Hydrochemical Characteristics and Quality Assessment of Shallow Groundwater in Xincai River Basin, Northern China

In order to investigate the environmental conditions of groundwater in Xincai River Basin, and further contribute more to rational development and utilization as well as scientific management of groundwater, we analyzed hydrochemical characteristics of groundwater using descriptive statistics, correlation matrices and ion ratio coefficients, and on that basis, assessed the quality of groundwater with revised Nemerow comprehensive pollution index method. The results showed that the major cations and anions in groundwater are Ca2+ and HCO3-, respectively, and the average values and coefficient variations of groundwater parameters are relatively large (except pH), which means high concentration and large spatial variation. The average value of rCl-/rCa2+ ratios is small, indicating a good hydrodynamic condition. Strong correlation exists between NH4+ and Ca2+, implying they may have the same origin, and strong correlations also exist between TDS and the major elements, implying that the major elements contribute much to the salinity of groundwater and the tendencies among them follow a similar trend. The groundwater quality assessment results show that the shallow groundwater quality in Xincai River Basin is relatively poor, and about half of the shallow groundwater is not suitable for drinking, which may be caused by excessive use of chemical fertilizers.