岡山大学 地球科学研究報告
Published by Okayama University Earth Science Reports Editorial Committee

岡山県の主要3河川の水質と地質の関係

木下 卓也 Ministry of Justice
松田 敏彦 Department of Earth Sciences, Faculity of Science, Okayama University
抄録
Concentrations of inorganic major components (Ca2+, Mg2+, Na+, K+, ΣFe, AI3+, HCO3, SO4, CI-, NO3, F- and SiO2) were measured in 57 water samples from three main rivers, the Yoshii, Asahi and Takahashi Rivers and their tributaries. The water quality is discussed in relation to the geological environment in the drainage basin of three rivers. The following results were obtained from the investigation. The degree of influence of rocks on the water quality was limestone≫basic rocks>clastic rocks>andesite>rhyolite>gramite. The influence of geology is clear in the riverhead but it is obscure in the downstream. The concentration of each component increases generally from the upper stream to the lower stream but that of SiO2 only decreases in the lower stream. Kaolinite is a stable mineral as a weathering prodouct from the ion compositions of three rivers. In a rough estimation, Yoshii, Asahi and Takahashi Rivers weather 303,000t, 433,000t and 1,033,000t of the rocks respectively from their basins in a year. The syrface of their basins are scraoed off 0.06mm, 0.11mm and 0.15mm respectively in a year.
キーワード
Water quality
River water
Geology of basin
Yoshii River
Asahi River
Takahashi River
Okayama Prefecture
ISSN
1340-7414
NCID
AN10506284