This work aims chemical classification and characterization of groundwater basin Santa Rosa, province of Catamarca, Argentina. This has a political, economic and social interest because water resources on the área should be managed strategically for human consumption, livestock and irrigation.
Groundwater sampling was carried out in 2014, with private and municipal wells. The samples were collected at 72 sites, to a máximum depht of about 250 m, distributed over the whole alluvial plain, that include the study área. The samples were analized for a total of 13 parameters: Potential Hydrogen , major , minor ions and trace non-metallic inorganic constituents (pH, Na +, Ca++, Mg ++,K +, HCO3-, Cl- , SO4 = ,SiO2, B, NO3-, F-, As).
Classification was obtained with application of statistical multivariate methods: Principal Component Analysis (PCA) that allow to identify and group the most significant system variables and Cluster Analysis (CA) classified wells in two classes or distinct groups (G1 and G2) considering the variables more indicative according to those found in the PCA.
Groups representation of water wells on geographical coordinates or locations, indicated spatial autocorrelation relating the Group 1 (G1) to the northwest of the region, while group 2 (G2) lies directly to the center and southeast of the study area. The observation of the locations notice that G1 is more compact that scattered G2.
For hydrochemical characterization of each group applied Kurlov criterion, that considers the anions and cations exceeding 20% of milliequivalents per liter. The results of this analysis associated G1 with sodium bicarbonate water type and G2 with sulfated sodium bicarbonate water type.
Hydrochemistry classification of studied watershed improves knowledge of water quality and is useful for defining indexes that facilitate resource monitoring, providing society tools for future management and exploitation.