• Journal of the Korean Geographical Society
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• v.49 no.2
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• pp.221-244
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• 2014

We suggested several implications by examining geochemical properties of sediments in Simjeok, Jangdo, and Hwaeomneup mountain wetlands which are natural preservation areas. Geochemical properties of wetland sediments show that all wetlands were included in the type of fens, but their distribution patterns were different from one another. We classified three sub-groups of sediments using the two step cluster analysis on the ratio of exchangeable cations. Wetland sediments can be grouped into Ca-dominated, Mg-dominated, and K-dominated types. Simjeok wetland have Ca-dominated sediments, while the sediments of Jangdo wetland indicate the Mg-dominated and Ca-dominated characteristics. Hwaeomneup wetland is composed of K-dominated sediment mainly. Different properties in the ratio are affected by various environmental factors such as geological, pedological, and vegetational settings. Because these geochemical properties will be affected by climate change and human impacts, these will be environmental indicator in mountain wetlands and be used in wetland management. This scheme can be used for classification of mountain wetlands. Therefore, we should work on geochemical properties of wetland sediments and classification schemes based on geochemical properties not only to widen understanding in geomorphic system or ecosystem of mountain wetlands but to conserve mountain wetlands properly.

• Journal of Korean Society of Forest Science
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• v.107 no.1
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• pp.59-70
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• 2018

The objective of this study was to develop erosion control dam for preventing disaster in consideration of characteristics of forested catchment near urban area, and to assess its stability and functionality to see its practicability in the field. Two types of hybrid erosion control dams were developed including debris flow prevention dam by using pillar and float board screen type and debris flow control dam by using groyne. Also, review about their static (sliding, overturning, bearing capacity) and dynamic (member force) stability was carried out. According to the result, most of the assessed items met standard safety level although there were some cases where assessed items were short of stability criteria against impact. Also, after miniature flume experiments based on the developed erosion control dam to prove structure function (material catch, deposit), it turned out the dam decreased flow sediment amount and velocity while increasing sediment-capturing capacity by 3.5 times on average compared to the one controlled without erosion control dam. When function of erosion control dam for forested catchment near urban area is quantified based on future flume experiments in a variety of conditions, the dams can be practically used in the urban area, contribution to effectively reducing debris flow damage.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.4
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• pp.246-258
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• 1988

Semi-quantitative analysis of $less-than-2{\mu}m$ clay minerals in thirty-nine superficial sediments from the Chinju Bay, southern coast of Korea, was made to reveal the distribution, provenance and dispersal pattern of fine-grained sediments. Additional nine samples were also taken from the Choryang Cheon (a river draining the kaolin-rich Hadong area) to investigate the influence of river a discharge. Grain size analysis for the Chinju Bay sediment samples was performed simultaneously as an aid to understand the sediment types and depositional environments. Except for the northeastern part, clayey mud predominates the entire bay. Average relative abundance of the four major clay minerals, I. I., illite, kaolinite, chlorite and smectite, is $55.1\%,\;23\%,\;21.5\%\;and\;0.4\%$, respectively. Although illite dominant clay mineral, the average content is about $10\~20\%$ tourer than that of the nearby continental shelf area. On the contrary, kaolinite content in the bay is about $10\%$ higher than that of the shelf area. Recent clay minerals of the Chinju Bay are mainly derived from the nearby inland area through numerous rivers and streams. Transport from shelf area, however. also seems to be important.

• Journal of the Mineralogical Society of Korea
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• v.19 no.4 s.50
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• pp.291-300
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• 2006

This study has been carried out to reveal the mineralogical compositions, the concentrations of heavy metals, and related factors in the sediments of the Kumho River which is the main tributary of the Nakdong River. Even though this river flows in a short distance, it runs through different geology and industrial areas and can be a good candidate to study different geological and anthropogenic factors affecting the concentrations of heavy metals in the sediment. The major rock-forming minerals were quartz and albite. Minor amount of orthoclase, microcline, and amphybole were also identified. Clay minerals including illite, chlorite, kaolinite were associated with those minerals. In the downstream, no noticeable changes in species and amount of minerals were observed, indicating there is almost no influence on the mineralogical compositions from rock types. The concentrations of heavy metals in the sediments are in the order of Zn > Pb > Cu > Ni > Cr > Co > Cd. Following the downstream, the concentrations of heavy metals generally increase, except Pb. The regional increase of the heavy metal content is well correlated with the location of the tributary. Without changes in mineral compositions, the main factors controlling the heavy metal contents are the locations of pollutant sources. Except Pb and Ni, most of the concentrations of heavy metals were thought to be enriched by the past pollutant sources.

• Journal of the Mineralogical Society of Korea
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• v.22 no.2
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• pp.129-138
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• 2009

The XRF core scanner was used, to analyze high resolution chemical elements in deep sea sediment cores from Clarion-Clipperton fracture zone of the northeastern Pacific. Comparison of data estimated by the XRF core scanner with ICP-AES showed relatively weak correlation coefficients between elements (especially Ba, Pb, Sr, Zr) except for Mn contents ($r^2$ > 0.89). However down-core variations of most elements seemed to be well matched each other and furthermore, XRF core scanner data reflected changes of sedimentary facies characterized by sediment colors. Mn/Al ratio dramatically changed at boundaries of facies in BC08-02-05 and BC08-02-13 but progressive changes occured in BC08-02-02, BC08-02-09 and BC08-02-10 where the sediments have been affected by bioturbations. The difference of Mn/Al ratio in each facies (Facies I, Facies II, Facies III) has been caused by redox condition of depositional environment. Vertical change of Mn/Al ratio were divided into two types probably affected by activities of benthic organisms in the study area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.1
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• pp.1-13
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• 2003

To investigate the community structure and meiofaunal density in seagrass/bare non-seagrass beds, a survey was conducted at three seagrass bed locations in Doomoojin of Baegryongdo, inner harbor of Eocheongdo in May 1999, and Yulim of Dolsando for every month from February to July 1999. Meiobenthic samples were collected from sediments within seagrass beds (SB) and non-seagrass bed (or adjacent to barren sand area, NSB). Nematodes were the most dominant group among representative 13 meiofaunal groups. The sub-dominant groups were benthic for-aminiferans, benthic harpacticoids, and annelids. The highest density of meiofauna was recorded at a seagrass bed of Yulim (7,244 ind/10 $\textrm{cm}^2$ in June), and lowest density was recorded at a non-seauass bed of Baegryoungdo (438 ind/ 10 $\textrm{cm}^2$ in May). For vertical distribution, the highest density of meiofauna was recorded at 0-2 cm depth, and the density abruptly decreased with depth in all stations. The density of meiofauna in size between 0.125 m and 0.25 mm was maximum. Sediment types for the study areas ranged from sandy to sandy mud by the Folk's classification. The density of total meiofauna, the number of taxa, and the density of the dominant groups (nematodes, benthic for-aminiferans, benthic harpacticoids, annelids) between SB and NSB were significantly different. The results clearly showed the importance of seagrass bed as suitable habitat for meiofauna.

• Journal of Wetlands Research
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• v.14 no.2
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• pp.265-275
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• 2012

As climate change is becoming a growing concern and the importance of water management is increasing, the retention of carbon and nutrients in wetland soils including inland and coastal area has become important. In this study, retention characteristics of organic matter and nutrients of coastal sediment and soils in different types of wetlands such as constructed wetland, natural (inland marsh, estuary, tidal flat) wetlands were investigated. A correlation analysis was also performed to understand the relationship among organic matter properties, nutrient concentrations and soil texture of wetland soils. The degree of retention of organic matter and nitrogen in wetland soils varied with the wetland type. Inland wetlands retain more nitrogen than estuary or coastal wetlands, and natural wetlands retain more organic matter and nitrogen than constructed ones. Coastal sediments in a bay area where seawater circulation is restricted have more nutrients than those in estuary or tidal flats where seawater circulates well. The results showed that the sediment chemical oxygen demand has a high correlation with the total organic carbon and the total nitrogen in the studied area.

• Journal of Yeungnam Medical Science
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• v.8 no.1
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• pp.42-52
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• 1991

Two types of urine dipstick assays, Multistix-SG and Combur-9-test RL, were compared for compatibility, accuracy, specificity and predictive values of a positive and negative test in 501 patients urine and artificially prepared specimen. We found that the results of semiquantitative tests of Multistix-SG and Combur-9-Test RL performed were statistically similar in patients specimen. The urinary leukocyte estrase tests of Combur-9-Test RL assays compared with urine sediment microscopy in regard to compatibility, sensitivity, specificity, and predictive values of a positive and negative test 83.7%, 48.1%, 90.3%, 47.4% and 90.1%, respectively. The urinar nitrite tests of Comber-9-Test RL assays compared with urine culture tests, in regard to compatibility, sensitivity, specificity, and predictive values of a positive and negative tests were 90.3%, 19.4%, 84.7%, 53.8% and 94.1%, respectively. For the urinary protein, the sulfosalicylic acid method was the most sensitive test for any kinds of protein, and Multistix-SG appeared more sensitive than Compur-9-Test RL for the albuminuria. For the urinary bilirubin and glusose, two dipstick assays were similar in their diganostic efficiency. Finally in the urinary occult blood tests, Combur-9-Test RL assays was more sensitive than Multistix-SG.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.103-112
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• 2011

This study aims to demonstrate the relationship between various factors and soil erosion or deposition, simulated from distributed rainfall-sediment-runoff model applications. We selected area, overland flow length, local slope as catchment representative characteristics among many important geographic factors and also used the grid-based accumulated rainfall as a representative hydro-climatic factor to assess the effect of these two different types of factors on erosion and deposition. The study catchment was divided based on the Strahler's stream order method for analysis of the relationship between area and erosion or deposition. Both erosion and deposition increased linearly as the catchment area became larger. Erosion occurred widely throughout the catchment, whereas deposition was observed at the grid-cells near the channel network with short overland flow lengths and mild slopes. In addition, the relationship results between grid-based accumulated rainfall and soil erosion or deposition showed that erosion increased gradually as rainfall amount increased, whereas deposition responded irregularly to variations in rainfall. Within the context of these results, it can be concluded that deposition is closely related with the geographic factors used in this study while erosion is significantly affected by rainfall.