Identification of Homogeneous Groundwater Quality Regions Using Factor and Cluster Analysis;A case study Ghir Plain of Fars Province

Because the lack of precipitation in arid and semi-arid regions and therefore limitation of surface water resources in theirs, water usage in agriculture, industry and drinking heavily dependent on groundwater. For this reason, the study and evaluation of the quality of these resources is more important. The present study was done in order to classify groundwater quality of Ghir plain using statistical techniques, including factor analysis (FA) and Hierarchical clustering techniques (HCA) (Based on K-means/K-medians cluster analysis (KCA) method), on qualitative data (14 parameters) in a 10-years period (1391-1381) and SYSTAT13, SPSS 18 and PcOrd softwares. Factor analysis results showed that the variables of SAR, Cl, Na, PH, SO4 and HCO3 with the highest factor loading respectively are the most important parameters to performing clustering analysis. In order to determine the optimum number of clusters used from Davis- Boldin index and according to this index, five clusters were determined for classification of wells. The Results revealed that the KCA and HCA methods have jointed 100% in order to classification. According to the classification results, amount of the parameters of groundwater samples increasing from first to fifth groups. However the wells are placed in Group 1, have the best water quality.