• 한국환경과학회지
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• 제5권4호
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• pp.481-494
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• 1996

This study was performed to investigate the relationship between concentrations of heavy metals in sediment and the depths of 27 sampling sites along the West Nakdong river in downstream of Nakdong River. The deepest site was Kangdong bridge nearby 20ft. From here, the depth was shallowed to Chidong gradually. In each site the smaller mesh was, the liger concentration of heavy metal becomed. Concentration of Zn, Cd, Cr and Cu at inflow point of Shinoe stream was 576.016 ppm, 262.307 ppm, 68.674 ppm and 61.634 ppm, respectively, the concentration was the higest at this point. From here, it was lowered gradually. The concentration of heavy metal at inflow point of Joman river was 155.328 ppm, 56.485 ppm, 25.200 ppm and 31.172 ppm, respectively, those concentrations were liger than other points with the exception of Shinoe stream. Therefore, woman river and Shinoe stream were the major source of pollution in West Nakdong river. Among two sources Shinoe stream was more important source of pollution. West Nakdong river has become lake by Noksan floodgate because it's pollution has had influence on Bonglim.

• The Korean Journal of Ecology
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• 제27권5호
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• pp.269-281
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• 2004

본 연구는 2003년 3월부터 2004년 2월까지 낙동강 하류지역에 도래하는 조류를 지역별로 구분하여 도래현황과 서식지 환경의 특성을 조사하였다. 조사결과 낙동강 하류에서 총 114종 94,481개체가 관찰·기록되었다. 이 중 종수와 개체수에서 대마등(Ⅰ)이 55종 21,781개체로 가장 많이 관찰되었는데 낙동강 하류의 전지역 중에서 대마등과 주변의 갯벌이 채식지와 휴식지로 좋은 조건을 갖추고 있기 때문으로 판단된다. 조류군집의 특성에서, 논병아리류는 하구언 아래(을숙도)지 역, 가마우지류는 수심 이 깊은 낙동강 본류와 서낙동강의 주변, 고니류와 혹부리오리 및 도요·물떼새는 하구언 하단부의 수심이 얕은 갯벌,수면성 오리류는 서낙동강(F)과 염막(C)지역, 잠수성 오리류는 비교적 수심이 깊고 서식 여건을 갖추고 있는 하구언 상단부와 서낙동강의 녹산수문 상단부를 주로 이용하고 있었다. 기타 산새류는 염 막(C)과 을숙도(A) 및 서낙동강(F) 지역에 많이 분포하고 있는데 이것은 을숙도 쓰레기 매립장의 인공 식재림, 일웅도의 유휴지와 염막으로 연결되는 지역으로 물새와 함께 일반 조류들의 서식공간으로 활용되고 있기 때문이라고 생각된다. 낙동강 하류지역은 낙동강 하구와 주남저수지의 사이에서 오리 기러기류의 채식지 및 휴식지로서 중요한 지역이지만 계속해서 개발의 유혹에서 벗어나지 못하는 지역 중의 한 곳이다. 이번 조사에서 나타난 결과는 수변지역으로는 대저수문지역(E), 서낙동강(F)의 녹산수문 상단부와 경작지로서는 염막(C)지역으로 인간의 간섭을 받지 않는 자연적인 서식지를 유지하면서 효과적으로 보존할 수 있는 철저한 관리가 요망되는 지역으로 판단된다.

• 한국환경과학회지
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• 제28권12호
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• pp.1071-1083
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• 2019

In this study, water quality levels were classified and water quality indices were calculated and analysed by using the water quality components of living environmental standards monitored 10 years (2008 ~ 2017) at four stations in the West Nakdong River. As a result of analyzing the monthly variation of the water quality components of the living environmental standards, the water quality in the West Nakdong River was worse downstream than upstream, and pollution at the WNR3 located in the downstream of the Jomangang was the most serious. As a result of classification of water quality levels, BOD and COD levels were the lowest, so water quality pollution in the West Nakdong River was found to be highly influenced by organic matters. The water quality index was the lowest in July and August at four stations, so water quality is showing the worst in summer. As a result of analyzing the correlation between the water quality components and the water quality index, the correlation between the TOC and the water quality index was high in the four stations, and the water quality index in the West Nakdong River was dominated by organic matters and nutrients.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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• pp.81.2-81.2
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• 2007

See Full Text

• 한국환경과학회지
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• 제3권4호
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• pp.409-416
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• 1994

This study was Performed to evaluate the contents of heavy metals in water, sediment and soil of the 7 different sampling points along the West Nakdong river, The results were as follows: the concentrations of Zn, p, Pb, Cd, Mn, Cu and As in the sediment were 197.48, 551.85, 67.01, 2.54, 491.39, 42.95 and 10.52ppm, respectively. The concentrations of Zn, p, Pb, Cd, Mn, Cu and As in the soil was 83.32, 482.89, 17.15, 1.02, 226.02, 26.15 and 7.29ppm, respectively. The concentration ratios of heavy metals In the water to the sediment were 593 - 12700 (Cd >> Cu > Zn > Mn > As > Pb) and that of the water to the soil were 152 - 5100 (Cu > Cd > Zn > Mn > As >Pb). The correlation coefficients of Cu and Pb weve high among the water, sediment and soil. Because the accumulation amounts of heavy metal in the sediment were high, the concentration of heavy metals in the sediment was higher than in soil. The correlation coefficient of heavy metals among water, sediment and soil was high (0.79 - 0.95). Key Words Distribution Characteristics, heavy metals, West Nakdong River.

• 생태와환경
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• 제47권1호
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• pp.62-69
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• 2014

Standing crop distribution of aquatic plants in the West Nakdong River and riparian wetlands in the Nakdong River were surveyed in May, July and September, 2010. Total 25 aquatic macrophyte species (submerged: 9, leaf-floating: 3, free-floating: 5, emergent: 8) were observed during the survey periods. Distribution area of aquatic plants and proportion of submerged communities were highest in Garakchi-deung ($212,032m^2$, 72.7%). The distribution area of aquatic plants was highest in Phragmites australis community ($421,584m^2$), followed by Hydrilla verticillata-Vallisneria natans community ($181,511m^2$), Potamogeton wrightii-Vallisneria natans community ($61,604m^2$), and Hydrocharis dubia community ($49,709m^2$). Garakch-ideung (212,032 kg) also had the highest aquatic plant production, followed by Suanchi-deung (15,546 kg), Daedong (5,813 kg), Dunchi-do (3,963 kg), Maekdo (1,463 kg), Yeommak (571 kg), Jungsa-do (530 kg), and Shinan (300 kg). Average standing crop of the study area were $147.8{\pm}20.8g\;DW{\cdot}m^{-2}$ in 1988, $96.1{\pm}20.0g\;DW{\cdot}m^{-2}$ in 2000, and $172.6{\pm}76.1g\;DW{\cdot}m^{-2}$ in 2010. For a sustainable management of river habitat and food source, aquatic plant should concurrently be surveyed with river environmental variables (i.e. sediment, nutrient, flow).

• 한국환경과학회지
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• 제18권9호
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• pp.971-981
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• 2009

An objective of this study is as follows: 1) performing sensitivity analysis and parameter estimation of RMA2 and RMA4 models for the West-Nakdong River, 2) drawing up alternatives of gates-operation for water-quality enhancement, and 3) quantitative evaluation of methodology of 'flow-restoration by gates-operation' among 'Comprehensive Plan Improving Water-Quality in the West-Nakdong River(WNR)' with the target water-quality(BOD at Nakbon-N point: below 4.3 mg/L). The parameters for the RMA2 (depth-averaged two-dimensional flow model) and RMA4 (depth-averaged two-dimensional water-quality model) were determined by sensitivity analysis. Result of parameter estimation for RMA2 and RMA4 models is $1,000\;Pa{\cdot}s$ of the eddy viscosity, 20 of the Peclet number, 0.025 of the Manning coefficient, and $1.0\;m^2/s$ of the diffusion coefficient. We have evaluated the effects of water-quality enhancement of the selected alternatives by numerical simulation technique with the models under the steady-state flow condition and the time-variant transport condition. Because of no-resuspension from river bottom and considering BOD as conservative matter, these simulation results slightly differ from real phenomena. In the case of $50\;m^3/s$ of Daejeo-gate inflow, two-dimensional flow pn results result represents that small velocity occurs in the Pyungkang Stream and no flow in the Maekdo River. In the WNR, there occurs the most rapid flow near timhae-bridge. In the WNR, changes of water-quality for the four selected simulation cases(6, 10, 30, $50\;m^3/s$ of the Daejeo-gate inflow) were predicted. Since the Daejeo-Gate and the Noksan-Gate can be opened up to 7 days, it would be found that sustainable inflow of $30\;m^3/s$ at the Daejeo-gate makes BOD in the WNR to be under the target of water-quality.

• 환경영향평가
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• 제17권3호
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• pp.189-200
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• 2008

As a transition zone between terrestrial and aquatic ecosystems, riparian areas of rivers and streams play significant roles in production and decomposition for river and stream systems. Understanding of the physical and ecological characteristics of riparian areas are, therefore, important for the management of river and stream systems. It is especially important to understand the characteristics of riparian areas for the Nakdong River in Korea which has a large watershed area and diverse land uses. This study aimed at collecting field data, according to stream types, which are essential for the management of riparian areas of the middle and lower reaches of the Nakdong River, Korea. Most riparian areas surveyed in this study had roads within 100 meters from river edges. Distances from water edge to banks were less than 1m for most riparian areas neighboring agricultural lands, indicating that those areas might be very vulnerable to pollutant inputs from non-point sources. Water quality data indicated that soil erosion in the riparian areas could be a major source of phosphorus input to the Nakdong River and land use patters might have a significant influence on nitrogen concentration in the river. Heavy metal concentrations in soils of the riparian areas of the river were below soil quality standards, except arsenic and chromium. Vegetation surveys showed that therophytes were the most frequently occurred riparian plants in the Nakdong River. Number of aquatic plant species increased downstream, with the most diverse aquatic plants observed in wetlands and irrigation canals of the West Nakdong River. Occurrence rate of naturalized plants and urbanization index were high in the survey sites adjacent to urban and agricultural areas.

• 수산해양기술연구
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• 제24권2호
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• pp.65-70
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• 1988

낙동강하구의 물리적 해황조사를 1986년 4월, 6월, 10월과 1987년 2월, 3월, 8월, 6회에 걸쳐 실시하고, 그 자료를 분석, 검토한 결과는 다음과 같다. 1. 음향측심에 의해 조사된 해저지형은 준설 또는 매립으로 인해 불규칙적인 요철이 생겼다. 2. 1986년에 관측된 결과에 의하면 동측수로에는 수류가 거의 없고 서측수로에 대부분의 유량이 흘렀기 때문에 낙조시의 최대속도는 1.5kt 정도였다. 3. 1987년 8월에 측정한 결과에 의하면 하구역에서의 흐름은 동측수로에서 약간 세게 나타날 정도였으나 서측수로에는 조석 때문에 약한 유동이 나타났다.

• Ocean and Polar Research
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• 제26권4호
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• pp.635-646
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• 2004

Chronic outbreaks of green tide in the Nakdong estuary toll a heavy socioeconomic cost. The paper investigates the influence of sediments on the nitrogen eutrophication, being claimed as the primary cause of green tide. To measure the flux of nitrate at the sediments-water interface, sediment cores were taken in Jan., Mar., May and Sep., 2000 at Noksan located in the West-Nakdong river estuary. The dissolved oxygen was profiled and then the pore water was extracted in situ. Core samples were analyzed for their textural characteristics. Cores were incubated by a novel technique to measure the fluxes of nitrate $(NO_3^-)$ and ammonia $(NH_4^+)$ at the sediment-water interface. The dissolved oxygen was depleted usually within several millimeters in the top sediments. Nitrate started to decrease drastically at the layer where dissolved oxygen was nearly depleted. Nitrate was also exhausted within several centimeters, followed by ammonia build up rapidly. The flux at the sediments-water interface calculated from the pore water concentrations revealed that nitrate was removed from the water column into the sediments. The sediment incubation experiment confirmed the above result. On the other hand ammonia were released from the sediment to the water column. As the incubation went on, however, the nitrate concentration in the overlying water was dropped below that of a top sediment. Then the flux is reversed, i.e., nitrate was released from the sediments to the water column. The implication is that the sediment can supply nitrate to the water column if it falls below a certain level. Thus it is likely that sediments in the eutrophicated river buffers the nitrate concentration in the water column, which leads to a prolonged green tide.