• Journal of the Korean Institute of Intelligent Systems
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• v.27 no.2
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• pp.119-125
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• 2017

The mud flat in Korea is the geographical feature generated from the sediment of rivers of Korea and China and it is the important topography for pollution purification and fishing industry. The mud flat is difficult to access such that it requires the aerial survey for the high-resolution spatial information of the area. In this study we used drones instead of the conventional aerial and remote sensing approaches which have shortcomings of costs and revisit times. We carried out GPS-based control point survey, temporal image acquisition using drones, bundle adjustment, stereo image processing for DSM and ortho photo generation, followed by co-registration between the spatio-temporal information.

• Journal of Environmental Impact Assessment
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• v.11 no.1
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• pp.51-66
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• 2002

The purpose of this study is to analyze the geomorphological environment changes of tidal flat in the Cheonsu Bay. Especially, it centers on the changes in the sedimentary environment using remote sensing data. Multi-temporal Landsat data and topographic maps were used in this study. The results are summarized as follows: the tidal flat of Cheonsu Bay changes in many ways depending on the direction of the tidal current. In the neighborhood of Ganwoldo, the scale of the tidal flat has continuously been expanded due to the superiority of sedimentation after a tide embankment was built. When we analyzed the grain size of sediments and implemented in-situ field survey, it was found that the innermost part of the bay consists of a mud flat, with the midway part mixed flat, and the nearest part to the sea sand flat. On the other hand, in the neighborhood of Seomot isle and its beach, sedimentation is superior in the eastern part whereas erosion is superior in the western part. In other words, the western coast of the beach is contacted with the open seas and under much influence of ocean wave. The eastern coast is placed at the entrance of the bay and has sand bar and tidal flat developed due to submarine deposits that are accumulated on the sea floor by the tidal current. In conclusions, remote sensing methods can be effectively applied for quantitative analysis of geomorphological changes in tidal flat, and it is expected that the proposed schemes can be applied to another geomorphological environments such as beach, sand dune, and sand wave.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.2
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• pp.117-126
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• 1999

Hampyong Bay is a semienclosed and macrotidal bay which opens to the eastern Yellow Sea through a narrow inlet in the southwestern coast of Korea. In order to understand the tidal-flat sedimentation in the semienclosed setting, morphology, sediments, accumulation rate and sea cliff erosion were investigated in the tidal flat of Hampyong Bay. The tidal flat of Hampyong Bay lacks intertidal drainage systems, and generally shows the concave-upward profile whose relief is designated by marked morphological features such as high-tide beaches, intertidal sand shoals and tidal creeks. Surfacial sediments of the tidal flat mainly consist of mud, sandy mud, gravelly mud, gravelly sand and muddy gravel, thus showing the textural characteristics of multimodal grain-size distribution, poorly sorting and positive skewness. The sediments generally coarsen landward due to the increase in coarse fraction content. Sedimentary structures are deeply bioturbated, but parallel lamination and lenticular bedding are locally found in the mudflat near mean low water line. Annual accumulation rates across the tidal flat (along Line SM) average -5.2 cm/yr with a range of -45.8~+4.2 cm/yr, indicating that the tidal flat is erosional. In general, erosion rates of upper and lower tidal flat are higher than those of middle tidal flat. Seasonally, the erosion rates are much higher during spring and winter when dominant wind direction corresponds to the long axis of Hampyong Bay. Sea cliffs are eroded at a rate of 1.4 m/yr. The biggest sea cliff erosion generally occurs 1~2 months later after tidal flats were extensively eroded. Such erosions of tidal Oats and sea cliffs in the semienclosed bay setting are interpreted to be due to wind waves coupled with local sea-level rise.

• Journal of The Geomorphological Association of Korea
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• v.18 no.4
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• pp.223-233
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• 2011

The aims of this study is about distribution characteristics of tidal coastal landforms, and that changing process in the Hampyeung Bay, which has a semi-enclosed bay like basin shape without inflow of stream, the mouth of open sea is narrow and forms with wide ends toward inland sea. The source of deposits are moved materials by tidal currents and from coastal slopes. Main landform elements of study area consist of tidal flat, tidal channels, intertidal sand bar, sea cliffs, and sea terrace. Tidal flats is classified with mud flat and mixed flat by grain size composition. Mud flats have developed at the shoreline area that tidal flat is closed to the continuity of gentle slope, and mixed flat developed at the foot of the sea cliffs and sea terraces. Quaternary deposits were identified in the coastal materials sedimented by the sea-level change. According to the analysis of grain size composition during last ten years, sands and silt has increased 2% and 6% respectively, clay has been decreased by 9%. The concaved tidal flats are colonized by salt plants. Areal changes of salt plants expanded near four times from 2.4km² at the year 2001 to 9.3km² at the year 2009. During the same periods, mean grain size became coarser from 6.5φ to 4.5φ at the salt plants area.

• Korean Journal of Microbiology
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• v.36 no.2
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• pp.130-135
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• 2000

Decomposition rate of organic matiter in the mud flat of Sunchon Bay was estimated. Physicochemical parameters, cellulose degradation rate. distribution of heterotrophic bacteria, and extracellular enzymatic activities were measured from August 1997 to July 1998. Soil temperatures, water contents, concentration of $PO_4$-P and organic matter were -1-~$30^{\circ}C$, 42.1-53.1%, 0.0779-0.1961 mgig and 1.99-7.64%, respectively. Decomposition rate of cellulose film ranged from 7.7 to 100%imonth, high in summer and low in winter. The number of heterotrophic bacteria ranged from $0.87{\times}10^6 to 3.6{\times}10^7 $CUFsIg dq soil. Enzymatic activities of phosphatase, $\alpha$-D-gluEosidase, $\beta$-D-glucosidase and cellobiohydrolase, which were measured as decomposition rate of methylumbelliferyl(MLiF)-substrate, were 152.23-1779.80 nMIhr, 2.67-202.18 nM/hr, 5.03-258.26 M h r and 3.42-63.07 nM/hr, respectively Cellulose degradaaon rate and extracellular extracellular enzymatic activities were conelated with each other, and showed high correlation coefticiency with soil temperature.

• Journal of the Korean earth science society
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• v.31 no.2
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• pp.139-150
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• 2010

This study investigated the depositional environment of the area of Anmyeondo in the mid-western coast of Korea. A total of 142 surface sediments were analyzed, and leveling survey was conducted as well in 12 transects at the sandy tidal flat in the area. The surface sediments are classified into several different types (slightly gravelly Sand, Sand, slightly gravelly sandy Mud, etc.) and they show fining-distribution toward the offshore. Textural parameters are characterized by being coarse, well sorted, positively skewed in the supratidal and intertidal flat, whereas being finer, poorly sorted, negatively skewed in the subtidal flat. According to the C-M diagram, the sediment transport modes are characterized by the mixed mode of bedload and graded suspension in supratidal and intertidal flat, and by graded suspension or uniform suspension in the subtidal flat. Histogram shows a bimodal distribution in the lower subtidal flat which is indicative of two sediment transport modes.

• Korean Journal of Environmental Biology
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• v.33 no.3
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• pp.274-278
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• 2015

A newly recorded glycerid polychaete collected from mud of the tidal flat in the southwestern coast of Korea is identified as Glycera fallax Quatrefages, 1850 based on the morphologies of papaillae and ailerons on proboscis, parapodial postsetal lobes, and branchiae. In this paper, we provide a detailed description and illustration of Korean materials of this species and a key to the species of the genus Glycera from Korean waters.

• The Korean Journal of Malacology
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• v.27 no.3
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• pp.191-192
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• 2011

Pulmonate snail, Onchidium hongkongensis from muddy flat of Muan-gun was recorded as new to the Korean molluscan fauna. Shell-less body light-gray or reddish-gray in colour, oval shaped with numerous pustules on dorsal surface usually covered with mud. Black pair of tentacles with terminal eyes. Including the new record in this study, the family Onchidiidae 2 genera and 2 species in the Korean waters.

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.170.2-171
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• 2000

No Abstract, See Full Text

• Ocean and Polar Research
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• v.36 no.3
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• pp.235-246
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• 2014

The thalassinidean upogebiid Upogebia yokoyai Makarov, 1938 was first collected and described based on the specimens from the upper tidal flat of sandy shores of Jeju Island, Korea. Although this species was already reported in Japan and Russia, this is the first report of its occurrence in Korea. Upogebia yokoyai differs clearly from other upogebiid species previously recorded in Korean waters, U. major and U. issaeffi, by spinulation of the dactylus and propodus of pereiopod 1. In addition, some morphological comparisons are provided for identification of the three Upogebia species in Korean waters.