• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.387-394
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• 2000

Water pollution characteristics were investigated in the Kyongan stream and major inlet parts of Paltang Reservoir from April to July, 2000. Water quality in the Kyongan stream was extremly deteriorated by treated wastewater discharge at near sewage wastewater treatment plant (SWTP) located in the upstream, and it is likely to influence eutrophication of the lower part of the stream. Water quality of the Kyongan stream showed a typical hypertrophic condition. Influxed concentrations with $NH_4$ and SRP into the main stream from SWTP were declined precipitously as water flowed toward the lower part of the stream, and chlorophyll- a explosively increased in the midstream. Average concentrations of $NH_4$, SRP and chlorophyll-a in the main stream were $1,343\;{\mu}g\;N/l$, $1,779\;{\mu}g\;P/l$ and $188\;{\mu}g\;l$, respectively. Particularly, phosphorus load was very high, and its influence on the algal growth stimulation was remarkable. In comparison with the water quality inflowing into Paltang Resevoir, pollution status of the Kyongan stream was more worse than that in the Pukhan River and the Namhan River. The results of this study indicate that the management of point source, SWTP effluent, is urgent to mitigate eutrophication of Paltang Reservoir, and requires further necessary controls of inorganic phosphorus loading.

• Journal of Korean Society on Water Environment
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• v.27 no.4
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• pp.397-404
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• 2011

This research investigates the runoff characteristics of refractory organic matters from Kyongan river watershed. Samples were taken 27 times during dry season, 4 times during rain events and analyzed into flow rate, Dissolved Organic Carbon (DOC), Particulate Organic Carbon (POC), Refractory Dissolved Organic Carbon (R-DOC), Refractory Particulate Organic Carbon (R-POC). R-DOC during dry season was the lowest in winter and showed a rising tendency in spring and R-POC changes less than R-DOC. The mass loading of Refractory Total Organic Carbon (R-TOC) in summer takes approximately 80% of 1 year mass loading. During rainy season, EMC of R-DOC was similar to R-DOC in dry season. But maximum EMC of R-POC was 12 times higher than that of R-POC in dry season. Results of the survey show that enhanced management of R-DOC in dry season and R-POC in rainy season is needed.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.5
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• pp.685-690
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• 2006

The differences in microbial community structures between planktonic microorganism and biofilm in rivers were investigated using respiratory quinone profiles. The compositions of microbial quinone for 4 tributaries of the Kyongan Stream located in/flowing through Yongin City, Gyeonggi-Do were analyzed. Ubiquinone(UQ)-8, UQ-9, menaquinone(MK)-6 and Plastoquinone(PQ)-9 were observed in all samples of planktonic microorganism and biofilm for the sites investigated, Most planktonic microorganism and biofilm had UQ-8(15 to 30%) and PQ-9(over 30%) as the dominant quinone type. These results indicated that oxygenic phototrophic microbes(cyanobacteria and/or eukaryotic phytoplankton) and UQ-8 containing proteobacteria constituted major microbial populations in the river. The quinone concentration in the river waters tested, which reflects the concentration of planktonic microorganisms, increases with increasing DOC. Further research into this is required. The microbial diversities of planktonic microorganism and biofilm calculated based on the composition of all quinones were in the range from 4.2 to 7.5, which was lower than those for activated sludge(ranging from 11 to 14.8) and soils(ranging from 13.4 to 16.8). The use of quinone profile appears to be a useful tool for the analysis of microbial community structure in river.

• Journal of Korea Soil Environment Society
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• v.5 no.3
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• pp.77-85
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• 2001

This study was carried out to show the groundwater quality in the shallow aquifer at the plastic film houses area near livestock areas in Kyong=n river. The study was conducted at 31 sites in Pogok Myon. Yongin City, Kyonggi Province on March, June and August in 1998, Medium value of CO $D_{cr}$ by survey months was as follows ; June(8.0mg/L) > April(4.4mg/L) > August(3.2mg/L). And the value of $NH_3$-N showed same tendency ; June (0.21mg/L) > April(0.08mg/L) > August (0.04mg/L). In case of nitrate- nitrogen, the changes by survey months were shown similar. But 28% of survey sites exceeded to agricultural groundwater quality reference level(20mg/L). And sulfur concentrations at some survey sites exceeded the reference level(50mg/L). But the other items of water quality were shown to suitable level for agriculture. The result showed that groundwater quality management should be taken for agricultural using at the livestock and plastic film house areas.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1027-1029
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• 2003

The primary uses of SWIR bands of ASTER data are to analyze geological features. In this study, we are attempting to evaluate the effect of using the narrow band A STER data for extracting information related to biophysical information of forest vegetation. ASTER and ETM+ data have been obtained simultaneously over the study area in Kyongan-River basin on May 8, 2003. Two data sets were initially processed to reduce atmospheric effects and converted to percent reflectance values, which make them comparable each other. ASTER and ETM+ reflectance were then analyzed by using the field survey data that include forest leaf area index (LAI), cover types, species composition, and stand density. Preliminary results show that ASTER reflectance were not much different to ETM+ reflectance to explain LAI.

• Korean Journal of Ecology and Environment
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• v.33 no.3 s.91
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• pp.304-310
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• 2000

Enclosure experiments to reduce the growth of Cyanophyceae were carried out using plants in Kyongan stream. Wet plants put into the enclosure at a rate of 2.5 g wet wt/l and at that time, the average concentration of chlorophyll a was ranged from 30 to $50\;{\mu}g/l$. The dominant species was Microcystis aeruginosa. Ginkgo, big cone pine and pine needles significantly inhibited the growth of Microcystis from the early days to the stages of log-Phase. Waterchestnut was the most inhibitory to the growth of Microcystis. Pine needles inhibited in 85% of the algal growth: ginkgo in 80%; big cone pine in 75%; waterchestnut in 78%; wildrice in 59%; and iris in 30%. At the treatment with 0.25 g dried plants/l, algae was declined at a rate of 90% by waterchestnut: 53% by pine needles. Phenolic compounds were purifled from decomposing big cone pine and waterchestnut.