• Title/Summary/Keyword: coastal water

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Study on the Cold Mass Occurrence in the Eastern Coast of the Korean Peninsula in Summer (하계 한국동해안 냉수대 발생의 시공간적 분포특성)

  • Suh Young-Sang;Hwang Jae-Dong
    • Journal of Environmental Science International
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    • v.14 no.10
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    • pp.945-953
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    • 2005
  • Daily time series of longshore sea surface temperature (SST) data at 3 stations, sea surface SST data at 58 stations in the eastern coast of the Korean Peninsular from 2001 to 2005 were used in order to study the temporal and spatial variations of the upwelling coastal cold water occurred in summer season. When the cold water occurred, SST has been decreased more than $-5^{\circ}C$ in a day. The cold water occurred frequently in the eastern coastal areas of Korea such as Ulgi, Kampo, Jukbyun. Daily variations of cold water temperature were quantified using remote control buoy system at Kijang in the southeastern coastal water from July to August in 2004. Hourly variations of SST occurred around $\pm3^{\circ}C$ when cold water disappeared at Kijang. There were close relationship between the strength of East Korean Warm Current, North Korean Cold Water and the scale of spatio-temporal cold water variations in summer season.

Neighboring Cage Fish Farming Affecting Water and Seabed Quality of the Jordanian Northern Gulf of Aqaba, Red Sea

  • Mohammad, Al-Zibdah;Firas, Oqaily;Tariq, Al-Najjar;Riyad, Manasrah
    • Ocean Science Journal
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    • v.43 no.1
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    • pp.9-16
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    • 2008
  • Environmental qualities of coastal water and bottom sediment were assessed at Jordan's northernmost tip of Gulf of Aqaba to evaluate possible impacts of the bordering fish pen cages in Eilat. Results showed significant differences between surface and bottom water in the chemical and physical variables in the different months of the year (2004-2005). Chlorophyll a was also significantly higher in bottom water when compared to that of the offshore water. Nitrate and ammonia were significantly higher in bottom water than the surface water at each individual station. The upper 2 cm of sediment sample recorded higher values of total phosphorus and organic matter. Seasonality affected the content of total phosphorus, organic matter, redox potential and color especially at the sediment layer below 3 cm of the sediment core. The present investigation showed slight modification of water and sediment qualities but no clear sign of eutrophication was observed. However, to maintain sustainability of healthy environmental conditions at the northern tip of Gulf of Aqaba potentials of any possible environmental risks arising from the fish farms or any other coastal investment should be carefully considered.

A Study on the Additional Installation of Coastal Wave Buoys in Smooth Water Areas to Prevent Marine Accidents (해양사고 예방을 위한 평수구역 내 파고부이 추가설치 검토)

  • Min-Kyoon Kang;Dong-Il Seol
    • Journal of Navigation and Port Research
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    • v.47 no.6
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    • pp.350-357
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    • 2023
  • Marine accidents frequently occur due to the unreasonable operation of ships excluded from ship departure control during marine special weather warnings within smooth water areas. Coastal wave buoys installed in smooth water areas are major reference indicators for ship departure control and can be seen as being directly connected to the safety of ships navigating smooth water areas and the coast. In this study, the location appropriateness of currently operating coastal wave buoys and additional installation in the smooth water areas were assessed by analyzing coastal marine accidents over the past 30 years (1991-2020), the main wind direction and wind speed of each major trading port, and the GICOMS ship track data in 2018. The study results showed that an additional coastal wave buoy should be installed at each of the major trading ports(Inchon Port, Pohang Port, Ulsan Port, and Busan Port) and that the location of the coastal wave buoy needs to be moved in the case of Busan Port. Based on various data analysis in this study, the suggestion for an additional installation and movement of the coastal wave buoy presented in this study is expected to contribute to improving the reliability of ship departure control and resolving safety blind spots.

A Model Study of Hypoxia in the Rappahannock Estuary, Verginia

  • Park, Kyeong
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1995.10a
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    • pp.108-109
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    • 1995
  • Hypoxia has persisted during summer in the bottom water of the lower portion of the Rappahannock Estuary, a western shore tributary of Chesapeake Bay. A laterally integrated two-dimensional, real-time model, consisting of linked hydrodynamic and water quality models, was developed to study the contributing processes for hypoxia. The hydrodynamic model gives the information of physical transport processes, both advective and diffusive, to the water quality model, which simulates the spatial and temporal distributions of eight water quality state variables. (omitted)

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Optimal Groundwater Management Model for Coastal Regions Using Parallel Genetic Algorithm

  • Park, Nam Sik;Hong, Sung Hun;Shim, Myung Geun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.77-89
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    • 2004
  • A computer model is developed to assess optimal ground water pumping rates and optimal locations of wells in a coastal region. A sharp interface model is used to simulate the freshwater and salt water flows. Drawdown, upconing, saltwater intrusion and the contamination of well are considered in this model. A genetic algorithm with parallel processing is used to identify the optimal solution.

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A Numerical Simulation on the Formation of Coastal Cliff (해안단애의 형성에 관한 수치모의)

  • Kim, Nam-Hyeong;Kang, Hyeon-U;Shin, Moon-Seup;Nishi, Ryuichiro
    • Journal of the Korean GEO-environmental Society
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    • v.3 no.2
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    • pp.71-79
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    • 2002
  • A numerical simulation has been performed on the generation of the coastal cliff which lies as the distinct boundary between the beach and the hinterland. As a result of storm surge, it is known that the steeper the initial beach slope, the larger the generation of the coastal cliff. The rise of water level added the mean water level accelerates the generation of the coastal cliff. In addition, the longshore distribution of the incident wave height is one factor that bring about the generation of the non-uniform coastal cliff in longshore direction. Therefore this study will be able to use for expecting the formation and erosion of coastal cliff in sand beach.

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Wave Reflection over an Arbitrarily Varying Topography

  • Cho, Yong-Sik;Lee, Changhoon
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1997.10a
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    • pp.39-44
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    • 1997
  • As wind waves generated in deep water approach nearshore zone, they experience various physical phenomena caused by bathymetric variations, nonlinear interactions among different wave components and interferences with man-made coastal structures. Among these, the bathymetric variations may play a significant role in the change of wave climate. The accurate calculation of reflection and transmission coefficients of incident waves over a bottom topography is indispensible for the proper and economical design of coastal structures. (omitted)

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Wave Reflection from Partially Perforated Wall Caisson Breakwater

  • K. D. Suh;Park, W. S.;Lee, D. S.
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1996.10a
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    • pp.176-183
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    • 1996
  • In order to reduce wave reflection from a breakwater, a perforated wall caisson is often used. A conventional perforated wall caisson breakwater for which the water depth inside the wave chamber is the same as that on the rubble mound berm has less weight than a vertical solid caisson with the same width and moreover the weight is concentrated on the rear side of the caisson. (omitted)

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Prediction System of Hydrodynamic Circulation and Freshwater Dispersion in Mokpo Coastal Zone (목포해역의 해수유동 및 담수확산 예측시스템)

  • Jung, Tae-Sung;Kim, Tae-Sik
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.11 no.1
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    • pp.13-23
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    • 2008
  • In coastal region, eutrophication, Do deficit and red tide are frequently occurred by influx of fresh water. When the fresh water containing pollutants is discharged into the sea, the surrounding water is contaminated by dispersion of freshwater flowing into coastal waters. The prediction and analysis about the dispersion process of the discharged fresh water should be conducted. A modeling system using GUI was developed to simulate hydrodynamic flow and fresh water dispersion in coastal waters and to analyze the results efficiently. The modeling module of the system includes a tide model using a finite element method and a fresh water dispersion model using a particle-tracking method. This system was applied to predict the tidal currents and fresh water dispersion in Mokpo coastal zone. To verify accuracy of the hydrodynamic model, the simulation results were compared with observed sea level and time variations of tidal currents showing a good agreement. The fresh water dispersion was verified with observed salinity distribution. The dispersion model also was verified with analytic solutions with advection-diffusion problems in 1-dimensional and 2-dimensional simple domain. The system is operated on GUI environment, to ease the model handling such as inputting data and displaying results. Therefore, anyone can use the system conveniently and observe easily and accurately the simulation results by using graphic functions included in the system. This system can be used widely to decrease the environmental disaster induced by inflow of fresh water into coastal waters.

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