Research On Evolution Of Groundwater Chemical Characteristics In The Western Jilin Province

The research on Water & Rock Interaction can finds out the transferring and changing characteristics of the chemicals in groundwater, the mechanisms of the physical chemistry reaction and the factors that affects these mechanisms, and determines the direction and the limitation of these reaction, then it will help to make the prediction of the chemical evolvement. West Jilin Province lies in the transition zone between humid east monsoon region and arid inland, and belongs to semi-arid and semi-humid continental monsoon climate zone. Water resources in the area is relative indigent, water quality in some places has been polluted, and problems induced by it are prominent, such as soil salinization, desertification, grassland degeneration, water loss and soil erosion etc. Research on evolution of groundwater chemical characteristics in the western Jilin province can help to discuss the impact and feedback that given to environment by groundwater, and the changes of groundwater under the influence of both natural and artificial factors, which will provide reliable support for reasonable exploitation of groundwater and improvement and protection of water quality.The Quaternary pore phratic water play a active role in water cycle, and the water quality is markedly influenced by topography, meteorological phenomena and hydrology so that the water quality can be polluted easily. In this paper the analysis and simulation of the chemical evolvement of the quaternary pore phratic water is the keystone. This study starts with the groundwater chemical characteristics in the western Jilin province. Firstly the characteristic of hydrochemical type of the quaternary pore phratic water and mineralization are analyzed, Secondly the Piper trilinear chat is protracted by the hydrochemical analysis software AquiChem V4.0, then the chemical characteristics and the evolution law of the quaternary pore phratic water can be reflected intuitionisticly by illustrated diagram. Based on the correlative water quality information,the law of special-temporal evolution of phratic chemical field is summarized. This law will help to clarify the formation action of phratic chemical component and the main factors that affect the phratic chemical evolution in study area, namely the condition of hydrogeology, meteorological phenomena, hydrological and human activities.Aiming at ulteriorly realize the geochemistry actions of the quaternary pore phratic auifer in the groundwater fluxion process. The inverse geochemistry simulation of the water & rock interaction of the quaternary pore phratic water in the western Jilin province on the basis of chemical thermodynamic elements and the principle of mass conservation. Firstly, two pieces of typical profile along with the groundwater fluxion direction will be chosen on the basis of hydrological condition, namely submarine bulge—Da'an profile (Ⅰ—Ⅰ'profile) and Wangfu—Qian'an—Qianguo profile (Ⅱ—Ⅱ'profile); Secondly, possible mineral facies that may bing to chemical reaction will be confirmed, then get the accurate saturation exponents of these mineral facies, and construct the water & rock interaction model. Finally, the solution to the water & rock interaction model will be get by the inverse geochemistry simulation software NETPATH2.0, and we can gain the final result of the phratic chemical evolution in study area. The simulation results show that: along with theⅠ—Ⅰ'profile, in the drainage process of the quaternary pore phratic water from Tao'erhe submarine bulge to Da'an, the geochemistry actions mainly include: the depositions of calcite, gesso and kaolin (or silica), the dissolution of albite, feldspar, halite and fluorite, the ion exchange between Na+ and Ca2+, and the type of groundwater changes from SO42--type to SO42-+Cl--type. along with theⅡ—Ⅱ'profile, in the runoff process from the boundary to sountheastern, the geochemistry actions mainly include: the depositions of calcite, halite and carbon dioxide, the dissolution of albite, feldspar and fluorite, and the type of groundwater changes from HCO3-+SO42--type to HCO3—type because of the dilution of surface water. The inverse geochemistry simulation of the water & rock interaction will help to study the evolution of groundwater quantificationally, and realize the interaction between the quaternary pore phratic water and environment, then provide scientific support for the reasonable exploitation of water resources and the protection of the eco-environment.