• 한국환경과학회지
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• 제8권3호
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• pp.331-336
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• 1999

The monthly water quality data measured at 14 stations located in the Geum-River watershed were clustered into 2 to 7 clusters. Furthermore, factor analyses were conducted on Gabcheon and Yugucheon to characterize the water qualtiy, based on the information obtained from the results of culster analysis. The results of cluster analysis show that the water quality charactersitic of main stream of the Geum-River is somewhat different from that of substream of the Geum-River. Furthermore, the water quality characteristic of Gabcheon which is expected to have the most serious water quality problems in the Geum-River watershed shows the most different water quality characteristic from Yugucheon. Based ont he factor loadings in each factor, Gabcheon and Yugucheon have their own water quality characteristics. This is mainly because of composite factors such as different population density, industrial activities, and land use conditions in Gabcheon and Yugucheon subwatersheds.

• 한국물환경학회지
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• 제29권3호
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• pp.400-408
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• 2013

Total phosphorus was set as a target indicator to prevent eutrophication and algae growth, etc., in three major rivers (Nakdong River, Geum River and Yeongsang/Seomjin River) for the second phase (2011 ~ 2015) in total maximum daily loads (TMDLs) system. However, total phosphorus management was restrictively introduced, i.e., upstream of the Lake Daechung, in the Geum River watershed. Total phosphorus concentration and trophic levels in downstream of the Lake Daechung (include Mangyeong and Dongjin rivers) were increased more than upstream. Therefore, it is necessary to expand total phosphorus management in all watersheds of the Geum River. If total phosphorus was managed in all area of the Geum River watershed, it is possible to decrease total phosphorus concentration and trophic levels, and solve the unbalanced water quality between up and downstream of the Lake Daechung.

• 한국물환경학회지
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• 제30권2호
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• pp.148-158
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• 2014

In order to assess the effect of TMDLs management and improve that in the future, it is necessary to analyze long-term changes in water quality during management period. Therefore, long term trend analysis of BOD was performed on thirty monitoring stations in Geum River TMDL unit watersheds. Nonparametric trend analysis method was used for analysis as the water quality data are generally not in normal distribution. The monthly median values of BOD during 2004~2010 were analyzed by Seasonal Mann-Kendall test and LOWESS(LOcally WEighted Scatter plot Smoother). And the effect of Total Maximum Daily Loads(TMDLs) management on water quality changes at each unit watershed was analyzed with the result of trend analysis. The Seasonal Mann-Kendall test results showed that BOD concentrations had the downward trend at 10 unit watersheds, upward trend at 4 unit watersheds and no significant trend at 16 unit watersheds. And the LOWESS analysis showed that BOD concentration began to decrease after mid-2009 at almost all of unit watersheds having no trend in implementation plan watershed. It was estimated that TMDLs improved water quality in Geum River water system and the improvement of water quality was made mainly in implementation plan unit watershed and tributaries.

• 한국물환경학회지
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• 제29권3호
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• pp.438-442
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• 2013

According to Geum-River restoration project, given conditions for management of water environment in the Geum-River were changed. Because of those changes, this study was investigated the establishment of water quality standards and water quality target in the Geum-River basin. For management of water environment in the Geum-River, the sub-basins and watersheds are newly divided and the water quality and ecosystem standards in the sub-basins are reestablished. Considering the consistency of water environment policy and legal system, the legal name of sub-basins and watersheds are unified. TMDL (total maximum daily load) should be implemented in the sub-basin where exceeds the water quality standards and the number of water pollutant among the water quality parameters which exceeds the water quality standards are extremely minimized. The water quality target of water pollutant for implementation of TMDL should be established same or higher concentration of water quality standards.

• 한국물환경학회지
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• 제25권2호
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• pp.212-220
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• 2009

In many studies, the Numeric Integration (NI) method has been widely used to calculate pollutant loads from the watershed because it is easy to apply. However, there have been many needs for more accurate pollutant loads estimation method with the restricted number of water quality samples. However, the ESTIMATOR model does not allow the users to define the regression model to explain the measured flow and water quality relationship, indicating the ESTIMATOR model is not flexible. The LOADEST model allows the user to choose the model type from 11 predefined general forms of regression equations. Annual loads of T-N and T-P with the LOADEST model were 0.70 times and 0.84 times of those by NI method, respectively. The coefficient of determination ($R^2$) of the LOADEST regression for the T-N and T-P were 0.92 and 0.72, respectively. This indicates that the load estimation regression model with the LOADEST for the study watershed explains the relationship between the observed flow and water quality data well reasonably well. Based on these findings, we suggest that the LOADEST model estimated regression equation could be used to estimate pollutant loads using the measured flow data for the study watershed.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권6호
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• pp.186-195
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• 2021

In Korea, groundwater quality is monitored through National Groundwater Quality Monitoring Network (NGQMN) administered by Ministry of Environment. For a given contaminant, compliance to groundwater quality standards is assessed on a annual basis by monitoring the number of incidents that concentration exceeds the regulatory limit. However, this approach provides only a fractional information about groundwater quality degradation, and more crucial information such as location and severity of the contamination cannot be obtained. For better groundwater quality management on a watershed, a more spatially informative and intuitive method is required. This study presents two statistical methods to convert point-wise monitoring data into information on groundwater quality status of a watershed by using a proposed grading scale. The proposed grading system is based on readily available reference standards that classify the water quality into 4 grades. The methods were evaluated with NO₃^-, Cl^-, and total coliform data in Geum River basin. The analyses revealed that groundwater in most watersheds of Geum River basin is good for domestic or/and drinking with no treatment. But, there was notable quality degradation in Bunam seawall and So-oak downstream standard watersheds contaminated by NO₃^- and Cl^-, respectively.

• 물과 미래
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• 제24권1호
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• pp.83-92
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• 1991

본 연구는 금강유역의 주요수위표 지점에서 하천유지유량을 산정하는데 그 목적이 있다. 하천유지 유량을 산정하는 방법에는 수요적인 측면과 공급적인 측면 두가지로 분류할 수 있다. 본 논문에서 하천유지유량의 개념은 평균갈수량과 환경보존유량중 큰 값으로 결정하였다. 하천유지유량의 산정에서 대청댐 상류지역은 평균갈수량으로, 대청댐 하류지역은 평균갈수량과 QUAL2E 모형으로 산정된 수질보전유량값 중 큰 값을 하천유지유량으로 결정하였다. 그 결과 대청댐 하류인 공주와 규암지점 모두 평균갈수량 값이 크게 나타났으며 그 값은 공주지점에서 33.82$m^3$/sec, 규암 지점은 51.51$m^3$/sec 이였다. 그러므로 금강유역의 하천유지유량의 산정은 평균갈수량으로 결정하는것이 타당하다고 판단되었다.

• 한국농공학회논문집
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• 제49권5호
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• pp.81-90
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• 2007

Watershed topographical information is required in hydrologic analysis, supporting efficient hydrologic model operation and managing water resources. Watershed topographical data extraction systems based on desktop GIS are abundant these days placing burdens for spatial data processing on users. This paper describes development of a Web-based Geographic Information Systems that can delineate the Geum River sub-basins and extract watershed topographical data in real time. Through this system, users can obtain a watershed boundary by selecting outlet location and then extracting topographical data including watershed area, boundary length, average altitude, slope distribution about the elevation range with Web browsers. Moreover, the system provides watershed hydrological data including land use, soil types, soil drainage conditions, and NRCS(Natural Resources Conservation Service) curve number for hydrologic model operation through grid overlay technique. The system operability was evaluated with the hydrological data of WAMIS(Water Management Information System) with the government operation Web site as reference data.

• 물과 미래
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• 제8권1호
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• pp.61-79
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• 1975

본연구는 1974년 건설부 수자원국의 연구사업중의 하나인 $\ulcorner$홍수량 추정을 위한 합성단위유량도유도의 연구$\Ircorner$의 일부로서 건설부에서 제공한 재정적 후원에 감사를 드린다.

• 한국물환경학회지
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• 제32권2호
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• pp.173-182
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• 2016

The objective of this study is to quantitatively analyze climate change effects by using statistical trends and a watershed model in the Yongdam dam watershed. The annual average air temperature was found to increase with statistical significance. In particular, greater increases were observed in autumn. Also, this study was performed to evaluate the potential climate change in the streamflow and water temperature using a watershed model (HSPF) with RCP climate change scenarios. The streamflow of Geum river showed a decrease of 5.1% and 0.2%, respectively, in the baseline data for the 2040s and 2080s. The seasonal impact of future climate change on the streamflow showed a decrease in the summer and an increase in the winter. The water temperature of Geum river showed an average increase of 0.7~1.0℃. Especially, the water temperature of Geum river showed an increase of 0.3~0.5℃ in the 2040s and 0.5~1.2℃ in the 2080s. The seasonal impact of future climate change on the water temperature showed an increase in winter and spring, with a decrease in summer. Therefore, it was determined that a statistical analysis-based meteorological and quantitative forecast of streamflow and water temperature using a watershed model is necessary to assess climate change impact and to establish plans for future water resource management.