10. KEY FACTORS DOMINATING THE GROUNDWATER CHEMICAL COMPOSITION IN BA RIA - VUNG TAU PROVINCE

Abstract

In Ba Ria - Vung Tau province, this study has determined that the dominant factors influencing the hydro-chemical composition of fractured aquifers are the replenishment of meteoric water, coupled with the processes of dissolution and leaching of Ca²⁺ and Mg²⁺ from weathered basaltic rocks (olivine and plagioclase minerals). Additionally, the exchange process contributes to the enrichment of Na⁺ by replacing Ca²⁺ and Mg²⁺. In porous aquifers, the central-to-sea cross-section highlights meteoric water dominance from rain and surface sources. Groundwater undergoes exchange-absorption with silicate minerals, enriching Ca²⁺ and Mg²⁺ (reducing Na⁺). Seaward, dissolution and leaching of salts in marine-origin sediments (mQ₂, mQ₁³, mQ₁^2-3, and mN₂²) prevail. The results of this paper provide necessary information for the effective management of groundwater quality.