• 한국환경과학회지
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• 제22권4호
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• pp.507-514
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• 2013

The Nakdong River being used as drinking water sources for the Busan metropolitan city has the vulnerability of water management due to the fact that industrial areas are located in the upper Nakdong River. This study used emergy analysis method to evaluate ecological-economics of water treatment systems of D water treatment plant (WTP) where located in the downstream of the Nakdong River. The emergy methodology is a system evaluation tool that uses energy as the common currency to compare different resources on a common basis. Emergy yield ratio (EYR) and emergy sustainability index (EmSI) of D WTP were 1.16 and 0.18, respectively. It means not resources and sustainable system but consumer goods and not sustainable system. Ratio of emergy benefit to the purchaser (EBP) shows 2.7 times higher than economic costs. To change the weak water source and situations we need to diversity water intake.

• 한국물환경학회지
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• 제39권3호
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• pp.215-222
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• 2023

Zooplankton are primary consumers in the food web connecting primary producers and predators such as small fish, playing an important role in energy transfer in aquatic ecosystems. Therefore, it is essential to understand the zooplankton community structure in material cycle and energy flow in aquatic ecosystems. Zooplankton in large rivers with a low flow rate would distribute vertically as in lakes. In this study, we collected zooplankton by surface water filtration and vertical haul method with 64 ㎛-mesh plankton net at three stations (ND-1, ND-2, ND-3) in Nakdong River fortnightly from June 2018 to December 2019. Species composition and individual densities were analyzed. All three stations showed differences in relative abundance of zooplankton groups between surface water and vertical integrated water, with the largest difference shown in the deepest station, ND-2. In vertically integrated water at ND-2, the relative abundance of rotifera was low by a maximum of 25% and that of cladocera was high by a maximum of 22% compared to surface water samples. These results indicate that surface water filtration method is not enough to represent the community structure of zooplankton compared to the vertical haul method in large rivers.

• 한국해양학회지:바다
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• 제11권1호
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• pp.11-20
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• 2006

낙동강 하구는 담수와 해수가 만나 복잡한 순환 양상을 보이는 지역으로, 1987년에 준공된 하구둑의 건설로 지형적인 변화와 함께 여러 가지 해양 환경적인 변화를 가져왔다. 하구둑 건설 전과 후의 특징을 보면, 건설 전에 비해 흐름이 약해졌고 조류가 흐름을 주도하던 혼합 기작이 담수의 방류가 주도하는 체계로 변하였다. 이러한 담수의 방류는 그 정도에 따라 낙동강 하구둑 하류부 담수의 거동과 혼합 특성을 변화시켰으며 해수 순환에도 큰 영향을 주었다 본 연구에서는 낙동강 하구둑 하류부의 유동 특성을 하구둑의 수문 개폐에 초점을 맞춰 분석하였다.

• 한국물환경학회지
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• 제30권5호
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• pp.539-548
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• 2014

This study was carried out to investigate algal community structures and their correlations with environmental factors on five weir areas in the Nakdong River, South Korea. Water qualities, hydrodynamics, meteorological conditions and algal species compositions were observed in studied sites from May 2010 to Dec. 2013. Results showed that average total phosphorus concentration of 2013 was decreased by 52.4% in comparing with that from 2010 to 2011. Chlorophyll.a concentrations were positive significant with water temperature, pH, total phosphorus and total nitrogen, but is not significant with turbidity and suspended solids. Seasonal successions of algae were observed that Stephanodiscus sp. was dominant species with 65.3% of dominant frequency in studied site. Large algal biomass of the low temperature-adapted diatoms were observed during temperature range of $4{\sim}9^{\circ}C$, but large cyanobacterial biomass mainly during high temperature period ranged from $22^{\circ}C$ to $32^{\circ}C$. Microcystis sp. dominated during high water temperature in summer. The yearly correlations of algal biomass with accumulated solar radiations were not significant but seasonal correlations of summer from June to August were significant with correlation coefficient 0.33 (p<0.05). There were not significant correlations between turbidities and algal biomass. Turbidity and suspended solids concentrations were not significant correlation with algal biomass. According to the results, algal communities had strong correlation with water temperature and had partially correlation with solar radiation. For an effective management of algal blooms, water managers should survey with more long-term monitoring of various environmental factors and algal communities.

• Environmental Engineering Research
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• 제17권2호
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• pp.95-102
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• 2012

To evaluate the effect of the 4 major rivers restoration project in the Nakdong River to water quality of the river, the Environmental Fluid Dynamics Code (EFDC) and Water Quality Analysis Simulation Program (WASP), are applied in series. Results showed overall decrease in biochemical oxygen demand ($BOD_5$) concentrations and increase in chlorophyll-a concentrations, while total nitrogen and total phosphorous concentrations did not show significant changes, relatively. Decrease in $BOD_5$ concentrations seems to be influenced by an increased hydraulic residence time, which may allow more time for the degradation of organic material. Changes in Chlorophyll-a (Chl-a) concentration, due to the project were more significant for the upper stream areas that show relatively low Chl-a concentration ranges (less than 20 g/L). After the introduction of the Geumho River in the middle part of the Nakdong River, rapid growth of phytoplankton was observed. However, in this middle part of the Nakdong River, the ratio of Chl-a concentration change are less significant, compared to the upper stream areas, due to the project. In the lower stream area, Chl-a concentration decreased after the project. This seems to be resulted from the decreased light availability, due to increased depth, while the nutrient concentrations have been high enough to support phytoplankton growth.

• 한국환경과학회지
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• 제7권2호
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• pp.165-170
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• 1998

The purpose of thins study was to investigate the pollutions of water Qualities in 30 water samples from Nakdong River Western Nakdong River, and Suyoung Stream. COB, BOD. T-N and negative ion(F, Cl+, NO3-, SO42-) of water samples were analysed and the correlationships between water qualities were examined. The mean concentrations of COD(20.26ppm), BOD(25.36ppm), and T-N(18.05ppm) were the highest in the water sample of Suyoung Stream among the three streams and those of F-(0.25ppm), Cl+(2770ppm), and SO42-(37.66ppm) In Western Nakdong River, that of NO3-(10.8 ppm) in Nakdong River. The water quality of Suyoung Stream was the worst among the three streams in hsn area. The correlationships between water qualities were as follows , BOD and COD showed very high correlationship(correlation cofficient, r=0.97),50,2- and NO3'did high one(0.75), and NOa'and COD, BOD did relatively high ones(0.56 and 0.48, respectively).

• Water Engineering Research
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• 제2권4호
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• pp.231-241
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• 2001

Since South Korea has uneven rainfall and deteriorating water quality, it is imperative to create a comprehensive water resources policy and management. This paper is to adopt a win-win policy for upstream-downstream local governments that have been in water rights-related disputer or conflicts in the process of allocating water and maintaining water quality. The Win-Win Policy can be an integrated river-basin approach. We define the win-win policy, introduce the win-win case of Delaware River and Colorado River in the United States, and suggest the win-win policy for Nakdong River in South Korea. Nakdong River is chosen for this paper because it has more serious problems in preserving water quantity and maintaining water quality.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.988-991
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• 2013

낙동강 하류 지역에는 합천 창녕보, 창녕 함안보, 낙동강하굿둑 좌안배수문 그리고 우안배수문의 수자원시설이 건설되어 운영되고 있다. 원거리에 위치한 각각의 시설물을 연계하여 통합 운영하는 것은 국가 수자원의 관리와 설비 운영의 효율과 효과 측면에서 중요하다. 이러한 이유로 ICT 기술을 활용하여 개별 시설물을 유기적으로 운영할 수 있는 시스템 구현을 계획하고 실행하였다. 부산 낙동강하굿둑 인근에 위치한 K-water 낙동강통합물관리센터에서 개별 시설들을 통합 운영할 수 있는 시스템을 구축하여 효율적인 수자원관리와 운영비용 절감 등의 상당한 기대효과가 있을 것으로 사료된다.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2003년도 International Symposium on Clean Environment
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• pp.99-102
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• 2003

The different methods such as HPLC, indirect- and direct-ELISA were employed for the analysis of microtoxins and the results of each method were compared in terms of the detection limit and accurary. Three toxins, microcystin-RR, -LR and -YR were clearly separated by HPLC using 0.05 M methanol and phosphate buffer used as a solvent system. The calibration curves for the toxins were linear in the range of 5 ng to 50 ng. The standard curves for the immunoassay of microcystin obtained by direct and indirect ELISA are compared. The linear responses of inhibitions of binding by microcystin in the direct and indirect competitive ELISA were in the range of 10 ng to 1000 ng and 50 pg to 160 pg, respectively. Distribution of microtoxins at 11 sites in the Nakdong river and several lakes in Korea was also studied. The most dominant microcystin variant in the test sites was found to be microcystin-RR.

• 한국환경과학회지
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• 제23권1호
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• pp.7-23
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• 2014

This study estimates unit for the nonpoint source(NPS), classified according to the existing Level-1(large scale) land cover map, by monitoring the measurement results from each Level-2(medium scale) land cover map, and verifies the applicability by comparison with previously calculated units using the Level-1 land cover map. The NPS pollutant loading for a basin is evaluated by applying the NPS pollutant unit to Dongcheon basin using the Level-2 land cover map. In addition, the BASINS/HSPF(Better Assessment Science Integrating point & Non-point Sources/Hydrological Simulation Program-Fortran) model is used to evaluate the reliability of the NPS pollutant loading computation by comparing the loading during precipitation in the Dongcheon basin. The NPS pollutant unit for the Level-2 land cover map is computed based on precipitation measured by the Sangju observatory in the Nakdong River basin. Finally, the feasibility of the NPS pollutant loading computation using a BASINS/HSPF model is evaluated by comparing and analyzing the NPS pollutant loading when estimated unit using the Level-2 land cover map and simulated using the BASINS/HSPF models.