@article{oai:soar-ir.repo.nii.ac.jp:00010773, author = {中路, 勉 and 港, 和行 and 橋本, 誠}, issue = {1}, journal = {信州大学農学部紀要}, month = {Jul}, note = {We tried to investigate the factors of water pollution of five lakes (SUWA L. ,KIZAKI L., NOJIRI L., TATESHINA L. and SHIRAKABA L.) by using the correlation analysis and the principal components analysis. The data used during the course of this investigation were obtained from the tables of water analysis of the public water area by NAGANO office. Six variables which were water temperature, pH, DO, BOD, COD and SS were used from the data. The results were as follows. 1. The water pollution by organic materials was pointed to SUWA L. among five lakes because of its hard eutrophication. The process of the water pollution of SHIRAKABA L. was similar to that of SUWA L. On the other hand, KIZAKI L. and NOJIRI L. were comparatively clean. 2. The negative correlation between water temperature and DO was more signifi cant in the case of the partial correlation coefficients than that of the correlation coefficients. 3. In the principal components analysis, the interpretation of first principal component was as follows. SUWAL. and SHIRAKABA L.: General index of the pollution by organic materials. KIZAKI L. and NOJIRI L. : Stability index of natural environment. 4. By using each principal component value and factor loading, these five lakes were classified into four groups according to their water qualities., Article, 信州大学農学部紀要 17(1): 89-100(1980)}, pages = {89--100}, title = {湖沼水質の統計学的研究(I) 長野県内湖沼水質への多変量解析の適用}, volume = {17}, year = {1980} }