• Title/Summary/Keyword: 延安

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Coastal Stratification Induced by Oceanographic Conditions of Open Sea in the East Sea on February, 2013 (2013년 2월 동해의 근해 해황에 의한 연안 성층)

  • Choi, Yong-Kyu;Kim, Sang-Woo;Jeong, Hee-Dong;Shim, Jeong-Min;Kwon, Kee-Young
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.4
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    • pp.327-333
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    • 2013
  • In order to see the stratification phenomenon in the coastal area induced by oceanographic conditions of the open sea, we analyzed the CTD (Conductivity-Temperature-Depth) data taken from the oceanographic survey on February 16~28, 2013. The stratification in Jukbyun coast was stronger than those of Sokcho and Gampo coast. Jukbyun line (104 line in the Serial Oceanographic Observation of National Fisheries Research and Development Institute) showed the anticyclonic eddy in the vertical distribution of temperature. The isotherm of $10^{\circ}C$ was concaved to the depth of 200 m in the middle station (station no. 9) of the line 104. It showed above $4^{\circ}C$ in positive temperature anomaly in the depth of 100~200 m in the middle station (station no. 9) of the line 104. This positive temperature anomaly was stretched to the coastal area with shallower depth. It is suggested that the stratification in Jukbyun coast was resulted from the onshoring of the Ulleung warm eddy. The movement of warm eddy may be act as a block to migration of cold water fishes like cod.

Empirical Study on the Performance Analysis and Function of Jindo Coastal Vessel Traffic Service (진도 연안VTS의 성과 분석 및 기능에 관한 실증적 연구)

  • Jeong, Jae-Yong;Jung, Cho-Young
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.18 no.4
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    • pp.308-315
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    • 2012
  • Hebei Spirit Oil Spill that happened in 2007 had prompted the need of revisiting the coastal safety. In response to this, Korea had made an effort to implement VTS in every coastline in the country. There are a lot of theoretical studies on VTS function nowadays, but coastal VTS are less frequently studied. In this paper, performance analysis results and accident prevention activities of Jindo Coastal VTS center were summarized and the Coastal VTS function are investigated. Jindo Coastal VTS covers relatively wide area and various places with various maritime traffic characteristics are the major navigation vessels, which means that it is important to control these vessels. Since the probability of accidents due to human error is relatively high in coastal area due to negligence tendency of crews during coastal area navigation, coastal VTS has to provide sufficient assistance to navigating vessels. Like most harbour VTS, Coastal VTS provides not only main information service, navigational assistance and traffic organization services but also various services related with advanced search-and-rescue assistance, marine national security, maritime crime prevention, oil spill response, traffic services for non-service vessel, and safety supervision for water leisure boats.

Numerical Experiments of Coastal Upwelling Occurred by Summer Winds in the East Sea of Korea (한국 동해 연안에서 하계 바람에 의해 발생하는 연안용승에 관한 수치실험)

  • Seo, Ho-San;Lim, Woo-Hyun;Kim, Dong-Sun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.4
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    • pp.347-353
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    • 2017
  • In this study, numerical experiments were conducted to identify distribution of rising flow and flux in the East Sea of Korea, where the coastal upwelling occurs. Temperature and salinity data from CTD observations and NIFS during summer 2013 were applied to the model. Numerical experiments were carried out with different wind speed (3, 6 m/s and 9 m/s) and direction (southerly and southwesterly), which represent the most frequent in summer conditions. As a result of calculation, upwelling flow rate was found to be highest in Pohang between five coasts(Hupo, Youngduk, Pohang, Ulsan and Busan). Comparing with southerly wind conditions, the rising flow rate is about 1.5 times greater when southwesterly wind was applied. Horizontal diffusion of the upwelling area is expected to have a speed of 17~22 km/day when a 9 m/s southwesterly wind is applied. If this wind continues over one week, a cold pool will be generated by upwelling that may reach to the Ulleung area.

The Assessment of Trophic State and the Importance of Benthic Boundary Layer in the Southern Coast of Korea (한국남부 연안의 영양상태 평가와 저층 경계면의 중요성)

  • 이재성;김기현;김성수;정래홍;박종수;최우정;김귀영;이필용;이영식
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.9 no.4
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    • pp.179-195
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    • 2004
  • The trophic state of the coastal waters of the southern part of Korea was assessed using biogeochemical data obtained from the National Marine Environmental Monitoring Program conducted by the National Fisheries Research and Development Institute for six years. The trophic state of different areas, analyzed by non-metric multi-dimensional scaling (MDS) analysis, could divide the areas into three groups. Masan Bay, with suboxic water masses and/or the highest concentrations of dissolved inorganic nitrogen and phosphorus occurred, was assessed as being in a hypertrophic state. Ulsan Bay, Onsan Bay, Busan and Jinhae Bay, located near strong point sources, were in a eutrophic state. Other areas, including Tongyong, Yosu, Mokpo and Jeju island, were evaluated as being in a mesotrophic state. During 1997 to 2002, the average values of excess nitrogen, which is the difference between the measured dissolved inorganic nitrogen (DIN) and the corrected DIN using the Redfield ratio, were positive at Ulsan, Onsan, and Busan, where there were inflows from polluted rivers. In contrast, those were negative values in Haengam Bay, Gwangyang Bay and nearby Yosu. This suggests that the limiting element for phytoplankton growth differed among sites. The time series data of excess nitrogen showed gradual decrease over time in the hypertrophic waters, but the opposite trend in the mesotrophic waters. This indicated that the ratio of nitrogen to phosphate varied according to the trophic state of the coastal waters. The enrichment of organic matter in sediment in eutrophic waters would disturb the normal pattern of biogeochemical cycling of nitrogen and phosphate. In order to assess the condition of the coastal environment, the benthic boundary layer should be considered.

A Basic Study of an Integrated Digital Map Generation to an Electronic Navigational Chart and a Digital Topographic Map for Coastal Development and Management (연안 개발 및 관리를 위한 육·해도 통합수치도 제작에 관한 기초연구)

  • Yi, Gi-Chul;Park, Chang-Ho;Kim, Jeong-Hee;Suh, Sang-Hyun;Jeong, Hui-Gyun;Choi, Joon-Young
    • Journal of the Korean Association of Geographic Information Studies
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    • v.2 no.1
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    • pp.1-11
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    • 1999
  • The Korean government is developing a systematic plan of integrated coastal management for effective conservation, utilization, and development of coastal areas. For this plan, integrated maps of land maps and nautical charts are indispensable. However, these maps are not made, nor studied yet in terms of integration, although digital maps(DM) on land and electronic nautical charts(ENC) have been recently developed by Korean Geography Institute and National Marine Investigation Institute, respectively. In this study, as preliminary studies to make eventual integrated maps, the concept of coastal areas are defined, specifically, coastal lines from DM and ENC are matched against each other. Issues on map production procedures, coordinate systems, and map projections, are carefully considered. A test coastal area located in Seo-Gu, Pusan, over 14 km of coastal lines is selected for the edge matching of coastal lines. RMS differences are 13.83 m and 4.37 m over man-made coastal lines and natural coast lines, respectively, which are quite larger considering a scale difference and other factors. However, no systematic differences are found.

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A Study on Generating a Coastal Flood Hazard Map Using GIS (GIS를 활용한 연안침수지도 제작에 관한 연구)

  • Won, Dea-Hee;Kim, Kye-Hyun;Park, Tae-Og;Choi, Hyun-Woo;Kwak, Tae-Sik
    • Journal of Korean Society for Geospatial Information Science
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    • v.12 no.1 s.28
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    • pp.69-77
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    • 2004
  • Since there are a lot of changes in climate on domestic and natural disasters owing to the disturbance-development of the land, damages of properties and human life frequently occur due to the coastal floodings. Accordingly, it is necessary to find the area where the danger of flooding coasts is relatively high and to inform resident the characteristics of the area As a part of preventive land management to minimize the flooding damages of the coastal area, this study suggested the generation of the coastal flood hazard map that provides detailed information such as refuge path, a place of refuge, and the location of medical supplies, food, and main rescue equipment, etc. This study selected the southern region of Daebu-do as an exemplary area, conducted a document study to establish GIS data, secured pre-structured data, and suggested the method of establishing GIS data fit to the study area. In particular, it emphasized the efficient construction of the geographical spatial data that were accurate, economic, objective, and realistic in supporting the modeling to predict the flooding zone. The specific type of established database was divided into flooding risk area, flooding warning area, and flooding-volume area. The prototype of coastal flood hazard map can be widely used for efficient disaster management. Furthermore, it is considered that the map could be applied for arousing residents' attentions to the flooding, prior education, and local governments' management actions against the danger of flooding.

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Current Status of Hyperspectral Data Processing Techniques for Monitoring Coastal Waters (연안해역 모니터링을 위한 초분광영상 처리기법 현황)

  • Kim, Sun-Hwa;Yang, Chan-Su
    • Journal of the Korean Association of Geographic Information Studies
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    • v.18 no.1
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    • pp.48-63
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    • 2015
  • In this study, we introduce various hyperspectral data processing techniques for the monitoring of shallow and coastal waters to enlarge the application range and to improve the accuracy of the end results in Korea. Unlike land, more accurate atmospheric correction is needed in coastal region showing relatively low reflectance in visible wavelengths. Sun-glint which occurs due to a geometry of sun-sea surface-sensor is another issue for the data processing in the ocean application of hyperspectal imagery. After the preprocessing of the hyperspectral data, a semi-analytical algorithm based on a radiative transfer model and a spectral library can be used for bathymetry mapping in coastal area, type classification and status monitoring of benthos or substrate classification. In general, semi-analytical algorithms using spectral information obtained from hyperspectral imagey shows higher accuracy than an empirical method using multispectral data. The water depth and quality are constraint factors in the ocean application of optical data. Although a radiative transfer model suggests the theoretical limit of about 25m in depth for bathymetry and bottom classification, hyperspectral data have been used practically at depths of up to 10 m in shallow and coastal waters. It means we have to focus on the maximum depth of water and water quality conditions that affect the coastal applicability of hyperspectral data, and to define the spectral library of coastal waters to classify the types of benthos and substrates.

Study on the Fairway Used by Coastal Passenger Ship at Mokpo Port (목포항 입출항 연안여객선의 이용 항로에 관한 고찰)

  • Lee, Li-Na;Lee, Hong-Hoon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.4
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    • pp.525-532
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    • 2022
  • The port of Mokpo operates the largest number of coastal passenger ships and routes in Korea. These coastal passenger ships pass through narrow channels in the south-west coast of Korea owing to the geographical effect. It is difficult to find a research for the safety of the marine traffic environment in the narrow channel used by coastal passenger ship. Therefore, in this study, the navigation safety of the target coastal passenger ship was analyzed in the narrow channel near the port of Mokpo using the Korea design standard for port and harbour facilities. As a result of the analysis, the width of the narrow channel between Maek-island and Dali-island is narrower than 1.5 times of the target ship's length over all, the degree of curvature of the narrow channel exceeds the standard value of 30°, and several fishing gears exist near the narrow channel. Finally, the following were suggested to improve the safety of navigation on the narrow channel: keeping one-way traffic during the day-time, and navigating through the designated fairway during night·visibility restriction·low tide.