• Journal of Environmental Health Sciences
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• v.27 no.3
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• pp.49-56
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• 2001

The water quality simulation was carried out to predict water quality in Tan stream of the Han river using water quality model, QUAL2E. In the end, the future variations in water quality of Tan stream were simulated and the prediction of the impacts of Tan stream on water quality in the Han river was carried out by applying the Tan stream simulation results into the model. The results are as follows. The predicted results of future water quality of Tan stream suggested that the concentrations of BOD, T-N and T-P at Chungdam bridge would increase to 0.68~0.77 mg/$\ell$, 1.33~1.62 mg/$\ell$ and 0.05~0.06 mg/$\ell$, respectively in 2006 and 2011 and that with the implementation of advanced treatment in Sungnam and Tanchun sewage treatment plants, the concentration of T-N would be reduced more as the amount of treated sewage increase, while the concentration of T-P would stay 0.49 mg/$\ell$. The results obtained from simulation of the impacts of future Tan stream water quality improvement on the main stream of the Han river showed that with implementation of advanced treatment in both Sungnam and Tanchun sewage treatment plants, the concentration of T-N, T-P and chlorophyll-a at Hangang bridge and Heangju bridge would be reduced by 11.6%, 7.7% and 20.9%, respectively in 2..6 and by 13.6%, 9.4% and 22.2%, respectively in 2011, which indicates that the effect on the reduction of T-N and T-P would be relatively significant while the effect on the decrease of algae would be slight.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.429-432
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• 2002

The purpose of this study was to get the change of stream water quality in upper stream of Dong-jin river stream, water samples were taken at samling site during 6 month with from march to August in 2002. The water temperature and pH of stream water were ranged $9.0{\sim}29.4^{\circ}C,\;6.48{\sim}9.33$, respectively. The COD values of stream water was ranged from 0.60 to 19.06. The content of T-N and T-P were $1.88{\sim}6.74mg/L$, $ND(not detcted){\sim}0.50mg/L$ by the livestock wastes and agricultural activity, respectively. Also, suspended solids of stream water was ranged $0.4mg/L{\sim}322.0mg/L$. The contents of heavy metal Zn, Cu, and Pb were $ND{\sim}0.070mg/L,\;ND{\sim}0.012mg/L,\;and\;ND{\sim}0.043mg/L$, respectively. Cd was not dected in all the samples.

• The Journal of Engineering Geology
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• v.29 no.4
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• pp.439-449
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• 2019

To prevent the drying-out of streams and to make effective use of stream water and groundwater, it is necessary to evaluate the impact of groundwater pumping on nearby streams. To this end, stream depletion due to groundwater pumping should be investigated in terms of various hydraulic characteristics of the aquifer and stream. This study used the Baalousha analytical solution, which accounts for stream-stage variation over time, to analyze stream depletion due to groundwater pumping for cases where the stream level decreases exponentially and recovers after the decrease. For conditions such as an aquifer transmissivity of 10~100 ㎡ d^-1, storage coefficient 0.05~0.3, streambed hydraulic conductance 0.1~1.0 m d^-1, stream-well distance 100~500 m, and stage recession coefficient 0.1~1.0 d^-1, the contribution of stream water (the dimensionless ratio of stream water reduction rate to groundwater pumping rate) was analyzed in cases where stream level change was considered. Considering the effect of stream-stage recession, the contribution of stream water is greatly reduced and is less affected by the stream-depletion factor, which is a function of the stream-to-well distance and hydraulic diffusivity. However, there is no significant difference in stream depletion under constant- and variable-stage recovery after recession. These results indicate that stream level control can distribute the relative impacts on stream water and aquifer storage during groundwater pumping

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.2
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• pp.17-24
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• 2002

This research was conducted to investigate the influences caused by solifluction soil on the physicochemistry of stream water quality at the riparian area four points in the northeastern part of the Bughansan National Park from March to May of 2001. The average pH of stream water was higher than those in the caused by solifluction soil. The average electrical conductivity of upstream water was about 0.8~1.7 times lower than those in the caused by solifluction soil, but the average electrical conductivity of downstream water was about 1.6~3.8 times higher than those in the caused by solifluction soil. Therefore, these results showed that the water quality of downstream was worse than that of upstream. Twelve factors including the physicochemistry on the stream water and caused by solifluction soil were analyzed by spss/pc+ for the data collected from during March to May of 2001. pH of stream water was very significantly correlated with pH and electrical conductivity at the caused by solifluction soil. And the electrical conductivity of stream water was very significantly correlated with electrical conductivity and the amount of cation($Na^+$, ${NH_4}^+$, $Mg^{2+}$) at the caused by solifluction soil.

• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.435-442
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• 1997

The research was carried out to investigate the contamination of stream water by the acid mine drainage originated from the abandoned coal mines and coal waste rock in Keumsan, Chungnam. The pH, sulfate and chemical compositions in the stream water were analyzed. At the polluted sites, the pH of stream water was the strong acid, ranging from 3.46 to 4.29. The pH shows negative correlations with sulfate, manganese, copper, zinc, iron and magnesium concentrations. Sulfate concentrations of the polluted stream water, 236.73-310.53mg/l, had 10 times more than those of the non-polluted stream water. The concentrations of heavy metals, Mn and Fe, in the polluted water were 0.56 - 0.83mg/l and 5.89 - 10.58mg/l, respectively. The Mn concentrations were 20 times higher than those of the non-polluted stream water. Compared with those in the non-polluted stream water, the Mg and Ca concentrations in the polluted stream water were high because of leaching from rock and soil to water by the acidifications. Calculated AMDI(Acid Mine Drainage Index) values are low in the polluted stream water, relative to those of the non-polluted water.

• Journal of Korea Water Resources Association
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• v.36 no.6
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• pp.1069-1082
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• 2003

The Cheongdocheon has the reaches under reduction of stream flow. We analysed the cause of the reduction. We investigated the current status of facilities for agricultural water use. We also compared the discharge measurements with the results from the continuous simulation of watershed runoff The satellite image was a tool to find some reaches of stream flow reduction under doubt. Agricultural reservoirs block up the stream and water does not flow over the reservoirs except by storm. They also discharge water through diversion channels and the water diverted does not flow through the natural stream. Farmers directly take water from the stream by weirs. The infiltration gallery of water below the stream ground makes the reach dryness perfect in Kamakchon. These are causes of the stream flow reduction. The discharge measurements are less than the simulation results of watershed runoff, and we guess that the reaches investigated have dried. We found the reaches of stream flow reduction that were under doubt from some KOMPSAT satellite images with the resolution of 6.6 m. Then, we confirmed the reduction of stream flow by a field investigation. All the above reaches have infiltration galleries of water below the stream ground. The research results are a case study on the cause analysis on the reduction of stream flow. One can obtain the KOMPSAT image for a low price and can get prior information to find the doubtful reach of stream flow reduction.

• Journal of Korean Society on Water Environment
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• v.35 no.3
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• pp.209-223
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• 2019

Broadly speaking, in order to analyze the water quality improvement effects of the implementation of the Total Water Pollutant Management System in the Sapgy-Lake waterways, a reference was made to the [Plans for implementation of the Total Maximum Daily Load(TMDL)] in 3 cities (Cheonan, Asan, Dangjin). The results of the investigation into the plans to reduce the pollutant load show in that region show that there are plans to reduce pollution for a total of 16 reduction facilities. As for the result of the computation of the reduction in the load, these measurements were computed at the Gokgyo-stream basin and Namwon-stream basin, with BOD and T-P at the Gokgyo-stream basin reduced by 13.9 % and 13.3 %, respectively, while BOD and T-P at the Namwon-stream were reduced by 3.7 % and 3.3 %, respectively. In this way, thus using the results of the water quality forecast of Sapgyo-Lake in measures for the improvement of water quality (in accordance with the implementation of the TMDL), and using the QUAL-MEV model and EFDC model, it is noted that BOD will be improved by 26.4 % from 6.1 mg/L to 4.5 mg/L 0.0 %, T-P by 36.7 % from 0.168 mg/L to 0.107 mg/L and TOC by 26.4 % from 7.7 mg/L to 5.6 mg/L. However, it is forecasted that the targeted standards for the medium influence area will not be achieved. Evidently, Gokgyo-stream and Namwon-stream have been implementing the Total Water Pollutant Management System for the BOD items since January 1, 2019, but the Sapgyo-stream and Muhan-stream were excluded from being designated as subject regions. As such, it is noted now that it is necessary to implement the TMDL for the entire Sapgyo-Lake water systems including Sapgyo-stream and Muhan-stream in order to improve the water quality of Sapgyo-Lake, and likewise the T-P should be designated as the substance subjected to management in addition to BOD.

• Journal of Korean Society on Water Environment
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• v.29 no.3
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• pp.343-353
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• 2013

Flow duration curve (FDC) can be developed by linking the daily flow data of stream flow monitoring network to 8-day interval flow data of the unit watersheds for the management of Total Maximum Daily Loads. This study investigated the applicable method for the development of long term FDC with the selection of the stream flow reference sites, and suggested the development of the FDC in 4 river basins. Out of 142 unit watersheds in 4 river basins, 107 unit watersheds were shown to estimate daily flow data for the unit watersheds from 2006 to 2010. Short term FDC could be developed in 64 unit watersheds (45%) and long term FDC in 43 unit watersheds (30%), while other 35 unit watersheds (25%) were revealed to have difficulties in the development of FDC itself. Limits in the development of the long term FDC includes no stream monitoring sites in certain unit watersheds, short duration of stream flow data set and missing data by abnormal water level measurements on the stream flow monitoring sites. To improve these limits, it is necessary to install new monitoring sites in the required areas, to keep up continuous monitoring and make normal water level observations on the stream flow monitoring sites, and to build up a special management system to enhance data reliability. The development of long term FDC for the unit watersheds can be established appropriately with the normal and durable measurement on the selected reference sites in the stream flow monitoring network.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.3 s.116
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• pp.1-11
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• 2006

This study analyzed characteristics of natural and human environments in Chuncheon's Gongji stream, and suggested nature-friendly planning strategies for self-purification of water quality, biodiversity improvement and conservative waterfront recreation. The environmental analysis included streambed structures, floodplain soils, water quality, vegetation, wildlife, and human facilities. Natural colonization of vegetation for the middle section of the study stream was obstructed by a straightened concrete revetment of baseflow channel, and vehicle movement and concrete parking lots across the floodplain. These human disturbances also deteriorated the naturalness of the stream landscape and limited habitation of bird species. However, natural sedimented wetlands in half of the channel width for the lower section of the stream contributed to a desirable vegetational landscape and greater bird occurrence. Based on BOD measurements, water quality of the stream fell under class $II{\sim}III$ of the stream water-quality standard, but it was worse around sewage outlets due to incomplete sewage collection especially during the dry season. Dominant fish species included typical inhabitants of good water-quality streams that are tolerant of adverse habitat changes. Nature-friendly planning strategies were established based on analysis of the environmental characteristics. They focused on not merely spatial zoning and layout divided into four zones - preservation, partial preservation, conservation and use -, but close-to-nature channel revetment techniques, natural water-purification facilities, biotope diversification, and water-friendly recreation and circulation. Strategies pursued both renewal of stream naturalness and hydraulic stability of streamflow by minimizing transformation of natural channel micro-topography and biotope, and by reflecting natural traces of streambed structures such as revetment scour and sedimentation.

• Korean Journal of Ecology and Environment
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• v.43 no.1
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• pp.117-128
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• 2010

The water qualities of Namdae-stream, Yeongok-stream and Sacheon-stream were examined, by using physicochemical factors, trophic status and epilithic diatoms from May 2008 to February 2009. The physicochemical water qualities of three streams were, except for some construction areas and sites of downstream, generally good, having less concentration than BOD of $2\;mg\;L^{-1}$. As for the sites of downstream, there were ongoing pollution such as graduation of nutrients in Namdae-stream and Sacheon-stream, due to salinity of seawater and topographical feature of the closed estuary. The examination of trophic status of Namdae-stream showed mesotrophic status in all the sites. Also, eutrophication was in progress as from the upstream to the downstream of Yeongok-stream, and Sacheon-stream showed eutrophic status in all its sites. As a result of the biological water quality assessment, Namdae-stream, excluding the downstream site, came out to be $\beta\sim\alpha$-oligosaprobic, and biological water quality was good, having TDI less than 50. Some construction sites and downstream site of Namdae-stream are $\beta$-mesosaprobic, and with the TDI over 70, the biological water quality assessment came out to be polluted. Yeongok-stream is $\beta\sim\alpha$-oligosaprobic, and its biological water quality is good, having TDI less than 40. Sacheon-stream, excluding the upstream site on May 2008 and February 2009, is $\beta\sim\alpha$-mesosaprobic, and its TDI over 70 shows that it has been polluted. The correlation analysis showed a high correlation in both DAlpo and TDI. Also, biological assessment of water quality (DAIpo, TDI) showed higher correlation with TSI rather than BOD.