Gibbs plot
The groundwater chemistry and evolution mechanisms in the study area are shown in Fig.6. The Gibbs plot of the study area shows that 90% of the sample locations are highly influenced by rock water interaction, and the remaining 10% of the sample locations are evaporation dominance. The increasing action of weathering of parent rock, oxidation-reduction, ion exchange, mineral dissolution, such as calcite and dolomite dissolution are the major factor that deteriorate the quality of groundwater. Twenty-eight samples fall under the calcite dissolution, and two samples fall in dolomite dissolution (Fig.7).