• Title/Summary/Keyword: Coastal Areas

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Numerical Simulation for Currents and Sedimentation due to Tsunami

  • Imamura, Fumihiko
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1992.08a
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    • pp.157-157
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    • 1992
  • Accuracy of numerical simulations of tsunami has a often been discussed in terms of the final run-up heights and inundated areas. The present technique of simulation is said to yield accurate results within an error of 15 % as long as run-up height concerns.(omitted)

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A Study on the Economic Values and Productivity Attained through a Reduction in Fishing Vessels Engaged in Coastal and Offshore Fisheries (연근해어업 어선감척사업으로 인한 생산성 및 투자 효과에 관한 연구)

  • Choi, Jong Du
    • Ocean and Polar Research
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    • v.36 no.4
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    • pp.343-351
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    • 2014
  • The purpose of this study is to estimate the economic value and productivity achieved through a reduction in fishing vessels engaged in coastal and offshore fisheries. We found that the value of increasing catch by types in offshore and coastal fisheries was about 17,338 billion won. To examine the economic value, a cost-benefit analysis was applied. This is based on the total cost of vessel reduction (4,576 billion won) assumed to be invested equally each year for five years. BCR and NPV with a discount rate (5.5%) were used to compare the profit of fishery activities in offshore and coastal areas. The model results showed that the NPV and BCR in offshore and coastal fisheries was 5,522 billion won and 2.340 respectively.

Numerical Analysis for Wave Propagation and Sediment Transport with Coastal Vegetation (연안식생에 의한 표사이동 특성에 관한 수치해석)

  • Lee, Seong-Dae
    • Journal of Ocean Engineering and Technology
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    • v.21 no.5
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    • pp.18-24
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    • 2007
  • The environmental value of coastal vegetation has been widely recognized. Coastal vegetation such as reed forests and seaweed performs several useful functions, including maintaining water quality, supporting fish (and, thus, fisheries), protecting beaches and land from wave attack, stabilizing sea beds and providing scenic value. However, studies on the physical and numerical process of wave propagation, sediment transport and bathymetric change are few and far between compared to those on the hydrodynamic roles of coastal vegetation. In general, vegetation flourishing along the coastal areas attenuates the incident waves through momentum exchange between stagnated water mass in the vegetated area and rapid mass in the un-vegetated area. This study develops a numerical model for describing the wave attenuation and sediment transport in a wave channel in a vegetation area. By comparing these results, the effects of vegetation properties, wave properties and model parameters are clarified.

Research Perspectives for Developing Seawater Intrusion Indicators in Changing Environments with Case Studies of Korean Coastal Aquifers: A Review

  • Chang, Sun Woo;Kim, Il Hwan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.44 no.4
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    • pp.465-482
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    • 2024
  • The global use of groundwater in coastal areas has increased. Events such as seawater intrusion (SWI) are expected to increase along with the acceleration of natural disasters owing to environmental changes such as climate change, resulting in large-scale damage worldwide. Current trends in the research of coastal groundwater and related natural disasters include testing and verifying technologies using major case studies from individual countries. We identified global research trends in coastal groundwater, related these trends to changing environments and climate, and confirmed the qualitative and quantitative growth of these studies. This study describes the theoretical background and techniques for coastal groundwater analysis and details regional-scale SWI indicators based on analytical and numerical studies. This review highlights recent technologies that consider uncertainty and promotes discussions on field data obtained using new technologies. Finally, the research findings and trends for a regional coastal aquifer in Korea are discussed to describe recent SWI approaches for groundwater resources.

Assessing Habitat Quality and Risk of Coastal Areasin Busan (부산 연안역의 서식지 질 및 위험도 평가)

  • Jeong, Sehwa;Sung, Kijune
    • Journal of Environmental Impact Assessment
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    • v.31 no.2
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    • pp.95-105
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    • 2022
  • Busan, where the coastal ecosystem health is deteriorating due to high development pressure and intensity of use, needs ecosystem management that considers humans and the natural environment together for sustainable use and ecosystem preservation of the coastal areas. In this study, the InVEST model was applied to assess the habitat status of the coastal land and coastal sea to manage the ecosystem based on habitats. As a result of the assessment of the coastal land, the habitat quality of Gadeok-do, Igidae, and Sinseondae, Gijang-gun are high, and Seo-gu, Jung-gu, Dong-gu, and Suyeong-gu are low. In the case of the coastal sea, the habitat risk of the Nakdong river estuary is low, and some areas of Yeongdo-gu, Saha-gu, Gangseo-gu are high. Therefore, for the sustainable use and preservation of coastal ecosystems, it is necessary to prepare ecosystem-based management measures to improve damaged habitats and reduce threats. In addition, the impact on coastal seas should be fully considered when planning coastal land development. The results of the InVEST habitat quality model in coastal land show similar tendencies to the biotope and environmental conservation value assessment map. The results of the habitat risk assessment in the coastal sea are expected to be utilized to identify habitats in the coastal sea and management of threat factors.

Development and Application of a Coastal Disaster Resilience Measurement Model for Climate Change Adaptation: Focusing on Coastal Erosion Cases (기후변화 적응을 위한 연안 재해 회복탄력성 측정 모형의 개발 및 적용: 연안침식 사례를 중심으로)

  • Seung Won Kang;Moon Suk Lee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.7
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    • pp.713-723
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    • 2023
  • Climate change is significantly affecting coastal areas, and its impacts are expected to intensify. Recent studies on climate change adaptation and risk assessment in coastal regions increasingly integrate the concepts of recovery resilience and vulnerability. The aim of this study is to develop a measurement model for coastal hazard recovery resilience in the context of climate change adaptation. Before constructing the measurement model, a comprehensive literature review was conducted on coastal hazard recovery resilience, establishing a conceptual framework that included operational definitions for vulnerability and recovery resilience, along with several feedback mechanisms. The measurement model for coastal hazard recovery resilience comprised four metrics (MRV, LRV, RTSPV, and ND) and a Coastal Resilience Index (CRI). The developed indices were applied to domestic coastal erosion cases, and regional analyses were performed based on the index grades. The results revealed that the four recovery resilience metrics provided insights into the diverse characteristics of coastal erosion recovery resilience at each location. Mapping the composite indices of coastal resilience indicated that the areas along the East Sea exhibited relatively lower coastal erosion recovery resilience than the West and South Sea regions. The developed recovery resilience measurement model can serve as a tool for discussions on post-adaptation strategies and is applicable for determining policy priorities among different vulnerable regional groups.

Distribution of Dissolved and Particulate Organic Carbon in the East China Sea in Summer (하계 동중국해에서의 용존 및 입자유기탄소의 분포 특성)

  • Kim, Soo-Kang;Choi, Young-Chan;Kim, Jin-Seok
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.11 no.3
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    • pp.124-131
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    • 2008
  • This study was conducted around the southwest sea areas of Jeju and coastal sea areas of China in August 2003 and September 2004 to research distribution patterns of dissolved inorganic nutrients, dissolved and particulate organic carbon. Distribution patterns of nutrients in the East China Sea in summer were shown to be influenced by water masses and phytoplankton. Water masses in the East China Sea in summer, except for coastal sea areas of china, showed less vertical mixing process, causing decline in the inflow of nutrients to surface water. Bottom water, however, showed high concentration, since nutrients made by dissolved organic matters from surface water were accumulated at the bottom. Sea areas with high concentration of chlorophyll a showed low concentration of nutrients and vice versa, indicating biological activities control dissolved inorganic nutrients. The distribution of dissolved organic carbon didn't show any correlation with salinity, temperatures, and water masses. Areas around the river mouth of the Changjiang showed high concentration of dissolved organic carbon more than $100{\mu}M$, but relatively low concentration in the southwest sea areas of Jeju, indicating that the river mouth of the Changjiang coastal water has a great influence on dissolved organic carbon in the East China Sea. Distribution patterns of particulate organic carbon in the research areas showed the highest concentration of average $9.23{\mu}M$ in coastal areas of China influenced by the river mouth of the Changjiang coastal water. By comparison, the concentration was relatively low at $3.04{\mu}M$ in the southeast sea areas of Jeju on which the Taiwan warm current has influence, and was $7.23{\mu}M$ in the central sea areas of Jeju. Thus, there is much indication that the river mouth of the Changjiang coastal water serves as a supplier of particulate organic carbon along with autogenous source. In general, if particulate organic carbon has a high correlation with the concentration of Chlorophyll a, it is thought that it is originated from autogenous source. However, the southeast sea areas of Jeju shows low salinity below 30, therefore it is proper to think that its origin is terrestrial source rather than that of autogenesis.

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Atmospheric Corrosion of Hot Dip Zinc Coated Steel in Coastal and Rural Areas of Vietnam

  • Tru, Nguyen Nhi;Duyen, Le Khac;Han, Tran Mai
    • Corrosion Science and Technology
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    • v.16 no.5
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    • pp.241-246
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    • 2017
  • The comparative results of corrosion testing in humid tropical atmosphere in rural and coastal areas for hot dipped zinc coatings are presented below. The test was conducted in outdoor conditions over a period of five years. The mass loss and other performance characteristics of two types of zinc coatings were evaluated, analysed and discussed in relation to the climatic and environmental parameters. The corrosion rates of the coatings exposed to coastal conditions were about three times higher than the corrosion rates appreciated in rural conditions. The data demonstrates that the corrosion process obeys an equation of the form $M=At^n$, where M is the loss of metal and t is the time of exposure. A and n are constants which values depend on the environmental characteristics and the physicochemical behavior of the corrosion products respectively. Corrosion is strongly influenced by atmospheric time of wetness (TOW) and airborne salinity. The nature and composition of corrosion products are also considered. Simonkolleite, a major crystalline phase, was found in the zinc corrosion products exposed to coastal conditions, while zinc hydroxide and zinc hydrosulfate are easily found in rural settings.