• Analytical Science and Technology
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• v.16 no.3
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• pp.232-239
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• 2003

The river sediments were collected from 4 points of Seoknam river, one point of Miho river and one point of the joining area of two rivers. For preparation of sample, three sediment samples were collected for the surface, middle and lower part of the sediment at each sampling point. The elemental concentrations were analyzed by neutron activation analysis using HANARO research reactor at Korea Atomic Energy Research Institute, and the concentrations of 30 elements were determined by the relative method using standard reference material of NIST. As a result of analysis, it was found that when the examination and prediction of contamination distribution about the site where the contamination site of river is connected to the lower river is done, the specific gravity of elements which is contained in the sediment and the speed of a current of river should be considered and also found that when the samples for concentration analysis in the river sediments are collected, for the establishment of regional representatives in samples, the range of sampling depth should be determined considering the specific gravity of elements and the speed of a current.

• Journal of Environmental Science International
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• v.15 no.7
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• pp.643-651
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• 2006

This study investigated the distributive property of micropollutants in sediment around Gwang-yang bay using simultaneous analytical method of 310 chemicals. In the results, the major micropollutants detected were CH type chemicals such as aliphatic, polycyclic compounds, benzenes, and CHN(O) type chemicals aromatic amines, and pesticides. Insecticides of pesticide type were frequently detected at all sampling site. The total concentration of micropollutants were higher in summer than in winter and measured within the range of $ND{\sim}36.50{\mu}g/L$. Also, because of effect of seomjin river, GY6 of all sampling site detected by the highest concentration, GY10 and 11 located in Gwang-yang outside bay were not detected the micropollutants. From the result of this study, we should estimated that the industrial complex located in Gwang-yang inside bay and an inflow of fresh water through the Seomjin river are major pollution sources of Gwang-yang bay.

• Journal of Korea Water Resources Association
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• v.51 no.2
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• pp.175-182
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• 2018

Coastal sediment archives are used as indicators of changes on shore sediment production and fluvial sediment transport, but rivers crossing coastal plains may not be efficient conveyors of sediment to the coast. In some case there is a net loss of sediment in lower coastal plain reaches, so that sediment input from an upstream exceeds the sediment yield (SY) at the river mouth. The main source of sediment in coastal area is the load from land. In Korea, data on suspended SY are limited owing to a lack of logistic support for systematic sediment sampling activities. This paper presents an integrated approach to estimate SY for ungauged coastal basins, using a soil erosion model and a sediment delivery ratio (SDR) model. For applying the SDR model, a basin specific parameter was validated on the basis of field data. The proposed relationships may be considered useful for predicting suspended SY in ungauged basins that have geologic, climatic and hydrologic conditions similar to the study area.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.125-132
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• 2010

Characterization of sediment quality is important for the proper management of surface water quality, yet sediment has not been monitored sufficiently. In this study, fecal indicator microorganism concentrations of sediments in the Geum River Basin were monitored. Sampling was carried out at one paddy field, one lakeshore and five monitoring stations in the lower reach of the Geum River Basin. Surface waters and sediments were sampled four times during rainy season. Total coliform concentrations of sediments were 12 times higher in average to those of surface waters while E. coli concentrations of sediments were six times higher. No correlation found between indicator microorganism concentration between surface waters and sediments.

• Economic and Environmental Geology
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• v.32 no.1
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• pp.63-72
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• 1999

In order to examine the contamination levels of trace elements in stream sediments in the Chungnam coal mine area, stream sediment and water samples were collected and analyzed for trace elements. The pH of stream water was neutral or weak-alkaline and the mobility of metal in stream sediments was supposed to be low. From the result of cluster analysis, non-polluted sampling stations can be distinguished from polluted sampling stations influenced by mining activities. The trace element concentrations in sediments from non-polluted zone were considered to be the natural backround concentrations of this area. The trace element concentrations in sediment samples from the mining area were higher than those from non-polluted area, and contaminated area of enriched trace element levels need to be properly managed. From the results of discriminant and regression analyses, concentrations of Cd, Cu, Pb AND zN and predicted values of Be, Mo, and Ni in Chungnam coal mine area were found to be lower than those in metal mining areas in Korea.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.3 no.3
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• pp.142-148
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• 1998

Environmental baseline information is necessary in order to assess the potential environmental impact of future manganese-nodule mining on the deep-seabed ecosystem. Total ATP (T-ATP), dissolved ATP (D-ATP) and particulate ATP (P-ATP) were measured to estimate total microbial biomass and to elucidate their vertical distribution patterns in the seabed of KODOS (Korea Deep Ocean Study) area, northeast equatorial Pacific Ocean. Within the upper 6 cm depth of sediment, the concentrations of T-ATP, D-ATP and P-ATP ranged from 4.4 to 40.6, from 0.6 to 16.1, and from 3.0 to 29.2 ng/g dry sediment, respectively. Approximately 84% of T-ATP, 81% of D-ATP, and 74% of P-ATP were present within the topmost 2 cm depth of sediment, and the distributions of ATP were well correlated with water content in the sediment. These results indicate that the distribution of total microbial biomass was largely determined by the supply of organic matter from surface water column. Fine-scale vertical variations of ATP were detected within 1-cm thick veneer of the sediment samples collected by multiple corer, while no apparent vertical changes were observed in the box-cored samples. It is evident that the box-core samples were disturbed extensively during sampling, which suggests that the multiple corer is a more appropriate sampling gear for measuring fine-scale vertical distribution pattern of ATP within thin sediment veneer. Overall results suggest that the concentrations of ATP, given their clear changes in vertical distribution pattern within 6 cm depth of sediment, are a suitable environmental baseline parameter in evaluating the variations of benthic microbial biomass that are likely to be caused by deep-seabed mining operation.

• Journal of Environmental Impact Assessment
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• v.9 no.2
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• pp.99-107
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• 2000

In order to solve water quality problem of domestic dam reservoir, many projects have been performed in a point of view to restoration of water quality. This study was carried out to evaluate the effect of release from sediment on water quality and release characteristics. Daecheong dam reservoir was investigated for two years, from 1998 to 1999. The nutrient release rates of Daecheong reservoir is less than foreign eutrophic reservoir at anoxic condition. For the evaluation of the effect of nutrient release on water quality, internal and external loading was calculated at Daecheong reservoir. As total phosphorus loading from sediment is calculated 9.3 ton/yr and inflow loading from Daecheong reservoir watershed 118 ton/yr, internal loading shows the portion of 7.88% to external loading. At this study, because sampling point was choosed at the point where much sediment is accumulated, experimental result is more than average release rates. Because Daecheong reservoir shows complete thermal stratification and anoxic condition below 30m from water surface in summer seasons, released phosphorus from sediment can not transfer to epilimnion and eventually resettles. Therefore sediment has insignificant impacts on water quality on Daecheong dam reservoir.

• Korean Journal of Ecology and Environment
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• v.54 no.3
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• pp.221-228
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• 2021

Recently, environmental DNA (eDNA)-based metabarcoding approaches have been proposed to evaluate the status of freshwater ecosystems owing to various advantages, including fast and easy sampling and minimal habitat disruption from sampling. Therefore, as a case study, we applied eDNA metabarcoding techniques to evaluate the effects of an abandoned mine land located near a headwater stream of Nakdonggang River, South Korea, by examining benthic macroinvertebrate diversity and compared the results with those obtained using the traditional Surber-net sampling method. The number of genera was higher in Surber-net sampling (29) than in the eDNA analysis (20). The genus richness tended to decrease from headwater to downstream in eDNA analysis, whereas richness tended to decrease at sites with acid-sulfated sediment areas using Surber-net sampling. Through cluster analysis and non-metric multidimensional scaling, the sampling sites were differentiated into two parts: acid-sulfated and other sites using Surber-net sampling, whereas they were grouped into the two lowest downstream and other sites using eDNA sampling. To evaluate freshwater ecosystems using eDNA analysis in practical applications, it is necessary to constantly upgrade the methodologies and compare the data with field survey methods.

• Journal of Environmental Science International
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• v.6 no.5
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• pp.513-520
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• 1997

This study was performed to investigate the riverbed structure and the pollution type in Nakdong River, Western Nakdong River. and Suyoung Stream. Sediment and water samples were collected at is in Nakdong River. in Western Nakdong River, and 8 states In Suyoung Stream from February 20, 1997 to June 15, 1997. The depth distributions of sampling sites in the three streams were measured and heavy metals(Cd, Pb, Cr, Cu) and pesticides in sediments and COD, BOD, and total nitrogen(T-N) in water samples were analysed. The deepest and the shallowest sites were strate 11(11.58m) and 9(3.35m) in Nakdong River, site 7(6.25m) and 4(2.06m) in Western Nakdong River, and site 8(2.89m) and 1(0. 61m) in Suyoung Stream , respectively. The mean concentration of Cd(45.79ppm) was higher In the sediment of Western Nakdong River than In other two streams and those of Pb(76.25ppm), Cr(48.13ppm), and Cu(77.50ppm) were higher in file sediment of Suyoung Stream than in other two streams. Pesticides(1 kind of organophosphorus and 3 kinds of organochlorine pesticide) were detected only in the sediment of Western Nakdong River. The mean concentrations of COD(20.26ppm), BOD(25.36ppm), and T-N(18.05ppm) were higher in the water sample of Suyoung Stream than In other two streams.

• Environmental Analysis Health and Toxicology
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• v.16 no.4
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• pp.161-170
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• 2001

In aqueous ecosystems, the level of toxicity is highly responsive dependant to multiple variables, including rainfall, sunlight, pH, adhesion, etc. Because Korea has particularly distinct wet and dry seasons, the toxicity of pollutants in rivers or streams is dependant on the sampling season and time. In order to examine the effects of rainfall on toxicity, sediment samples were collected from five sites along the Keumho river. It was found that Microtox toxicity levels were generally higher during the dry season than the wet season. It indicated that river pollutants are carried off more quickly by the water during the wet season. As a result, it was recommended that the point sources of pollutants of the Keumho river would be placed between KH3 (Paldalgyo) and KH4(Keumhogyo), KH4(Keumhogyo) and KH5(Dasa).