• 제목/요약/키워드: coastal sea

검색결과 3,161건 처리시간 0.029초

Distribution and Characteristics of PAHs in Bivalves from Gwangyang Bay, Korea

  • Yim, U.H.;Hong, S.H.;Shim, W.J.;Oh, J.R.
    • 환경생물
    • /
    • 제22권
    • /
    • pp.78-85
    • /
    • 2004
  • Polyeyclic aromatic hydrocarbons (PAHs) were quantitatively determined in bivalves from Gwangyang Bay. Twenty-four kinds of target PAHs were detected in the entire samples. Total PAHs concentrations ranged 86.1∼1,210 ng g$\^$-1/ dry weight with a average concentration of 309 ng g$\^$-1/, which is much lower than those of other industrialized bays in Korea. Strong tidal currents and artificial interferences like reclamation and dredging activity were suggested as major reason for disparity between highly industrialization and low contamination status. There was no correlation between total PAHs and lipid contents, implying that lipid content is not the one major parameter for the accumulation of PAHs by bivalves. Input sources were inferred as petrogenic and pyrogenic PAHs. With help of PCA analysis, signals of seasonal variations, not only concentrations but also compositions were found.

Vertical Temperature Profile in the Yellow Sea according to the Variations of Air Temperature

  • CHO Kyu-Dae;CHO Kwang-Woo
    • 한국수산과학회지
    • /
    • 제21권1호
    • /
    • pp.1-10
    • /
    • 1988
  • The vertical temperature profiles of the Yellow Sea in summer are investigated by means of the nine air temperature (AT) patterns which are classified with the AT of winter and summer. The sea surface temperature (SST) is high when the AT of summer is high, and vice versa. The gradient of thermocline in the offshore region is higher than that in the coastal region and is not always favorable with the AT patterns. The relation between sea bottom temperature (SBT) and the AT of winter is favorable when the SBT is averaged in the coastal and offshore stations. In addition, the SST of coastal stations is higher than that of offshore stations because of the strong mixing by the tidal current in the coastal region. The correlation between the AT and the SST of August is favorable (r=0.44-0.69), while the correlation between the AT of February and the SBT of August is not favorable except the stations, A2 (r=0.57) and B2 (r=0.61).

  • PDF

해양환경영향평가 관련 협의에 의한 연안이용분석 (Analysis of Coastal Area Utilization by Consultation of Marine Environmental Impact Assessment Related-Systems)

  • 이대인;엄기혁;권기영;김귀영;윤성순;장주형
    • 환경영향평가
    • /
    • 제17권2호
    • /
    • pp.97-103
    • /
    • 2008
  • This study presented politic proposals and diverse utilization-type in coastal areas by analyzing results of reviewed related-statements of marine environment during the one year period of 2007 by Marine Environmental Impact Assessment Center. Total of 358 cases were reviewed, which was a significant increase from 270 in 2006. Consultation on the utilization of sea areas (CUSA) accounted for the largest number of 165 (46.1%) and it was followed by 104 cases of environmental impact assessment (EIA) (29.0%) and 89 cases of prior environmental review (PER) (24.9%). As such, evaluation statements (EIA+PER) related to consultations of the Ministry of Environment accounted for approximately 54% of the entire cases reviewed. To analyze the overall results of reviewing marine-related evaluation statements, utilization and planning were conducted by 47.9%, 38.4% and 13.7% in the South Sea, West Sea and East Sea of Korea, respectively. In evaluation statements (EIA+PER), port construction, industrial complex construction, urban management plan and road construction took up most of the part by 40.9%, 20.2%, 10.4% and 7.3%, respectively. In terms of CUSA-statement, it was evaluated that consultations were mostly carried out on use and reclamation of public water surface in coastal areas and on sea aggregate extraction process in EEZ. The largest number of plans for coastal use were established for Jeollanam-do, followed by Gyeongsangnam-do, Chungcheongnam-do, Gyeongsangbuk-do and Gyeonggi-do. In particular, development plans were concentrated on Jeollanam-do and Gyeongsangnam-do with stable marine environment and outstanding view of the nature. In most cases, these regions are adjacent to the areas designated as a sea area for environmental management and fisheries resources protection zone. Therefore, conflicts exist between development and preservation. Also, rather than random development, more detailed marine environmental impact assessment, gathering of public opinions and politic harmony are essentially required. For efficient coastal management and environmentally sound and sustainable development, fulfilling consistent and transparent coastal policies as well as active and reliable decision making to center on coastal environment by management bodies will be important.

Numerical simulation of Hydrodynamics and water properties in the Yellow Sea. I. Climatological inter-annual variability

  • Kim, Chang-S.;Lim, Hak-Soo;Yoon, Jong-Joo;Chu, Peter-C.
    • Journal of the korean society of oceanography
    • /
    • 제39권1호
    • /
    • pp.72-95
    • /
    • 2004
  • The Yellow Sea is characterized by relatively shallow water depth, varying range of tidal action and very complex coastal geometry such as islands, bays, peninsulas, tidal flats, shoals etc. The dynamic system is controlled by tides, regional winds, river discharge, and interaction with the Kuroshio. The circulation, water mass properties and their variability in the Yellow Sea are very complicated and still far from clear understanding. In this study, an effort to improve our understanding the dynamic feature of the Yellow Sea system was conducted using numerical simulation with the ROMS model, applying climatologic forcing such as winds, heat flux and fresh water precipitation. The inter-annual variability of general circulation and thermohaline structure throughout the year has been obtained, which has been compared with observational data sets. The simulated horizontal distribution and vertical cross-sectional structures of temperature and salinity show a good agreement with the observational data indicating significantly the water masses such as Yellow Sea Warm Water, Yellow Sea Bottom Cold Water, Changjiang River Diluted Water and other sporadically observed coastal waters around the Yellow Sea. The tidal effects on circulation and dynamic features such as coastal tidal fronts and coastal mixing are predominant in the Yellow Sea. Hence the tidal effects on those dynamic features are dealt in the accompanying paper (Kim et at., 2004). The ROMS model adopts curvilinear grid with horizontal resolution of 35 km and 20 vertical grid spacing confirming to relatively realistic bottom topography. The model was initialized with the LEVITUS climatologic data and forced by the monthly mean air-sea fluxes of momentum, heat and fresh water derived from COADS. On the open boundaries, climatological temperature and salinity are nudged every 20 days for data assimilation to stabilize the modeling implementation. This study demonstrates a Yellow Sea version of Atlantic Basin experiment conducted by Haidvogel et al. (2000) experiment that the ROMS simulates the dynamic variability of temperature, salinity, and velocity fields in the ocean. However the present study has been improved to deal with the large river system, open boundary nudging process and further with combination of the tidal forcing that is a significant feature in the Yellow Sea.

Application of Remote Sensing and GIS technology for monitoring coastal changes in estuary area of the Red river system, Vietnam

  • Lan, Pham Thi;Son, Tong Si;Gunasekara, Kavinda;Nhan, Nguyen Thi;Hien, La Phu
    • 한국측량학회지
    • /
    • 제31권6_2호
    • /
    • pp.529-538
    • /
    • 2013
  • Coastline is the most dynamic part of seascape since its shape is affected by various factors. Coastal zone is an area with immense geological, geomorphological and ecological interest. Monitoring coastal change is very important for safe navigation, coastal resource management. This paper shows a result of monitoring coastal morphological changes using Remote Sensing and GIS. Study was carried out to obtain intensity of erosion, deposition and sand bar movement in the Red River Delta. Satellite images of ALOS/AVNIR-2 and Landsat were used for the monitoring of coastal morphological changes over the period of 1975 to 2009. Band rationing and threshold technique was used for the coastline extraction. Tidal levels at the time of image acquisition varied from -0.89m to 2.87m. Therefore, coastline from another image at a different tidal level in the same year was considered to get the corrected coastline by interpolation technique. A series of points were generated along the coastal line from 1975 image and were established as reference points to see the change in later periods. The changes were measured in Euclidean distances from these reference points. Positive values represented deposition to the sea and negative values are erosion. The result showed that the Red river delta area expanded to the sea 3500m in Red river mouth, and 2873m in Thai Binh river mouth from 1975 to 2009. The erosion process occurred continuously from 1975 up to now with the average magnitude 23.77m/year from 1975 to 1989 and 7.85m/year from 2001 to 2009 in Giao Thuy area. From 1975 to 2009, total 1095.2ha of settlement area was eroded by sea. On the other hand, land expanded to the sea in 4786.24ha of mangrove and 1673.98ha of aquaculture.

파랑하중을 받는 해안구조물의 거동특성 분석 및 재료 설계강도 산정에 관한 연구 (A Study on Behaviour Characteristics Analysis and Materials Design Strength Decision of the Coastal Structures under Sea Wave Loads)

  • 정지승;문인기;유찬호
    • 한국지반환경공학회 논문집
    • /
    • 제14권7호
    • /
    • pp.57-66
    • /
    • 2013
  • 해안구조물의 기능은 파랑과 조류, 침식 등의 자연현상에 복잡하게 거동한다. 이러한 해안구조물의 재료는 파랑과 직접적으로 접하고 있으며 구조물의 안정성에도 직접적으로 영향을 주기 때문에 매우 중요하다. 이러한 이유로 해안구조물은 파랑하중을 받는 동안의 거동과 구조물의 설계기준이 지속적으로 요구되어왔다. 특히 파랑하중과 구조물의 상호작용을 고려한 설계기준 및 연구는 아직도 미흡한 실정이다. 이에 본 연구에서는 파랑하중으로 인한 해안구조물과 재료의 거동특성을 살펴보았으며, 파랑고에 의해 직접적인 영향을 받게 되는 것을 확인하였다.

VARIATIONS IN THE SOYA WARM CURRENT OBSERVED BY HF OCEAN RADAR, COASTAL TIDE GAUGES AND SATELLITE ALTIMETRY

  • Ebuchi, Naoto;Fukamachi, Yasushi;Ohshima, Kay I.;Shirasawa, Kunio;Wakatsuchi, Masaaki
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
    • /
    • pp.17-20
    • /
    • 2006
  • Three HF ocean radar stations were installed at the Soya/La Perouse Strait in the Sea of Okhotsk in order to monitor the Soya Warm Current. The frequency of the HF radar is 13.9 MHz, and the range and azimuth resolutions are 3 km and $5^{\circ}$, respectively. The radar covers a range of approximately 70 km from the coast. It is shown that the HF radars clearly capture seasonal and short-term variations of the Soya Warm Current. The velocity of the Soya Warm Current reaches its maximum, approximately 1 m $s^{-1}$, in summer, and weakens in winter. The velocity core is located 20 to 30 km from the coast, and its width is approximately 50 km. The surface transport by the Soya Warm Current shows a significant correlation with the sea level difference along the strait, as derived from coastal tide gauge records. The cross-current sea level difference, which is estimated from the sea level anomalies observed by the Jason-1 altimeter and a coastal tide gauge, also exhibits variation in concert with the surface transport and along-current sea level difference.

  • PDF

항공기 결항과 연쇄 교통사고를 야기한 연안안개 사례 연구 (A Case Study of Coastal Fog Event Causing Flight Cancellation and Traffic Accidents)

  • 김영철
    • 한국항공운항학회지
    • /
    • 제25권1호
    • /
    • pp.1-10
    • /
    • 2017
  • A heavy foggy event accompanying with complex coastal fog was investigated in this study. This heavy foggy event occurred on FEB 11, 2015. Due to reduced visibility with this foggy event induced more than 100times serial traffic accidents over the Young-jong highway, and Flights from 04:30 AM to 10:00 AM were cancelled on Inchon International Airport. This heavy foggy event was occurred in synoptic and mesoscale environments but dense coastal fog were combined with a combination of sea fog, steam fog, and radiation fog. This kind of coastal fog can predicted by accurate analysis of the direction of the air flow, sea surface temperature(SST), and 925hPa isotherms from numerical weather prediction charts and real time analysis charts.

잠제에 의한 쇄파 및 쇄파에 의해 발생하는 고주파수파동압 (Wave Breaking and Breaking Wave-Induced High Frequency Pressure over Submerged Breakwater)

  • Koichiro IWATA;Koji KAWASAKI;Hirokazu SUMI
    • 한국해안해양공학회:학술대회논문집
    • /
    • 한국해안해양공학회 2002년도 한국해안해양공학발표논문집 Proceedings of Coastal and Ocean Engineering in Korea
    • /
    • pp.14-23
    • /
    • 2002
  • Wave breaking and breaking wave-induced hydrodynamics are very important subjects in the field of coastal and ocean hydrodynamics and engineering. In the coastal zone, a submerged breakwater has been increasingly popular, since it is one of nature-matching structures with multi- functions such as (1) wave energy dissipation by wave breaking and friction, (2) oxygen supply to sea by wave breaking and breaking wave, (3) water purification by entrained air bubbles, (4) keeping. good seascape. and (5) good habitat for sea livings. Recently, the breaking wave-induced high frequency pressure over a submerged breakwater is said to have a function of gathering sea livings around the structure, which has encouraged the construction of the submerged breakwater in coastal zone. (omitted)

  • PDF

Upwelling Proxy Improvement and Validation Using Satellite Remote Sensing along Southwest of the East Sea: Case Study in 2019

  • Kim, Deoksu;Bae, Dukwon;Choi, Jang-Geun;Jo, Young-Heon
    • 대한원격탐사학회지
    • /
    • 제38권4호
    • /
    • pp.387-394
    • /
    • 2022
  • Coastal upwelling is a significantly imperative process for understanding the interactions between physical and ecological processes and has been investigated incessantly. In this study, we explored the upwelling index, specifically upwelling age (UA). UA enabled us to observe the initiating, sustaining, and decaying upwelling processes. Although the sensitivity of many other geophysical parameters to estimate UA has been investigated, the wind direction has not been evaluated. Thus, we assessed the appropriate wind direction for the UA and obtained efficient upwelling signals from the four coastal stations. Furthermore, we applied the UA and compared it with the satellite sea level anomaly, sea surface temperature, and chlorophyll-a changes to validate how UA depicts their spatial extents. Thus, UA can predict the timing of coastal upwelling events using predicted geophysical parameters.