The objective of study was to analyze seasonal and inter-annual patterns of water chemistry of Miho Stream watershed during 2004 - 2007 along with some influences of tributaries and summer monsoon on the stream water quality. For the study, eight physico-chemical parameters such as nitrogen, phosphorus, BOD, COD and chlorophyll-a (CHL) etc. were analyzed in relation to spatial and temporal variability of seven sampling sites of the mainstream and some tributaries in the watershed. In the upstream reach, Mean of BOD, COD and TP averaged 3.2 mg/L, 6.5 mg/L and 186 μg/L, respectively, indicating an eutrophic conditions as a III-rank in the stream water quality criteria from the Ministry of Environment, Korea(MEK). The eutrophic water was due to a combined effect of Chiljang tributary with high nutrients (TP=844 μg/L, TN=8.087 mg/L) and the point sources from some wastewater treatment plants. In the meantime, BOD, TN, and TP in the downstream reach were about > 1.2-1.5 folds than the values of the midstream reaches. This was mainly attributed to effluents of nutrient rich-water (mean TN: 11.980 mg/L) from two tributaries of Musim Stream and Suknam Stream, which is directly influenced by nearby wastewater disposal plants. Seasonal analysis of water chemistry showed that summer monsoon rainfall was one of the important factors influencing the water quality, and water quality had a large spatial heterogeneity during the rainfall period. In the premonsoon, BOD in the downstream averaged 6.0±2.47 mg/L, which was 1.4-fold greater than the mean of upstream reach. Mean of CHL-a as an indicator of primary productivity in the water body, was > 2.2 - 2.9 fold in the downstream than in the upstream, and this was a result of the high phosphorus loading from the watershed. Overall, our data suggest that some nutrient controls in point-source tributary streams are required for efficient water quality management of Miho Stream.

Abstract
 1. 서 론
 2. 재료 및 방법
  2.1. 조사 지역 개요 및 조사 지점
  2.2. 조사 기간 및 방법
 3. 결과 및 고찰
  3.1. 유입 지천 및 본류의 공간적 수질 특성
  3.2. 수계내의 강우 특성 및 계절별 수질 변이
  3.3. 몬순 강우 전․중․후의 상․하류간 수질특성 비교
 4. 결 론
 참 고 문 헌

• 김지일(충남대학교 생명시스템과학대학 생명과학과) | Ji-Il Kim (Department of Biological Sciences, College of Biosciences and Biotechnology, Chungnam National University)
• 최지웅(충남대학교 생명시스템과학대학 생명과학과) | Ji-Woong Choi (Department of Biological Sciences, College of Biosciences and Biotechnology, Chungnam National University)
• 안광국(충남대학교 생명시스템과학대학 생명과학과) | Kwang-Guk An (Department of Biological Sciences, College of Biosciences and Biotechnology, Chungnam National University) Corresponding author