• Journal of Environmental Science International
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• v.21 no.1
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• pp.31-39
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• 2012

The objective of this study is to provide pollutant loads delivery ratio for flow duration in Oenam-cheon watershed, which is upstream watershed of Juam Lake. To calculate the delivery ratio by flow duration, rating curves and discharge-loads curves using measured data were established, then Flow Duration Curve(FDC) and pollutant loads delivery ratio curves were constructed. The results show that the delivery ratios for $BOD_5$ for abundant flow($Q_{95}$), ordinary flow($Q_{185}$), low flow($Q_{275}$), and drought flow($Q_{355}$) were 23.9, 12.7, 7.1, and 2.9%, respectively. The delivery ratios of same flow regime for T-N were 58.4, 31.2, 17.2 and 7.1%, respectively. While, the delivery ratios T-P were 17.3, 7.5, 3.4, and 1.1% respectively. In general, delivery ratio of high flow condition showed higher value due to the influence of nonpoint source pollution. Based on the study results, generalized equations were developed for delivery ratio and discharge per unit area, which could be used for ungaged watershed with similar pollution sources.

• Journal of Applied Biological Chemistry
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• v.53 no.4
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• pp.232-238
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• 2010

In order to investigate the treatment efficiency of pollutants in free water surface constructed wetlands (FWS CWs) with lotus (Nelumbo nucifera) cultivation pond, the experiment was consisted of two sites (site I and II) in Lake Juam, Korea. The sites were configured a lotus cultivation pond (with fertilizer application) - a dropwort bed - a reed bed for site I, and a lotus cultivation pond (without fertilizer application) - a dropwort bed - a reed bed for site II. Removal rate of COD in site I and II were 13.3% and 26.0%, respectively. Removal rate of total nitrogen (TN) was 29.7% for site I, and 36.3% for site II. Removal rate of total phosphorus (TP) in site I and II were 36.0% and 36.5%, respectively. COD, TN and TP in effluent from site I (with fertilizer) was higher than that in site II (without fertilizer), showing that COD, TN and TP in effluent were strongly influenced by fertilizer addition. Therefore, in order to satisfy established water-quality standards, the amount of fertilizer used in lotus cultivation showed be evaluated.

• Korean Journal of Environmental Biology
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• v.41 no.2
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• pp.101-108
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• 2023

Recently, in relation to climate change, many studies have been conducted to predict the potential habitat area and distribution range of tilapia and the suitability of habitat for each species. Most tilapia are tropical fish that cannot survive at water temperatures below 10 to 12℃, although some tilapia can survive at 6 to 8℃. This study predicted habitable areas and the possibility of spreading of habitat ranges of tilapia (Oreochromis niloticus and Oreochromis aureus) known to inhabit domestic streams. Due to climate change, it was found that habitats in the Geum River, Mangyeong River, Dongjin River, Seomjin River, Taehwa River, Hyeongsan River, and the flowing in East Sea were possible by 2050. In addition, it was confirmed that tilapia could inhabit the preferred lentic ecosystem such as Tamjin Lake, Naju Lake, Juam Lake, Sangsa Lake, Jinyang Lake, Junam Reservoir, and Hoedong Reservoir. In particular, in the case of tilapia, which lives in tributaries of the Geumho River, Dalseo Stream, and the Nakdong River, its range of habitat is expected to expand to the middle and lower of the Nakdong River system. Therefore, it is judged that it is necessary to prepare physical and institutional management measures to prevent the spread of the local population where tilapia currently inhabits and to prevent introduction to new habitats.

• Korean Journal of Ecology and Environment
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• v.36 no.4 s.105
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• pp.403-412
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• 2003

Temporal and spatial variations of size-structured phytoplankton (chlorophyll a) were investigated over an annual cycle (February-October, 2003) to elucidate phytoplankton dynamics in the Juam Reservoir, Chonnam. Physical properties were also measured to investigate the relationship between the properties and temporal and spatial variations of size structured phytoplankton using simple linear regression. Phytoplankton (chlorophyll a) were grouped into three size classes: micro-size(> 20 ${\mu}m$), nano-size (3-20 ${\mu}m$) and pico-size (< 3 ${\mu}m$) in this study. Physical properties included water temperature, light attenuation coefficients, PAR (photosynthetically active radiation) and turbidity. Maximum chlorophyll a was observed in April, 2003 in the lower region whereas a peak of chlorophyll a developed in October, 2003 in the upper region. Large cell-sized phytoplankton (micro-size class)were dominant in the events of the chlorophyll a peaks. Potential mechanisms in the physical properties affecting the size-structured phytoplankton dynamics in the Juam Reservoir were discussed.

• Journal of Environmental Health Sciences
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• v.30 no.5 s.81
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• pp.402-409
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• 2004

I performed the research about the drinking water treatment by precoat filtration and activated carbon adsorption process in the D water treatment plant at Gwangju. D water treatment plant inlet water is supplied from Juam lake in Jeollanamdo. The results are as follows; 1. Element disk used in this experiment are R(pore size $10{\mu}m$), B(pore size $20{\mu}m$). And diatomaceous earth are A(cake pore size $3.5{\mu}m$), B(cake pore size $7{\mu}m$) and C(cake pore size $17{\mu}m$) 2. Filtrate of precoat filter during 30 min are B-C 10.2 > BB 5.7 > R-A 5.4 ($m^3/m^2$). 3. The water quality through B-C+AC and R-A+AC are DOC 1.76 mg/1, 1.288 m/l respectively. 4. total THMs produced by chlorination are $84.2{\mu}g/l$(B-C+AC), $66.11{\mu}g/l$ (R-A+AC), $97{\mu}g/l$ (rapid sand filtration water) respectively. 5. The R-A+AC and B-C+AC process can be substitute of CWTS.

• Journal of Environmental Science International
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• v.15 no.9
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• pp.865-870
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• 2006

Recently, Total Organic Carbon (TOC) which can be measured instantly can be used as an organic pollutant index instead of BOD or COD due to the diversity of pollutants and non-degradable problem. The primary purpose of the present study is to reveal the properties of time series data for TOC which have been measured by real-time monitoring in Juam Lake and, in particularly, to understand the long- and short-term characteristics with the extraction of the respective components based on the different return periods. For the purpose, we proposed Discrete Wavelet Transform (DWT) as the methodology. The results from the DWT showed that the different components according to the respective periodicities could be extracted from the time series data for TOC and the variation of each component with respect to time could emerge from the return periods and the respective energy ratios of the decomposed components against the raw data.

• Journal of the Korean Geographical Society
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• v.52 no.1
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• pp.15-24
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• 2017

Management of non-point sources for water quality control practice is complicating but very important. Sediments mainly from croplands are prioritized in non-point source management due to the sediment attached phosphorous. In this study, flow and sediment yields are modeled in Oenam watershed located in Hwasun, Jeollanam-do, a upstream of Juam Lake. A spatially distributed model and GIS(Geographic Information System) data was used to find out hot spots of sediment yields, to analyze the effectiveness of filter strips, and to visualize the effectiveness. The impacts of filter strips was estimated on the reduction of flow and sediments at 17.2% and 46.4% respectively when the filter strips were installed in the sub-watersheds with the most serious sediment yields.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.790-794
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• 2012

우리나라는 여름철에 강우가 편중되어 있고 동고서저의 산악지형으로 수자원확보가 어려운 실정이며 이는 곧 하천의 유지유량확보의 어려움과도 직결된다. 이러한 수자원확보를 위해 최근 기존 저수지 둑을 높이는 사업이 전국적으로 활발히 진행되고 있으며 이는 저수지나 댐의 수체와 같은 수자원을 보다 적극적으로 활용하여 그 가치를 높임과 동시에 하천에 대한 활용도를 높이고자 하는 데 그 목적이 있다. 따라서 저수지나 댐의 저류량에 기여하는 강우량, 유입량과 같은 수문학적 자료의 심도 있는 분석이 필요하며 수문변수들이 나타내는 복잡한 패턴에 대한 연구가 이루어져야 할 것이다. 본 연구에서는 저수지나 댐의 저류량에 직접적으로 영향을 주는 수문변수들을 전체적으로 파악하기 위해 수집된 수문자료의 각각의 특성 및 자료들 사이의 복합적인 관계를 파악하였으며 이를 위하여 패턴분류 분야에서 그 적용타당성이 입증된 자기조직화 지도(Self-Organizing Map: SOM)를 이용하였다. 본 연구의 대상지점은 섬진강 유역내에 위치한 주암호를 대상지점으로 선정하였으며 패턴분석에 사용한 수문자료의 기간은 2007~2010년까지 5년간의 월평균 자료를 활용하였다. SOM의 적용 결과, 측정수문자료에 대한 전체적인 특성을 패턴분류를 통해 분류하였으며, 각 변수에 대한 패턴별 상대성을 고려한 클러스터별 특성 및 시간적 이질성을 파악할 수 있었다. 이는 측정 자료에 대한 분석 기법개발의 일환으로 향후 수자원 확보에 대한 개발 및 정책의 기초자료로 활용될 것으로 기대된다.

• Korean Journal of Ecology and Environment
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• v.38 no.4 s.114
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• pp.445-453
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• 2005

Relative importance between bottom-up and top-down controls on phytoplankton dynamics was investigated in the Juam Reservoir, Chonnam based on the results from statistical analyses including regression and artificial neural network (ANN) modeling. Effects of nutrients on size-structured phytoplankton dynamics were explored by simple linear regression analysis and relative importance between bottom-up and top-down controls was estimated based on results from the artificial neural network analyses. Although there is a limitation in determining direct grazing effects since chlorophyll a : pheopigments ratios, indirect index for grazing activity rather than grazing rates or herbivores biomass were used, the results from regression analysis showed that nutrients especially orthophosphates were positively correlated with the phytoplankton biomass and chlorophyll a : pheopigments ratios were also positively correlated with the phytoplankton biomass at lower coefficient of determination ($r^2$) compared to orthophosphates. The simulation results from ANN suggested that the bottom-up mechanisms including water temperature and availability of nutrients, especially orthophosphates were more important than top-down mechanisms such as grazing in the phytoplankton dynamics.

• Journal of Wetlands Research
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• v.14 no.4
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• pp.479-488
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• 2012

This study evaluates treatment efficiencies of pollutants in Boknae bio-park constructed wetlands surrounding Juam Lake for 5 years from January 2006 to December 2010, in order to treat non-point pollutants effectively. The analysis of monthly treatment efficiency of pollutants shows that the scope of BOD is -19.11~37.72%, and of COD is 30.14~27.38%, thus the monthly deviation COD is relatively higher than BOD, and the scope of SS is -54.07~64.82%. Moreover, the analysis of seasonal treatment efficiency of pollutants shows that the treatment efficiency of TN is higher than 36.8% on average for 5 years in the spring and winter, and of TP relatively lower than other pollutants, however, the seasons don't make much difference to the treatment efficiency of TP.