• 한국환경과학회지
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• 제27권10호
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• pp.883-899
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• 2018

In this study, water quality data of eight main sites in the Geumho River watershed were collected and analyzed for long-term changes in water quality over the period from 2005 to 2015. The results showed that BOD concentration was gradually improved by the Total Maximum Daily Load (TMDL), stages 1 and 2. Recently, a tendency of increasing BOD concentration was observed in the downstream section of the river. The concentration of COD was analyzed to be contaminated throughout the water system regardless of the water quality improvement project, and the TN concentration tended to increase in the midstream of the river from 2013. The TP concentration has clearly decreased from 2012 after the second stage of TMDL. For the statistical analysis of PCA ordination, monthly water qualities (pH, DO, Electrical Conductivity (EC), Water Temperature (WT), BOD, COD, TN, TP, TOC, and SS) and flow rate data for 5 years from 2012 to 2016 were used. Seasonally the Geumho River showed an increase in the TN concentration at point sources during the dry season (December to February). TP showed the effect of non-point sources in the summer, because rainfall has caused a rise in flow rate in the upstream. Besides, the origin of pollution source was changed from non-point sources with BOD, COD, and TOC.

• 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.

• 환경영향평가
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• 제28권3호
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• pp.215-230
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• 2019

본 연구는 한강 수계의 주요 지류 하천에 통계분석을 이용하여 수질특성을 파악하고 하천 등급화 방법에 따른 우선으로 관리되어야 할 지류 하천을 선정하여 수질 개선 방안을 제시하는 것이다. 한강 수계의 주요 15개 지류 하천을 대상으로 2017년 1월부터 12월까지 유량 및 수질을 모니터링 하였다. 상관 분석 결과 하천 유량은 수질 항목 간의 상관성(p>0.05)이 있지 않았으나 COD와 TOC는 통계적으로 유의한 수준의 높은 상관성을 나타냈다(r=0.957, p<0.01). 주성분 분석 결과 유기오염 물질 및 영양염류에 의한 오염이 수질변동의 주요한 요인으로 나타났으며 BOD, COD, TOC, TN, TP는 일원 분산분석 결과 계절별로 유의한 수준에서 차이가 있는 것으로 나타났다(p<0.05). 정량적 지표에 따른 하천 등급화 결과 수질개선이 필요한 지류 하천은 공공하수처리시설 방류수의 영향을 받는 굴포천, 안양천, 왕숙천, 탄천 등으로 나타났다. 본 연구를 통하여 한강 수계의 수질 개선이 필요한 지류 하천을 선정할 수 있었으며 효율적인 수질 관리를 위한 중요한 자료로 활용될 수 있을 것으로 판단된다.

• 한국조경학회지
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• 제25권3호
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• pp.222-233
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• 1997

Riparian zone occupies not more than 5% of the total watershed area and can be considered in between the terrestrial and aquatic ecology as that does not fall under both of them. Unlike to common terrestrial plant that can e seen on other land, the riparian vegetation that exist in riparian zone can be classified into various groups because of their peculiar living form. The recognition of importance of terrestrial environment has considered the importance of natural river due to which even today, the movement throughout the world to retrograde the river development is taking place customarily. In this research, noticing the actual condition of the river management reality, the original capacity of river landscaping of Han river has been quantified grasping the actual condition of riparian vegetation from distribution area surveying and analysis. The objective of the research is to find out the river retrogression and maintenance methods based on the ecological environmental quality around the river by maintaining the river plants having high natural capacity and river planning method based on the harmony between conservation of river environment and use of riparian zone.

• 하천과문화
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• 제9권4호
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• pp.70-73
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• 2013

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2012년도 학술발표회
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• pp.26-26
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• 2012

The Kurobe river, which runs through eastern Toyama Prefecture is one of the most famous rivers for wild water because of its steep slope in the range from 1/5 to 1/120. This river forms an alluvial fan in the range up to 13 kilometers from the sea. In this region, significant seepage flow occurs and thus the stream sometimes been intermitted. Moreover, the amount of seepage flow seems to vary with the groundwater level of the region. To keep the river environment healthy for flora and fauna, especially to conserve good condition for spawning of fishes, an appropriate environmental flow should be maintained in the river. To achieve this target, controlling of the upstream reservoir has to be studied in depth. One of the major problems to decide the amount of water to be released from the reservoir to maintain the environmental flow is to estimate the amount of water leaked into the groundwater from the river. This phenomenon is affected by the river flow rate as well as the groundwater level in the alluvial fan and the conditions vary in space and time. Thus, a grid-based hydrological cycle analysis model NK-GHM has been applied to clarify the hydrological cycle componentsin this area including seepage/discharge from/to the river. The model was tested by comparing with river flow rate, groundwater levels and other observations and found that the model described those observations well. Consequently, the seepage from the Kurobe river was found significant but it was also found that the groundwater in this region has been preserved by the recharge from the irrigation water supply into paddy fields in the alluvial fan.

• 자원환경지질
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• 제39권3호
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• pp.269-284
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• 2006

지하수위와 하천수위와의 상호반응과 수리적으로 다른 특성을 가지는 각 층별(실트질 모래층, 자갈모래층, 풍화대층) 반응관계를 알아보기 위하여 시계열 분석에서 많이 사용되어 온 방법인 자기상관분석과 교차상관분석방법을 이용하였다. 만경강 하천부지에 각 층을 대표하는 깊이에서 지하수위를 관측한 결과, 지하수위가 강수량보다는 하천수위변동에 민감하게 반응하고 있었다. 연구지역의 하천수위변동은 만경강 제수문의 조절과 조석의 영향을 받아 주기적인 수위변동이 우세하기 때문에 강수량과의 상관성은 낮다. 다심도 관정에서 각층별 하천수위에 대한 지하수위 반응은 시간지연 없이 서로 같이 변동하는 것으로 나타났으며, 반응시간은 하천과 가까운 관정에서 30-60분 이내로 빠르며 하천에서 거리가 멀어지면서 반응시간은 대체로 늦게 나타났다. 그러나 하천과 멀리 떨어져 있는 관정이더라도 하천수위에 대하여 빠른 반응을 보이는 관정이 있으며, 이는 하천과 대수층과의 높은 수리적 연결성을 나타낸다. 지하수위의 하천에 대한 반응양상이 다르게 나타나는 것은 대수층의 수리적 불균질성에 의한 것으로 사료된다. 연구지역의 하천은 대체로 지하수위가 하천수위보다 높게 관측되고 있기 때문에 지하수가 하천으로 유출되는 이득하천의 성격을 가지고 있다고 판단되나, 하천의 급격한 수위상승에 따라 역으로 하천의 물이 지하수로 공급되는 손실하천의 성격도 보여주었다. 하천수위와 대수층이 연결된 시스템에서 시계열분석으로서의 자기 및 교차상관분석은 수리적 상호관계를 파악하기 위한 유용한 도구로 활용될 수 있다.

• 대한환경공학회지
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• 제39권11호
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• pp.641-649
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• 2017

본 연구에서는 오염원의 변화 특성이 다양한 임진강유역을 대상으로 통계분석을 이용하여 상관분석, 주성분 및 요인분석, 군집분석을 통해 수질특성을 파악하였다. 신천3 지점의 평균 수질농도가 BOD 13.4 mg/L, COD 19.9 mg/L, TN 11.145 mg/L, TP 0.336 mg/L, TOC 14.2 mg/L로 높게 나와 전체 유역 중 신천 유역에 대한 집중적인 수질관리가 필요한 것으로 나타났다. 전체 수질측정 자료의 상관분석 결과 COD는 TOC, BOD, TN 수질인자와 유의한 상관관계를 보여 유기물과 영양염류인자간의 상관성이 높은 것으로 나타났다. 주성분분석 결과 전체 측정소 자료는 81.221%로 2개의 주성분, 계절별 자료는 96.241%로 3개의 주성분이 추출되었다. 요인분석 결과 전체 측정소 자료와 계절별 자료의 수질영향 요인은 공통적으로 BOD, COD, TN, TP, TOC 항목이 나타났다. 시 공간적 군집분석 결과 계절별 특성 및 토지이용에 따라 각각 4개, 3개 그룹으로 나타났다. 본 연구는 임진강유역을 중심으로 8년간 시 공간적 특성을 고려한 수질 요인을 분석한 것으로 향후 유역환경변화에 따른 임진강 유역의 수질 변화를 이해하기 위한 기초 분석 자료가 될 것이다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.142-142
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• 2023

Humans inevitably and continuously produce wastewater in daily life worldwide. To decrease the degradation of river water bodies and aquatic ecosystem therein, humans have built systems at different scales to collect, drain, and treat household-produced wastewater. Particularly, municipal wastewater treatment plants (WWTPs) with centralized controls have played a key role in reducing loads of nutrients in domestic wastewater for the last few decades. Notwithstanding such contributions, impaired rivers regarding water quality and habitat integrity still exist at the whole river basin scale. It is highly attributable to the absence of dilution capacity of receiving streams and/or the accumulation of the pollutant loads along flow paths. To improve the perspective for individual WWTPs assessment, the first crucial step is to achieve systematic understanding on spatial distribution characteristics of all WWTPs together in a given river basin. By taking the initiative, our former study showed spatial hierarchical distributions of WWTPs in three large urbanized river basins in Germany. In this study, we uncover how municipal WWTPs in the contiguous United States are distributed along river networks in a give river basin. The extended spatial scope allows to deal with wide ranges in geomorphological attributes, hydro-climatic conditions, and socio-economic status. Furthermore, we identify the relation of the findings with multiple factors related to human activities, such as the spatial distribution of human settlements, the degree of economy development, and the fraction of communities served by WWTPs. Generalizable patterns found in this study are expected to contribute to establishing viable management plans for recent water-environmental challenges caused by WWTP-discharges to river water bodies.

• 상하수도학회지
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• 제31권1호
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• pp.93-101
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• 2017

In this study, we investigated the correlation between the number of cyanobacterial species and the water quality factors after installation of Nakdong river weirs. Factor analyses of water quality factors were also performed. The results of correlations showed that there was no significant water quality with the cyanobacterial concentration but the correlation coefficient of nutrients increased from the upstream to the downstream. There was a significant correlation between W T and pH as important water quality factors for the growth of cyanobacteria. In the downstream region of Nakdong river, algae were more frequently detected than in the upstream region, and the blooms of algae species seem to be influenced by the higher pH and the influx of the phosphorus from the upstream tributaries. Nutrient concentration was higher in the downstream region than in the upstream region due to the effects of tributaries Geumho river and Nam river in Nakdong river. As a result of the factor analyses, nitrogen species were the principal factors in the upper region, and phorsphorus species were the principal factors in the downstream region.