Influence of hydro-geochemical processes on groundwater quality through geostatistical techniques in Kadava River basin, Western India

Hydrogeochemistry and groundwater quality of the Kadava River Basin have been performed by analyzing 40 groundwater samples for pre- and post-monsoon seasons of 2011 through different geostatistical techniques. Analyses showed that the concentrations of Mg2+ exceeded Ca2+ in both the seasons suggesting silicate weathering as a source of ions. Average Ca+Mg values contribute 73.53% of total cations and signify the major supply of mafic minerals. Elevated TDS and TH limit drinking potential and other beneficial uses indicate permanently hard water. The average concentrations of the anions were found within Indian PL except NO3, attributed to use of fertilizers. The spatial distribution maps show the EC, Mg, Na, Cl, and SO4 to be generally higher for both the seasons in flood plain deposits than denuded landforms and middle-level/high-level plateaus containing fractured basalt aquifers. It is confirmed that silicate weathering is the dominant process followed by carbonate weathering. Inputs of TDS, Cl, SO4, Mg, Na, and NO3 are influenced by rainfall and human activities. Groundwater sample numbers 20, 37, and 38 have been severely impacted from agricultural runoff as these samples are located along the surface water flow path. The high loading of TDS and TH is controlled by the Mg, Na, Cl, and SO4 ions. Elevated concentration of Na over Ca represents the ion exchange between Ca and Na. High contents of Mg, Na, Cl, and SO4 corroborate that the groundwater is influenced by anthropogenic sources. This study is an insight for water managers to address groundwater pollution problems.