Water quality parameters reduction of the Lamtakong river basin (Thailand) using statistical analyses

Data reduction is very important when dealing with river pollution analysis. Lamtakong River is a small river but it is one of the most significant water resources in Thailand for several community water supply systems, large farming and irrigation areas, and waste water drainage systems. This research aimed to reduce the large number of locations and water quality parameters down to a manageable number. Cluster analysis, a statistical method for sorting groups of similar data into clusters, was applied for grouping of homogeneous locations based on water quality. Of total 15 monitoring sites, 7 sites were chosen for cluster analysis which distinguished them into 2 groups, the upstream and downstream groups. Factor analysis, a statistical method for selecting a few representative variables from many variables, was used to reduce the number of water quality parameters. In this study, the factor analysis technique reduced 17 water quality parameters down to 8 for both the upstream and downstream sections. Five of the reduced parameters are the same for both river sections. The three exceptions demonstrate the different characteristics of the 2 river sections