31-Hydrogeochemistry of Groundwater in Western Warud Taluka,Amravati District, Maharashtra

Abstract

Qualitative and quantitative hydrogeochemical changes occurring in the Deccan aquifer system along the flow path of the Kobi Nala and the Dhawagiri Nala watersheds in the Western Warud Taluka, Amravati District, Maharashtra, has been analyzed. Based on the chemical composition of the groundwater, the recharge to discharge areas are characterized by Mg > Ca > Alk, Ca > Mg > Alk, Ca > Alk > Mg and Alk > Ca > Mg hydro chemical facies. Along the flow path the depletion of Mg contents is due to fixation of Mg in clay structure. The middle zone there is depletion of Ca and increase in alkali representing cation exchange. In the last phase there is depletion of Ca by oversaturation. The groundwater is dominated by Ca, Mg > Na + K-HCO3 + CO3 hydro chemical type followed by Na+K-HCO3+CO3 and Na+ K-SO4+Cl+NO3 indicating cation - anion exchange processes. The natures of hydrochemical changes occurring in the aquifers of the Deccan trap domain are quantified on the basis of multivariate correlation coefficients. The study reveals a strong correlation for Mg-HCO3 due to the solubility function and CO2 enrichment. The moderate correlation of Ca-HCO3 is due to mobility of Ca as compared to Mg. Similarly a strong correlation of Alk-HCO3; represent stoichiometric proportion of the hydro chemical constituents in shallow aquifers. Mg-Sat, CaSO4 relation has been similarly viewed. The groundwater mineralogy derived from multivariate correlation coefficients corresponds satisfactorily with the results obtained from the established physico-chemical methods.