河川底質物からみた四国地方河川の地球化学的環境影響評価 : 四万十川,加茂川,吉野川の例

Shimanto, Kamo and Yoshino Rivers are famous typical rivers which flow in Shikoku Island, Shikoku district, southwest Japan Arc. These three rivers are relatively free from the large city. That is river sediment from these rivers may remain the natural chemical features. The content analysis and elution (liquate out) test on the heavy metals of Cd, CN, Pb, Cr, As, Hg, Ni, Zn and Cu were carried out for environment assessment. The samples were extracted from the river sediment at intervals of several km. We cannot detect human impact by heavy metals from the all sampling points of three rivers. The chemical data of the river sediment from these Shikoku areas is expected to be used widely as standard that estimates about human impact.