WATER CHEMISTRY OF SNOW, RIVER, SPRING AND HOT SPRING IN THE WAGAGAWA BASIN

Abstract

To investigate the river and ground water chemistry in the snow area, chemical composition and oxygen and hydrogen isotopic ratios of water in the Wagagawa basin were studied. During spring season, most dissolved component in river water was diluted by spring runoff. However, NO^-₃ concentration was maintained high because NO-₃ concentration in the snow was high. Spring and hot spring water contained a lot of SO^2-₄. High SO^2-₄ concentration was thought to depend on hydrothermal activity which induced copper sulfide deposits.δ D andδ ¹⁸O were measured in order to estimate the origin of water. All waters were on two kinds of meteoric line.δ ¹⁸ and δ ¹⁸O in the snow were thought to be higher than those of summer precipitation. Those of hot spring were extremely low. Therefore, the origin was thought to have arisen from precipitation at high altitude or past precipitation when the temperature was colder than that at present.