• 한국물환경학회지
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• 제24권2호
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• pp.206-213
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• 2008

Fish fauna and community structure were investigated at 2003, 2004 and 2006 in Lake Paldang and its inflows. In this survey, we collected 54 species belong to 14 families. Family Cyprinidae take 51.9% (28 species), Cobitidae and Gobiidae occupied 7.4% (each 4 species), respectively. E. erythropterus (11.8%) was dominant species and L. macrochirus (10.2%), designated as an ecosystem-invasive alien fish species by Ministry of Environment, M. yaluensis (9.1%), Z. platypus (7.7%) and R. brunneus (6.7%) were dominated in turn. H. molitrix, C. lutheri, P. altivelis, S. microdorsalis, L. costata. S. gracilis majimae, A. rivularis, P. koreanus. S. scherzeri and O. platycephala were rare species (less than 0.1% in relative abundance). In-lake area, 36 species of fishes belonging to 11 families were collected, and 48 species of 13 families were from inflows. The number of Korean endemic species were 19 species (35.2%), and 4 kinds of exotic species (7.4%), that is, C. cuvieri, H. molitrix, L. macrochirus and M. salmoides were found at this survey area. It was revealed by the analysis of fish community that diversity and richness indices were prominent at tributaries, and dominance index was high at the main body of Lake Paldang. Fish fauna showed rapid decline after dam construction which make the mid-Han river systems to lentic ecosystem, so many of meander-riffle fishes were disappeared dramatically. But after 1990s when installation of small scale wastewater treatment plants started in watershed, the water quality of small tributaries was improved. And also, expansion of the natural macrophytic vegetation of littoral zone should contribute to the development of diverse fish fauna in Lake Paldang.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.174-174
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• 2022

수질지수는 여러 수질 데이터 값을 수학적으로 결합하고 다 변수 특성을 줄여 수치 및 등급으로 나타낸 지표이다. 수질지수를 통해 수질을 평가하고 서로 다른 위치와 시간의 수역을 종합적으로 비교할 수 있으며 수자원관리에 있어 정책입안자, 의사결정자, 국민이 수질에 대해 일반적이고 쉽게 이해할 수 있다. 현재 환경부에서는 국내수질자동측정망 최근 12시간 데이터 값을 근거로 실시간수질지수 RTWQI(Real-Time Water Quality)값을 제공한다. 국내 호소에 설치된 수질 자동측정망은 총 8개소이며 매 시간 공통 항목인 수온, pH, DO, 전기전도도, TOC 5개, 선택항목인 탁도, Chl-a, TN, TP, 중금속, 생물감시항목 등 27개를 측정한다. RTWQI는 캐나다에서 2001년에 개발된 CCME WQI(Canadian Council of Ministers of the Environment Water Quality Index) 산출식을 기초하였으며 F1(기준치를 위반하는 수질항목의 개수/ 총 수질항목 개수), F2(기준치를 위반한 샘플들의 총 횟수/총 샘플횟수) F3(기준치를 위반한 정도) 3가지의 요소로 계산된다. 그러나RTWQI 산출식의 기초인 CCME WQI는 개발 이후 여러 문제점들은 개선되었으나 F1이 다른 F2, F3 보다 CCME WQI 점수의 기여도가 2배 이상 높은 문제점은 개선하지 못하였다. 본 연구에서는 수질자동측정망이 설치된 2012년 7월부터 2021년 12월 동안 매 시간 별 수질 데이터를 이용하였다. 또한 CCME WQI 문제점을 개선한 MWQI(Modification of Canadian water qaulity index)를 기초하여 실시간 수질지수를 재 산정하였다. 추가적으로 Pearson 상관관계 분석 및 추가 통계분석을 통해 환경부에서 제공하는 기존의 RTWQI, 개선된 실시간수질지수, 한국형 호소수질평가지수 LQI(Lake Water Quality Index)를 비교 및 평가하였다. 이러한 연구를 통해 정확성 높은 수질지수를 찾고 수자원 관리 정책 수립에 적극 활용 될 수 있을 것으로 사료된다.

• 한국물환경학회지
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• 제37권2호
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• pp.114-127
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• 2021

Water pollution in the lower reaches of the Namhan River is getting worse due to drought and a decrease in water quantity due to climatic changes and hence is affecting the water quality of Paldang Lake. Accordingly, we have used a water quality index (WQI) and statistical analysis in this study to identify the characteristics of the water quality in the lower reaches of the Namhan River, the main causes of water pollution, and tributaries that need priority management. Typically, 10 items (WT, pH, EC, DO, BOD, COD, SS, T-N, T-P, and TOC) were used as the water quality factors for the statistical analysis, and the matrix of data was set as 324 × 10·1. The correlation analysis demonstrated a strong correlation between Chemical Oxygen Demand (COD) and T-P with a high statistical significance (r=0.700, p<0.01). Furthermore, the result of principal component analysis (PCA) revealed that the main factors affecting the change in water quality were T-P and organic substances introduced into the water by rainfall. Based on the Mann-Kendall test, a statistically significant increase in pH was observed in SH-1, DL, SH-2, CM, and BH, along with an increase in WQI in SH-2 and SM. BH was identified as a tributary that needs priority management in the lower reaches of the Namhan River, with a "Somewhat poor" (IV) grade in T-P, "Fair" grade in WQI, and "Marginal" grade in summer.

• 한국물환경학회지
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• 제27권5호
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• pp.625-633
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• 2011

A long-term water quality monitoring in the Han River Basin reveals a consistent increasing trend for the concentration of refractory organic matter (R-OM) in major monitoring sites of the watershed. Because the determination of R-OM concentrations typically requires a long time of microbial incubation, it is essential to present the estimation indices for R-OM for an efficient watershed management. In this study, a number of surface water samples were classified into three groups, each of which were collected from Lake Paldang, rivers at rain and non-rain events, respectively. The corresponding R-OM concentrations were correlated with biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC) concentrations as well as ultraviolet and fluorescence intensities of the filtered samples. Among the traditional organic matter parameters, TOC exhibited the highest correlation coefficient with the R-OM concentrations regardless of the types of the sample groups. The equations for conversing TOC into R-OM concentrations were finally suggested as $0.43{\times}TOC+1.12$, $0.44{\times}TOC+0.61$, $0.24{\times}TOC+1.28$ for river samples at rain and non-rain events, and lake samples, respectively. TOC-BOD(C), the values of the TOC concentrations subtracted by carbon-converted BOD concentrations, was a good index for estimating the absolute concentrations of R-OM. UV absorbance at 254 nm was well correlated with R-OM concentrations of river samples while fluorescence intensities at 350 nm showed an excellent relationship with R-OM concentration of the lake samples. Our results suggests that simple spectroscopic parameters could be applied for in-situ monitoring tool techniques in watersheds.

• 한국환경과학회지
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• 제16권5호
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• pp.571-581
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• 2007

본 연구는 생태계 모델을 이용하여 수질오염이 심각한 시화호의 수질을 재현하고, 시화호 내로 유입하는 육상기원 오염부하량의 변동에 따른 시화호의 수질변화를 살펴보았다. 모델에 의해 계산된 화학적 산소요구량 결과는 관측치와의 상관성이 양호하였으며, 하천이 밀집한 호의 내측 수역에서 $8{\sim}9mg/L$의 높은 농도분포를 나타내었고, 방조제 수문이 위치한 남서쪽 수역에서 5 mg/L 내외의 가장 낮은 농도분포 특성을 보였다. 시화호로 유입하는 육상오염부하가 시화호의 수질에 미치는 영향을 살펴보았는데, 육상오염부하량을 95% 삭감시켜도 시화호의 화학적산소요구량 농도는 3 mg/L 내외로 계산되었으며, 이것은 해역생활환경 II등급 기준인 2mg/L를 초과하는 것으로써 육상으로부터 유입되는 오염부하의 삭감만으로는 수질개선에 한계가 있는 것으로 예측되었다. 한편, 퇴적물을 인위적으로 개선하여 퇴적물로부터 인과 질소의 용출량과 저층 산소소비율을 삭감시켰을 경우에 시화호 수질의 개선효과가 나타났다. 특히, 육상으로부터 유입하는 유기물 및 영양염류 부하와 퇴적물에 의한 영양염류 용출부하 및 산소소비율을 동시에 삭감하였을 경우에 시화호 내 대부분의 수역에서 $1.5{\sim}2.0mg/L$ 이내로 수질이 크게 개선되는 것으로 나타났다. 따라서, 시화호는 육상기원 오염부하량을 상당량 삭감하여도 목표수질 기준을 만족하기가 상당히 어려울 것으로 예측되었고, 퇴적물을 인위적으로 개선시키면 보다 뚜렷한 수질 개선의 효과를 얻을 수 있는 것으로 나타났다. 시화호 내측과 외측수역과의 해수 교환량이 적고 퇴적물의 오염이 심한 현 상태의 환경조건에서 해역생활환경 III등급 기준인 4 mg/L 이하를 달성하기 위한 시화호의 환경용량은 화학적산소요구량 기준으로 5 톤/일로 산정되었다. 향후 시화호의 수질관리를 위해서는 시화호를 포함한 유역별로 뚜렷한 개선목표를 설정하고 배출원별 할당부하량을 산정하여 오염물질 총량관리를 통해 시화호 주변 유역의 점원, 비점원 및 시화호 내퇴적물 등을 종합적으로 고려하여 관리해 나가야 할 것으로 판단된다.

• 한국수자원학회논문집
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• 제33권2호
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• pp.237-245
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• 2000

시화배수갑문은 당초 내측 담수호의 수위관리를 위하여 설계되었으나 호수의 수질 악화를 방지하기 위하여 배수갑문을 당초 계획보다 잦은 빈도로 작동시키고 있다. 이에 따라 강한 유입 흐름의 영향을 받는 내측 배수로의 바닥이 상당히 넓은 범위에 걸쳐 침식되고 있다. 최근에 침식이 진행되는 것을 막기위하여 에이프런 전면부 일부 구간을 수중콘크리트로 타설하여 바닥보강을 시행하였다. 본 연구는 수리모형실험을 통하여 바닥보강 시행 이전과 이후에 대하여 수리현상을 파악하고 유입흐름의 에너지 변화와 바닥 암석의 저항력 등을 파악하여 향후 침식의 추이를 예측하기 위하여 실시하였다. Annandale(1995)은 침식지수 이론을 도입하여 많은 실험을 통하여 침식지수와 흐름의 에너지 감쇠 간의 관계를 파악하였으며 암석의 침식여부를 판단할 수 있는 기준을 제시하였다. 암석의 침식지수는 지질조사에서 시추한 시편의 분석결과를 토대로 결정하였으며 수류의 에너지 감쇠는 수리모형실험 결과로부터 전수두의 감쇠량의 추정을 통하여 계산하였다. 이와 같이 결정된 두 값을 주어진 기준도상에 도시하여 그 위치에 따라 침식가능성을 판단하였다.

• 환경생물
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• 제18권1호
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• pp.95-104
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• 2000

In order to elucidate chatracteristics of water quality and seasonal dynamics of phytoplankton community in Kyungpo lake, the weekly variation of algal population and 11 environmental factors were investigated from March 1998 to February 1999. A total 121 species of phytoplankton belonged to 57 genera, 4 genera 7 species of the Euglenophyceae, 1 genera 2 species of the Chrysophyceae, 2 genera 3 species of the Cryptophyceae, 1 genera 1 species of the Dinophyceae, 6 genera 9 species of the Cyanophyceae, 28 genera 78 species of the Bacillario-phyceae and 15 genera 21 species of the Chlorophyceae, was identified. Cryptomonas sp., Chamydomonas sp., Nitzschia frustulum, Oscillatoria sp., Lyngbya sp, and Dictyosphaerium pulchellum occurred successively as dominant phytoplankton species from March 1998 to February 1999. Density of phytoplankton cell number showed the peak in early April when Chlamydomoas sp. was dominated. The diversity index of phytoplankton community showed low values in the dominating period of Cryptomonas sp. and Chlamydomonas sp. The concentration of chlorophyll a fluctuated between 1.09 and 107.7$\mu\textrm{g}$ㆍ1$^{-1}$. Water temperature, salinity, DO, conduc tivity and SS were ranged 0.5-27.8$^{\circ}C$, 2.8-25.2 ppt, 4.62-19.21 mgO$_2$ㆍ1$^{-1}$, 5.33-34.76 mS/cm and 0.017-0.184 mgㆍ1$^{-1}$, respectively. Annual means of Secchi disc transparency was 36cm and thai of pH value was 8.5. The concentrations of PO$_4$-P was ranged 0.0012-0.077 mgㆍ1$^{-1}$ , and showed high value from August to October. The concentrations of NO$_2$-N, NO$_3$-N and NH$_4$-N was ranged 0.0011-0.1 mgㆍ1$^{-1}$, 0.074-3.33mgㆍ1$^{-1}$ and 0.0024-0.259 mgㆍ1$^{-1}$, respectively. Among environmental factors, water temperature was negatively correlated with DO, salinity and conductivity, DO was positively correlated with salinity and conductivity. Chlorophyll a, one of the indicies of eutropication in lake, was negatively correlated with NH$_4$-N. The cell density of Cryptomonas sp., which was the most dominant species in this lake, was negatively correlated with transparency. [Kyoungpo lake, Phytoplankton, Cryptomonas sp. , Chlamydomonas sp., Seasonal variation].

• 한국물환경학회지
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• 제26권6호
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• pp.1016-1027
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• 2010

The phosphorus contribution rate on water quality of North and South-Han River, and Gyungan-cheon by effluents from environmental fundamental facilities located in upstream basin of Paldang Lake were analyzed. QUALKO2 model was selected for the analysis of contrubution rate, and was constructed considering the location of the main point sources and all facilities in study area. The pollutant loading rates and arrival rates for each unit-watershed in study area were calculated for model operation. For the calibration and verification of model, 2006 water quality dataset from Ministry of Environment and the effluent loadings of the environmental fundamental facilities were used. Reliability Index (RI) method was used to estimate the validity of the results of calibration and verification. The phosphorous contribution rate(%) for each environmental fundamental facility were analyzed by excepting the effluent loading of the facility. The contribution rate was analyzed for each facility, facility groups separated by each main river and each unit-watershed. The main results of analysis for each facility are as follows; (i) the phosphorous contribution of B1 facility is 50%, which is the highest phosphorous contribution rate among those of nine facilities in the North-Han River Basin; (ii) the highest phosphorous contribution is 55.6% from J facility among eight facilities in the Gyungan Stream Basin; (iii) 40% from E treatment facility is the highest among those of twenty eight facilities in the South-Han River Basin.

• 한국환경과학회지
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• 제19권11호
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• pp.1445-1456
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• 2010

This study presented seasonal changes of the phytoplankton community in Junam reservoir by pollution and water quality of the lake. The water storage of the reservoir is 5.3 million ton, most of which are being utilized for agricultural, industrial and residential purposes. The annual precipitation during the investigation period was 1,868.9 mm, increasing by 20% from the average annual level of 1,506.7 mm in 2009. The annual average water storage was 57.3%. It decreased during agricultural season and then increased again after monsoon rainfall. The loads of BOD were $3,799kgday^{-1}$, and 81% of them came from livestock and household. The TN and TP loads were $1,164kgday^{-1}$ and $170kgday^{-1}$, respectively, and 76% of them came from livestock. We assessed water quality of the Junam reservoir using 17 variables. According to the result, the reservoir met the fourth grade, meaning slightly bad, because of high concentration of COD, SS and chlorophyll-a. Eutrophication assessment was conducted by revised Carlson's Index (TSIm, Aizaki), and it was found that the entire lake was eutrophicated with high chlorophyll-a concentration all through the year, except during February to April and in July. A total of 76 phytoplankton species were identified from the samples. Among them, the largest number of species were Chlorophyceae with 33 species(43.4%), followed by Bacilliophyceae with 27 species(35.5%), Cyanophyceae with 8 species(10.5%), and Cryptophyceae with species(10.5%). The total cell number of phytoplankton was the highest in October(7,884 cells $mL^{-1}$) among Cyanophyceae and Bacilliophyceae. The seasonal succession of Chlorophyceae (Chlamydomonas spp.), Cyanophyceae(Microcystis aeruginosa) and Cryptophyceae(Rhodomonas spp.) was observed during January to May, July to September and October to December respectively.

• 한국환경농학회지
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• 제26권1호
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• pp.7-16
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• 2007

The objective of this research was to review the correlation between microalgae and agricultural water quality. Although microalgae has been considered as an essential factor for control1ing of water ecosystem, little attention has been paid for evaluating of microalgae as an important factor for water quality management. But it can be use to make us know the water pollution state at saprobic system, LTSI (Lake Tropic State Index), DAIpo (Diatom Assemblage Index to Organic Pollution), and AGP (Algal growth potential). In saprobic system, it is used microalgae such as Actinastrum hantzschii var. fluviatile, Asterionella gracillima, Coelastrum microporum, Synedra acus, Dictyosphaerium pulchellum, Micractinium pusillum, Cyclotella meneghiniana, Microcystis aeruginosa, Scenedesmus quadricauda, and Nitzschia palea for assessment water quality. In addition, they have ecologically significant characteristics such as dominant species, cosmopolitan species, redtide causative species etc. Also, microalgae such as Botryococcus braunii, B. sp., Chlorella vulgaris, C. sp., Phormidium sp., Scenedesmus quadricauda, Selenastrum capricornutum, Spirulina maxima, and S. platensis have an effect on improvement of water quality.