关键词: 地下水地球化学, 计算机模拟, 蒸发浓缩作用, 石羊河流域

Abstract: Computer simulation method is one of the most powerful tools in studying evolution of groundwater geochemistry,water-rock interaction and geochemical controls responsible for the water quality changes.And this method has been widely adopted to study groundwater geochemical process at present.Shiyang River basin is situated to the east of Hexi Corridor,with typical features of arid area,long exploitation history,abundant observation data and lots of water-supplying wells.Therefore,the basin is selected as an ideal place to perform computer simulation study on its groundwater geochemistry.It is demonstrated that part of Wuwei basin and Hongyanshan reservoir are the calcite dissolution areas,whereas the Minqin basin is the precipitation area of dolomite and calcite,and the evaporation is the main controls on this process.The groundwater geochemistry of Wuwei basin is dominated by rainfall,and that of Minqin basin is controlled by evaporation.The rising of SO₄^2-/HCO₃^- ratio indicates that the hydrochemical type of the study area is changing from bicarbonate to sulphate,implying the worsening trend of the regional groundwater quality.

Key words: groundwater geochemistry, computer simulation, evaporation, Shiyang River basin