2006 Volume 50 Pages 1369-1374
Change in the plankton and the increased phytoplankton confirmed in the Okutama reservoir indicate the progress of eutrophication. This paper discusses the factors deteriorating the water quality of the reservoir and aggravating eutrophication. The principal component analysis is used for the factorial experiment of the eutrophication. The results suggest that four principal components can explain the factors and influenced water quality. In addition, This paper examined correlations between the principal component scores for 24 years and countermeasures for the water quality preservation and against the cold water. Finally, it can be concluded that the factors that influenced the water quality of the reservoir most were the river water temperature rise and the cold water countermeasure.
