• Title/Summary/Keyword: Coastal Zone

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Basic Marine Environmental Characteristics of Suspended Sediments in the Inner Shelf Zone off Tae-An Peninsula, West Coast of Korea (한반도 서해 태안반도 연근해 부유퇴적물의 기초 해양환경적 특성)

  • 최진용;박용안
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.1 no.1
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    • pp.46-54
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    • 1996
  • A study on the concentrations of total suspended matters (TSM) and their distribution pattern was conducted off the west coast of Tae-An Peninsula during the spring season. Especially non-destructive and fine-tuned analysis for the size-distribution of suspended matters was made using SPECTREX instrument. Water masses were characterized by the typical tidal front, with vertically homogenous coastal waters and the strong thermoclines on the offshore area. Concentrations of suspended matters were generally less than 10 mg/l, but the concentrations increased up to 25 mg/l at the bottom waters and mid-depth waters. Mean particle size of the suspended matters were generally 5-6$\mu\textrm{m}$ and 8-10$\mu\textrm{m}$ for the fine-grained suspended matters and the coarse-grained suspended matters, respectively. They are considered to be composed dominantly of detrital materials. On the coastal area, landward side of tidal front, bottom sediments can be easily resuspended by the strong tidal currents, and therefore, deposition of suspended materials are thought to be rather limited. On the offshore area, however, suspended sediments mostly supplied from the northern part of the present study area near Kyunggi Bay are thought to be transported southward and/or southwestward along the mid- depth layer of strong thermocline.

Change of Nearshore Random Waves in Response to Sea-level Rise (해수면 상승에 따른 연안 지역 불규칙파의 변화)

  • Cheon, Se-Hyeon;Suh, Kyung-Duck
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.25 no.4
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    • pp.244-254
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    • 2013
  • In this study, a method has been developed for estimating the change of nearshore random waves in response to sea-level rise, by extending the method proposed for regular waves by Townend in 1994. The relative changes in wavelength, refraction coefficient, shoaling coefficient, and wave height for random waves are presented as functions of relative change in water depth. The changes in wavelength and refraction coefficient are calculated by using the significant wave period and principal wave direction in the regular-wave formulas. On the other hand, the changes in shoaling coefficient and wave height are calculated by using the formulas proposed for shoaling and transformation of random waves in the nearshore area including surf zone. The results are proposed in the form of both formulas and graphs. In particular, the relative change in wave height is compared with the result for regular waves.

An Analytical Solution of Progressive Wave-Induced Residual Pore-Water Pressure in Seabed (진행파동장하 해저지반내 잔류간극수압의 해석해)

  • Lee, Kwang-Ho;Kim, Dong-Wook;Kim, Do-Sam;Kim, Tae-Hyung;Kim, Kyu-Han;Ryu, Heung Won
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.3
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    • pp.159-167
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    • 2015
  • In this paper, the errors found in the existed analytical solutions described the mechanism of residual pore-water pressure accumulation were examined and a new analytical was proposed. The new analytical solution was derived by using a Fourier series expansion and separation of variables was verified by comparison with the existed both analytical and numerical solutions and experimental result. The new analytical solution is very simple that there is no need for numerical integration for deep soil thickness. In addition, the solutions of the residual pore-water pressure for finite, deep, and shallow soil thickness reveled that it is possible to approach from finite to shallow soil thickness, but not possible to deep soil thickness because there was discontinues zone between finite and deep soil thickness.

Paleoenvironmental Research Using Diatoms from Core Sediments in the Heuksan Mud belt, Korea (흑산 니질대 코어퇴적물에서 산출된 규조를 이용한 고환경 연구)

  • Bak, Young-Suk;Chang, Tae Soo
    • Journal of the Korean earth science society
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    • v.37 no.6
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    • pp.325-331
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    • 2016
  • Three diatom assemblage zones were erected from HMB-103 core sediment of the Heuksan Mud Belt. The paleoenvironmental changes were reconstructed basing on diatom analyses using indicator species, cold and warm water species, and salinity. Seventy-six species belonging to 41 genera were identified in the core sediments. The number of diatom valves per gram of dry sediment ranged from 0.1 to $15.4{\times}10^4g^{-1}$. As a result, diatom assemblage I in about 45,000 yr B.P showed a high abundance in cold species indicating a major influence by the Korea Coastal Current. Diatom assemblage II from 14,000 to 11,646 yr B.P is characterized by rare abundance and indicative of the cold periods at Younger Dryas with the lower sea-level. However, diatom assemblage III from 11,646 yr B.P to Holocene was more affected by the Yellow Sea Warm Current while the progressive sea level rise.

Analysis of 3 Dimension Topography by Real-Time Kinematic GPS Surveying (RTK GPS 측량에 의한 3차원 지형 해석)

  • 신상철;서철수
    • Spatial Information Research
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    • v.9 no.2
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    • pp.309-324
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    • 2001
  • To apply the real-time kinematic GPS surveying technique, this research has tried to obtain the TOKYO datum first from the continuous reference stations distributed all over the country. Then, analysis of the geography of a coastal area including both of land and sea has been carried out by the post-processed continuous kinematic GPS technique and the real-time kinematic GPS surveying technique. After considering the initial conditions and measuring time zone for real-time kinematic GPS, post-processed and the real-time kinematic GPS measurements have been carried out. A new system has been proposed to store measured data by using a program developed to store GPS data in real time and to monitor the satellite condition through controller simultaneously. The accuracy of GPS data acquired in real time was as good as that acquired by post processing. It is expected that it will be useful for the analysis of coastal geographic characteristics because DTM can be also constructed for the harbor reclamation, the dredging and the variation of soil movement in a river.

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Evaluation of the new coastal protection scheme at Mamaia Bay in the nearshore of the Black Sea

  • Niculescu, Dragos M.;Rusu, Eugen V.C.
    • Ocean Systems Engineering
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    • v.8 no.1
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    • pp.1-20
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    • 2018
  • The target area of the proposed study, Mamaia beach, is a narrow stretch of sand barrier island that sits between the Siutghiol Lake and the Black Sea. In the northern part of the bay, is located the Midia Port, where between 1966 and 1971 a long extension of 5 km of the offshore was built. Because of this extension, the natural flow of sediments has been significantly changed. Thus, the southern part of the Mamaia Bay had less sand nourishment which meant that the coast was eroding and to prevent it a protection of six dikes was built. After approximately forty years of coastal erosion, the south of the Mamaia Bay had in 2016 a new protection scheme, which includes first of all the beach nourishment and a new dike structure (groins scheme for protection) to protect it. From this perspective, the objective of the proposed study is to evaluate the effectiveness of the old Master plan against the new one by modeling the outcome of the two scenarios and to perform a comparison with a third one, in which the protection dikes do not exist and only the artificial nourishment has been done. In order to assess the wave processes and the current patterns along the shoreline, a complex computational framework has been applied in the target area. This joins the SWAN spectral phase averaged model with the 1D surf model. Furthermore, new UAV technology was also used to map out, chart and validate the numerical model outputs within the target zone for a better evaluation of the trends expected in the shoreline dynamics.

The Lichen Flora of Oases of Continental Antarctic, and the Ecological Adaptations of Antarctic Lichens

  • Andreev, Mikhail
    • 한국균학회소식:학술대회논문집
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    • 2006.10a
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    • pp.24-28
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    • 2006
  • Author have studies lichen flora of the most important ice-free areas of Continental Antarctic: Bunger Hills, and the vicinity of Prudz Bay (Larsemann Hills, and Radok Lake in Prince Charles Mountains). Totally 44 lichen species from 22 genera were reported for Bunger Hills and 50 lichen species from 22 genera and 10 families: Acarosporaceae, Lecanoraceae, Lecideaceae, Parmeliaceae, Pertusariaceae, Physciaceae, Rhizocarpaceae, Stereocaulaceae, Theloschistaceae, and Umbilicariaceaewere reported for the Prudz Bay Region. 20 lichen species were found in the region for the first time. Phytogeographic analysis indicated a relatively high proportion of species with bipolar distribution - about 50% of recorded lichen species. About 30% of lichens normally don't extend into maritime zone occurring in continental Antarctic only. The most common lichen families in the region are Buelliaceae, Lecanoraceae and Teloschistaceae. The water supply and not a temperature is the critical factor for lichens in the Continental Antarctic. Moisture appears to be supplied for lichens not only from snow-melt water but mainly from air. In Maritime Antarctic, due to high air humidity macrolichens form communities everywhere (Himantormia, Usnea and Umbilicaria). In oases of Continental Antarctic extensive sites are lacking in lichen cover, even if the ground is normally snow free. Lichens occur at humid sites with moisture which were brought by winds over the ice cap and poorly developed or absent in dry areas. Of particular significance for lichens are substrate characteristics, animals influence and salinity brought by wind in coastal areas. Most rich lichen vegetation developed in oases around nests of snow petrels, where the melt water is enriched by nutrients. In contrast, the most pure vegetation is on mobile sand and gravel and in salted coastal habitats.

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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.

On the primary productivity in the southern sea of korea (한국남해역(韓國南海域)의 일차생산력(一次生産力))

  • CHUNG, CHANG-SOO;YANG, DONG-BEOM
    • 한국해양학회지
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    • v.26 no.3
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    • pp.242-254
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    • 1991
  • Southern sea of Korea was investigated for primary productivity during four scientific cruises of Korea Ocean research and Development Institute. Frontal structure appeared to be an important physical characteristic in enhancing the phytoplankton production in the study area. Relatively high productivity was occurred near the front between Tsushima Warm Current Water and Coastal Waters of China continent in March 1990 and in November 1989, and near the front between Tsushima Warm Current Water and Korean coastal Water in April 1989. In August 1988 high productive zone was limited to the tidal front off the southwestern coast of Korea. Nutrient supply related to the frontal structure might play a dominant role in increasing the primary productivity but mechanisms of nutrient enrichment are not clear. Average column productivity showed its maximum in April 1989 (1727 mgC/m$^2$/day). In the costal Waters of the china Continent incident light may be an important factor in regulating the regulating the phytoplankton production because of low light penetration rate resulting from high turbidity.

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The Future Tasks for Reorganization of International Fisheries Order between Korea, China and Japan in Northeast Asian Seas (동북아 수역의 신 어업질서 성립과 향후 과제)

  • Kim, Dae Young
    • Ocean policy research
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    • v.33 no.2
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    • pp.57-82
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    • 2018
  • This study aimed to review the reorganization of fisheries and the future tasks in accordance with the establishment of new fishery order in the Northeast Asian Seas. As the United Nations Convention on the Law of the Sea, which recognized the sovereign rights of Coastal States in a 200-nautical mile exclusive economic zone (EEZ), entered into force in 1994, the three countries of Korea, China and Japan ratified the United Nations Convention on the Law of the Sea in 1996 and started negotiations to establish a new fishery order consistent with the EEZ system. However, a conflict of interest occurred because of differences in fisheries between countries, negotiations many times have proceeded, resulting in the signing of fishery agreement between China and Japan in 1997, Korea and Japan in 1998, and Korea and China in 2000. Each fishery arrangement consists of a dual system of EEZ and provisional waters (middle waters, provisional waters). The two countries are engaged in mutual fishing based on coastal states in EEZ, and in the fishing operation under the principle of flag state in provisional waters. There are overlapping or ambiguous jurisdictions in the intermediate waters and provisional waters that are jointly available to both fisheries. The presence of these seas is a challenge to the establishment of a reasonable international fisheries management system for the entire Northeast Asian Seas. In this context, the challenges of the reorganization of the new fisheries order are as follows: 1) conversion to a fishery order for coexistence of fisheries, 2) expansion to an international fishery management system, and 3) establishment of a multilateral fishery cooperation system. Although the jurisdiction of their own waters has been expanded through the establishment of EEZ according to new fishery order, the need for mutual cooperation grows when considering the movement and migration of fishery resources, fishery management, fish consumption and trade. In addition to the fisheries cooperation between the governments, it is also necessary to revitalize the civil cooperation focused on fishermen who exploit fishing grounds together.