Hydrochemical assessment of groundwater using statistical methods and ionic ratios in Aliguodarz, Lorestan, west of Iran

Hydrochemistry of groundwater is considered as an appropriate guide to recognize the occurred reactions in aquifers and water sources. In the present study, composite diagrams, saturation indices (SI), and statistic parameters were used as a tool to interpret groundwater chemistry (SICalcite 0.16 to 1.19; SIDolomite 0.10 to 1.0, SIGypsum -2.35 to -1.74; SIHalite -8.86 to -7.5; SIAragonite 0.02 to 1.04; SIAnhydrite -2.57 to -1.96 ). According to composite diagrams, factors like dissolution, weathering of silicates and carbonate formations were determined as the most effective ones on chemical compounds of the groundwater in the area. Moreover, calculation of the saturation indices for the samples revealed that ions like calcite, dolomite, and aragonite were in the super-saturated mood while inertia, gypsum, and halite were in the under-saturated mood. The total density of soluble ions (TDI) versus the density of anions showed that as the TDI density increased the density of bicarbonate, calcium, and magnesium linearly. However, potassium remained unchanged. Statistic parameters in the Pearson correlation proved that the electrical conductivity (EC) and total dissolved solids (TDS) had the highest correlation. Moreover, there was a high correlation between the EC, TDS, and total hardness with HCO3. The first, second and third components with more than 70% variability justified statistic population in the principal component analysis method, revealing that the first factor was determined as the most effective factor on the groundwater of the region. This factor included a set of dissolution, sedimentation and ionic exchange.