Geochemical Modelling of Ground Water by Cluster Analysis in Hard Rock Area of Kadiri Schist Belt, Anantapur District, Andhra Pradesh (India)

An assessment of the quality of ground water for the Kadiri schist belt of Anantapur district has been carried out with an objective to determine the hydrochemical variability. A total of 41 representative samples from different geological formations were collected in both pre-and post-monsoon seasons and analyzed for the major chemical constituents, viz. Ca, Mg, Na, K, CO3, HCO3, SO4, Cl, F, pH and EC. Cluster analysis, a multivariate statistical tool, has been used in the study as qualitative means for differentiating ground waters into distinctive types. Based on hydrochemistry, chemical variability deciphered from cluster analysis suggests three distinct types of ground waters, viz. mixed type (Si-Ec-Ca-Cl-SO4-Mg or Ca-Cl-EC-Si-Mg) and Na-HCO3 type in both pre-and post-monsoon, whereas in post-monsoon in addition to these two types one more type has been formed in the form of SO4. Sulphate type occurs only in the post-monsoon season due to the use of excessive sulfate fertilizers to improve the yield of the crops. Ground water of the study area is (except fluorine) within the permissible limits for domestic and irrigation purposes.