• Title/Summary/Keyword: 延安

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Effect of El Niño and La Niña on the Coastal Upwelling in East Sea, South Korea (엘니뇨와 라니냐가 한국 동해 연안용승에 미치는 영향)

  • Seo, Ho-San;Kim, Dong-Sun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.1
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    • pp.75-83
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    • 2020
  • This study investigated the effects of El Niño and La Niña on coastal upwelling in the East Sea of Korea using long-term (1967-2017) water temperature observation data and Oceanic Niño Index (ONI). As a result of time series analysis of water temperature, the occurrence frequency of summer coastal upwelling was the highest in the southeastern (Ulgi ~ Gimpo) coast. In 1987-1988 and 1997-1998, when the annual fluctuations of ONI plunged more than 2.5, the water temperature in whole coast areas of the East Sea (Busan ~ Goseung) rose by 4 ~ 7 ℃. The temperature structure of the East Sea coastal water was different when El Niño was strong with ONI above 1.5 and La Niña with strong ONI below -0.8. When El Niño is strong, the water temperature anomaly in coastal waters is negative. This is due to the strong baroclinic tilting and the formation of shallow temperature stratification in the coastal waters. The strong La Niña season is opposite to the strong El Niño season, whereas the water temperature anomaly is positive. In addition, the baroclinic tilting is weaker than the time of strong El Niño and the temperature stratification is formed deeper than the time of strong El Niño. The formation of temperature stratification at shallow depths when El Niño is strong can increase the probability of occurrence coastal upwelling caused by southerly winds in the summer season. On the contrary, when La Niña is strong, occurrence of coastal upwelling is less likely even if the southerly wind blows continuously. This is because the temperature stratification is formed at deeper than when El Niño is strong.

A Study on the Competitiveness Improvement of Coastal Shipping for Northeast Asia Logistics-Hub (동북아(東北亞) 물류거점화(物流據點化)를 위한 연안해운(沿岸海運) 경쟁력(競爭力) 제고방안(提高方案)에 관(關)한 연구(硏究))

  • Lee, Yon-Jae;Ahn, Ki-Myung;Kim, Kwang-Hee;Kim, Hyun-Duk
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.29 no.1
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    • pp.441-449
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    • 2005
  • The purpose of this research is to present the improvement measure of lagging behind coastal shipping system to be a logistic hub-nation with a competitive edge. For this purpose, this research tries to find out major northeast asia environment factors and accordingly the effects of its. The effects of coastal shipping system's development strategy is analysed by structural equation model and multiple regression model. Research results show that three types of coastal shipping developing strategy(connected transportation system, structure of coastal shipping system, governmental support policy) will contribute much to be logistic hub-nation. The contribution effects is increasing cargo from strengthened feeder transport system and maximizing logistic service &minimizing logistic costs. From the result, some implications are derived as follow. First, familiar environmental balanced ocean-coastal transport system is required. Second the one-stop logistic service system is necessary to build excusive feeder port, and to establish Ro-Ro ship & high-speed ship, etc.. Third, governmental support policy and subsidy(tax exempted oil & various tax benefits) are required to bring up lagging behind coastal shipping system to be a logistic hub-nation with a competitive edge.

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Seasonal Changes in Water Masses and Phytoplankton Communities in the Western Part of South Coastal Waters, Korea (남해 서부연안의 수괴 및 식물플랑크톤 군집의 계절적 변동)

  • Jung, Seung Won;Park, Jong Gyu;Jeong, Do Hyun;Lim, Dhongil
    • Korean Journal of Environmental Biology
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    • v.30 no.4
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    • pp.328-338
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    • 2012
  • We investigated seasonal changes in the marine environments and phytoplankton communities in the western part of south coastal waters of Korea during May 2009 and February 2010. In multidimensional scaling analysis of in situ data obtained by shipboard observations, the coastal waters comprised four different water masses: Yellow Sea water mass (YW) of low temperature and salinity, and high suspended solids and nutrient concentrations; south-western coastal water mass (SW) of high salinity and nutrient concentrations; Tsushima Current water mass (TW) of low nutrient concentrations, and high temperature and salinity; and closed bay water mass (CW). The spatial extent of these water masses varied according to seasonal environmental characteristics. In particular, at most study sites, TW expanded during autumn toward coastal waters. Phytoplankton abundances peaked during autumn in CW and spring in YW, which coincided with periods of high nutrient concentrations. In particular, diatoms predominated, and attained an abundance of more than 90% in most water masses. However, dinoflagellates in TW comprised a proportion of approximately 20% abundance.

Developing Coast Vulnerable Area Information Management System using Web GIS (Web GIS를 이용한 연안위험취약지역 정보시스템 구축)

  • Pak, Hyeon-Cheol;Kim, Hyoung-Sub;Jo, Myung-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.4
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    • pp.155-164
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    • 2005
  • The coast has been known as very vulnerable area. This area has nature disasters such as typhoon, tidal wave, flood and storm almost every year. In this study, coast vulnerable area information management system was developed to manage the coastal facilities and vulnerable area through Web GIS. This system is able to visualize the damage area and support the official work related to coast as efficient DSS(Decision Supporting System). Moreover, the foundation for domestic coast information management is expected by acquiring less cost and time. For this, GIS DB was first constructed by acquiring damage factor data such as typhoon, tidal wave, flood and storm. Then GIS analysis methods and high resolution satellite images are used to possibly present the results of retrieve as table, map, graph, inundation simulation in real time.

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The Characteristics of Coastal Zone Management Methods in U.S.A -Focus on Zoning & Integrated Methods of Different Kind Data- (미국 연안구역(Coastal Zone) 관리수단의 특성 -조닝방식과 이종 데이터 간 통합방법을 중심으로-)

  • Oh, Ji-Hoon;Lee, Seok-Hwan;Lee, Hee-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.9
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    • pp.3590-3598
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    • 2010
  • It is necessary to collect the coastal zone data, to prepare the objective analysis methods, and to build the scientific and technical support system for the efficient management of coastal zone in local aspect. This study analyzes the coastal zoning methods and the integrated methods of different kind data by case study of U.S.A coastal zone. The characteristics of coastal zone management methods in U.S.A are as follows; the concrete indices and methods of establishing coastal zone which can respond to the local values and land use, related data analysis methods for supporting spatial decision making, and establishment and administration of bureau for the spatial information construction and integration of coastal zone. This study suggest the technical implications which can build the domestic coastal zone management in local level on the basis of the common values of the coastal zoning methods and integrated methods of heterogeneous data in U.S.A.

Characteristics of Wave Attenuation with Coastal Wetland Vegetation (연안 습지식생에 의한 파랑감쇠 특성)

  • Lee, Seong-Dae
    • Journal of Wetlands Research
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    • v.18 no.1
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    • pp.84-93
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    • 2016
  • As a transition region between ocean and land, coastal wetlands are significant ecosystems that maintain water quality, provide natural habitat for a variety of species, and slow down erosion. The energy of coastal waves and storm surges are reduced by vegetation cover, which also helps to maintain wetlands through increased sediment deposition. Wave attenuation by vegetation is a highly dynamic process and its quantification is important for understanding shore protection and modeling coastal hydrodynamics. In this study, laboratory experiments were used to quantify wave attenuation as a function of vegetation type as well as wave conditions. Wave attenuation characteristics were investigated under regular waves for rigid model vegetation. Laboratory hydraulic test and numerical analysis were conducted to investigate regular wave attenuation through emergent vegetation with wave steepness ak and relative water depth kh. The normalized wave attenuation was analyzed to the decay equation of Dalrymple et al.(1984) to determine the vegetation transmission coefficients, damping factor and drag coefficients. It was found that drag coefficient was better correlated to Keulegan-Carpenter number than Reynolds number and that the damping increased as wave steepness increased.

A Study on the reinvigoration strategy for Coastal Passenger Service: focused on the main service line at Tongyoung (연안여객선관광사업의 활성화 방안에 관한 연구 - 통영지역 주요항로를 중심으로 -)

  • Ahn, Ki-Myung;Kim, Hyun-Duk;Lee, Sung-Yhun
    • Journal of Korea Port Economic Association
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    • v.24 no.1
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    • pp.11-22
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    • 2008
  • This paper aims at investigating the reinvigoration strategy for main coastal passenger service line in Tongyoung. SWOT analysis and BCG matrix are used to sort out the their competitiveness as environmental market position. As a result of environmental situation, Tongyoung area has a positive internal and external competitive advantage, with strong land and sea tourist attractions. But a small-scale coastal passenger service firms and depression of local economy are represented as the barrier of attracting more passenger. The results of BCG matrix analysis are individual firms managing coastal passenger service in Tongyoung have a stable market position against Korean coastal passenger market in terms of market growth rate and share.

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A Study on Geo-Ontological Application of Coastal Information (연안정보의 지오-온톨로지 적용에 관한 연구)

  • Kang, Jeon-Young;Hwang, Chulsue
    • Journal of the Korean Geographical Society
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    • v.48 no.1
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    • pp.112-127
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    • 2013
  • It is unsuitable for Korean coastal information to work specific tasks because the coastal information of the current provides simple information, and thus the coastal information is required to reprocess. Therefore, this paper intends to present the ontology model for managing the coastal information using Geo-Ontology and seek application of ontology. The contents of this paper follow as; First of all, I considered the base theories for ontology and related researches. Second, I built Geo-Ontology which defines taxonomy of geographical features and their relationships. Third, I designed and implemented the coastal information ontology about basin of coast, Masan, using Geo-Ontology. Fourth, I carried out semantic queries and reasoning, assessment of the coastal information ontology. This paper will be a base study for many projects which are currently being conducted to integrate spatial information for more effective administrative works and easier maintenance and management of data. Also, this paper is significant in the sense that it is the study preparing for linked data.

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Seasonal Variation in Species Composition of Demersal Fish in the Coastal Water off Uljin and Hupo in the East Sea of Korea in 2002 (2002년 동해 울진과 후포 연안 저어류 종조성의 계절 변동)

  • Lee, Tae-Won
    • Korean Journal of Ichthyology
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    • v.23 no.3
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    • pp.187-197
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    • 2011
  • Fish species composition and size frequency distribution of major species were analyzed using seasonal samples collected by an otter trawl in the coastal water off Uljin and Hupo in 2002. Fish collected during the study were 20 species, 1,927 individuals and 53,969 g off Uljin, and 23 species, 2,762 individuals and 146,550 g off Hupo. Liparis tessellatus, Glyptocephalus stelleri and Cleisthenes pinetorum were predominated in abundance, and these 3 species were accounted for 70.9% in the number of individuals and 83.8% in biomass off Uljin, and 90.3% and 70.9% off Hupo, respectively. In the Korean coastal water of the East Sea, the migrating pelagic fish were predominated in catch by set net or gill net, and species composition varied greatly by season. Meanwhile, the fish collected by an otter trawl in the coastal water off Uljin and Hupo were dominated by the resident demersal fishes and did not show any clear seasonal trend in species composition. Collected G. stelleri and C. pinetorum were mainly composed of young fish, and size data as depth indicated that they moved into deeper shelf as they grew.