• Title/Summary/Keyword: Coastal water

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Two-Dimensional Wave Flume with Water Circulating System for Controlling Water Level (수위 조절 회류시스템을 갖춘 2차원 조파수조)

  • Oh, Sang-Ho;Lee, Dal Soo
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.30 no.6
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    • pp.337-342
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    • 2018
  • Wave flume that enables generating water waves is a core research facility for physical experiment related to coastal engineering works. Recently, a new wave flume of 50 m length was constructed in Korea. The wave flume has a sloped section on its bottom. A novel wave generating system incorporating most-updated wave maker theory was introduced to the flume. In addition, water circulating system for adjusting water level was installed beneath the flume. These technical features and detailed specifications of the wave flume are described in this paper.

A Study on the Initial Behavior of Dredged Material Disposal in the Coastal Water (연안수역에서 투기준설토의 초기거동에 관한 연구)

    • Journal of Korean Port Research
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    • v.9 no.1
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    • pp.45-56
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    • 1995
  • Investigation of the physical behavior of dredged material disposal in coastal water includes estimations of water column concentration in the receiving water, exposure time, the initial deposition pattern as well as thickness of material at the dumping fields near the estuary area. Calculation based on vertical setting and horizontal advection of single particles ignore the effects of bulk properties of the disposed material, vertical and horizontal diffusion, and material dilution due to the entrainment of ambient water during descent. This paper focuses on the spatial and temporal changes in the dumping fields for the water column and bottom at a hypothetically confined coastal water, where the ambient time-invariant velocity and density profiles are applied, within the initial time period following the instantaneous release of the dredged material. This model accounts the behavior of material after release divided into three phases: convective descent, dynamic collapse and long-term passive dispersion

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Coastal Water Circulation Modeling with Water Exchange through Permeable Dike (투수성 호안제체을 통한 해수교환을 고려한 해수유동 모의)

  • Jung, Tae-Sung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.18 no.4
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    • pp.301-307
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    • 2006
  • In coastal zones with high tidal ranges like Korean western coast, port construction and reclamation projects have been increased. Most of the projects include sea-dyke construction. In the sea-dykes constructed to protect sea water intrusion, sea water was exchanged through the permeable dykes. The water level inside the area enclosed by the dykes changes with time due to tidal action of outer sea, but the tidal range is smaller than that of outside because of strong friction. In numerical modeling of coastal circulation the water exchange through the dykes has been neglected, which has produced inaccurate estimation neglecting the water exchange. In this study a method, which can consider water exchange through sea-dyke, was suggested and the modeling accuracy was improved. A groundwater theory was utilized to explain the phenomena.

Distribution of Anchovy Eggs and Larvae off the Western and Southern Coasts of Korea (한국남해 및 서해 연안해역에서의 멸치난치어의 분포)

  • KIM Jin Yeong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.16 no.4
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    • pp.401-409
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    • 1983
  • The distribution of anchovy eggs and larvae was studied using the ichthyoplankton samples and oceanographic data collected in the western and southern waters of Korea over the period of April through June in 1981 and 1982. Three water masses, the Tsushima Warm Current, the South Korean Coatal Water and the Yellow Sea Bottom Cold Water, are found to exert extensive influences of the distribution of anchovy eggs and larvae. The Tsushima Warm Current contacts with the South Korean Coastal Water to produce a coastal front between Cheju Island and Tsushima Island in the southern waters of Korea. Off the west coast of Korea, a coastal front is also formed running parallel with the western coast-line of Korea in the area between the Yellow Sea Bottom Cold Water and the extended part of the South Korean Coastal Water. In the southern waters of Korea anchovy eggs were found chiefly in the coastal waters inside the front, and larvae appeared to both sides on the front. The distribution of anchovy eggs and larvae off the west coast of Korea, however, was limited largely to the coastal waters of more than $12^{\circ}C$ in temperature. In the southern waters of Korea prelarvae appeared in the coastal area, and postlarvae in the offshore area. While in the western waters of Korea prelarvae were found in the southern part of the waters, and postlarvae in the northern part. Anchovy eggs and larvae were distributed in the considerably limited area of the coastal waters off the south coast of Korea in 1981 when the temperature gradient of the coastal front was sharper than in 1982.

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Study On The Coastal Cold Water Near Ulsan

  • Lee, Ki-Baik
    • 한국해양학회지
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    • v.13 no.2
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    • pp.5-10
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    • 1978
  • The coastal cold water near Ulsan, Korea, almost always appears in summer. From the results of some data analysis, it is found that this cold water has an important relation to the anticlockwise circulation appearing near the coast where the anticlockwise circulation turns its current direction from south to east.

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Distribution of Coastal Ground Water Discharge from Surficial Aquifers of Major River Districts (권역별 충적층 지하수의 해안 유출량 분포)

  • Han, Soo Young;Hong, Sung Hun;Park, Namsik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.1B
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    • pp.1-6
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    • 2006
  • Amount of coastal ground water discharge(CGD) of surficial aquifer via coastlines of Nakdong River watershed, Seomjin River watershed, Youngsan River watershed and Keum River watershed is estimated. Compared to other major hydrological components, such as evapo-transpiration and river discharge, CGD is not so large in the amount. However, it is important since coastal ground water can be developed relatively free of environmental impact on downstream area and since most of coastal areas currently suffers water shortage. Regional groundwater investigation data and assessment based on Darcy's law are used for estimating coastal groundwater discharge. In this work the amount of CGD across the coastlines of the four rivers is estimated as 1.8 billion cubic meter per year and that is about 2.3 percentage of total amount of annual precipitation. Nakdong River watershed is most appropriate region in view of developing groundwater.

Evaluation of the Possibility of Developing Organic Matter Indicators in Coastal Environments: Utilization of Dissolved Organic Carbon and Fluorescent Dissolved Organic Matter (연안환경에서 유기물 지표 개발을 위한 가능성 평가: 용존유기탄소와 형광용존유기물질 활용)

  • Lee, Min-Young;Yang, Kyungsun;Kim, Sunchan;Kim, Tae-Hoon
    • Ocean and Polar Research
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    • v.43 no.2
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    • pp.65-72
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    • 2021
  • In order to evaluate the dissolved organic carbon (DOC) and fluorescent dissolved organic matter (FDOM), as indicators of organic matter in the coastal environments, we measured the concentrations of DOC, FDOM, and chemical oxygen demand (COD) in saline groundwater (Woljeong, Pyoseon, and Hwasun beaches) and coastal seawater (Haengwon, Gwideok, Pyoseon, and Yeongnak) in Jeju, Korea. The highest concentrations of DOC and COD in groundwater were found in Woljeong and Pyoseon, and those in coastal water were observed in Haengwon and Pyoseon, indicating that the higher concentrations of DOC and COD seem to be associated with saline groundwater-driven dissolved organic matter (DOM) and/or biogeochemical processes. According to origin and optical properties of DOM using FDOM as a tracer, proportion of humic-like FDOM, more refractory DOM, was relatively greater in the groundwater than in the coastal water. With regard to this result, there was no relationship between DOC and COD in groundwater, while DOC showed a good positive correlation (r2 = 0.66) with COD in coastal water. This result indicates that COD as an indicator of assessment of DOM has a limitation in which it is difficult to quantify refractory DOM. Although DOC is a potential alternative to COD in the coastal environments, particulate organic carbon cannot be negligible due to relatively higher concentration compared to the open ocean. Therefore, the use of total organic carbon (TOC) as a replacement of COD in the coastal ocean is important, and the evaluation criterion of the TOC is necessary in order to evaluate of organic matter indicator in the various coastal environments.