Investigating Seawater Intrusion in Republic of South Africa’s Heuningnes, Cape Agulhas Using Hydrogeochemistry and Seawater Fraction Techniques

The Heuningnes Catchment in the Republic of South Africa was used as a case study this research to describe application saltwater fraction/quantification and hydrogeochemistry methods evaluate extent saline intrusion coastal aquifers. argument is that presence seawater incursion may be conclusively determined by combining examination major ions, fraction, stable isotopes water, bromide, geochemical modeling. Using oxygen (18O) deuterium (2H), ions chemistry, composition, modeling, genesis salinity mixing different water masses were examined. Twenty-nine (29) samples groundwater All showed facies Na-Cl type, indicating seawater-related origin. significance aquifers under natural conditions shown hydrogeochemical characteristics key derived from ionic ratios, which demonstrated substantial adherence lines among endmembers for freshwater well (seawater). quantification contribution percentages varied 0.01 43%, with three having concentrations above 50%. It clear analysis determination proportion impacted fresh groundwater. In addition, chloride concentration ranged 81.5 26,557.5 mg/L, corresponding δ18O values ranging −5.5‰ −0.9‰, suggested mixing. Br−/Cl− ratios evaporation had played part elevating well. Since saturation indices below zero, mineral dissolution could also contribute salinization Further proof investigated catchment supplied modeling bromide. Even though such tools not verified multiple widespread generalization, offered scientifically significant understanding on has useful recommendations aquifer setting similar environments.