Evaluating the Groundwater Quality Variations Using Factor Analysis Combined with Information Entropy Theory

Introduction The chemical characteristic of groundwater as a major source of water supply for human life is an important factor in determining the usage of it for agriculture, industry and drinking. Useful techniques and different methods of studying the chemical composition of groundwater such as correlation coefficient, descriptive statistics, factor analysis and cluster analysis provide an understanding of the main factors that contribute to groundwater salinity and also sources of contamination. Shannon proposed entropy as a measure of uncertainly, a theory recently applied in various fields. Although the ability of the entropy theory has quantified to evaluate uncertainty for hydrological variables and parameters in models of water resources systems, studies have not fully explored its application for describing and evaluating large-scale characteristics of groundwater quality. The three objectives of this study included: (1) applying cluster analysis and GIS technique to recognition of spatial classification of groundwater resources; (2) using factor analysis to interpret major factors that affect groundwater quality in Lenjanat, and (3) investigating the stability and spatial variation of influential factors.