• 한국물환경학회지
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• 제33권5호
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• pp.525-530
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• 2017

The attainment ratios of the water quality goals of the 114 mid-watershed representative stations, examined during the period2011 to 2015, were evaluated in the study. Of the four major river basins, the attainment ratio on water quality goal of the Geum River basin turned out to be the lowest. As a result of formal evaluation of the attainment ratios of BOD, COD and TOC, it was found that the attainment ratio of COD was much lower than that of BOD and TOC (I a circumstance thought to be caused by the higher COD/BOD and COD/TOC ratios of the water quality of the river than those of the environmental water quality standard). As well, higher COD/BOD and COD/TOC of wastewater discharged from point and non-point sources (other than those of the environmental water quality standards) might possibly represent one of the reasons. We also compared attainment ratio between the main stream and tributaries, which indicated that the higher attainment ratio was present in the main stream. The attainment ratio is also documented as more significant in the winter season than the summer season, possibly due to the contribution of non-point pollutants swept in by rain during the summer season during documented periods of high precipitation. Thus, water quality management in summer season and improvement of water quality of the tributaries might be important as a means of increasing attainment ratio on water quality goal.

• 대한지리학회지
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• 제32권4호
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• pp.445-462
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• 1997

본 연구의 목적은 서울의 인접 지역인 포천군, 남양주시, 구리시를 흐르고 있는 왕숙천을 대상으로 하천유역의 자연 및 인문환경의 특징을 조사, 유역내 하천수질의 시${\cdot}$공간적 특성을 파악함과 아울러 이를 토대로 한 유역의 물환경 관리대책을 고찰하는데 있다. 본 연구 결과 다음과 같은 결론에 도달하였다.1. 관측항목 중 유역의 자연적 시${\cdot}$공간 특성을 가장 잘 반영하고 있는 것은 수온으로 판명되었다. 왕숙천의 월별 하천본류의 수온은 전반적으로 상류가 낮고 하류가 높게 관측되었다. 2. 하천 본류의 pH 및 EC, TDS 값은 각각의 지류의 값에 크게 영향을 받는 인위적 수질요소이다. 특히, EC와 TDS 값은 지류의 오염물질 유입으로 인한 본류의 영향을 파악하는 가장 좋은 수질조사 항목으로 판단되었다. 3. 왕숙천에서 측정된 COD 값을 호소의 수질 환경기준에 적용해 보면 대다수의 지점에서 5급수의 수질을 보이고 있어 유역내의 하천수가 심각하게 오염되어 있는 것으로 나타났다. 4. 왕숙천변에 거주하고 있는 사람들의 왕숙천에 대한 인지도는 하천의 상류와 중${\cdot}$하류의 지역별로 크게 차이가 있는 것으로 나타났으며, 왕숙천의 유역환경을 개선시키기 위하여 지역주민들의 하천에 대한 인지도를 높이고 친환경적 하천관을 배양시키는 정책이 실시되어야 한다.

• 한국물환경학회지
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• 제23권6호
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• pp.814-821
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• 2007

This study was estimated water quality to raw water quality management of the Maeri intake station in the Nakdong River using Multivariate Analysis. The results of Principle Component Analysis was explained up to 76.9% of total water quality by three principle components. The 1st, 2nd was explained 44.7%, 17.9% and third was explained 14.3%. Also, the three factors was derived from Factor Analysis. The 1st factor was estimated as the matabolism and organic matter pattern related to algal growth. The 2nd factor was judged as the pollution of pattern related to the discharge from stream of the Nakdong River and 3rd factor was viewed as the hydrological variation pattern related to particle matter. The results of Cluster Analysis were classified into three groups.

• 상하수도학회지
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• 제23권1호
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• pp.15-22
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• 2009

This study reports the serial use of a 3-D hydrodynamic model, EFDC-Hydro and a dynamic water quality model WASP7.2 that are maintained by USEPA. The 48 km section of the Geum River downstream between Daechung Dam and Gongju was selected as a sample study site. Topographical information was used to accurately represent morphology of the study site and boundary conditions were derived from governmental databases including WAMIS by Ministry of Land and Ocean and WEIS by Ministry of Environment. EFDC-Hydro was successfully calibrated for observed water level and WASP was calibrated using monthly observed water quality data obtained from the above sources. It was found that the current water quality target of BOD for the Geum River-H point could not be met on monthly basis though every other tributary of the area would meet its own water quality target as assigned in Korean TMDL. This study proposed the new target BOD water quality for the Gabcheon and Mihocheon as 4.3 and 3.6 mg/l, respectively so that the Geum River-H point can meet the target. When Sejong City is constructed, it is estimated that effluent discharge limit of BOD must be less than 4.5 mg/l to meet water quality of the point. This study shows that it is possible to carry out more precise modeling considering both water movement and water kinetics by using EFDC and WASP simultaneously.

• 상하수도학회지
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• 제11권2호
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• pp.40-49
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• 1997

From water management point of view, the industrialization that we have achieved in the last decades brought out two major changes: water shortage and water quality deterioration. They are getting the big obstacles we must overcome to continuously pursue industrialization for further development in the next century. Many plans using dams and advanced treatment methods have been developed for control of quantity and quality, respectively. In this paper, an alternative is conceptually reviewed which is much different from the plans in regard that the alternative looks at system itself. It is based on an interceptor system coupling with a concept of zero-discharge. This system allows no discharge of wastewaters from point-sources to waterbodies which are very sensitive in terms of water quality. In addition reuse of treated effluents is emphasized to a maximum extent. The application of the system to the Nak-Dong river basin indicated that an interceptor system will need from the middle reaches of the basin where industrialization gets heavier. Since wastewaters are not directly discharged to the river, water quality of the down stream will improve. Treated effluents will be able to be reused at a number of industrial complex which currently get water from the Nak-Dong river. This reuse will help alleviate water shortage. The biggest problem anticipated is cost for building and operating such system. A cost-sharing plan among the beneficiaries is considered. Further research is suggested focusing on detailed engineering and technical matters for potential implementation.

• 한국물환경학회지
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• 제33권2호
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• pp.219-229
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• 2017

A watershed-river linked modeling system was developed to forecast the water quality, particularly weekly changes in chlorophyll-a concentration, of the Yeongsan River, Korea. Hydrological Simulation Program-Fortran (HSPF) and Environmental Fluid Dynamics Code (EFDC) were adopted as the basic model framework. In this study, the EFDC model was modified to effectively simulate the operational condition and flow of multi-functional weirs constructed in the main channel of rivers. The model was tested against hydrologic, water quality and algal data collected at the right upstream sites of two weirs in 2014. The mean absolute errors (MAEs) of the model calibration on the annual variations of river stage, TN, TP, and algal concentration are 0.03 ~ 0.10 m, 0.65 ~ 0.67 mg/L, 0.03 ~ 0.04 mg/L, and $9.7{\sim}10.8mg/m^3$, respectively. On the other hand, the MAE values of forecasting results for chlorophyll-a level at the same sites in 2015 range from 18.7 to $22.4mg/m^3$, which are higher than those of model calibration. The increased errors in forecasting are mainly attributed to the higher uncertainties of weather forecasting data compared to the observed data used in model calibration.

• 한국수자원학회논문집
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• 제33권2호
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• pp.145-157
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• 2000

본 연구에서는 금강 대청댐하류의 본류구간에서 갈수시간에 대해서 WASP5모형 중에서 수질모의 부분인 EUTRO5모형과 1차원 정상류 수리모형인 HEC-2모형을 연계한 수질모형을 이용하여 대청조정지댐으로부터 강경수위표 지점까지 수질의 변화를 모의하였다. 수질 및 유량자료의 수집을 위하여 대청댐으로부터 금강하류에 위치한 주요 수위표지점에서 1998년 12월, 1999년 1월과 3월의 3회에 걸쳐 관측하였다. 수질모의모형은 1999년 1월 자료를 이용하여 보정되어지고, 1998년 12월자료와 1999년 3월자료를 이용하여 검증되어졌다. 모형에 의해서 모의된 수질변수들의 거리에 따른 변화는 1999년 3월자료를 이용하여 모의된 chlorophyll-a, BOD5, NH3-N, PO4-P와 같은 수질변수를 제외하고는 관측된 수질변수값과 거의 일치하였다. 또한 NH3-N과 PO4-P가 증가 혹은 감소되어 갑천과 미호천으로부터 금강본류로 유입된다고 가정하는 경우에 금강본류에서의 chlorophyII-a의 농도를 모의하였다. 모의한 바에 의하면 갑천과 미호천에서 NH3-N과 PO4-P가 70% 감소되어져 금강본류로 유입된다고 가정하는 경우를 제외하고는 거의 미미한 chlorophyII-a 농도변화율을 보였다.

• 한국환경보건학회지
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• 제27권2호
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• pp.119-126
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• 2001

The key point in establishing water quality management measures is how to decide the load reduction for pollution sources. This study was performed to compare reduction methods for BOD loadings to achieve water quality standards at the end of the Yeongsan river. The target year is 2006 and 2011 and reduction methods are uniform treatment and treatment by influence rate. Using QUAL2E model, the study was performed under the conditions of establishing and non-establishing the publicly owned treatment works(POTWs). Uniform treatment which allocate the same reduction rate to pollution sources showed that all streams into the river should be applied for the reduction. However, treatment by influence rate which allocate the reduction rate by the order of influence rate showed that achieving target quality might be possible with a few streams for the reduction. But total amount of load reduction of streams was not significantly different from two methods.

• 한국물환경학회지
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• 제31권6호
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• pp.723-731
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• 2015

We investigated the spatial and temporal patterns of water quality in the Gangjung-Goryoung weir that is located in the middle area of the Nakdong river, Korea. The monitoring results indicated that there are discernible vertical differences in water quality during the pre- and post-monsoon periods (May to September). During this period, it was observed that the weak thermal stratification formed at the maximum level, and pH, Chl-a, and DO concentrations in the surface layer were higher than those in the bottom layer. This vertical difference was especially noticeable for DO concentrations: there were DO depletions at the bottom layer in late June to early August. During the summer monsoon period with heavy rainfall, there was a decline in vertical differences in water quality. From this study, it was suggested that continuous monitoring of vertical profiles could become a useful tool for identifying the spatial and temporal distributions of water quality and for developing the best management policy for water quality in the Nakdong river.

• The Korean Journal of Ecology
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• 제24권4호
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• pp.253-258
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• 2001

Land use pattern in the Wangsuk river watershed was investigated on the bases of physiognomic vegetation maps made from the aerial photograph interpretation and field check. Landscape structure was analyzed using a GIS program supported by ArcView. Landscape structure depended on the geographical position of the river, such as the upper, middle and lower river. Watersheds of the upper and middle rivers were dominated by forests composed of secondary forest and plantation. But agricultural fields dominated that of the middle and lower river. Urban area and agricultural fields increased in from the upper toward the lower river watersheds. In addition to, a transformation of agricultural pattern into an institutional agriculture was characteristic in the middle and lower river basins. Water qualities of the Wangsuk river were usually better in the order of the upper, middle, and lower river, but they were fluctuated according to the site. Such fluctuation would due to self-purification of the river and land use pattern of the watershed as the non-point source. In this viewpoint, a strategy to manage the water quality in the level of watershed is urgently required.