• 한국환경과학회지
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• 제26권2호
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• pp.211-220
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• 2017

For areas with the diverse contamination sources, the change of 4-nitrophenol contamination and impact of potential contamination sources have been evaluated using monitoring data and a numerical model (HydroGeoSphere). The model considered several parameters including land cover, precipitation, and flow rate. And, the model has been performed to investigate the effect of decay rate of 4-nitrophenol. The results of the simulations showed that the influence on 4-nitrophenol in downstream was mainly greater than that in upstream, and the tributaries did not significantly affect the mainstream because of their low flow rates. In addition, the effect of contamination sources was simulated for each section, then the measured data were higher than the corresponding simulated data in most sections of the Geumho river. In particular, the impact of the potential contamination sources in the upstream area was much higher than that in the other area, thus more monitoring data for the upstream area is required.

• 대한환경공학회지
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• 제32권6호
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• pp.615-624
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• 2010

낙동강 수계에서의 인공 사향물질들의 검출현황을 조사한 결과, 다환 사향물질인 HHCB, AHTN, AHMI 및 ADBI 4종과 염화 사향물질인 MK 1종이 검출었으며, 본류에서는 HHCB, AHTN 및 MK 3종만이 검출되었다. 낙동강 수계에 검출된 인공 사향물질들의 구성비율을 조사한 결과, HHCB가 50% 이상을 차지하여 가장 높게 나타났고, 다음으로 MK와 AHTN이 높은 비율을 나타내었다. 낙동강 본류에서 가장 높은 검출농도를 나타낸 지점은 고령지점 (고령교)으로 2월과 9월에 각각 280.4 ng/L와 195.3 ng/L가 검출되었고, 지류에서는 진천천 지점으로 2월에 2146.6 ng/L와 9월에 1386.4 ng/L의 검출농도를 나타내었다. 인공 사향물질들은 낙동강 상류부근에서는 거의 검출되지 않았으나 중류부근인 구미 지점부터 하수처리장 방류수의 영향을 받아서 농도가 증가하였고, 금호강과 진천천 (hot spot)의 영향을 많이 받는 고령지점에서 최대농도를 나타낸 후 하류로 갈수록 희석효과에 의해 농도가 점점 감소하였다.

• 한국수자원학회논문집
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• 제47권3호
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• pp.269-283
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• 2014

본 연구에서는 기상청에서 제공하는 RCP 기후변화시나리오를 이용하여 기후변화와 유역유출특성에 따른 환경영향을 평가하였다. SWAT모형을 이용한 미래 댐 유입량 평가, HEC-ResSim 모형을 이용한 댐 안전성 평가 및 하류 유황분석을 수행하였다. 또한, 기존 수질관측자료를 이용하여 Seasonal-Kendall Test를 통해 수질변화 추세에 대해 분석하였고, SWAT과 HEC-ResSim 모형으로 도출된 방류량 및 지류유출량을 Qual2E모형에 적용하여 미래 수질변화 추세에 대해 분석하였다. 다음과 같은 유역 통합환경검토 기법은 하천환경에 대한 과학적 물환경 관리 체계를 확보하고, 기후변화 등 새로운 환경문제에 선제적으로 대응하기 위한 지침을 마련할 수 있을 것이다.

• 생태와환경
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• 제52권2호
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• pp.81-93
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• 2019

지구 온난화에 따른 기온 상승, 보나 댐의 건설로 인한 체류시간의 변화는 식물플랑크톤의 이상증식을 일으키며 이로 인한 수계의 부영양화, 녹조 현상은 상수원 수질 악화에 영향을 미쳐 심각한 사회적 문제로 대두되고 있다. 본 연구와 같이 일차생산력과 환경요인들의 상관관계를 확인하는 것은 일차생산력의 조절인자 파악에 매우 효과적이다. 또한 HPLC-CHEMTAX 분석 방법은 간편하며 짧은 시간 안에 식물플랑크톤의 색소 비 값을 기반으로 각 군집의 상대적인 기여도 추정이 가능하다. 이러한 연구 방법들을 적용할 경우 수 생태 건강성 평가 및 식물플랑크톤 이상증식에 영향을 주는 군집조성을 빠르게 파악할 수 있어 조류 예보제 및 수계관리에 있어 효과적으로 활용될 수 있을 것으로 판단된다.

• 한국수자원학회논문집
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• 제53권10호
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• pp.877-887
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• 2020

우리나라 4대강 사업에 의해 건설된 낙동강의 달성보와 함안보, 금강의 세종보와 백제보, 영산강의 송촌보와 죽산보를 대상으로 3차원 수리-수질모델을 이용하여 가동보 운영에 따른 수질 및 녹조 현상 예측 결과를 비교 분석하였다. 가동보를 전면 개방하였을 때, 금강과 영산강에서는 상류에 위치한 세종보와 승촌보에서 연중 및 하절기 Chl-a 농도와 남조류 농도가 감소되는 것으로 예측되었으나, 하류에 위치하는 백제보와 죽산보에서는 하절기에 모두 증가되는 것으로 나타났다. 금강과 영산강에서 수문이 닫힌 경우, 상류에서는 체류시간이 증가하여 조류가 성장에 필요한 용존성 무기인을 충분히 섭취하면서 조류 농도가 증가하지만, 하류에서는 용존성 무기인이 고갈되어 상대적으로 조류의 성장이 제한되는 현상이 발생하는 것으로 분석된다. 반면 낙동강의 달성보 및 함안보에서는 연평균과 하절기 평균 농도가 모두 증가하는 것으로 나타났다. 낙동강에서는 금강과 영산강과 같이 용존성 무기인의 농도가 심각하게 증가하지 않은 반면 수문 개방으로 수심이 감소함에 따라 조류가 이용하는 평균 광량이 증가하면서, 조류의 성장이 증가한 것으로 분석된다. 결과적으로 수문을 전면 개방 또는 폐쇄하였을 경우, 녹조현상 발생 특성은 위치에 따라 수리학적 체류시간, 용존성 무기인 농도 및 수위변화에 따른 광량의 변화 등에 의해 서로 다르게 나타나는 것으로 분석된다.

• 한국관개배수논문집
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• 제13권2호
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• pp.283-292
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• 2006

The characteristics of nonpoint source pollutant loads in upstream of Nakdong River were studied through analysis of pollutant loads of 10 sub-watersheds divided based on administrative district. The discharge and pollutant concentration of each sub-watershed were collected from Nakdong-River Water Research Institute and Daegu Regional Environmental office, respectively. Pollution items analysed in this study were BOD, T-N and T-P. The delivery loads of the nonpoint source pollutions of each sub-watershed were calculated after analysing the concentration of the pollution of each site. Several points were found from the results. Firstly, in general, city areas including Sangju, Andong showed higher degree of nonpoint pollution than country areas including Cheongsong, Yeongyang. The sub-watersheds located upstream side, such as Yeongju, Bonghwa, Necessarily show better water quality than the sub-watersheds located downstream side, such as Mungyeong, Uiseong. This result indicates that a given pollution condition within the watershed can be more sensitive than location factor to the level of water quality. Secondly, the delivery load and area of watershed were not necessarily correlated in the sense of water quality, while the discharge was shown to be highly correlated to the delively load of pollution. Lastly, sewage and waste caused from population and livestock, as well as landuse factor, were found to significantly contribute to the water pollution. Alternative solutions for controlling pollution source, therefore, should be provided to meet target levels of water quality in these regions.

• 물과 미래
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• 제8권2호
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• pp.81-92
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• 1975

Calculation of the monthly water balance for Nakdong River basin for the period from 1958 to 1968 is made by determining three components independently: precipitation, runoff and evapotranspiration. The areal precipitation is computed by the Thiessen method using the records of nine meteorological stations in the basin, and the runoff is the flow gauged at Jindong which is located on the most downstream. For the computation of evapotranspiration, the Morton method is adopted because this method is relatively fit best in the calculation of water balance among the Morton, Penman and Thornthwaite methods. The values of Morton evapotransp iration are corrected by the factor of 0.82 in the basin in order to bring the error to zero. The areal evapotranspiration is the arithmetic mean of the Morton estimates at the stations. Mean water balance components in the Nakdong river basin are 1117.0mm, 600.6mm and 516.4m for precipitation, runoff and evapotranspiration respectively. Accordingly, the mean runoff ratio comes out to be 0.54. The smallest values of runoff coefficient are due for Daegu area, while the largest ones are for the southwest of the basin with the higher rainfall and high elevations there. The amount of runoff obtained by both Thornthwaite and Budyko methods for water balance computations indicate 59 and 60 per cent of actual values which are lower than the expected. An attempt is made to find the best reliable rainfall-runoff relation among the four methods proposed by Schreiber, 01'dekop, Budyko and Sellers. The modified equation of Schreiber type for annual runoff coefficient could be obtained with the smallest mean error of 11 per cent.

• 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.

• 한국환경과학회지
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• 제24권8호
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• pp.1085-1099
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• 2015

The purposes of this study were to suggest the methodology to select prior areas in the environmental pollution survey for livestock excreta (EPSLE) as well as to elucidate the validity of the methodology. In this study, the prior areas in the EPSLE were determined by examining the number of compost facilities categorized according to the three levels of size including the basin, the sub-basin and the watershed, respectively, based on the data from "Annual Nation-wide Pollution Sources Survey (2012)". The results suggested that the list of prior basins were Nakdong, Geum, Youngsan and Han river basins in order. Also, it was examined that the prior sub-basins in the four river basins including Nakdong, Geum, Youngsan and Han rivers were Naesung Stream, Geumgang Gongju, Juam Dam and Namhan Downstream, respectively. The prior watersheds in the sub-basins of Naesung stream, Geumgang Gongju, Juam Dam and Namhan Downstream were Seocheon Downstream, Geum Stream, Gyeombaek Suwipyo and Yanghwa Stream, respectively. The validity of the methodology used in this study was elucidated by analyzing the correlation of the number of compost facilities with the concentrations of T-N and T-P observed in the end-points of sub-basins. The results of correlation analysis showed that the concentrations of T-N and T-P increased with the number of compost facilities. Specifically, there was the stronger correlation between the number of compost facilities and the concentrations of T-N than that for T-P. Consequently, it was proved that the methodology used in this work was valid and rational for the selection of prior areas in environmental pollution survey for EPSLE.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.1612-1615
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• 2009

Water supply reliability indexes (WSRI) is estimated for assessment of water supply capacity in the downstream for parallel reservoir system in Nakdong River, South Korea, using allocation rule (AR) according to the water supply capacity of each reservoir and the characteristic of parallel reservoir system. The result of the analyzing parallel reservoir system for Andong and Imha reservoir in Nakdong River does not include evidences available enough to decide whether the results of water supply analysis are excellent in the current reliability evaluation or not. However, AR (C) shows a good result in the water supply capacity for each reservoir based on the connected operation system and the total water supply capacity at the control point of downstream by the average water supply capacity and possible range of water supply capacity suggested by this study. The average water supply capacity is analyzed by the reliability of monthly average water supply capacity. Furthermore, the possible range of water supply capacity is estimated by the standard deviation when water deficit occurs. Therefore, AR (C) is useful to establish and estimate the planning water supply capacity according to the monthly water supply condition and the possible range of water supply capacity when the water supply capacity deficit occurs, South Korea.