2000 Volume 44 Pages 229-234
Wells of the four study areas in Yamanashi Prefecture were grouped on the basis of groundwater qualities. Grouping was based on the scores of principal components of the major ion concentrations. Spatial distribution of grouped wells was consistent with the topography and with the distributions of water temperature and 1, 1, 1-trichloroethene concentration. Similar quality wells grouped by cluster analysis using the principal component scores line up geometrically along the groundwater flow direction estimated with the computer model, USGS MODFLOW. These results supported the hypothesis that the wells of similar quality line up in the direction of the groundwater flow. This characteristic resulted from the human activity which supply the environmental tracers into the groundwater. The semivariogram of the scores of principal component was effective to some extent to find the anisotropy of water quality, if its calculation takes the azimuth into consideration.
