• The Journal of the Petrological Society of Korea
• /
• v.16 no.4
• /
• pp.208-216
• /
• 2007

Based on digital geologic and geomorphic maps of 1 : 250,000 scale, distributive ratios of rock types were obtained by ArcGIS 9.0 program in the Gyeonggi, Seoul and Incheon areas of the Gyeonggi province. In the Gyeonggi area, 37 rock types are developed, and their geologic ages can be classified into Precambrian, Age-unknown, Triassic, Jurassic, Cretaceous and Quatemary. Among them, distributive ratios are decreasing in the order of Jurassic Daebo granites, Precambrian banded gneiss of Gyeonggi gneiss complex and Quatemary alluvium, all of which comprise about 83.7% of the rock types in the area. In the Seoul and Incheon areas, 10 and 15 rock types are developed, respectively., with the firmer being classified into Precambrian, Jurassic and Quatemary, and the latter into Precambrian, Jurassic, Cretaceous and Quatemary. In the Seoul area, distributive ratios are decreasing in the order of banded gneiss of Gyeonggi gneiss complex, Daebo granites and alluvium, which consist of 95.5% of the rocks in the area. In the Incheon area, distributive ratios are decreasing in the order of alluvium, Daebo granites, banded gneiss of Gyeonggi gneiss complex, reclaimed land, and schists of Gyeonggi gneiss complex, which occupy about 96.2% of the rocks in the area. The ratio of alluvium in the Incheon area is greater than that of Gyeonggi and Seoul areas, and the ratio of reclaimed land in the Incheon area is greater that of the Seoul, which can be attributed to the recent reclamation of the land for the industrial results such as new town development along the coastline of the Gyeonggi Bay.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2004.04a
• /
• pp.179-186
• /
• 2004

Introduction of wave model, considered the effect of shoaling, refraction, diffraction, partial reflection, bottom friction, breaking at the coastal waters of complex bathymetry, is a very important factor for most coastal engineering design and disaster prevention problems. As waves move from deeper waters to shallow coastal waters, the fundamental wave parameters will change and the wave energy is redistributed along wave crests due to the depth variation, the presence of islands, coastal protection structures, irregularities of the enclosing shore boundaries, and other geological features. Moreover, waves undergo severe change inside the surf zone where wave breaking occurs and in the regions where reflected waves from coastline and structural boundaries interact with the incident waves. Therefore, the application of mild-slope equation model in this field would help for understanding of wave transformation mechanism where many other models could not deal with up to now. The purpose of this study is to form a extended mild-slope equation wave model and make comparison and analysis on variation of harbor responses in the vicinities of Pohang Old Harbor and Pohang New Port, etc. due to construction of New Port in Youngil Bay. This type of trial might be a milestone for port development in macroscale, where the induced impact analysis in the existing port due to the developemnt could be easily neglected.

• Journal of Navigation and Port Research
• /
• v.28 no.5
• /
• pp.421-428
• /
• 2004

Introduction of wave model, considered the effect of shoaling, refraction, diffraction, partial reflection, bottom friction, breaking at the coastal waters of complex bathymetry, is a very important factor for most coastal engineering design and disaster prevention problems. As waves move from deeper waters to shallow coastal waters, the fundamental wave parameters will change and the wave energy is redistributed along wave crests due to the depth variation, the presence of islands, coastal protection structures, irregularities of the enclosing shore boundaries, and other geological features. Moreover, waves undergo severe change inside the surf zone where wave breaking occurs and in the regions where reflected waves from coastline and structural boundaries interact with the incident waves. Therefore, the application of mild-slope equation model in this field would help for understanding of wave transformation mechanism where many other models could not deal with up to now. The purpose of this study is to form a extended mild-slope equation wave model and make comparison and analysis on variation of harbor responses in the vicinities of Pohang Old Harbor and Pohang New Port, etc. due to construction of New Port in Youngil Bay. This type of trial might be a milestone for port development in macroscale, where the induced impact analysis in the existing port due to the development could be easily neglected.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.8 no.1
• /
• pp.35-43
• /
• 2003

Recent geomorphological changes and late Quaternary depositional sequences of Gwangyang Bay are studied based on bathymetric maps, surface sediments, and seismic profiles. As a result of the reclamation of coastal area for an industrial complex construction, the coastline of Gwangyang Bay has rapidly been changed and the area of it has now been reduced by about 25 ％ in the last 30 years. In addition, the bottom topography is actively modified by dredging for navigation channels. In surfical sediment distribution, the western part of Gwangyang Bay is dominated by mud facies, whereas the eastern part of the Bay is dominated by sand-mud mixing facies. Depositional sequences above the basement are divided into two units: Unit I in upper layer and Unit II in lower one. These depositional units are unconformably bounded by middle reflector-M. Unit II, mostly occupying the channel areas, is interpreted as fluvial-origin deposits during sea-level lowstand. Unit I typically shows a progradational pattern from the Seomjin River mouth to the Yeosu Strait, which is interpreted as deltaic deposits supplied from the Seomjin River during the Holocene sea-level highstand. The shallow gas within the sediments Is widely distributed in most area, and locally exposed onto the sea-bed due to dredging.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.34 no.5
• /
• pp.135-143
• /
• 2022

Rock platforms and TTP (breakwater) are dangerous environments commonly subject to tidal and high wave energy on the open coast. This paper is a study on risk assessment to provide risk information, which is a representative method for preventing coastal safety accidents. Risk assessment based on geo-morphological information was conducted for the Halmi-Halabi rock platform in Anmyeon-eup, Taean-gun, Chungcheongnam-do. As a result of the risk assessment in 16 directions, the risk was evaluated high in the NE, ENE, S, SSW, and W directions, where there are many sections with slopes exceeding ±20°, and the NW direction was the lowest. Geo-morphology on rock platform is central to understanding what makes one stretch of complex coastline more hazardous than another, and it can be used to create site-specific morphological risk item. In particular, it will be assisting coastal managers in an effort to reduce the number of injuries and drowning incidents by providing hazard information to assess the relative risk.