• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.4
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• pp.320-324
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• 2008

In order to identify the change of tidal characteristics on average in the Asan Bay due to the construction of the Hwaong (Namyang Bay) tidal barrier (HTB), the tide data at Pyongtack (PT) and Anheung (AH) for the periods from 1993 to 2006 were analyzed using the harmonic analysis method, and major and shallow water tidal constituents were compared. The semidiurnal tidal amplitudes at PT increased while those at AH decreased after the tidal barrier construction. In particular, the amplitudes at PT increased abruptly during the period of $2002{\sim}2003$ when HTB was completed. On the other hand, the amplitudes of the diurnal tides at PT and AH showed minimal change. This suggests that the tidal characteristics change in the Asan Bay may be related to the construction of HTB. The cause of this change is different from either blocking the tidal wave propagation by the Keum River tidal barrier or removing 'choking effect' by the Yeongsan River tidal barrier. The $M_4/M_2$ ratio increased and their phase difference decreased after the completion of HTB. Accordingly, these changes may result in increase of tidal range, decrease of the flood duration and increase of the flood current velocity, inducing more sediments into the Asan Bay.

• Journal of the Korean earth science society
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• v.22 no.1
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• pp.30-39
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• 2001

To consider the distribution of the surface sediments and sedimentary processes in tidal flat after the construction of sea-walls in the semiclosed Muan Bay, the southwest coast of Korea, studies on the sediments and sedimentation rates along two transect lines from February 1999 to March 2000 were carried out. The surface sediments in the bay are classified into 5 facies on the basis of textural parameters. The gravelly sediments including the cobbles and pebbles deposited in the bay-mouth are relic sediments which are formed in nearshore and fluvial environments at the low stand of sea level. In addition, it is considered that the muddy sediments widely distributed on the tidal flat might be originated from suspended matter transported from several rivers and/or offshore. Although the sedimentation rates on the tidal flat vary with season, their estimation rates are -8.9 mm/yr on Line-GR and -48.9 mm/yr on Line-YH, respectively. The erosion-dominated processes in the tidal flat would be caused by strengthened ebb tides due to the decrease of tidal choking at Mokpogu and the migration of tidal currents at the bay-mouth. The hydrodynamical changes mentioned above are interpreted to be occurred after/before the construction of sea-dike/sea-walls in coastal zone of Mokpo.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1007-1011
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• 2004

영산강하구언과 영암 및 금호방조제 건설에 의해 목포해역에서는 조석확폭현상이 발생하여 만조위가 상승함에 따라 저지대에 침수피해를 야기시킨 바 있다. 이는 목포구의 'tidal choking effect' 기능이 상실됨에 기인한다는 결론을 선행인구(강주환, 1996)에서 얻은 바 있다. 본 인구에서는 선행연구에 비해 전체 영역이 확대되었으며 격자크기가 작아졌을 뿐 아니라 관심영역에는 세부역을 도입하여 더욱 세밀한 격자체계를 구성하였다. 이에 따라 조간대 처리가 한층 정밀해졌으며, 천해조 경계조건 부여와 함계 낙조우세를 실제에 가깝게 재현시킬 수 있게 되었다. 또한 방조제 건설후 낙조우세가 심화되는 자정을 모의할 수 있게 됨에 따라 소류사 이동양상의 변화된 패턴 역시 파악할 수 있었으며, 만조위 상승에 따른 침식유발 효과와 더불어 인근 해역의 침식 원인을 부분적으로 규명할 수 있었다.

• Journal of Navigation and Port Research
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• v.29 no.4
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• pp.327-333
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• 2005

Sea level (MSL, MHWL, or MLWL) change has been main concern to scientists and engineers and it can be primarily due to both change of climate and vertical movement of land. This paper reports the intensive analysis of the sea level changes and broad discussion of the future at the southwestern coast of Korean peninsula. Regression analysis was conducted to investigate general tendency and periodicity of the sea levels at the six different study sites such as Gunsan-I(inner port), Gunsan-O(outer port), Mokpo, Yeosu, Heuksan and Jeju and the results were compared with global values. Besides the changes of sea levels due to global warming, the influence of the man-made structure such as seadike and seawall was attempted to quantify using the minimization of the Root Mean Square(RMS) error. The results show that it is a general tendency that the values of mean sea level rise at the southwestern coast of Korean Peninsula, especially at Gunsan-I and Jeju, are somewhat larger compared to global average values. There is also some evidence that tidal amplifications are found just after construction of man-made structure at Gunsan-I and Mokpo. However, both sites show different mechanism in relation to tidal choking, tidal flat and river discharge. The impact due to construction of man-made structure is considerably larger at Mokpo site, while the impacts due to man-made structure and the effect of sea level rise are relatively identical at Gunsan-I site. This study is expected to provide some intuition to future design.