抄録
Water samples (number of samples = 52) were collected from the vicinity of the southern foot of Mt. Fuji, central Japan, and were analyzed for major elements (Si, Al, Fe, Mg, Ca, Na, K, Cl-, HCO3-, NO3-, etc.) and other chemical properties (pH, EC, ORP, etc.). The results show that major element concentrations increase with decreasing elevation, particularly at a low-elevation site.
In the Yoshihara area, located at the southwestern foot, anion and cation concentrations vary widely and increase from west to east. In this area, water samples with a high total concentration tend to contain a high NO3- concentration, suggesting NO3- pollution of the groundwater. By contrast, in the southeastern area, NO3- pollution was not recognized. Based on nitrogen isotopic and ionic concentration data, the high NO3- concentration in the southwestern area is considered to be due to inorganic fertilizer (e.g. (NH4)2SO4) used at tea farms. Analytical results show two groundwater flows in a high-elevation area along the Urui River and in the direction from a high-elevation site at the southwestern foot toward Susono City, and that they mix together at a low-elevation site. In the southeastern foot area, two groundwater flows derive from a high-elevation site on Mt. Fuji along the Gotenba mudflow and the Mishima lava flow. The latter groundwater mixes with groundwater derived from Ashitaka and the Hakone mountains.
