• Title/Summary/Keyword: coastal sea

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Coastal Forest Construction and Non-Structural Measures for Preventing Tsunami Damage - In Case of Japan - (쓰나미에 대비(對備)한 해안림(海岸林) 조성(造成)과 비구조물(非構造物) 대책(對策) - 일본(日本)의 사례(事例)를 중심(中心)으로 -)

  • Chun, Kun-Woo;Kim, Suk-Woo;Kim, Keong-Nam;Nakashima, Yuhki;Ezaki, Tsugio
    • Journal of Korean Society of Forest Science
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    • v.94 no.3 s.160
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    • pp.197-204
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    • 2005
  • This study was conducted to investigate the effect of tsunami which occurred in coastal area of the East Sea in Korea, the function of coastal forest for the reduction of tsunami's speed and energy, and the non-structural measures through the research data of tsunami in Japan. The results showed that tsunami which occurred in the East Sea in 1983 and 1993 reached coastal area of Korea one hour and fifty minutes later from Japan, and caused a loss of lives and property and flooding damage. If 60 m width of coastal forest was formed, the speed was decreased by 30%, the energy by 10%. Therefore, the width of coastal forest must be at least 60 m, of which the stand structure is the multiple-layered forest of mixed-forest, and the wave preventing measures have to be constructed together. In addition, non-structural measures as tsunami warning and survival strategies must be prepared.

Distribution And Abundance Of Copepods In The Gulf Of Alaska And The Bering Sea In Summer 1978 (하계(夏季) Alaska만(灣)과 Bering해(海)의 Copepods의 분포조성(分布組成))

  • Lee, Sam Seuk
    • 한국해양학회지
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    • v.15 no.1
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    • pp.17-33
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    • 1980
  • The materials were obtained in the eastern Gulf of Alaska and the south- eastern Bering Sea during the cruise of the research vessel, Ohdae San, from July to October 1978. A total of 76 samples were taken by NORPAC net from a depth of 200 meters or less in coastal areas. 1. The surface water temperature in the coastal waters, varing from 9 to 10$^{\circ}C$, was lower than that in offshore waters which varied from 10 to 12.9$^{\circ}C$ in the eastern Gulf of Alaska. Thermocline was formed in the 30∼50 meter layer. Salinity of the coastal waters of Kenai Peninsula and Kodiak was 30 which was slightly lower than that of offshore. 2. The water temperature of the surface layer down to 30 meters varied from 7 to 10$^{\circ}C$ and from 1 to 9$^{\circ}C$ in the layer below 30 meters in the south-eastern Bering Sea. Meandering thermal front spread from the Alaska Peninsula to St. Matthew Island by way of St. Paul, and a thermocline was found at the 30∼50 meter layer Salinity ranged from 31.0 to 33.0 and that of northern and coastal waters was little lower than that of offshore. 3. Zooplankton biomass fluctuated from 0.1 to 23.6cc/10㎥ in the eastern Gulf of Alaska and 2.0 to 26.1cc/10㎥ in the south-eastern Bering Sea. Plankton was rich in the following areas, the inshore Kodiak waters, the northern Bering Sea, the Coastal waters and waters adjacent to Alutian islands however, poor in the central Bering Sea. In general, the south-eastern Bering Sea has a higher concentration of plankton volume than the eastern Gulf of Alaska. 4. Twenty three species representing 17 genera of copepods were identified from the samples. These were mostly composed of the cold water species, such as Pseudocalanus minutus, Acartia longiremis, Metridia lucens and Eucalanus bungii var. bungii. 5. The cold oceanic species were composed of Calanus cristatus, C.plumchrus, Metridia lucens, Eucalanus bungii var. bungii and Scolecithricella minor. The cold neritic species were Centropages abdominalis, Pseudocalanus minutus, Acartia longiremis, Eurytemora herdmanii, Pontella pulvinata, P. longipedata and Tortanus discaudatus. On the other hand, the warm oceanic species were Calanus tenuicornis and Oithona plumifera. The cosmopolitan species were Calanus finmarchicus and Oithona similis. 6. It was suggested that the cold oceanic species, Eucalanus bungii var. bungii and Metridia lucens in the south-eastern Bering Sea can be recommended as a valuable indicator species for finding the fishing grounds of demersal fish such as pollock and yellowfin sole in this area.

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A Study on Sea Water and Ocean Current in the Sea Adjacent to Korea Peninsula - Expansion of Coastal Waters and Its Effect on Temperature Variations in The South Sea of Korea - (한반도 근해의 해류와 해수 특성 -남해연안수 확장과 수온변화-)

  • NA Jung-Yul;HAN Sang-Kyu;CHO Kyu-Dae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.23 no.4
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    • pp.267-279
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    • 1990
  • The temporal and spatial distribution of the coastal cold waters which was formed due to winter colling in the South Sea of Korea was analyzed by IR images from satellite and in situ data from shipboard observations. The coastal waters are known to be consisted of the Yellow Sea Coastal Waters(YSCW) and the South Korean Coastal Waters(SKCW). The former is driven around the Chuja-do and drifted into the Cheju Strait by residual currents, while the latter expands toward offsea by southward wind forcing. The expansion patterns of the SKCW were observed as sinking expansion or drifting expansion such that both were strongly dependent on the surface heat flux conditions. Under the condition of positive heat flux(warmer sea surface) or when the sea surface heat is lost to the atmosphere, the surface water started sinking and eventually expanded toward the open sea causing the cooling of the water column. For the negative heat flux the surface water was just drifted horizontally and expanded seaward and in this case only the surface layer of water was cooled.

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A Prediction on the Wetlands Change of Suncheon Bay by the Sea Level Rise (해수면 상승에 따른 순천만 습지 변화 예측)

  • MOON, Bora;KIM, Dong-Myung;LEE, Suk-Mo
    • Journal of Fisheries and Marine Sciences Education
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    • v.29 no.3
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    • pp.627-635
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    • 2017
  • Sea level rise caused by climate change has become a global issue. Sea level rise seems to be an important factor of the research for coastal areas as it affects topography and vegetation of coasts and especially for the plan of coastal wetlands restoration which needs to be carried out for a long term, it has to be considered sufficiently. The coastal wetlands in Korea was damaged by the land reclamation project but recent concerns on the restoration have increased as its value is evaluated highly. Suncheon Bay had also reclaimed from wetlands to rice field once however this site is very active for restoration nowadays. This study estimated an effect according to sea level rise by 2100, reappearing the none dike condition of Suncheon Bay so that it can be taken account of a future plan of wetland restoration. The Sea Level Affecting Marshes Model(SLAMM) was selected as predicting model. The input data such as DEM(Digital Elevation Model), slope, wetlands category, sea level rise senario, tidal range and accretion rate was applied for the simulation. The results showed a decrease in tidal flat, an increase in sea area and a change of the rice field to transitional salt marsh consistently by 2100. These results of this study could be used as baseline data in the future plan of ecological restoration in Suncheon Bay.

Computation of Meteorologically-Induced Circulation on the East China Sea using a Fine Grid Three-dimensional Numerical Model (세격자삼차원 수치 모형에 의한 동중국해의 기상학적으로 유발된 해류순환의 산정)

  • Park, Byung-Ho;Suh, Kyung-Suk
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.4 no.1
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    • pp.45-58
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    • 1992
  • A three-dimensional hydrodynamic numerical model is used to compute the annual and seasonal meteorologically-induced residual circulation on the Yellow Sea and the East China Sea continental shelf. The model is formulated having irregular coastal boundaires and non-uniform depth distribution representative of nature. The previous three-dimensional model of the East China Sea (Choi. 19U) has been further refined to resolve the flow over the continental shelf in more detail. The mesh resolution of the present finite difference grid system used is 4 minutes latitude by 5 minutes longitude over the entire shelf. The circulation pattern showing depth and spatial distribution of currents over the Yellow Sea and the East China Sea is presented. Meteorologically-induced currents are subsequently used to compute turn-over times for the three depths (surface. mid-depth. bottom) and the total water column of various regions of the Yellow Sea and the East China Sea.

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Physical Oceanographic Characteristics in Hupo Coastal area during Summer and Autumn, 2007 (2007년 하계 및 추계 경상북도 후포연악역 물리적 해황특성)

  • Hwang, Jae-Dong;Lee, Yong-Hwa;Shim, Jeong-Min;Young, Seok-Hyun;Jin, Hyun-Gook;Kim, Young-Suk;Kwon, Kee-Young;Yoon, Sang-Chol
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.41 no.6
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    • pp.505-510
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    • 2008
  • To understand the oceanographic characteristics of Hupo coastal waters as regards the East Korean Warm Current and the North Korean Cold Current, current direction and velocity were investigated by deploying a current meter in Hupo coastal waters during the summer and fall of 2007. Wind data were obtained from the homepage of the Korea Meteorological Administration. Water temperature was measured using a temperature meter attached to the current meter and a mini log. During summer, a south wind prevailed, while during the fall the wind blew from the north. Cold surface waters occurred on a large scale in summer, while in the fall, warm bottom water occurred frequently. After mid-November, when the surface water was cooler than $15^{\circ}C$, there was no difference in water temperature between the surface and bottom layers.

Observation and Record of Sea Turtles in Bycatch and Stranding from Jeju Island of Korea (우리나라 제주도에서 관찰된 바다거북의 좌초와 혼획)

  • Jung, Min-Min;Moon, Dae-Yeon;Kim, Seong-Ho;Kim, Heung-Soo;Kim, Jae-Woo
    • Journal of Fisheries and Marine Sciences Education
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    • v.24 no.5
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    • pp.662-669
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    • 2012
  • Bycatch and stranding of sea turtles from Jeju coastal water of Korea were monitered from 2008 to 2009. A total of 41 sea turtles, consisting of 12 greens (Chelonia mydas), 3 loggerheads (Caretta caretta), 1 hawksbill (Eretmochelys imbricata) and 25 unidentified species, were recorded and observed in those area. Reported stranding and bycatch reached to a peak in August. The largest number of bycatch occurred in the coastal waters around Aewol-eup located in northwest area of Jeju Island. Most of the bycatch were taken by set nets and gill nets, which prevailed over the fishing grounds in the coastal waters of the Jeju Island. It is suggested that an appropriate monitoring system be necessary to conserve endangered sea turtle species in Jeju of Korea.

Characteristics of Concentration Distribution of Coastal Urban Air Pollutants (연안 도시 대기오염 물질의 농도분포 특성)

  • 박종길;석경하;김지형;차주완
    • Journal of Environmental Science International
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    • v.11 no.12
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    • pp.1243-1252
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    • 2002
  • This paper aims to find the characteristics of concentration distribution of coastal urban air pollutants. For this purpose, It was used the daily meteorological data and the hourly concentration data for $O_3$and NO$_2$ in Busan metropolitan city from 1994 to 1996. It was investigated the annual and monthly distribution of ozone and nitrogen dioxide concentration at each site in Busan, and also investigated the characteristics of concentration change of air pollutants with time under the sea breeze. As a results, the concentration of nitrogen dioxide and ozone tend to be increased every year and nitrogen dioxide concentration is higher than ozone concentration at all sites in Busan. The concentration of ozone is high in summer season and low in winter season, but the concentration of nitrogen dioxide have a reversed trend. The monthly peak concentration of ozone occurred in April and September, while the monthly minimum concentration of nitrogen dioxide occurred in August. Their trend were identified by sites near the coastline than sites stands apart from the coastline. The sea breeze occurred annual mean 81 day in Busan from 1994 to 1996. The main wind direction of sea breeze was classified into southwesterly and southeasterly. In case of southwesterly, It was pronounced the south wind and southwest wind. In case of southeasterly, the occurrence frequency of east wind was high. Especially, the concentrations of urban air pollutants, such as ozone and nitrogen dioxide, were high on time which the sea breeze flow, and the areas that ozone concentration was high moved from outside part to central part of city with time. In costal urban such as Busan, the wind direction of sea breeze is influenced the change of ozone and nitrogen dioxide concentration on time which the sea breeze flow at each site and also influenced the change of air pollutants concentration of sites on the pathway of sea breeze.

A Study of Damage District Forecast by Combine Topograph Modeling of Insular Areas Using GIS

  • Choi, Byoung Gil;Na, Young Woo;Ahn, Soon Myoung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.2
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    • pp.113-122
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    • 2017
  • Natural disasters caused by climate change are increasing globally. There are few studies on the quantitative analysis methods for predicting damages in the island area due to sea level rise. Therefore, it is necessary to study the damage prediction analysis method using the GIS which can quantitatively analyze. In this paper, we analyze the cause and status of sea level rise, quantify the vulnerability index, establish an integrated terrestrial modeling method of the ocean and land, and establish a method of analyzing the damage area and damage scale due to sea level rise using GIS and the method of making the damage prediction figure was studied. In order to extract the other affected areas to sea level rise are apart of the terrain model is generated by one requires a terrain modeling of target areas are offshore and vertical reference system differences in land, found the need for correction by a tidal observations and geoid model there was. Grading of terrain, coastline erosion rate, coastal slope, sea level rise rate, and even average by vulnerable factors due to sea level rise indicates that quantitative damage prediction is possible due to sea level rise in the island area. In the case of vulnerable areas extracted by GIS, residential areas and living areas are concentrated on the coastal area due to the nature of the book area, and field survey shows that coastal changes and erosion are caused by sea level rise or tsunami.

Improvement in the Simulation of Sea Surface Wind over the Complex Coastal Area Using WRF Model (WRF 모형을 통한 복잡 연안지역에서의 해상풍 모의 개선)

  • Kim, Yoo-Keun;Jeong, Ju-Hee;Bae, Joo-Hyun;Oh, In-Bo;Kweon, Ji-Hye;Seo, Jang-Won
    • Journal of Korean Society for Atmospheric Environment
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    • v.22 no.3
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    • pp.309-323
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    • 2006
  • We focus on the improvement in the simulation of sea surface wind over complex coastal area located in the southeastern Korea. In this study, it was carried out sensitivity experiment based on PBL schemes and dynamic frame of MM5 and WRF. Two widely used PBL parameterization schemes were chosen : Medium-Range Forecast (MRF) and Mellor-Yamada-Janjic (MYJ). Thereafter, two cases of sea fog days with weak wind speed and typhoon days with strong wind speed were simulated and analyzed. The result of experiments indicated that wind fold of WRF model was shown more similar distribution with observational data, compared with that of MM5. Simulation of sea surface wind during sea fog days with weak wind speed and typhoon days with strong wind speed were shown similar horizontal distribution with observational data using MYJ and MRF PBL schemes of WRF model, respectively. Horizontal distribution of sea surface wind was more sensitive according to dynamic frame and PBL Schemes of model during sea fog days and typhoon days, respectively.