• Title/Summary/Keyword: 延安

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A Study on the Assembling Factors and Catch Fluctuation of Fyke Net Grounds in the Coastal Waters of Yosu(I) -Relation between Catch Fluctuation of Common Mullet, Mugil Cephalus and Temperature and Salinity - (여수 연안 승망 어장의 환경요인과 어획변동에 관한 연구(I) -수온.염분과 어획량과의 관계 -)

  • 김동수;주찬순
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.37 no.2
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    • pp.71-77
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    • 2001
  • In order to find out the environmental factors influencing the catch of fyke nets in the coastal waters Yosu, the oceanographic factors, i.e., the waters temperature and the salinity were observed respectively from April to November in 1999, and each of them was compared with the catch of common mullet, Mugil cephalus by fyke net. The results obtained are summerized as follows : 1. The water temperature was ranged from 13.0 to $25^\circ$C and water temperature increased from April to August and decreased on September to November. 2. The range salinity in the fishing grounds was from 28.6 to 33.8$\textperthousand$, and salinity was high from April to June. From July, however, the salinity decreased to continue a low value still september. 3. The catches of common mullet caught by funnel net were the highest in may and the smallest in November. The ranges of optimum water temperature for the funnel nets fishing was 15.0 to $16.0^\circ$C, the ranges of optimum salinity for fishing varied between from 32.6 to 33.8$\textperthousand$.

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Analysis of Influences on the Coast Construction Facilities depending on Sea Level Rise (해수면 상승에 따른 연안 건설시설물의 영향 분석)

  • Park, Jun-Young;Bu, Yang-Su;Lee, Dong-Wook
    • Proceedings of the KAIS Fall Conference
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    • 2009.05a
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    • pp.825-828
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    • 2009
  • 기후변화는 기상재해뿐만 아니라 지속적인 해수면 상승의 원인이 되고 있으며, 자연 생태계화 인간의 사회, 경제시스템 전반에 걸쳐 영향을 미치고 있으며, 건설분야도 이와 무관하지 않다. 특히 기후변화는 해수면 상승으로 이어져 사회기반시설인 항구, 연안도로, 철도, 빌딩 등과 연안산업인 석유 및 석유화학공장, 그리고 서비스업인 관광에 대한 위협으로 나타나고 있다. 이러한 해수면 상승은 토지 및 건물의 재산 가치 하락과 해수면 상승에 따른 보호비용 증대, 구조물의 급속한 노후화에 따른 유지관리비용의 증가뿐만 아니라 정치적 제도적 불안 및 사회동요 등을 유발할 수 있다. 우리나라의 경우, 지난 100년간 6대 도시 평균기온이 약 $1.5^{\circ}C$ 상승하였으며, 해수면(제주기준)은 40년간 22cm가 상승하였다. 특히 제주의 경우 매년 5mm씩의 해수면 상승을 보이고 있으며 이는 전 지구 해수면 상승률보다 3배 높은 수치이다. 본 연구는 해수면의 상승에 따른 건설분야의 영향을 분석하기 위한 선도적인 연구로서, 연구의 범위를 제주지역에 국한하였으며, 해수면 상승에 따른 영향 지역을 추출하고, 영향 지역 내 건설시설물 정보를 추출하기 위한 절차를 규명하였다. 본 연구 결과는 유지보수 및 시설물 이설에 따른 공사비 산출의 근거가 될 뿐만 아니라 관련 예산 확보에 대한 근거 자료로 활용될 수 있을 것이다. 향후 관련 지역의 유지보수 및 이설 공사비 정보의 추출 및 DB 구축을 통해 연안 건설 시설물의 이설에 따른 공사비를 예측할 수 있을 것이다.

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Characteristic Analysis on the Wind Data in the Pohang Coastal Zone (포항 연안 바람자료의 특성분석)

  • Jeong, Weon Mu;Cho, Hongyeon;Baek, Wondae
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.3
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    • pp.190-196
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    • 2015
  • The estimation method of the sea wind information using the nearby land wind data have been widely used. However, it is insufficient to examine the limitation of the method based on the characteristics of the wind data. In this study, the characteristics of the wind data are analysed and compared to check the limitation of the existing conventional method. The data are observed at the same time period in the land and sea stations in Pohang coastal zone. In particular, the analysis are focused on the direction data simply overlooked in the analysis target. The method is suggested as a useful tool for the various analysis of the wind direction data. The results show that the statistical informations between the land and sea wind data are quite different though the lineal distance between stations are not large (${\fallingdotseq}3.8km$). The difference is attributed to come from the geometrical gradient and elevation difference between land and sea areas. As a consequence, the quantitative estimation error should be checked preliminarily using the land-sea monitoring data sets because the sea wind estimation using land data is essentially unacceptable.

The Distributions of Copepods and Chaetognaths in the Southern Waters of Korea and Their Relationship to the Characteristics of Water Masses (한국 남해의 요각류 및 모악류의 분포와 수괴특성)

  • PARK Joo-Suck;LEE Sam-Seuk;KANG Young-Shil;LEE Byung-Don;Hun Sung-Hoi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.23 no.3
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    • pp.245-252
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    • 1990
  • The distributions of copepods and chaetognaths in waters off the southern coast of Korea were investigated to evaluate their reliability as indicator species of different water masses. The samples for this study were collected vertically from about 5m above the bottom at 28 stations along 8 transects in three different months, February, April, and August, 1988. The sampling gear used was 0.45-meter NORPAC plankton net fitted with 0.33mm mesh. Acartia clausi, Centropages abdominalis, and Sagitta crassa were found to be reliable indicator species of neritic cold waters; Pleuromamma gracilis, Undinula darwini, Calocalanus plumulosus, Calanopia elliptica, and Sagitta enflata were of oceanic warm waters; Temora discaudata and Centropages furcatus were of neritic warm waters. According to the cluster analyses of the species found, the distinctive area in February was divisible into two regions or water masses, the coastal and off-shore regions; in April, however, it was divisible into four regions. In August, it was divisible into three areas, further indicating the strength of the Kuroshio tributaries pushing toward the coast.

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Relationships between Spatio-temporal Distribution of Cochlodinium polykrikoides Red Tide and Meso-scale Variation of Oceanographic Environment around the Korean Waters (C. polykrikoides 적조의 시공간분포와 중규모 해양환경 변동간의 관계성)

  • Suh, Young-Sang;Jang, Lee-Hyun;Kim, Hak-Gyoon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.6 no.3
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    • pp.139-150
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    • 2003
  • There was a close relationship between spatio-temporal distribution of Cochlodinium polykrikoides red tide and meso-scale variation of oceanographic environment around the Korean waters. Oceanographic conditions of Narodo island, where red tide usually first occurred during summer seasons were formation of the thermohaline frontal zone from 1995 to 2001. Huge C. polykrikoides red tides were observed in every uneven year during the past 7 years (1995~2001) and quasi-biennial oscillation also occurred in the oceanographic variations of sea surface temperature and salinity in the northern part of the East China Sea during the same years. The distribution area and moving pattern of C. polykrikoides red tides were definitely depended on the temporal and spatial variation of upwelling cold water originated form the southeastern coast of the Korean peninsula in summer season.

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An Assessment of the Conservation Status for Coastal Sand Dunes in Incheon: Focused on the Jung gu, Ongjin gun in Incheon (인천광역시 연안 해안사구 보전현황 평가 연구: 중구, 옹진군을 중심으로)

  • Park, KyoungMoon;Kim, SungWoo;An, TaeSun
    • Journal of the Korean Geographical Society
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    • v.51 no.3
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    • pp.345-365
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    • 2016
  • This paper is a research that investigated the distribution and status of coastal sand dunes spread along the shoreline of Ongjin-gun, Jung-gu in Incheon and evaluated their conservation status. In Incheon, the length of coastline along the West Sea shoreline is 1,053km. thus leading to an assumption that coastal sand dunes are dispersed their as many as other regional local government. However, there are no enough basic data on the distribution, characteristics, and the management status of other areas besides the 5 places on the list by the Ministry of Environment. Considering this fact, this paper additionally drew 21 coastal sand dunes in the shoreline of Incheon, including the 5 places on the list by the Ministry of Environment, through the standard of coastal sandhill selection. The additionally selected aimed to propose how to develop basic materials on the conservation status of coastal sandhills in Incheon through characteristic analysis by sandhill and qualitative evaluation.

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Column experiment for contaminated coastal sediment bioremediation using biostimulating agent (연안오염저질의 생물정화를 위한 생물활성촉진제의 효능 평가 : 현장 컬럼실험)

  • Woo, Jung-Hui;Song, Young-Chae;Subah, Bakthavachallam
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2014.10a
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    • pp.83-84
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    • 2014
  • This study evaluated the effectiveness of biostimulating agent in contaminated coastal sediment. The study was conducted via column tests in coastal sea wherein two separate columns were employed for two different polymers used and another column for a blank. The biostimulating agent was made by mixing sea sediment with biostimulants viz acetate, nitrate, sulfate. The biostimulating agent was then rolled into balls, dried and coated with either Cellulose Acetate (CA) or Polysulfone (PS) to control the release of the biostimulants. The pH was around 7.6~8 for 4 months while COD, TP and TN were significantly lower in the column containing biostimulating agents. Heavy metal(Fe, Zn, Cd, Cr, Pb, Cu) was converted to stable forms and PS coated biostimulating agent had a high efficiency of heavy metals distribution.

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Water Column Correction of Airborne Hyperspectral Image for Benthic Cover Type Classification of Coastal Area (연안 해저 피복 분류를 위한 항공 초분광영상의 수심보정)

  • Shin, Jung Il;Cho, Hyung Gab;Kim, Sung Hak;Choi, Im Ho;Jung, Kyu Kui
    • Spatial Information Research
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    • v.23 no.2
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    • pp.31-38
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    • 2015
  • Remote sensing data is used to increasing efficiency on benthic cover type survey. Satellite and aerial imagery has variance of reflectance by water column effect even if bottom is consisted with same cover type and condition. This study tried to analyze advances of surveying extent and accuracy through water column correction of CASI-1500 hyperspectral image. Study area is coast of Gangneung city, South Korea where benthic environment is rapidly changing with bleaching of coral reef. Water column correction coefficient was estimated using regression models between water reflectance ($R_W$) and depth for sand bottom then the coefficients were applied to whole image. The results shows that expanded interpretable depth from 6-7m to 15m and decreased variation of reflectance by depth. Additionally, water column corrected reflectance image shows 13%p increased accuracy on benthic cover type classification.

Hierarchical Bayesian Model Based Nonstationary Frequency Analysis for Extreme Sea Level (계층적 베이지안 모델을 적용한 극치 해수위 비정상성 빈도 분석)

  • Kim, Yong-Tak;Uranchimeg, Sumiya;Kwon, Hyun-Han;Hwang, Kyu Nam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.28 no.1
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    • pp.34-43
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    • 2016
  • Urban development and population increases are continuously progressed in the coastal areas in Korea, thus it is expected that vulnerability towards coastal disasters by sea level rise (SLR) would be accelerated. This study investigated trend of the sea level data using Mann-Kendall (MK) test, and the results showed that the increasing trends of annual average sea level at 17 locations were statistically significant. For annual maximum extremes, seven locations exhibited statistically significant trends. In this study, non-stationary frequency analysis for the annual extreme data together with average sea level data as a covariate was performed. Non-stationary frequency analysis results showed that sea level at the coastal areas of Korean Peninsula would be increased from a minimum of 60.33 mm to a maximum of 214.90 mm by 2100.

Numerical Simulation of Water Level Change at the Coastal Area in the East Sea with the Inverted Barometer Effect (역기압 효과를 반영한 동해 연안 수위 변동 수치 재현)

  • Hyun, Sang Kwon;Kim, Sung Eun;Jin, Jae Yull;Do, Jong Dae
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.28 no.1
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    • pp.13-26
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    • 2016
  • Sea water level variations are generally influenced by a variety of factors such as tides, meteorological forces, water temperature, salinity, wave, and topography, etc. Among non-tidal conditions, atmospheric pressure is one of the major factors causing water level changes. In the East Sea, due to small tidal range which is opposite to large tidal range of the Yellow Sea, it is difficult to predict water level changes using a numerical model, which consider tidal forcing only. This study focuses on the effects of atmospheric pressure variations on sea level predictions along the eastern coast of Korea. Telemac-2D model is simulated with the Inverted Barometer Effect(IBE), and then its results are analyzed. In comparison between observed data and predictions, the correlation of prediction with IBE and tide is better than that of tide-only case. Therefore, IBE is strongly suggested to be considered for the numerical simulations of sea level changes in the East Sea.