. Annual water qualities were clearly classified into 4 clusters by PCA; year cluster 1997, 1998 and 2000-2002, 1999 and 2003-2006/2008. By this multi-variate analysis the annual trends were summarized as follows; In recent years, salinity increased, whereas dissolved inorganic nitrogen, nitrate nitrogen and COD decreased and water quality generally continued to be in good condition in Gsrolim coastal areas without inflow of freshwater from land. Garolim coastal areas are required to be conserved continuously as important coastal areas for fisheries.

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The Use of National Names for International Bodies of Water: Critical Perspective (공해(公海)에 대한 국가지명 사용: 비판적 관점)

  • 알렉산더B.머피
    • Journal of the Korean Geographical Society
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    • v.34 no.5
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    • pp.507-516
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    • 1999
  • More than twenty-five major international bodies of water bear the names of particular nations or states. Many of these are not names are widely accepted, but considerable disagreement has developed in some cases. A systematic examination of the level of conflict over the use of national names for international bodies of water indicates that conflict is most likely to develop where shifting power relations among interested states produce concern about the hegemonic ambitions of the state after which the body of water is named. This is the case in the three situations where considerable contention exists over the use of a national name for an international body of water: the Persian Gulf/Arabian Sea, the Sea of Japan/East Sea, and the South China SealBien Dong. Cases evidencing little contention are those where either no state has a significant interest in the naming issue, or where the name that is attached to the body of water is that of a state that has not been a historic threat to others in the region. Naming international bodies of water after nations or states is potentially problematic because such appellations can connote ownership or control by a single people or political entity. An understanding of the controversies surrounding these place names requires consideration of the geopolitical context in which they are embedded.

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Effects of Deep Sea Water Treatment on the Inhibition of Over-Growth of Plug Seedlings (해양심층수 처리가 육묘 시 도장억제에 미치는 영향)

  • Kang Won-He;Hong Sung-Yu
    • Korean Journal of Organic Agriculture
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    • v.14 no.1
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    • pp.85-95
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    • 2006
  • The investigation of the effect of the deep sea water in different concentration (0%, 10%, 20%, 30%, 40%) on the inhibition of growth, fresh weight, dry weight of the tomato, hot pepper, cucumber plug seedlings were conducted. As the concentration of the deep sea water was higher, the greater inhibition was noticed. The height were decreased at the rate of 8%, 25%, 32% in tomato, 9%, 26%, 27% in hot pepper, and 21%, 50%, 58% in cucumber plug seedlings as compare to local check. The fresh weights were decreased highly, as the concentration of the deep sea water increased. Tomato seedlings showed the decrease rate of 12%, 23%, 33% at above the ground part of plants, and 2%, 30%, 52% at under the ground parts. Likewise, Hot pepper seedlings showed the decrease rate of 1.1%, 5.7%, 15.4% at above the ground part of plants, and 22.1%, 25%, 47.1%, respectively at under the ground parts. The fresh weight of cucumber was decreased at the rate of 8.1%, 36%, 51% in the above the ground, and 6.2%, 11%, 65% at the under the ground parts. In tomato, hot pepper, and cucumber seedlings, the dry weight was decreased as the concentration of deep sea water was increased. Thirty percent of deep sea water treatment reduced the dry weight of the seedlings as half of the control seedlings. One of the important factors of the seedling quality is compactness. Compactness was highest at 20% deep sea water in all the three crop seedlings.

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A Study on Estimation of Design Tidal level Considering Sea Level Change in the Korean Peninsula (한반도의 해수면 상승을 고려한 설계조위 산정에 관한 연구)

  • Choo, Tai Ho;Sim, Su Yong;Yang, Da Un;Park, Sang Jin;Kwak, Kil Sin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.4
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    • pp.464-473
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    • 2016
  • The air temperatures of the coast and inland are rising due to an increase in carbon dioxide emissions and abnormal climate phenomena caused by global warming, El Nino, La Nina and so on. The sea levels of the Earth are rising by approximately 2.0 mm per year (global average value) due to the thermal expansion of sea water, melting of glaciers and other causes by global warming. On the other hand, when it comes to designing a hydraulic structure or coastal hydraulic structure, the standard of the design water level is decided by analyzing four largeness tide values and a harmonic constant with the observed tidal water level or simulating numerical model. Therefore, the design tidal water level needs to consider an increasing speed of the seawater level, which corresponds to the design frequency. In the present study, the observed tidal water levels targeting 46 tidal stations operated by the Korea Hydrographic and Oceanographic Administration (KHOA) from the beginning of observations to 2015 per hour were collected. The variation of the monthly and yearly and increasing ratio were performed and divided into 7 seas, such as east and west part of the Southern Sea, south part and middle of the East Sea, south part and middle of the Western Sea, and Jeju Sea. The current study could be used to determine the cause of local seawater rises and reflect the design tidal water level as basic data.