Thirty groundwater samples were taken from Assiut’s northern outskirts. The physicochemical
properties of these samples were investigated. For the evaluation of water–rock interaction,
the saturation index (SI), chloro-alkaline indices (CAI1 and CAI2), Gibbs ratios for cations and anions
(GC and GA), principal component analysis (PCA), and hierarchical cluster analysis (HCA) were
used. (1)With the exception of five samples that were supersaturated, the rest of the groundwater
samples were under-saturated with carbonate mineral dissolution (calcite, dolomite, and aragonite)
and evaporite mineral dissolution (anhydrite, gypsum, halite, and sylvite). (2) The presence of ion
exchange between alkali elements (Na+ + K+) and earth alkaline elements (Ca2+ + Mg2+) is explained
by the positive values of the chloro-alkaline indices. (3) In four groundwater samples, negative
chloro-alkaline indices suggest reverse ion exchange and an increasing alkali element content. (4) The
Gibbs diagram demonstrates that, with the exception of four samples that reflect saline groundwater,
the majority of the groundwater samples are freshwater recharging from the fresh surface water in
the research area. (5) Groundwater types include Ca-HCO3 (11%), Mg-HCO3 (48%), Na-HCO3 (23%),
Mg-Cl (13%), and Na-Cl (3%). (6) The alkali, earth alkaline elements, and sulphate are the key controls
on groundwater salinity, according to PCA and HCA. (7) The somewhat saline groundwater in the
research area’s western desert margins should not be used since it poses a health danger to people