高頻度調査による淀川本川およびその支川の重金属の流出特性評価

抄録

The runoff characteristics of heavy metals in the R. Yodo and its tributary streams, R. Amano and R. Funahashi, were established by observation every third day during 1999-2000. The changes in heavy metal concentrations were frequently fluctuating, especially, in the rivers with small catchment and were ruled mainly by fluctuation of flow. As the observation with high frequency often met with the condition of storm runoff in the rivers, the determined values of heavy metals exceeded sometimes the environmental standard values or the quasi ones. Applying the regression equation, L=a·Qⁿ, to heavy metals, the n values exceeded 1.0, and their correlation coefficients of almost heavy metals were larger than 0.65. During downflow process in the R. Yodo and its three large tributaries, the concentrations of many heavy metals in the R. Katsura at Miyamae Bridge were the highest values. Recently, many new kinds of heavy metal elements became to be determined sometimes over their quantitative limits. As the runoff concentrations and loadings of heavy metals become larger quantities during storm events, it is apprehended that the risks for aquatic lives, drinking water and the Osaka Bay area flowed into by the R. Yodo should rise up.