HYDROGEOCHEMICAL ASSESSMENT OF GROUNDWATER QUALITY IN SHIMABARA, NAGASAKI, JAPAN

Abstract

 Hydrogeochemical processes were investigated based on groundwater chemistry date. The ions composition of groundwater in forest area is influenced by precipitation, and that in upland field and urban area are controlled by water-rock interaction. The both results of CAI and Na⁺ / Cl^- indicated that ion exchange occurred between Ca²⁺, Mg²⁺ in liquid phase and Na⁺, K⁺ on solid phase. The silicate, calcite, and dolomite dissolution are predominant processes compared to alkali feldspar for mineral dissolution. Ion exchange and mineral dissolution are also suggested by Durov diagram.