Assessment of hydrogeochemical characterization and groundwater quality using geostatistical and gis techniques: A case in the north part of Italy

One hundred and fifty-six groundwater samples were collected from the Aosta Valley region, Italy and analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH), major cations (Ca²⁺, Mg²⁺, Na⁺ and K⁺), major anions (HCO₃¯, F,¯ Cl¯, NO₃¯, SO₄²¯) to evaluate the hydrogeochemical characterization as well as water quality of the area. A geographic information system (GIS) tool was used to study the spatial variation in the groundwater parameters of the study area. The analytical results show slightly acidic to slightly alkaline nature of the groundwater in the study area. The TDS exceed the desirable limit of 500 mg L¯¹ in 43% of the groundwater samples. HCO₃¯ and SO₄²¯ are the dominant anions, while cation chemistry is dominated by Ca²⁺and Mg²⁺. The data plotted on the Piper and Gibbs diagrams as well as statistical analysis reveals that the groundwater chemistry was mainly controlled by rock weathering processes in the study area. Ca²⁺-Mg²⁺-HCO₃¯and Ca²⁺-Mg²⁺-Cl¯ -SO₄²¯ were the dominant hydrogeochemical facies in the groundwater of the study area. For quality assessment, values of analyzed parameters were compared with the World Health Organization (WHO) water quality standard, which shows that the concentrations of TDS, Ca²⁺, SO₄²¯ and TH are exceeding the desirable limits in some water samples. This study could be useful in implementing future measures in groundwater resource management of the area.