Evaluation of land use and geological effect on groundwater characteristics in Bandung metropolitan using a hydrochemical and statistical approach

Groundwater is often used as clean water since it requires less water treatment. However, the quality will depend on the environmental conditions and human activities. Our research is conducted in Bandung Metropolitan, an urbanized area where groundwater is preferable, but the quality is becoming concerning. The objective of this study is to determine whether natural or human activities have a greater impact on groundwater quality. A total of 113 samples were collected from nine geological conditions spanning three primary land use types. The samples were analyzed for seven major ions (Na + , K + , Ca 2+ , Mg 2+ , HCO 3 − , SO 4 2 − , and Cl − ), which occur naturally in natural water but may be elevated due to human activities. Based on the Piper diagram, fifty-three samples are categorized as Ca-HCO 3 , with the dominant cation being Ca 2+ and the dominant anion being HCO 3 − . Furthermore, the multivariate statistical analysis reveals that 74% of all ions are related to geological conditions and anthropogenic activities. In detail, high contents of Ca 2+ , as the dominant cation, are significantly correlated by all land uses and most geological formations. In addition, cation contents were significantly correlated with land uses, but the correlation varied for each type of geological formation. All land uses surely correlate with all major ions, but the geology depends on the type of formation.