• Journal of the Mineralogical Society of Korea
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• v.5 no.1
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• pp.32-41
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• 1992

An XRD quantitative analytical method using calculated XRD patterns was discussed in this study, Deep-seabed sediments commonly contain smectite, illite, chlorite, and kaolinite, and XRD pattern of each clay mineral of appropriate chemical composition was simulated by using an XRD pattern calculation method. Theoretical peak intensities of specific reflections of four clay minerals (the 001 reflections of smectite and illite, the 004 reflection of chlorite, and the 002 reflection of kaolinite) were measured from calculated patterns, and MIF(mineral intensity factor)value of each phase was determined from the intensities of calculated patterns. The peak intensities obtaine from experimental XRD patterns of sediments were corrected using the MIF values so that the calibrated intensity values for the specimens are linearly proportional to the weight fraction of each phase, which is normalized to 100 wt%. The MIF method can provide accurate quantitaive results without the necessity of correcting the factors by the mass absorption coefficient of each phase. This method excludes the necessity of standard specimens having compositions that are similar to those of clay minerals in the sediment samples. Therefore, quantitaive analysis using XRD calculation method can be utilized for the specimens, for which the standard specimens are very difficult or impossible to obtain. this quantitative method can provide rapid, routine analysis results for a large number of samples which occur in similar geological environments.

• Journal of the Mineralogical Society of Korea
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• v.31 no.4
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• pp.257-266
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• 2018

East China Sea (ECS) is known to be supplied with large amounts of sediments form Huanghe, Changjiang and various rivers in Korea. Many studies have been conducted to identify the effects of rivers and deposition process of ECS, but no consensus has been reached. In this study, clay minerals, rare earth elements (REEs) and grain size were analyzed to study the provenance and sedimentation environment of core 99MAP-P63 in ECS. Clay mineral contents of 99MAP-P63 are abundant in order of illite, chlorite, kaolinite, and smectite. The provenance of 99MAP-P63 sediments using clay minerals is interpreted as the Changjiang regardless of depth. As a result of REEs analysis, 99MAP-P63 sediments are very similar to Chinese rivers sediments. Therefore, the provenance of 99MAP-P63 is Changjiang, and the influence of Korean river seems to be insignificant. 99MAP-P63 sediments are generally classified as sandy silt, but the top of the core is divided into sand with a sand contents of 85 %. Compared with surrounding cores, sandy silt sediments arecorresponded to the low stand stage when sea-level was low, and the sediments were thought to have been supplied directly through the paleo-Changjiang. Sandy sediments in uppermost of core are corresponded to transgressive stage. Although distance from estuary was increased due to sea-level rise, it was possible to supply coarse sediments due to high bottom stress, and the paleo-Changjiang sediments deposited in study area were re-deposited.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.687-697
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• 2019

By monitoring sediment grain size and level variation of tidal flat surface for 6 years (2005-2011), and also by mooring TISDOS (tidal-flat sediment dynamics observation system) on the low intertidal flat in 2008, we investigated the sedimentary environment of tidal flat in the dammed Yeongsan River Estuary. The tidal flat of the Yeongsan River Estuary lost 82 % of its area because of coastal development projects, and a narrow tidal flat below mean sea level now remains. Most of the tidal flat sediments are composed of silt up to 70-94 %, and show the characteristics of clay deficiency and silt dominance. This is closely related with the coastal development, which led to the destruction of high tidal flats where most mud settled, and the modification of tidal current patterns. Moreover, the estuarine tidal-flat sediments reveal seasonal variation. They are coarse with abundant silt during windy autumn to spring, fine with abundant clay during the less-windy and high-discharge summer. This phenomenon indicates that the behavior of sediment particles on the low intertidal flats of the Yeongsan River Estuary is influenced by wind waves for silt and fresh water discharge and the tidal process for clay. Monitoring results of the altitude of tidal flat surface showed that the study area had eroded at an average rate of -2.6 cm/y during the period of 2005-2011, and also that an unusual deposition with a rate of 4 cm/y occurred in 2010. The erosion can be explained by an increased tidal amplitude and a strengthened ebb-dominant tidal asymmetry after the construction of an estuary dike and the Yeongam Kumho Seawall. The deposition in 2010 seems to have been closely related to the mass production of suspended materials from dredging of the estuary.

• Journal of the Mineralogical Society of Korea
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• v.32 no.4
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• pp.235-247
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• 2019

The Central South Sea Mud (CSSM), developed in the Seomjin River estuary, is known to be supplied with sediments from Heuksan Mud Belt (HMB) and Seomjin River. However, in order to form a mud belt, more sediments must be supplied than supplied in the above areas. Therefore, research on additional sources should be conducted. In this study, clay minerals, major elements analyzes were performed on cores 16PCT-GC01 and 16PCT-GC03 in order to investigate the transition in the provenance and transport pathway of sediments in CSSM. The Huanghe sediments are characterized by higher smectite and the Changjiang sediments are characterized by higher illite. Korean river sediments contain more kaolinite and chlorite than those of chinese rivers. Korean river sediments have higher Al, Fe, K concentraion than Chinese river sediments and Chinese rivers have higher Ca, Mg, Na than those of Korean rivers. Therefore, clay minerals and major elements can be a useful indicator for provenance. Based on our results, CSSM can be divided into three sediment units. Unit 3, which corresponds to the lowstand stage, is interpreted that sediments from Huanghe were supplied to the study area by coastal or tidal currents. Unit 2, which corresponds to the transgressive stage, is interpreted to have a weaker Huanghe effect and a stronger Changjiang and Korean rivers effect. Unit 1, which corresponds to the highstand stage when the sea level is the same as present and current circulation system is formed, is interpreted that sediments from Changjiang and Korean rivers are supplied to the research area through the current.

• Journal of Korea Water Resources Association
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• v.56 no.12
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• pp.919-928
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• 2023

Rainfall characteristics in Korea are concentrated during the summer flood season. In particular, when a large amount of turbid water flows into the dam due to the increasing trend of concentrated rainfall due to abnormal rainfall and abnormal weather conditions, prolonged turbid water phenomenon occurs due to the overturning phenomenon. Much research is being conducted on turbid water prediction to solve these problems. To predict turbid water, turbid water data from the upstream inflow is required, but spatial and temporal data resolution is currently insufficient. To improve temporal resolution, the development of the Turbidity-SS conversion equation is necessary, and to improve spatial resolution, multi-item water quality measurement instrument (YSI), Laser In-Situ Scattering and Transmissometry (LISST), and hyperspectral sensors are needed. Sensor-based measurement can improve the spatial resolution of turbid water by measuring line and surface unit data. In addition, in the case of LISST-200X, it is possible to collect data on particle size, etc., so it can be used in the Turbidity-SS conversion equation for fraction (Clay: Silt: Sand). In addition, among recent remote sensing methods, the spatial distribution of turbid water can be presented when using UAVs with higher spatial and temporal resolutions than other payloads and hyperspectral sensors with high spectral and radiometric resolutions. Therefore, in this study, the Turbidity-SS conversion equation was calculated according to the fraction through laboratory analysis using LISST-200X and YSI-EXO, and sensor-based field measurements including UAV (Matrice 600) and hyperspectral sensor (microHSI 410 SHARK) were used. Through this, the spatial distribution of turbidity and suspended sediment concentration, and the turbidity calculated using the Turbidity-SS conversion equation based on the measured suspended sediment concentration, was presented. Through this, we attempted to review the applicability of the Turbidity-SS conversion equation and understand the current status of turbid water occurrence.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.8
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• pp.420-427
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• 2016

This study was conducted on the sediment remediation using micro-bubble to remove fine particles. For this study, characteristics of contamination and release in sediment were analyzed. And then, the characteristics of bubbles on removal efficiency was investigated at various operation conditions. In particle size distribution of the sediment used for the study, the proportion of clay and silt (<0.075 mm) was about 7.7%, sand (0.075~4.75 mm) was about 67.8%, and gravel (${\geq}4.75$) was 24.5%. Total nitrogen (TN) and total phosphorus (TP) of the sediment were 2,790~3,260, 261~311 mg/kg respectively. Ignition loss and water content were 4.1~9.6, 32.9~53.2% respectively. In analysis of removal efficiency according to operation conditions of micro-bubble, it was the highest when operation condition is pressure 6 atm, pressurized water ratio 30%, and coagulant dosage 15 ppm. At the time, the sediment's removal efficiency was 19.9%. Accordingly removal efficiency of TN and TP were 21.4, 22.6% respectively. Finally a research was found that fine particles in sediment were almost removed by micro-bubble, which led to decrease nutrients' release at about 20.1~64.3% in comparison to sediment including lots of fine particles.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.4
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• pp.1-11
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• 2001

This study was carried out to analyze the characteristics of forest environmental and stream morphological factors by using the quantification theory(I) for evaluation of the watershed stability. Present annual mean sediment yield of erosion control dams were investigated in 167 sites of erosion control dam constructed during 1986 to 1999 in Gyeongbuk. The results obtained from this study were summarized as follows; According to the coefficients of partial correlation, each factor affecting to sediment was shown in order of gravel contents, number of first streams order, number of total streams, length of total streams, forest type, length of main stream, parent rock, stand age, soil texture, stream order, slope gradient, soil depth and aspect. Descriptions of class I were as follow; Igneous rock of parent rock, hardwood stands of forest type, less than 20 year of stand age, less than 30cm of soil depth, sandy clay loam of soil texture, more than 41% of gravel contents, south~east of aspect, 2,501~3,500m of length of main stream, 21~25 of number of total streams, 5,501~10,000m of length of total streams, 3 or more than 4 of stream order, more than 16 of number of first stream orders and more than $31^{\circ}$ of slope gradient. Descriptions of class II were as follow; Metamorphic rock of parent rock, coniferous stands of forest type, more than 25 year of stand age, 31~40cm of soil depth, silt loam of soil texture, 11~20% of gravel contents, north~west of aspect, 2,501~3,500m of length of main stream, 16~20 of number of total streams, 3,501~5,500m of length of total streams, 3 of stream order, 11~15 of number of first stream orders and more than $31^{\circ}$ of slope gradient. Descriptions of class III were as follow; Sedimentary rock of parent rock, mixed stands of forest type, more than 25 year of stand age, more than 51cm of soil depth, silty clay loam of soil texture, less than 10% of gravel contents, south~west of aspect, less than 500m of length of main stream, less than 5 of number of total streams, less than 1,000m of length of total streams, less than 1 of stream order, less than 2 of number of first stream orders and less than $25^{\circ}$ of slope gradient. The prediction method of suitable site for erosion control dam divided into class I, II, and III for the convenience of use. The score of class I evaluated as a very unstable area was more than 8.4494. A score of class II was 8.4493 to 6.0452, it was evaluated as a moderate stable area, and class III was less than 6.0541, it was evaluated as a very stable area.

• 한국해양학회지
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• v.19 no.2
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• pp.153-162
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• 1984

This study was conducted to interpret the relations between the polychaete community and its environments in Kwangyang Bay during July, 1982. The type of sediments in the study area varies from sand to clay and the organic content obtained by ignition was in the ranges of 0.3% to 15.4%. The polychaetes which occurred at 25 stations comprised 70 species representing 63 genera and had an average density of 490 animals/m$\^$2/. The most abundant species were Lagis bocki (20%), Lumbrineris longifolia (10%), Chohe teres (7%), and Sternaspis scutata (5%). The polychaete populations show the highest density in muddy sand sediments and have a tendency to decrease their abundance in finer sediments such as bud and clay. The individual numbers of each feeding type show the same tendency. Kwangyang Bay consists of three distinct characteristic communities, representing different physical and biological factors: delta community, muddy flat community and channel community. Delta community has very poor organisms and seems to be determined by physical factors such as tidal current, and by sediment conditions and seems to be determined by physical factors such as tidal current, and by sediment conditions and by the food availability. Muddy flat community shows more diverse and higher abundance than delta community but seems to be impoverished by the stress of oxygen deficiency in sediments. Channel community has the highest density in the study area and comprises more various feeding types. This is probably due to the supply of allochthonous materials from the Seomjin River and offshore as food, the heterogeneous sediments and some biological interactions within habitats.

• Journal of the Korean Geotechnical Society
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• v.28 no.10
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• pp.55-68
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• 2012

The west seacoast has approximately 83% of tidal flat in Korea. Gyeonggi-do and Inchon has 35.1%. This study was carried out to understand depositional environment and properties of tidal deposits that distributed in the Gyeonggi bay. On the basis of observation and description on mineralogical, geochemical, physical properties, detailed sedimentary unit has been respectively distinguished Based on. stratigraphic position, facies and unconformity, the intertidal zones are classified into four sedimentary units, and bedrock over the units has been developed in the order of Unit 4${\rightarrow}$Unit 3${\rightarrow}$Unit 2${\rightarrow}$Unit 1. The intertidal sediment deposits of Gyeonggi Bay were compared with those of west coast. In Cheongra area all strata of Unit 4-Unit 3-Unit 2-Unit 1 appear. In Yeongjong-do Unit 2-Unit 1, in Incheon Bridge and Songdo area Unit 4-Unit 3-Unit 1 are observed. In Daesan area Unit 4-Unit 3-Unit 1 are observed. Average clay mineral content ratio is 8.2% in Cheongra area, 2.9% in Yeongjong Island, 18.4% in Incheon Bridge, 24.6% in Songdo area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.250-256
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• 2000

The purpose of this study was to investigate the adsorption kinetics of heavy metals (Cu, Cd and Pb) using three tidal flat sediments and two yellow loesses. The relationship between adsorption rate calculated by non-linear regression model and chemical parameters was estimated. The contents of ignitiot loss (I.L.) am Fe, Mn and Al oxides of yellow loess were higher $1.5{\~}6 times$ than those of tidal flat sediments. But the contents of silt and clay of tidal flat sediment in Eueunri was higher than others. Heavy metals adsorption were occured rapidly in the intial 30 min and the concentration of adsorbed heavy metals were $4.1{\~}14.7\;{\mu}g/g\;for\;Cu,\;2.8{\~}16.7\;{\mu}g/g\;for\;Cd\;and\;43.4{\~}101.7\;{\mu}g/g$ for Pb, showing a high cumulative adsorption of $8{\~}70{\%}\;for\;Cu,\;18{\~}31{\%}\;for\;Cd and\;19{\~}52{\%}$ for Pb after 3hr. In initial concentration of $0.5{\times}10^(-5)M$, adsorption rate of heavy metals by the tidal flat sediments and yellow loesses was the sequence Pb>Cu^gt;Cd. The adsorption kinetics of Cu, Cd and Pb was found to be one-site kinetic model. Especially, in the case of Cu, there was a high negative ($R^2= -0.88{\~}-0.99$) linear correlation between chemical parameter such as I.L., Al oxide, silt and clay, and adsorption rate coefficients ($K_a$) calculated by non-linear model.