• Journal of Ocean Engineering and Technology
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• v.15 no.4
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• pp.28-37
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• 2001

The water quality in Yongil Bay is getting worse due to the sewage and the waste water from the surrounding industrial complex. The study aims to simulate the current system that is necessary to build ecosystem model for the optium water quality control and clarify the correlation of current system characteristics with water quality in Yongil Bay. To clarify the characteristics of coastal water movement system and verify the applicability of the 3-D model, the current system was simulated using 3-D model baroclinic model which considers tidal current and density effects. As the results of numerical experiments, it is proved the 3-D model is the most applicable on appearing the current system of the stratificated Yongil Bay difference of density. Form the results of simulation considered tidal current only, it can be clarified that the water body flows in the inner bay through the bottom layer and flows out the outer bay through the surface layer in Yongil Bay. And the fresh water from the Hyongsan river and the thermal discharge form POSCO have a little effect on the current system in Yongil Bay, but the diffusion of heat and salt has an important effect upon the formation of the density stratification of the water quality distribution is closely related with the current structure characteristics as well as the tidal residual current system in Yongil Bay.

• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.13-14
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• 2003

It is generally well known that Quaternary is characteristic geologically in terms of glacial and interglacial repeats and their associated unconformity formation. This paper deals with the first finding of the characteristic and significant meaningful unconformity between Holocene and late Pleistocene, which implies submergence and emergence of the tidal sedimentary basin along the western coastal zone of Korea during interglacial stage(IOS-5e) and glacial time(IOS-2). The stratigraphy of intertidal deposits in the Haenam Bay, western coast of Korea shows two depositional sequence units (Unit I of Holocene and Unit II of late Pleistocene) bounded by an erosional surface of disconformity. The disconformity is related to the latest Pleistocene sea-level lowstands (probably during the LGM). The Unit II is interpreted as intertidal deposit showing tidal sedimentary structures and crab burrow ichnology and has two parts (the upper part and the lower part) showing different lithology and character. The upper part of Unit II shows characteristic subaerial exposure features (emergence) and its related lithology. Such subaerially exposed upper part (more or less 4m to 5m in thickness) is characterized by yellow-brownish sediment color, cryoturbat-ed structure, crab burrow ichnofacies and high value of shear strength. Geochemical and clay mineral analyses of the upper part sediments also indicate subaerial exposure and weathering. In particular, very high value of magnetic susceptibility of the upper part in comparison to that of the lower part is interpreted as pedogenetic weathering during the subaerial exposure period.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.10a
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• pp.246-252
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• 2000

The water quality in Yeongil Bay is getting worse due to the sewage and the waste water from the surrounding industrial complex The study aims to simulate the current system that is necessary to built ecosystem model for the optium water quality control and clarify the correlation of current system characteristics with water quality in Yongil Bay. To clarify the characteristics of coastal water movement system and verify the applicability of the 3-D model, the current system was simulated using 3-D baroclinic model considered tidal current and density effects. As the results of numerical experiments, it is proved the 3-D model is the most appliable on the Yongil Bay where current flows slowly and the flow direction is varied by depths. From the results of simulation considered tidal current only, It am be clearly said the water in Yongil Bay flows in through the surface layer and flows out through the bottom layer. And the fresh water from the Hyongsan river and the heated discharge from POSCO have little effect on the current structure in Yonggil Bay, but have and important effect upon the density structure by diffusion of heat and salt. And the water quality distribution is closely related with the current structure characteristics as well as the tidal residual current system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.194-198
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• 2004

This study was conducted to identify the appropriate nitrogen fertilizer application rate for improving rice quality in tidal reclaimed area, at the Gyehwado substation of the Honam Agricultural Research Institute during 2002-2(103. The experimental fields contained 0.1% (low salinity) and 0.3-0.4% (medium salinity) Nacl in soil solution. Plant height at panicle formation stage was tall ay heavy nitrogen level and the effect of heavy nitrogen was higher in low than in high soil salinity condition. Heading date was not affected by applied nitrogen levels from 8 to 16 kg/10a in low soil salinity condition but it was one day later in 24 kg/10a nitrogen level when compared with the standard nitrogen level,20 kg/10a. In middle soil salinity condition, the heading date was one day earlier in 8 to 16 kg/10a and similar in 24 kg/10a, when compared with 20 kg/10a nitrogen level. And also it was four days later in middle than in low soil salinity condition. In low soil salinity condition, grain number $\textrm{m}^2$ increased but ripened grain ratio decreased as the nitrogen application increased and finally, milled rice yield was not different among heavy nitrogen application levels compared with 12 kg/10a. Head rice ratio was high and protein content was low in 12 kg/10a or lower nitrogen level. In middle soil salinity condition, grain number $\textrm{m}^2$ increased and ripened grain ratio was not affected as the nitrogen application increased. And finally, milled rice yield increased with increasing nitrogen application levels, Head rice ratio was high and protein content was not affected by nitrogen application levels. Therefore, on the basis of milled rice yield and rice grain quality inreclaimed land, the appropriate nitrogen application level would be 12 kg/10a in low soil salinity condition and 20 kg/10a in middle soil salinity condition.

• Journal of the Korean earth science society
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• v.24 no.1
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• pp.46-60
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• 2003

In Namyang Bay of western Korea, macrotidal-flat deposits are divisible into three late Quaternary units: Unit M1 of upper marine mud, Unit T1 of middle siderite-bearing terrestrial clay, and Unit M2 of lower marine mud. Unit M1 represents typical Holocene intertidal mudflat deposits, showing a coarsening-upward textural trend. It probably resulted from the continual retrogradation of tidal flat during the mid-to-late Holocene sea-level rise. Reddish brown-color Unit T1 consists of homogeneous clay with abundant freshwater siderite grains and plant remains. Unit T1 is clearly separated from the overlying Unit M1 by a sharp lithologic boundary. Radiocarbon age, siderite grains and lithologic features indicate that Unit T1 is originated from freshwater bog or swamp deposition infilling the localized topographic lows during the early Holocene age. Overlain unconformably by early Holocene swamp clay, Unit M2 is orange to yellow in color and mottled, suggesting significant degree of weathering during the sea-level lowstand. Such subaerial oxidation is confirmed in the vertical profiles of geotechnical properties, clay mineral assemblages and magnetic susceptibility. Unit M2 appears to be correlated with the upper part of the late Pleistocene tidal deposits developed along the western Korean coast. The sedimentary succession of the Namyang-Bay tidal-flat deposit provides stratigraphic information for the Holocene-late Pleistocene unconformity and also permits an assessment of the preservation potential of the late Pleistocene marginal marine deposit along the western coast of Korea.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.12 no.4
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• pp.203-209
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• 2000

Mokpo coastal zone suffers from increase of tidal amplitude by the reclamation projects of Youngsan River Scadike, Youngam and Keumho Seawalls, resulting inundation oflower lands. Tidal records at Mokpo harbor show jumps just after each construction not only in the mcan high water level but also in extreme one. Thus the design water levels must be newly estimated by a frequency analysis with the data of period after the last construction. But this period is at most 6 years yet, which restrains the normal frequency analysis. In this paper, new approach of converting the past data to the present one by a numerical model is proposed. Converted 32 years and observed 6 years data enables normal frequency analysis.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.98-105
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• 2023

This paper studies the effects of global climate change on Gyeonggi Bay and appropriate adaptation strategies. Located along the west coast of Korea, Gyeonggi Bay is renowned as one of the five most important global tidal flats (wetlands). Due to climate change in Gyeonggi Bay, the water temperature is predicted to increase by 1.44 ℃ by the year 2100, the salinity to decrease by 1.1 PSU, the sea level to rise by 35.2 cm, and approximately 150.5 km² of the coast to be submerged due to the rising sea levels. Adaptation strategies to combat negative impacts of climate change on the ecological environment of Gyeonggi Bay include 1) supporting the self-adaptation capability of Gyeonggi Bay's natural environment to be sustainable, and 2) protecting lowlands adjacent to tidal flats and low-lying areas of the coast against human involvement to reserve more space for upslope shifts of biota with rising sea levels.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2006.09a
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• pp.189-192
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• 2006

• Proceedings of the Korea Contents Association Conference
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• 2010.05a
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• pp.638-640
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• 2010

본 연구에서는 조력발전소 가동조건을 적용한 발전량 산정 프로그램을 이용하여 시화호 홍수위를 분석하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.11 no.2
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• pp.35-41
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• 1993

The height differences in Mean Sea Level is an important factor in geodetic leveling net, because MSL is the reference datum for height. Geodesists and Oceanographers agree on the height differences in MSL in the east-west direction, but they disagree almost always on the north-south slope, each suspecting systematic errors in the leveling methods of the others. A promising method for determining this slope is comparison of MSL at the tidal station connected by geodetic leveling. The slopes of the sea surface along the coast of Korean Peninsular is estimated from conventional local MSL at the tidal station and bench mark height of first order leveling net in Korea. As a reference level surface, MSL at Inchon is chosen. The results indicate that sea level rises along coast of Korean Peninsular from south to north about 5.5 cm/latitude. In the east-west direction, sea level along East Sea coast stands about 5 cm higher than that along Yellow Sea coast. These are not invariable but provisional phenomena. It may become certain provided that the exact MSL is estimated.