• 한국습지학회지
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• 제25권4호
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• pp.326-334
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• 2023

본 연구는 낙동강수계 지류에서의 장기 수질모니터링 자료를 이용하여 수질의 목표수질 초과율, 증가 추세를 검토하여 지류에서 문제 되는 물질이 무엇인지 파악하는 것이 목적이다. 낙동강수계에서는 중점 관리가 필요한 38개 지류에 대하여 월 1회 모니터링이 수행되고 있으며 이 자료를 이용하여 지점별 목표수질 초과 및 증가 경향을 분석하였다. 분석 항목은 하천 수질 기준으로 평가가 가능한 DO, BOD, COD, TOC, SS, 총인, 분원성 대장균군, 총대장균군 8개 항목이다. 분석 결과, 목표수질 초과율이 50% 이상이며 증가추세인 항목은 TOC, 분원성 대장균과 총대장균수로 나타났으며 초과율이 50% 이하이나 증가 경향을 가진 항목은 SS로 나타났다. TOC는 난분해성 물질의 증가로 인한 원인으로 판단되며 대장균의 지속적인 증가는 향후 하수처리시설에서의 방류수질 중 대장균의 관리가 필요할 것으로 판단된다.

• 한국물환경학회지
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• 제21권5호
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• pp.511-515
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• 2005

CBOD(carbonaceous BOD) decay rate was investigated for the execution of water quality model in Nakdong-Rive basin. Estimation of laboratory-derived CBOD decay rate, $k_l$ and CBOD decay rate in natural waters, $k_d$ were carried out. Hydraulic factors were applied for the calculation of $k_d$. Values of biochemical oxygen demand were investigated in Weagwan, Koreong, Jeokpo, Namgi and Mulgeom sites for the four times. The ranges of $k_l$ value were $0.04{\pm}0.01{\sim}0.14{\pm}0.03$. The values of $k_l$ in upstream sites were much larger than those in the downstream sites. The values of $k_d$ were 0.025, 0.036, 0.005 and 0.001 at Weagwan, Jeokpo, Namgi and Mulgeom, respectively, indicating that values of $k_d$ were generally larger than those of $k_l$.

• 환경영향평가
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• 제21권1호
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• pp.219-227
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• 2012

Daily solar radiation is essential for water resources planning and environmental impact assessment. However, radiation data is not commonly available in Korea other than in big cities, and there has been no direct measurement for rural areas where water resources planning and environmental impact assessment is usually most needed. In general, missing radiation data is estimated from nearby regional stations within a certain distance, and this study compared two dominant methods (modified Angstrom equation and transmittance interpolation method) at six stations in Nakdong River watershed area. Two methods shows a similar level of accuracy but the transmittance interpolation method is likely to be superior in that there is no need for any measurement element since the modified Angstrom equation require the sunshine hour measurement. This study will contribute to improve water resource and water quality management in Nakdong River watershed.

• Environmental Engineering Research
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• 제19권3호
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• pp.197-203
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• 2014

This study estimated spatial and seasonal variation of water quality to understand characteristics of Nakdong river basin, Korea. All together 11 parameters (discharge, water temperature, dissolved oxygen, 5-day biochemical oxygen demand, chemical oxygen demand, pH, suspended solids, electrical conductivity, total nitrogen, total phosphorus, and total organic carbon) at 22 different sites for the period of 2003-2011 were analyzed using multivariate statistical techniques (cluster analysis, principal component analysis and factor analysis). Hierarchical cluster analysis grouped whole river basin into three zones, i.e., relatively less polluted (LP), medium polluted (MP) and highly polluted (HP) based on similarity of water quality characteristics. The results of factor analysis/principal component analysis explained up to 83.0%, 81.7% and 82.7% of total variance in water quality data of LP, MP, and HP zones, respectively. The rotated components of PCA obtained from factor analysis indicate that the parameters responsible for water quality variations were mainly related to discharge and total pollution loads (non-point pollution source) in LP, MP and HP areas; organic and nutrient pollution in LP and HP zones; and temperature, DO and TN in LP zone. This study demonstrates the usefulness of multivariate statistical techniques for analysis and interpretation of multi-parameter, multi-location and multi-year data sets.

• 한국물환경학회지
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• 제31권2호
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• pp.110-119
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• 2015

The construction of the eight large weirs in the Nakdong River, the second largest river in Korea, caused big changes in the physical environment of the water system. Algal communities and their correlations with environmental factors, mainly nutrients were studied at five weir areas in the Nakdong River from 2010 to 2013. Water quality, hydrodynamics and algal composition were investigated. Results showed that flow velocities were reduced compared with that before weir construction near the areas where are located in the mid and upstreams of the Nakdong River. A seasonal algal community succession was observed and it was mainly correlated with temperature and phosphorus. Diatoms were dominated from winter to spring months and massive diatomic blooms of Stephanodiscus sp. occurred early in March during survey period. Cyanobacterial blooms of Microcystis sp. occurred from July to September 2013 and was preceded by the lower total phosphorus concentration of $0.05mg\;L^{-1}$. The correlations between total phosphorus concentrations and algal abundances were not significant during the survey periods. However, significant correlation with cyanobacteria was found in the period of weir construction after only at the GG survey site and blooms periods of 7 times in the survey sites, and its correlation coefficients were 0.53 (p<0.001) and 0.42 (p<0.01) respectively. When algal bloom was observed, partially low nutrient concentration was observed in the Nakdong River. In conclusion, partially low nutrient concentration which may result from algal bloom was observed, and we presume it caused the reduction of algal abundunces.

• 한국농공학회논문집
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• 제57권6호
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• pp.153-162
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• 2015

In this study, we analyzed the trends of water quality along the main stream in Nakdong river basin using the recent data and seasonal Mann-Kendall test. Monthly averaged values of DO, BOD, SS, COD, TN, and TP from 1989 to 2014 for 14 stations (including 2 TMDLs stations) were used in the study. The trend analysis results showed that BOD and TP at most stations has decreasing temporal trend except a few stations while COD and SS showed increasing trend at most stations. Temporal trends in TN at 8 stations were found to be statistically significant and 5 of them showed increasing temporal trend. Temporally averaged BOD, COD, TN and TP were generally increasing as going downstream and the worst water quality were found at Goryeong and Hyunpung station. Overall, water quality of Nakdong river especially in COD, SS, and TN getting worse in time at most stations and as going downstream.

• 환경영향평가
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• 제29권1호
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• pp.61-77
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• 2020

현재 국내 주요 공공수역은 국가차원 아래 체계적인 물환경 관리가 되어왔고, 특히 하천, 호소 등 생태계의 실태파악 및 대응을 위해 지속적인 모니터링 및 관리가 이루어져 왔다. 그 중, 수질측정망은 수질측정 주기가 8일에서 한 달 주기로 조사되는 반면, 자동측정망의 경우, 실시간 자료를 수집함으로써 일 데이터 자료를 제공하고 있다. 따라서 측정망 자료를 활용하여 동일한 수질항목에 대해 추세변화를 분석하고 통계적 방법을 통해 비교하였다. Mann-kendall test 결과 Water Temperature (WT)와 DO는 모든 지점이 통계적으로 유의하지 않은 것으로 확인되었고, 특히 TOC에서는 4개 지점, TN은 2개 지점, TP는 3개 지점, Water Temperature (WT)는 7개 지점, pH는 2개 지점, EC는 5개 지점, DO는 6개 지점에서 동일한 추세 경향을 보였다. LOWESS 분석 결과, TOC와 pH의 측정망 결과는 서로 다른 추세를 보이는 것으로 분석되었다. 지점별, 항목간 상관관계 분석결과에 따르면 안동댐하류-안동1 지점에서는 TP, 도개-산곡지점에서는 TOC, 고령(자동)-고령 지점에서는 pH, 적포-창녕 지점에서는 TP, 감천-감천2-1 지점에서는 TN, TP, pH, EC, DO 항목을 제외하고 나머지 항목에서 유의한 양의 상관관계를 보이는 것으로 분석되었다. 그리고 신암-상주2 지점과 남강-남강4 지점에서는 모든 항목에서 유의한 양의 상관관계를 나타내는 것으로 분석되었다.

• 한국농공학회논문집
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• 제62권6호
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• pp.97-109
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• 2020

The objective of this study was to assess spatial variation of the target water quality criteria and excess rate in Nakdong river basin after the Total Maximum Daily Loads (TMDLs). For this, 41 total water quality monitoring stations were selected BOD and T-P data were collected from 2003 to 2019. The annual average water quality of BOD and T-P were calculated and compared with the target water quality for each stations by peroid. As a result of analyzing the BOD, Kumho A, Nakbon F, Namgang D, Miryang B, Wicheon B and Hoecheon A exceeded the target water quality criteria for two consecutive times. For T-P, Nakbon N, Naeseung B, Miryang A, Hwanggang A and Hoecheon A exceeded the target water quality criteria twice in a row. In the case of T-P, the target water quality excess rate was relatively low after the TMDLs implementation compared to before the TMDLs implementation. However, in the case of BOD, there was no difference in the target water quality excess rate before and after TMDLs. As a result, the overall annual average water quality shows a decreasing trend, but it is necessary to manage the water quality for the Nakdong river basin that exceed the target water quality.

• 환경영향평가
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• 제21권4호
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• pp.543-552
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• 2012

Namgang mid-watershed is located in downstream of Nakdong river basin. There are many pollution sources arround this area and it's control is important to manage a water quality of Nakdong river. A target year of Namgang mid-watershed water environment management plan is 2013. To predict a water quality at downstream of Namgang, we have investigated and forecasted the pollutant source and it's loading. There are some plan to construction the sewage treatment plants to improve the water quality of Nam river. Those are considered on predicting water quality. As results, it is shown that the population is 343,326 and sewerage supply rate is 79.2% and the livestock is 1,662,000 in Namgang mid-watershed. It is estimated that the population is 333,980, the sewerage supply rate is 86.9% in 2013. The milk cow and cattle were estimated upward and the pigs were downward by 2013. The generated loading of BOD and TP is 75,957 kg/day and 4,311 kg/day, discharged loading is 18,481 kg/day and 988 kg/day respectively in 2006. It were predicted upward the discharged loading of BOD and TP by 4.08% and 6.3% respectively. The results of water quality prediction of Namgang4 site were 2.5 mg/L of BOD and 0.120 mg/L of TP in 2013. It is over the target water quality at that site in 2015 about 25.0% and 9.1% respectively. Consequently, there need another counterplan to reduce the pollutants in that mid-watershed.

• 지질공학
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• 제33권1호
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• pp.51-59
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• 2023

낙동강은 수중 생태계의 안전을 위한 자연자원으로서의 기능뿐만 아니라 유역주민들이 상수원수로 사용하고 있다. 사람들의 생활에 이용될 여러 산업에서 발생시키는 폐수와 사람들이 뱉어내는 오·하수 등은 방류수 기준을 만족시켜 낙동강으로 유입시키고 있다. 낙동강본류에서 모니터링되어 공개되고 있는 50개 지점의 수질 자료를 활용하여 신·구 유기물질 항목 간의 상관성을 살펴보았다. 낙동강본류에서 나타나는 신유기물질 항목인 TOC와 구유기물질 항목인 COD는 결정계수(R²)가 0.6134로 나타나 상관성은 높다고 할 수 있다. TOC·COD를 이용하여 평가한 각 지점의 수질 등급에서는 그 차이가 무시할 수준을 넘어섬을 알 수 있다. 즉 COD를 대체하여 TOC를 활용하여 낙동강본류의 평가할 때 상대적으로 더 양호한 등급으로 나타났다. 따라서 TOC의 수질 등급을 재검토할 필요성이 여전히 남아있고 COD의 지속적인 모니터링이 요구된다고 할 수 있다. 이에 더해 신·구 유기물질에 영향을 미치는 인위적인 오염원과 자연적인 요소들에 대해 발생 원인이 명확하게 규명되어야 낙동강의 수질등급을 활용한 물관리가 가능할 것이다.