• Title/Summary/Keyword: Coastal engineering

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Effects of Wave Action on Seawater Intrusion in Coastal Aquifer and Mitigation Strategies (파랑작용이 해안대수층의 해수침투에 미치는 영향 및 저감방안)

  • Lee, Woo-Dong;Jeong, Yeong-Han;Hur, Dong-Soo
    • Journal of Ocean Engineering and Technology
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    • v.31 no.1
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    • pp.47-59
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    • 2017
  • This study conducted numerical simulations using LES-WASS-3D ver. 2.0 to analyze the seawater intrusion characteristics of the incident waves in a coastal aquifer. LES-WASS-3D directly analyzed the nonlinear interaction between the seawater and freshwater in a coastal aquifer, as well as the wave-current interaction in the coastal area. First, the LES-WASS-3D results were compared with the existing experimental results for the mean water level under wave action in the coastal aquifer and seawater penetration into the coastal aquifer. The mean water level, shape and position of the seawater-freshwater interface, and intrusion distance were well implemented in the results. This confirmed the validity and effectiveness of LES-WASS-3D. The overall seawater penetration distance increases in the coastal aquifer as a result of wave set-up and run-up in the swash zone caused by continuous wave actions, and it increases with the wave height and period. Furthermore, a numerical verification was performed by comparing the suggested existing structure and newly suggested curtain wall as a measure against seawater penetration. An existing underground dam showed a better effect with increased height. Additionally, the suggested curtain wall had a better effect when the embedded depth was increased.

Assessment of Coastal Landscape in Jeju City and Busan City (제주시와 부산시 해안변의 해안경관보전을 위한 경관평가)

  • Cho, Eun-Il;Lee, Byung-Gul
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.14 no.2
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    • pp.127-133
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    • 2008
  • We assessed the coastal landscape of Jeju and Busan cities, respectively. In the study, we tried to estimate the coastal landscape based on the micro-scale and visualization landscape concepts. According to the estimation, the seawater pumping line causes the serious problem of coastal landscape. It means that water management treatment system of coastal region has been an important problem in Jeju city and Busan city since the slight problem was not corrected such as the distributions of pipeline of the pumping system making a bad view in coastal region. To solve the problem, we observed the pipeline distributions that were on the surface around the coastal region. we proposed two methods, that is, one is a short time treatment, the other is a long time one. The short is based on the colour treatment, which is pipeline colour changing into surround natural one. The long time is the construction design method which needs construction management method. Although the later method was very useful in Jeju island and Busan city. However, it takes a lot of time and money. Therefore, in the situation, the short time plan is more useful method than the long time one.

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A Basic Study of an Integrated Digital Map Generation to an Electronic Navigational Chart and a Digital Topographic Map for Coastal Development and Management (연안 개발 및 관리를 위한 육·해도 통합수치도 제작에 관한 기초연구)

  • Yi, Gi-Chul;Park, Chang-Ho;Kim, Jeong-Hee;Suh, Sang-Hyun;Jeong, Hui-Gyun;Choi, Joon-Young
    • Journal of the Korean Association of Geographic Information Studies
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    • v.2 no.1
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    • pp.1-11
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    • 1999
  • The Korean government is developing a systematic plan of integrated coastal management for effective conservation, utilization, and development of coastal areas. For this plan, integrated maps of land maps and nautical charts are indispensable. However, these maps are not made, nor studied yet in terms of integration, although digital maps(DM) on land and electronic nautical charts(ENC) have been recently developed by Korean Geography Institute and National Marine Investigation Institute, respectively. In this study, as preliminary studies to make eventual integrated maps, the concept of coastal areas are defined, specifically, coastal lines from DM and ENC are matched against each other. Issues on map production procedures, coordinate systems, and map projections, are carefully considered. A test coastal area located in Seo-Gu, Pusan, over 14 km of coastal lines is selected for the edge matching of coastal lines. RMS differences are 13.83 m and 4.37 m over man-made coastal lines and natural coast lines, respectively, which are quite larger considering a scale difference and other factors. However, no systematic differences are found.

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Development of Predicting Function for Wind Wave Damage based on Disaster Statistics: Focused on East Sea and Jeju Island (재해통계기반 풍랑피해액예측함수 개발 : 동해안, 제주를 중심으로)

  • Choo, Tai-Ho;Kwon, Jae-Wook;Yun, Gwan-Seon;Yang, Da-Un;Kwak, Kil-Sin
    • Journal of the Korean Society for Environmental Technology
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    • v.18 no.2
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    • pp.165-172
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    • 2017
  • In current stage, it is hard to predict the scale of damage caused by natural disaster and it is hard to deal with it. However, in case of disaster planning level, if it is possible to predict the scale of disaster then quick reaction can be done which will reduce the damage. In the present study, therefore, function of wind wave damage estimation among various disaster is developed. Damage of wind wave and typhoon in eastern and Jeju coastal zone was collected from disaster report (1991~2014) published by Ministry of Public Safety and Security and to reflect inflation rate, 2014 damage cost was converted. Also, wave height, wind speed, wave direction, wave period, etc was collected from Meteorological Administration and Korea Hydrographic and Oceanographic Administration web site. To reflect the characteristic of coastal zone when wave damage occurs, CODI(Coastal Disaster Index), COSI(Coastal Sensitivity Index), CPII(Coastal Potential Impact Index) published by Korea Hydrographic and Oceanographic Agency in 2015 were used. When damage occurs, function predicting wind wave damage was developed through weather condition, regional characteristic index and correlation of damage cost.

Change of Coastal Ocean According to Kwang Yang Bay Development based on Landsat TM Images

  • Lee, Byung-Gul;Choo, Hyo-Sang;Lee, Gyu-Hyung
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.4 no.3
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    • pp.149-156
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    • 2000
  • This study presents an investigation of the changes that have occurred in the coastal ocean area of Kwangyang Bay located in the South Coastal region of Korea using remote sensing data based on Landsat Thematic Mapper (TM) multispectral digital data from 1988 and 1996. The coastal changes were detected using the digital histogram method and vector trace method. All the images were preprocessed, i.e. geometrically corrected, before the training set selection. when comparing the histograms of 7-band TM data, it was found that the band 5 image exhibited two critical Digital Number(DN) peaks, thereby indicating new coastal water and coastal land data. Based on this information, the coastal ocean area of the band 5 image was calculated using the vector tracing method supported by a CAD program. The result shows that the coastal ocean area decreased by about 5 % between 1988 to 1994. Accordingly, this gives a strong indication that the continuing land development will have a serious impact on the ecosystem of Kwangyang Bay.

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