Geochemical Evolution of Groundwater Filler in Yuncheng Basin of Shanxi Province
运城盆地漏斗区水文地球化学演化规律 研究

Yun Chen Basin is located at the southwest of Shanxi province. Because of its special hydrogeological and climatic condition, the groundwater quality is not so good in many place of Yuncheng Basin. Salt water and semi-salt water is detected in some observation wells. And the groundwater fill is forming and extending with the excess exploitation of groundwater in the past two decades. In the groundwater fill areas, the hydrodynamic condition is changed largely, which make the geochemical reaction path become more complexity in these areas. The hydro-geochemical system of aquifer in the groundwater fill area of Yun Cheng Basin is analyzed in this paper. The hydro-geochemistry is affected and by dissolution and evaporation on the groundwater flow path. The chemistry types of groundwater are multiplex. The geochemical modeling software NETPATH models the hydro-geochemical evolution process, which is in most common use in recent years. The calculate result shows that the dissolution of gypsum and rock salt in the aquiferous play a dominant role in the hydro-geochemical evolution process on the whole flow path, and the dissolution is equal to precipitation of the fluorite and talc, which indicates the groundwater dissolves the gypsum and rock salt in the aquiferous along the flow path. And the concentration of chloride, sulphate, and sodium arising from edge to center of the groundwater fill, and the groundwater quality is worse and worse. The calculation result also indicates that the hydro-geochemical evolution rule of the groundwater fill area is change distinctly in a shorter time scale by the disturbing of human activity. The calcite in the aquiferous has the trend from dissolution to precipitation on the modeling flow path. The total change volume of calcite is 14.565 in 1990, while which is become -10.145 in 2000.