Characterization of Water quality of the Yodo River by Multivariate Analysis

In order to elucidate the characteristics of water quality fluctuation of the Yodo river, the correlation and the principal component analysis was carried out by using the daily data which were obtained by the measurement with 11 items at TOYOSATO Station. This analysis was also applied to the monthly data from 1973 to 1985 which were quoted from the Yodo River conference reports and compared with the analytical results on TOYOSATO Station. The first component indicated the dilution efficiency of flow rate and wash loading effect. The second component represented the bioactivity and effect of temperature. The third component indicated the suspended matter at HIRAKATA Station. However it was not indicated at TOYOSATO Station. This is because at that point suspended solids settle and the characteristics of the water quality are changed.