Reverse Simulation Method In The Ordos Basin, Central River Formation Groundwater Evolution

Water quality of Erdos Cretaceous Groundwater is effected by many factors and it's variety is intricacy, at present, we have mastered the distributing of cretaceous groundwater's chemical field, but we are not clearly know the essence of the groundwater's formation. Some traditional hydrogeochemical approach can only research the formation of groundwater with qualitative manner. In the dissertation, we use Basis of chemical Thermodynamics, conservation of mass, Mass action law, and inverse modeling to simulate water-rock interaction of Huanhe group of Cretaceous . This is the first time to quantitative analyze the process of the evolution of the Groundwater of Huanhe group. Through these research, we post the form mechanism of groundwater's chemical field and sum up the law of mineral dissolve and precipitation. Accordingly, these provide science gist to develop and use ground water in a rational manner.This text mainly divided into two parts, the ex-part introduce the method of the Geochemical modeling of water-rock interaction. The method includes some calculating principles, such as equilibrium distribution calculation of aqueous species, index saturation calculation method that can judge the state of mineral dissolve and precipitation, and build up the geochemistry model and model's numerical method. According to the chemical element balance, the electric charge balance, the electronics balance and the alkalinity balance. Another part we use simulation of water-rock interaction on some typical section of Cretaceous. By this we receive some conclusions: in first section, in the process of discharge of groundwater of Huanhe group, mostly take place Calcite and Quartz's precipitation, and Sylvite, Gypsum, Halite, Sepiolite's dissolve, and ion-exchange action of Na⁺, Mg²⁺, Ca²⁺. In second section, in the process of discharge of groundwater, mostly take place Calcite, Dolomite, Ca-Montmorillon, Quartz's precipitation and Gypsum, Halite, Albite'sdissolve.The whole research express that this simulation is very useful, it cananalyze evolution process of groundwater quantificationally. It also canexplain the formation condition of the hydrogeochemistry field and provide the evidence to build up of the ground water system model. At the same time, we must do more research on Erdos Cretaceous about water-rock interaction, so we can understand the relation between Cretaceous Groundwater and environment better.