• 한국수자원학회논문집
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• 제35권2호
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• pp.149-159
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• 2002

삽교호유역에 위치한 19개 수질관측지점에서 측정된 월별수질자료를 이용하여 수질관측지점을 2개에서 7개의 수질특성으로 분류하였으며, 그에 따른 수질요인분석을 실시하였다. 군집분석결과 삽교호유역의 각 하천은 개개의 수질특성을 보이고 있으며, 삽교호, 삽효천, 무한천 및 곡교천의 4개 그룹으로 나눌 수가 있었다. 수질분석결과에 의하면 삽교호에서는 부유물질의 농도가 다른 하천보다 높았는데 이는 하천으로부터 유입되는 풍부한 영양염에 의한 식물플랑크톤의 생물량 증가에 따른 것으로 사료된다. 또한 곡교천의 수질은 다른 하천에 비해 생화학적산소요구량은 3.5∼4.8배, 화학적산소요구량은 1.7∼2.5배 높았으며, 전반적으로 삽교호 유역의 수질은 부영양상태를 훨씬 초과하였다. 요인분석결과 삽교천과 무한천은 농경지와 주거지에 의한 수질요인이 지배적이었고, 곡교천은 천안도시지역으로부터 유입되는 과다한 유기물유입과 상류에 위치한 하수처리장의 영향을 복합적으로 받고 있는 것으로 사료된다. 삽교호의 수질은 삽교천과 무한천및 곡교천에서 높은 부하를 보인 인자가 주된 오염요인으로 나타났다.

• 한국농공학회논문집
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• 제57권5호
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• pp.89-99
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• 2015

In this research, 1,032 data of precise safety inspection from 2004 to 2013 are gathered and constructed for finding effective safety inspection systems. Items are extracted from constructed data and factors for typology are decided with statistical method such as principle component analysis and cluster analysis. For factor decision, we extruded independent characteristics such as morphological and geographical characteristic, and deleted items which can be expressed by combination of independent characteristics. Four factors such as total storage, watershed ratio, levee length ratio, and spillway length ratio are extracted in this process. In cluster analysis, levee length ratio is excluded because it is not separated as cluster. Finally nine types of agricultural reservoir are extruded by total storage, watershed ratio, and spillway length ratio with frequency analysis.

• 한국관개배수논문집
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• 제18권2호
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• pp.66-75
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• 2011

Multivariate statistical analysis was applied to 110 dam heightening reservoir to classify the building conditions for waterfront centered around cultivated area using data of land cover, landscape, additional water quantity, local economic, tourism resources, and accessibility related variables. Five factors were extracted through factor analysis based on eigen value criteria of more than one. These five factors together account for 68.2% of the total variance. Characteristics of five factors for the downstream of dam heightening reservoirs are building conditions of waterfront, economic conditions, additional water quantity, eco-tours, and accessibility of tourism resources respectively. Five clusters were classified through cluster analysis based on factor score. The classified result shows that third cluster has remunerative terms for building waterfront.

• 한국농공학회논문집
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• 제57권1호
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• pp.59-67
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• 2015

Because reservoirs that supply irrigation water play an important role in water resource management, it is necessary to evaluate the vulnerability of this particular water supply resource. The purpose of this study is to provide water supply risk maps of agricultural reservoirs in South Korea using irrigation vulnerability model and cluster analysis. To quantify water supply risk, irrigation vulnerability indices are estimated to evaluate the performance of the water supply on the agricultural reservoir system using a probability theory and reliability analysis. First, the irrigation vulnerability probabilities of 1,346 reservoirs managed by Korea Rural Community Corporation (KRC) were analyzed using meteorological data on 54 meteorological stations over the past 30 years (1981-2010). Second, using the K-mean method of non-hierarchical cluster analysis and pre-simulation approach, cluster analysis was applied to classify into three groups for characterizing irrigation vulnerability in reservoirs. The morphology index, watershed area, irrigated area, and ratio between watershed and irrigated area are selected as the clustering analysis parameters. It is suggested that the water supply risk map be utilized as a basis for the establishment of risk management measures, and could provide effective information for a reasonable decision making on drought risk mitigation.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.311-314
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• 2004

To identify the effect of geology and land use, the hydrogeochemical and multivariate statitstical analysis were executed for stream water collected in headwater region of Daecheong reservoir. Hydrogeochemical analysis was showed the effect of weathering process such as dissolution of calc-silicate minerals to hydrochemistry of stream water with contrasting geology. Cluster and principal components analysis can also help to identify the source of dissolved components in stream water.

• 한국관개배수논문집
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• 제17권2호
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• pp.17-27
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• 2010

In order to manage the water quality in reservoir, it is necessary to understand the temporal and spatial variation of reservoirs and to classify the reservoirs. In this research, agricultural reservoirs are classified according to physical characteristics (depth, residence time, shape of the reservoir etc) and water quality using multivatriate analysis (PCA and CA). CA (Cluster Analysis) method classify reservoirs into several groups as a similarity of the reservoirs, but it is difficult to indicate a full list to the one table. In case of PCA (Principle Component Analysis) method, it has the advantage for the classification on the reservoirs depending on the water quality similarity and also it is useful to analyze the relationship between related factors through correlation analysis. However PCA is limited to classify into several groups based on the characteristics of the reservoirs and each user should be classified as randomly subjective according to the relative position of the reservoir in the figure. In conclusions, compared to conventional reservoirs classification methods, both CA and PCA methods are considered to be a classification method that describes the nature of the reservoir well, but classification results has a restriction on use, so further research will be needed to complement.

• 한국물환경학회지
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• 제27권6호
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• pp.794-803
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• 2011

Self Organizing Map (SOM) was applied for pattern classification of hydrological and water quality data measured at Jangseong Reservoir on a monthly basis. The primary objective of the present study is to understand better data characteristics and relationship between the data. For the purpose, two SOMs were configured by a methodologically systematic approach with appropriate methods for data transformation, determination of map size and side lengths of the map. The SOMs constructed at the respective measurement stations for water quality data (JSD1 and JSD2) commonly classified the respective datasets into five clusters by Davies-Bouldin Index (DBI). The trained SOMs were fine-tuned by Ward's method of a hierarchical cluster analysis. On the one hand, the patterns with high values of standardized reference vectors for hydrological variables revealed the high possibility of eutrophication by TN or TP in the reservoir, in general. On the other hand, the clusters with low values of standardized reference vectors for hydrological variables showed the patterns with high COD concentration. In particular, Clsuter1 at JSD1 and Cluster5 at JSD2 represented the worst condition of water quality with high reference vectors for rainfall and storage in the reservoir. Consequently, SOM is applicable to identify the patterns of potential eutrophication in reservoirs according to the better understanding of data characteristics and their relationship.

• 생명과학회지
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• 제19권12호
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• pp.1758-1763
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• 2009

2008년 4월부터 8월까지 2회에 걸쳐 낙동강 수계권에 속하는 총 10개 호소의 유입, 유출부에 서식하는 저서성대형무척추동물의 군집구조를 조사한 결과는 다음과 같다. 본 조사에서 확인된 저서성대형무척추동물은 총 16목 29과 42종 9,427.6개체였으며, 우점종은 깔따구류(Chironomus spp.), 아우점종은 네점하루살이(Ecdyonurus levis)로 나타났다. 전체 조사지점에서 하루살이목이 17.81%로 가장 많은 종수를 점하였고, 파리목이 64.00%로 가장 많은 개체수를 점하였다. 평균 우점도는 0.68, 종다양도 2.42, 종풍부도 2.96, 종균등도는 0.54로 산출되었다. 총 10개 지점 중 St. 2인 영천호에서 51종으로 가장 많이 출현하였고, St. 9 질날벌에서 21종으로 가장 적게 출현하였다. 군집안정성 분석 결과, 모든 조사지점에서 특성군Ⅰ에 해당하는 종이 가장 많이 출현하여 상대적 저항력과 회복력이 모두 높은 것으로 나타났다. 각 지점에서 확인된 저서성대형무척추 동물을 이용하여 지점별 유사도를 분석한 결과, 유사도가 가장 높은 곳은 St. 7 번개늪과 St. 8 장척호로 파악되었다.

• 한국석유지질학회:학술대회논문집
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• 한국석유지질학회 1998년도 제5차 학술발표회 발표논문집
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• pp.10-14
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• 1998

A systematic methodology is developed for the electrofacies determination from wireline log data using multivariate statistical analysis. To consider corresponding contribution of each log and reduce the computational dimension, multivariate logs are transformed into a single variable through principal components analysis. Resultant principal components logs are segmented using the statistical zonation method to enhance the efficiency and quality of the interpreted results. Hierarchical cluster analysis is then used to group the segments into electrofacies. Optimal number of groups is determined on the basis of the ratio of within-group variance to total variance and core data. This technique is applied to the wells in the Korea Continental Shelf. The results of field application demonstrate that the prediction of lithology based on the electrofacies classification matches well to the core and the cutting data with high reliability This methodology for electrofacies classification can be used to define the reservoir characteristics which are helpful to the reservoir management.

• 환경생물
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• 제31권4호
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• pp.411-418
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• 2013

새만금호는 새만금 간척사업을 통해 2006년에 완공된 인공 호로 현재 담수화가 진행되고 있다. 본 연구는 새만금호 내의 염도 별 어류분포를 확인하여 담수화가 진행되고 있는 새만금호의 어류분포 변화 예측에 도움이 되는 자료를 마련하고자 실시하였다. 어류조사는 새만금 호내 10지점에 대해 총 4회에 걸쳐(2012년 2월~10월) 어류군집과 염도를 조사하였다. 조사결과 전체지점에서 총 34과 71종이 채집되었으며, 우점종은 Thryssa kammalensis (16.1%), 아우점종은 Konosirus punctatus (12.8%)로 새만금호내 해양성 어류의 우점현상을 나타냈다. Bray-Curtis Cluster 분석을 실시한 결과 어류는 4개(A=St. 1, 6, B=St. 2, 3, 7, 8, C=St. 4, 9, 10, D=St. 5)의 그룹으로 구분되었다. Cluster 구분에 따른 지점별 평균 염도는 A=0.2 psu, B=14.2 psu, C=19.5 psu, D=23.5 psu로 차이를 보였으며, 그룹별 1차 담수어, 주연어, 해산어의 비율이 차이가 나타나 4개 그룹의 어류 분포는 염도에 따라 종의 구성이 달라지는 것을 확인할 수 있었다.