長野県王滝村の天然水の水質について

Abstract

To investigate the water qualities of natural waters in Ohtaki Village, where there was a large-scale landslide caused by the Western Nagano Prefecture Earthquake in 1984, water samples on river streams were taken in 1992.(1) Water qualities are classified into three types, Ca-(HCO3) 2, Ca-SO4 and Na-HCO3 as likely results by YOSIOKA et al. and OKUDA et al. .(2) Water qualities are shown two principal components PCl which shows degree of weathering and PC2 which shows Ca-(HCO3) 2 type or Ca-SO4 type.(3) Water quality values of PC1 and PC2 on Denjo-river were small before the earthquake, and larger after it and gradually tend to decrease.