Abstract: Statistical analysis, Piper diagram, saturation index and the correlations of chemical parameters were used to reveal the hydrogeochemistry and hydrogeochemical evolution of shallow groundwater in the southern part of the Yellow River alluvial plain of Zhongwei section. The water quality for agricultural and domestic uses was also assessed in the study. The results suggest that the shallow groundwater in the study area is fresh to moderately mineralized water. Higher Ca2+ and HCO3- are observed in low mineralized water, while Na+ and SO42- are common ions in high mineralized water. Major Hydrochemical facies for groundwater with TDS <1 g/L are HCO3-Ca¿Mg and HCO3-Ca¿Na¿Mg, and for groundwater with TDS >1 g/L, SO4¿Cl-Na and SO4¿Cl-Na¿Mg¿Ca are the predominant hydrochemical types. The main reactions took place in the groundwater system are the dissolution/precipitation of gypsum, fluorite, halite, calcite and dolomite. The cation exchange is also important in controlling groundwater chemistry. Water samples assessed in the paper are in acceptable quality for agricultural use, but most of them are not fit for direct drinking. TDS, TH, Cl- and SO42- are the main indices resulting in the poor drinking water quality. |