• Journal of the Korean earth science society
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• v.37 no.2
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• pp.89-106
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• 2016

The Gochang open-coast intertidal flat is located in the southwestern coast of Korea (the eastern part of the Yellow Sea), characterized by macro-tidal range, an open-coast type, and sand substrates. This study has investigated seasonal variation in sedimentary facies of surface sediments in the Gochang intertidal flat. In the four seasons of February, May, August, and November, 2014, surface sediments of 252 sites in total were sampled and analyzed along three survey lines. The surface sediments of the Gochang intertidal flat in 2014 consisted mainly of fine-grained sand sediments showing a trend in grain size to be coarser in winter and finer in summer. Based on seasonal wave and tidal level data recorded near the study area, it was interpreted that the seasonal effects of wave were stronger than those of tide as a factor controlling surface sedimentation. High waves in winter resulted in the coarsening trend of grain size in surface sediments, whereas, during summer time, the sediments became finer by relatively low waves. Spatial sedimentary facies of the Gochang intertidal flat in 2014 represented that seasonal deviation of the upper tidal zone was larger than that of the lower tidal zone, hence sediments getting coarser in grain size and poorly sorted in the upper tidal zone. From upper to lower tidal zone, the grain size became finer and sediments were better-sorted, showing smaller seasonal deviations.

• The Korean Journal of Quaternary Research
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• v.34 no.1
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• pp.15-30
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• 2024

Typhoon effects on macrotide open-coast intertidal sediments were investigated in the Gochang Gwangseungri sandy intertidal flat on the Korean western coast. Variations in the surface sediment texture, accumulation, and sedimentary facies were observed before and after the Typhoon Kompasu in 2010. The typhoon Kompasu landed on the southwestern coast of the Korean Peninsula and passed inland between September 1st and 2nd, 2010, respectively. Surface sediments and their accumulation before and after the typhoon were sampled and measured at intervals of 30 m along a survey line on the Gwangseungri intertidal flat. The intertidal areas were divided into high, middle, and lower tidal zones based on the mean high-wate level, mean sea level, and mean low-water level, respectively. The surface sediments of each tidal zone show rare variations in grain size and sorting of sediment texture before and after the typhoon Kompasu, whereas negative skewness values increased in the middle and lower tidal zones after the typhoon rather than before the typhoon. Surface accumulation represents deposition in the upper and middle tidal zone and erosion in the lower tidal zones after the typhoon. The accumulation decreased from the high to the lower tidal zones.

• Journal of the Korean earth science society
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• v.40 no.2
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• pp.149-162
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• 2019

In the macro-tide open coast of the Korean western coast, typhoon effects were investigated in terms of variations on topography, surface sediment, and sedimentary environment, which appeared before and after the typhoon Kompasu of 2010. The Kompasu of small size and strong intensity landed on the southwestern coast of the Korean Peninsula and passed across the inland between September 1st and 2nd in 2010. Topography and surface sediments before and after the typhoon were measured and sampled along the survey line of 22 sites in the Gochang Donghori intertidal flat. The intertidal area was divided into high tidal zone, middle tidal zone, and lower tidal zone on the basis of mean high water level, mean sea level, and mean low water level. Topographic variation before and after the typhoon represented deposition of average 0.03 m in high tidal zone, erosion of average -0.15 m in middle tidal zone, and erosion of average -0.39 m in lower tidal zone, respectively. Surface sediments of the intertidal flat consisted mainly of fine to medium sands, and the ratio of fine sand was the largest both before and after the typhoon. Surface sediments after the typhoon became finer in mean grain size showing well sorting rather than those before the typhoon.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.3
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• pp.181-188
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• 2009

The macro tidal flat of the Gochanggun Myongsasipri, located on the southwestern coast of Korea, is studied in terms of seasonal variations of surface sediment and sedimentary environment. Surface sediments of 45 sites in the winter (February) and the summer (August) are sampled across three survey lines (15 sites in each survey line), respectively. The tidal flat of open-coast Myongsasipri is mainly composed of fine to medium sand, the distribution of which shows a coast-parallel trend. Grain-size distribution has a bi-modal trend, and grain size in the winter is coarser than that in the summer. During the winter, the upper tidal flat is dominated by medium sand, while the lower tidal flat is dominated by find sand. Such a feature is attributed to wave-dominated sedimentation in the winter. The finer grains of the summer rather than that of the winter and relationship between texture parameters suggest that tidal energy plays an important role in tidal-flat sedimentation during the summer. This study represents an environmental change from wave-dominated conditions in the winter to tide-dominated conditions in the summer as a result of the seasonal variation in the intensity of onshore-directed winds and waves in the Myongsasipri tidal flat.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.248-249
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• 2000

연안 및 조간대에 서식하고 있는 해산 무척추동물들은 수시로 염분변화에 노출되고 있으므로, 저염분에 노출되고 있는 시간은 생존하기 위하여 수행하는 생리적 조정의 결과로서 성장률 감소를 수반하는 스트레스의 중요한 요인이다. 또한 염분은 해산과 기수지역 생물의 생리적 과정에 영향을 미치며, 종의 분포를 결정 짓는 주요한 환경 요인 중 하나이며, 염분변화에 의해 패류에서 발생하는 전형적인 반응은 섭이활동의 저하, 성장률의 감소와 패각의 폐쇄 등이다(Bohle, 1972; Widdows, 1985). (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.610-611
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• 2001

연안 및 조간대에 서식하고 있는 정착성이거나 이동이 적은 패류들은 조석주기와 분포 등에 의해 일정한 주기로 공기 노출에 직면하고 있으므로 이러한 생물들은 먹이를 섭취하는 시간에 제한을 받으며, 온도의 변화 및 건조에 스트레스를 받고 있다. 공기노출시 패류의 생리적 반응은 종에 따라 다르게 나타나며, 전형적으로 패각을 닫는 형태와 패각을 여는 형태로 나누어지며, 일반적으로 공기에 노출된 후 다시 물에 잠김에 따라 빠르게 대사를 회복시킨다. (중략)

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.743-752
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• 2015

We studied the spatio-temporal microalgal (phytoplankton and benthic diatoms) and environmental changes of the Hajeonri intertidal zone from February to November 2014. Seawater and phytoplankton analysis were conducted all through the months. The species, composition and abundance of phytoplankton and environmental factors were measured. As a result, diatom was dominant among a total of 113 species identified. On a seasonal basis (Feb. May, Aug., Nov.), we carried out studies on benthic diatoms on the surface of the sediments and their habitats at nine stations on the transect line at Hajeonri at low tide. The grain of the surface sediments was mainly composed of sandy silt and sandy mud. Organic pollution level was low. Benthic microalgal biomass (chlorophyll ${\alpha}$) was high in the spring and summer. A total of 163 benthic diatom species were identified. Navicula sp.1 and Paralia sulcata were dominant over the study period. Five diatom species were observed both in water column and on surface sediment at the same time.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.484-491
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• 2015

The productivity of Manila clam(Ruditapes philippinarum) aquaculture farm is closely related to suitable site selection, so it is essential to assess the habitat suitable for aquaculture species in order to manage yield. This study evaluated the habitat suitable index(HSI) with 9 sites for tidal flat farm, Gochang(Hajun) on May 2014. The suitability index was selected Growth(hydrodynamics, chlorophyll a), Survival(sediment-sand, silt-clay) and Water Environment(dissolved oxygen, salinity). Both Weight and No weight were tried for objective judgment as HSI scoring method. As a result, it shows lower tidal flat(HSI; No weight: 0.60~0.76, Weight: 0.47~0.70) is higher than upper(HSI; No weight: 0.25~0.27, Weight: 0.09~0.10), hydrodynamics and sediment particle size are the most effective. This research can consider the potential suitable site for Manila clam through scientific approach, and provide the basis for optimal management practices in tidal flat farm.