• Journal of Wetlands Research
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• v.8 no.3
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• pp.51-65
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• 2006

Surface sediments for sedimentary analyses were sampled at 199 stations in the study area in August 2003. The surface sediments consisted of six sedimentary facies. Generally, sandy mud sediments dominated in the southern tidal flat of Ganghwa Island and sand sediments dominated in channel and subtidal zones of the western part of Ganghwa Island. The area of sandy mud sediment extended to eastward tidal flat compared to sedimentary facies in August 1997. In 30 surface sediment samples from the Ganghwa tidal flat and subtidal zone, 61 species were recorded in total assemblages, including 34 species of living population. Ammonia beccarii and Elphidium etigoense in living population and Ammonia beccarii, Elphidium etigoense, Jadammina sp. and Textularia earlandi in total assemblage were widely distributed. Generally, relatively large numbers of species and high values of species diversity occurred in the area of western part of tidal flat. Cluster analysis of total assemblages discriminates four biofacies. Biofacies 1 indicated eastern part of the tidal flat and biofacies 4 indicated western part of the tidal flat. Biofacies 3 were transitional zone between biofacies 1 and 4.

• Journal of Wetlands Research
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• v.6 no.1
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• pp.167-178
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• 2004

The southern tidal flat of Kanghwa Island is one of the biggest flats on the west coast of Korea. Tide is typically a semidiurnal with maximum range of about 10m. The tidal flat receives large amount of sediments from Han River system. Surface sediments for sedimentary analyses were sampled at 83 stations in the study area in August 2003. The surface sediments consisted of five sedimentary facies. Generally, sandy mud sediments dominated in the southern tidal flat of Kanghwa Island, whereas sand sediments dominated in channel and subtidal zones of the western part of Kanghwa Island. The area of sandy mud sediment extended to eastward tidal flat compared to sedimentary facies in August 1997. Sedimentary facies analysis of three core sediments from the tidal flat to the south of the Kangwha Island revealed three sedimentary facies: trough-cross-bedded sand, laminated silt, and bioturbated silt. Distribution of the facies in the cores suggested that sedimentation rates has been generally high in the margin of main tidal channel, especially in the east of the Donggeum Island. Twelve-and-half-hour anchoring survey was carried out for measurements of hydrodynamic parameters at Yeomha channel near Choji Bridge(K1) and channel near Donggeum Island(K2) in June 2003. Residual flows indicated strong ebb-dominated tidal currents. Depth-integrated net suspended sediment loads for one tidal cycle were seaward movement with 309,217.9kg/m and 128,123.1kg/m at station K1 and K2, respectively. The higher value of net suspended sediment loads at station K1 suggested that lots of suspended sediments from Han River deposited in the eastern part of tidal flat.

• Journal of the Korea Institute of Building Construction
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• v.16 no.6
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• pp.571-578
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• 2016

Recently, review on viability of various industrial by product and natural materials as raw material for concrete has been actively done in aspect of environment-friendly issue and depletion of natural resource. This study conducted fundamental study on the possibility of utilizing mud flat as admixture and filling material for concrete. First, chemical analysis on the viability of mud flat as admixture was done and the researchers compared it with the substance of fly ash and blast furnace slag. According to the result, substance content was proven to be inadequate. In addition, as the replacement rate of mud flat increased, compressive strength and tensile strength decreased. According to the estimated result of chemical substance analysis, possibility of utilizing mud flat as admixture was low. According to the result of experiment done as filling material, 10% ~ 30% replacement rate of mud flat manifested more than 8 Mpa of compressive strength of block which may be utilized for secondary product. However, additional experiment such as making block is required afterward. According to the result of flow experiment, as the replacement rate of mud flat increased, flow value decreased, and through chloride content analysis test, it was proven that mud flat is inappropriate to be applied as steel beam using structure since it has high content of sodium. It may be utilized as products that does not use steel beam such as internal brick.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.198-205
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• 2010

The purpose of this study is to investigate the characteristics of the grain size distribution and organic matters to understand the current status of the tidal flat sediment for efficient management of Suncheon Bay. We investigated the characteristics of the surface sediments in the mouth area of the Suncheon Bay at fifteen stations in April and July, 2009. Specific conclusions were as follows. The sediments in the most part of tidal flat was shown as muddy facies(clay and silt contents was more than 90%), whereas in the tidal river affected by water flow from the Dongstream was shown as sandy facies. The analyzed values of the tidal flat sediment were in the range of $1.9{\sim}3.8{\phi}$(mean $2.5{\phi}$) for sorting, and -1.5~3.2(mean -0.3) for skewness, and 1.5~14.1(mean 3.9) for kurtosis. So we knew that the tidal flat sediments in the Suncheon Bay was mainly composed by fine-grained sediment. Erosion was happened in the tidal river, whereas sedimentation was occurred in the tidal flat. The most of organic matters was derived from the Dongstream. Total organic matters shown as ignition loss was 5.75%, COD and $H_2S$ values were lower than the eutrophication level(COD; 20.0 mg/g dry, $H_2S$; 0.2 mg S/g dry). From our research the tidal flat of the Suncheon Bay is relatively fine, but a part of the flat was exceed the environmental standard. So we have to establish effective countermeasures to reduce the organic matters and nutrients derived from stream for environmental preservation of the Suncheon bay and conduct scientifically sustainable monitering for streams flowing into Suncheon Bay and tidal flat.

• The Science & Technology
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• v.33 no.9 s.376
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• pp.48-53
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• 2000

간척사업은 환경친화적으로 계속 추진 필요, 갯벌보다 농지가치가 훨씬 더 크다

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.6
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• pp.453-461
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• 2009

Camera monitoring of topographical changes of intertidal flat was performed at Daehang-ri mud flat outside Semangeum sea dike No. 1, where creation of mud flat was reported after sea dike construction. Ground survey on the mud flat is often limited only to points or few line surveys because of difficulty of walking and limitation of working hours by flood/ebb. This study uses natures of tide that the water lines moving on the intertidal flat during a flood indicate depth contours between low and high tide. Ground coordinates for the water lines extracted from the consecutive images of intertidal flat are calculated and information of topography is acquired by integrating all the water line data. Analysis of 6 camera monitoring data between September 2005 and September 2009 shows 0.127 m deposition per year on the average and variation of deposition/erosion in space and time.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.1
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• pp.9-13
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• 2015

Field experiment were carried out to investigate the formation of ground water flow and remediation of muddy tidal flat by installation of porous pile at the tidal flat of brackish river located in Hiroshima City, Japan. After the installation of porous pile, the concentrations of Dissolved Oxygen (DO) in the interstitial water in the porous pile increased with maximum concentration of 4 mg/L due to a formation of groundwater flow. It was observed that a increase in Oxidation Reduction Potential (ORP) and a decrease in Ignition Loss (IL) in the porous pile site and these must be caused by the increase of dissolved oxygen in the interstitial water. From these results obtained above, it is concluded that the porous pile is an effective technology for remediation of muddy tidal flats.

• Journal of Wetlands Research
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• v.12 no.3
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• pp.67-78
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• 2010

Surface sedimentary facies and the change of microphytobenthos distribution in Geunso Bay tidal flat were monitored using remotely sensed data. Sediment distribution was analyzed along with the spectral reflectance based on the in situ data, and the spectral characteristics of the area where microphytobenthos occupied was examined. A medium to low spatial resolution of satellite image was not suitable for the detection of the surface sediments changes in the study area due to its ambiguity in the sedimentary facies boundary, but the seasonal changes of microphytobenthos distribution could be obviously detected. However, area of predominance of sand grains and seagrass distribution could be distinctly identified from a high spatial resolution remote sensing image. From this, it is expected that KOMPSAT-2 satellite images can be applied effectively to the study on the surface sedimentary facies and detailed ecological mapping in a tidal flat.

• Journal of Wetlands Research
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• v.12 no.3
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• pp.15-20
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• 2010

The contamination loadings generated in Changwon City are coming into Masan Bay through the Bongam tidal flat except the loadings collected and transferred by sewer lines to the wastewater treatment plant. The recovery of waterbirds, shellfishes, and fishes has been quite well recognized in recent years after the first implementation of Masan Bay TPLM (Total Pollution Loads Management) in Korea. This tidal flat has been conserved by the cooperation of several stakeholders and utilized as an ecosystem field site for in situ education. A large industrial complex has been operated since 1970's, therefore increasing the level of pollutants in estuary and costal sediments, especially by heavy metals. Zinc, copper, and lesd contamination of sediment was revealed at higher level by Clean-up guideline (MOMAF) or heavily polluted level by SQC (USEPA). There was a significant difference between two sites at the 95% confidence level, which implies no homogeneity in the processes of transport and deposition even at 500 m of distance. The heavy metal concentrations in the Bongam sediments have been gradually decreased with comparing the data of 2006, and 2009.

• 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.