Resumen de Evaluation of water quality using geochemical modeling in the Bellary Nala Command area, Belgaum district, Karnataka State, India
P. Ravikumar, K.L. Prakash, R.K. Somashekar
The present study aimed at assessment of geochemical composition of 25 water samples to evaluate their suitability for drinking and irrigation purposes in the Bellary Nala command area. Geochemical modeling carried out using PHREEQC program confirmed that majority of the samples in the study area were saturated and/or supersaturated with respect to anhydrite, calcite and gypsum while few were undersaturated with respect to calcite, gypsum, fluorite and halite. From Piper trilinear diagram, Ca2+-Mg2+-HCO3 - was found to be the dominant water type (~68 %), which could be as a result of dissolution of carbonate minerals such as dolomite and calcite prevailing in the study area. However, cation-exchange processes could be responsible for the formation of the Ca2+-Mg2+-Cl--SO4 2- water type (~32 %) from the CaSO4 and NaCl types, which in turn formed due to the dissolution of anhydrite, gypsum and halite. Wilcox's and USSL graphical representations showed that majority of the samples belong to good to permissible and high salinity-low sodium (C3S1) category, respectively. Factor analysis concluded that the water quality parameters and saturation indices that are falling under factors 1 and 2 with a strong loading (>75 %) and eigen values (>1) are mainly responsible for controlling the variation in the groundwater chemistry, accounting to 83.3 and 80.72 % of total variance, respectively.
