• Title/Summary/Keyword: West Coast

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Water Mass Distribution and Seasonal Circulation Northwest of Cheju Island in 1994

  • PANG Ig-Chan;RHO Hong-Kil;LEE Jae-Hak;LIE Heung-Jae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.29 no.6
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    • pp.862-875
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    • 1996
  • The CTD data observed in the sea northwest of Cheju Island have been analyzed to figure out the seasonal circulation around Cheju Island. Warm and saline waters flow into the Yellow Sea through the middle region of the Yellow Sea in winter and along the west coast of Korean Peninsula in summer. On the other hand, cold and less saline waters flow out of the Yellow Sea through the middle region in summer and along the west coast of Korean Peninsula in winter. These flows make the seasonal circulation around Cheju Island. As dynamics, the monsoon wind and the variation of Kuroshio transport have been suggested. Comparing the observational result, the circulation driven by the variation of Kuroshio transport is strengthened by monsoon winds in the numerical model.

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Analysis and Assessment of Environmental Factors in the Small Scale Marine Ranch around the Gunsan Coastal Areas (소규모 바다목장의 해양 환경 분석 및 평가 - 군산주변해역)

  • Kim, Jong-Hwa
    • Journal of Fisheries and Marine Sciences Education
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    • v.20 no.3
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    • pp.487-499
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    • 2008
  • This study was analyzed and assessed the environmental factors on small marine ranching sites around Gunsan Coast, West Sea of Korea. Standards of assessment are followed in the reports on the choice of marine ranching sites and regulation factors of proper site on marine artificial reefs of MOMAF. Max. current speed around Gunsan were ranged between 25.52 ~ 57.49cm/sec. These values were satisfied by comparing assessment factor such as current speed.. Factors of temperature, salinity, transparency and pH were evaluated as the proper extent. DO was not distributed as the proper extent due to different criterion. between the same assessment factor. COD, SS and nutrients were partly suited to the criteria. Especially, SS was almost higher than that of criterion. So, we are proposed to be reflected in environment characteristics of West Coast such as SS. Moreover, the extent of pollution load factors have to be specified clearly in the regulations of assessment criteria.

Detection of Urchin Barren Using Airborne Hyperspectral Imagery and SAM Technique - Focusing on the West Sea Island Areas (항공 초분광 영상과 SAM 기법을 이용한 백화현상 탐지 -서해 도서 지역을 중심으로-)

  • Yong-Suk Kim
    • Journal of Environmental Science International
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    • v.33 no.7
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    • pp.533-546
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    • 2024
  • The coastal urchin barren phenomenon in our country began to spread and expand from the 1980s, centering on the southern coast and Jeju Island, and by the 1990s, it appeared along the east coast and nationwide. The urchin barren phenomenon is mainly conducted through field surveys by diving, but recently, various surveying techniques have been applied. In this study, a spectral library for terrestrial and marine areas was established for the identification of urchin barrens using airborne hyperspectral imagery, and the distribution area was analyzed through the SAM (spectral angle mapper) algorithm. An analysis of the urchin barren phenomenon in the five islands of the West Sea revealed that it occurrs in most areas, with the combined severity of the urchin barren phenomenon in Sapsido and Oeyeondo being approximately 19.9%. Hyperspectral imagery is expected to be highly useful not only for detecting the urchin barren phenomenon but also for managing and monitoring marine fishery resources through the classification of seaweeds.

The Sea Level Slopes along the Korean Peninsular Coast based on the First Order Levelling Net in Korea (1등 수준망에 기준한 한반도 연안의 해면경사)

  • 이창경
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.11 no.2
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    • pp.35-41
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    • 1993
  • The height differences in Mean Sea Level is an important factor in geodetic leveling net, because MSL is the reference datum for height. Geodesists and Oceanographers agree on the height differences in MSL in the east-west direction, but they disagree almost always on the north-south slope, each suspecting systematic errors in the leveling methods of the others. A promising method for determining this slope is comparison of MSL at the tidal station connected by geodetic leveling. The slopes of the sea surface along the coast of Korean Peninsular is estimated from conventional local MSL at the tidal station and bench mark height of first order leveling net in Korea. As a reference level surface, MSL at Inchon is chosen. The results indicate that sea level rises along coast of Korean Peninsular from south to north about 5.5 cm/latitude. In the east-west direction, sea level along East Sea coast stands about 5 cm higher than that along Yellow Sea coast. These are not invariable but provisional phenomena. It may become certain provided that the exact MSL is estimated.

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Analysis of Regional Effects of the Seasonal Management Policy on Coal-fired Power Plant Using Difference-in-difference Method (이중차분법을 이용한 석탄화력발전소에 대한 미세먼지 계절관리제의 지역별 효과 분석)

  • Kang, Heecha
    • Environmental and Resource Economics Review
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    • v.31 no.3
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    • pp.343-365
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    • 2022
  • This paper tries to identify the effect of reducing PM2.5 concentration of the First Seasonal Management Policy implemented by Korean government by using statistical method. In particular, this paper tests the hypothesis that this policy effect may differ by region (west-coast, south-coast, and east-coast). To this end, this paper analyzed only pure policy effects by removing temporal abnormalities such as COVID-19, warm winter temperature during the policy implementation period (December 2019 to March 2020) by using the difference-in-difference method (DID). As a result of the analysis, this policy had the effect of reducing PM2.5, but the effect is not homogenous by region. In particular, PM2.5 reducing effect is the largest in west-coast region and south-coast region folllows, but its effect is not statistically significant in the east-cost region. In conclusion, this paper drew implications that the current Seasonal mamangement policy which is implemented regardless of the regional difference needs to be changed.

Biomass of Shellfish in the Saemangeum Tidal Flat on the West Coast of Korea (새만금 갯벌의 패류 생물량)

  • KIM Jong-Sheek;HWANG Sun-Do
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.6
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    • pp.757-761
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    • 2003
  • Spatial distribution and biomass of commercial shellfish were investigated in the Saemangeum tidal flat on the west coast of Korea during August 1999. Thirteen species of shellifsh were collected. Major dominant species of the study area were Umbonium thomasi with a density of $6.7\;ind.{\cdot}m^{-2}\;(38.2\%)$, Mactra veneriformis with $6.6\;ind.{\cdot}m^{-2}\;(37.4\%)$ and Reticunassa festiva with $1.3\;ind.{\cdot}m^{-2}\;(7.2\%)$. Commercially important species such as M. veneriformis ($90.7\;ind.{\cdot}m^{-2}\;69.3\%$), M. lusoria ($15.6\;ind.{\cdot}m^{-2}\;11.9\%)$), C. sinensis ($8.7\;ind.{\cdot}m^{-2}\;6.7\%)$) were dominant in total weight. Most of the shellfish were distributed between the mid-littoral and sub-littoral zones, but C. sinensis and L. flexuosa were distributed mainly in the polluted areas of the supra-littoral zone. The spatial distribution pattern of each shellifsh species generally resembles the Mangyeong and Dongjin estuary. Biomass of commercially important species, M. veneriformis, M. lusoria, C. sinensis and Ruditapes philippinarum in the tidal flat (ca. 850 ha) was estimated to be 774, 135, 67 and 10 tons, respectively.

A Study on the Application of Coastal Disaster Prevention Considering Climate Change (기후변화를 고려한 연안지역 재해예방기법 적용방안 연구)

  • Lee, Sung Hyun;Kim, Bo Ram;Im, Jun Hyeok;Oh, Kuk Ryul;Sim, Ou Bae
    • Journal of Climate Change Research
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    • v.9 no.4
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    • pp.369-376
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    • 2018
  • Korea is surrounded by the West Sea, the South Sea, and the East Sea. There are various points at which large and small rivers flow into the sea, and areas where these rivers meet the coast are vulnerable to disasters. Thus, it is necessary to study disaster prevention techniques based on coastal characteristics and the pattern of disasters. In this study, we analyzed the risk factors of disaster districts analyzed in comprehensive plans for the reduction of damage to coastal cities from storms and floods. As a result of standardization, four factors (tide level, intensive rainfall & typhoon, wave, and tsunami) were identified. Intensive rainfall & typhoon occurred along the West Sea, the South Sea, and the East Sea coast. Factors that should be considered to influence disasters are tide level for the West Sea, tsunami and tide level for the South Sea, and wave in the East Sea. In addition, disaster prevention techniques to address these factors are presented, focusing on domestic and overseas cases.

Effects of Storm Waves Caused by Typhoon Bolaven (1215) on Korean Coast: A Comparative Analysis with Deepwater Design Waves

  • Taegeon Hwang;Seung-Chul Seo;Hoyeong Jin;Hyeseong Oh;Woo-Dong Lee
    • Journal of Ocean Engineering and Technology
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    • v.38 no.4
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    • pp.149-163
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    • 2024
  • This paper employs the third-generation simulating waves nearshore (SWAN) ocean wave model to estimate and analyze storm waves induced by Typhoon Bolaven, focusing on its impact along the west coast and Jeju Island of Korea. Utilizing reanalyzed meteorological data from the Japan Meteorological Agency meso scale model (JMA-MSM), the study simulated storm waves from Typhoon Bolaven, which maintained its intensity up to high latitudes as it approached the Korean Peninsula in 2012. Validation of the SWAN model against observed wave data demonstrated a strong correlation, particularly in regions where wind speeds exceeded 20 m/s and wave heights surpassed 5 m. Results indicate significant storm wave heights across Jeju Island and Korea's west and southwest seas, with coastal grid points near islands recording storm wave heights exceeding 90% of the 50-year return period design wave heights. Notably, specific grid points near islands in the northern West Sea and southwest Jeju Island estimated storm wave heights at 90.22% and 91.48% of the design values, respectively. The paper highlights the increased uncertainty and vulnerability in coastal disaster predictions due to event-driven typhoons and emphasizes the need for enhanced accuracy and speed in typhoon wave predictions amid the escalating climate crisis.

Seasonal Variation of Airborne Chlorides in Coast by Sea Area and Region, South Korea (해역 및 지역에 따른 해안가 대기중 염분량의 계절적 변동)

  • Jung, Jahe;Lee, Jong-Suk
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.5
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    • pp.611-619
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    • 2023
  • The first survey of the airborne chlorides along the nationwide coast of South Korea was conducted 18 years ago, and the area index of coastal airborne chlorides and salt attack environmental rating are being utilized in the design, construction, and maintenance of domestic structures. However, due to environmental changessuch as climate change and coastal topography changes, changes of airborne chlorides along the coast are expected to occurregionally and by sea area. Therefore, the second survey has been conducted since 2021. Inthis paper, we analyzed the seasonal variations of airborne chlorides along the coast by region and sea area for one year of the second survey. Additionally, we compared the results withthe survey results of Japan's coastal airborne chlorides, which islocated close to South Korea and has a similar climate, to increase the objectivityofthe analysis. The averageairborne chloridesin the second surveywas highest on the west coast, and the seasonal variation was also the largest on the west coast. Looking at the seasonal variations by sea area, the East Sea had highairborne chloridesinthe summer and autumn,theWestSea inthe autumnandwinter, and the SouthSea in the summer. In addition, compared to the firstsurvey, allsea areasshowed short periods ofsignificantly higher coastalsalinity and clearerseasonal variations.