Abstract
Multivariate statistical techniques, principal component and cluster analysis were applied to the data on groundwater quality of Limestone aquifer in the southern region of Okinawa, Japan, to extract principal factors corresponding to the different sources of variation in the hydrochemistry, with the objective of defining the main controls on the hydrochemistry at the regional scale. As a result of principal component analysis, ground water quality in the region could be classified into four principal components, that is, the groundwater is affected according to salt water and fertilizer (component 1), limestone dissolution (component 2), a redox state of a ground-water (component 3) and nitrogen accumulation/ denitrification (component 4). The cluster analysis was classified into four clusters according to the pollution situation of groundwater pollution in the study area, and the classification result was affected by season.
