Response Mechanism And Numerical Simulation Of Hydrochemical Components Of Groundwater On Water Level Fluctuation

Due to the demand for industrial and agricultural production,the shallow groundwater of the People's Victory Canal Irrigation District was exploited in a short period of time,making the water level dynamics sharply.With the fluctuations of the groundwater level,the hydrogeological and water chemical components of the aqueous layer will vary.In order to study the distribution status and migration process of the conventional water chemical component of groundwater in the aquifer,this paper is fully grasped based on the existing geological and hydrological geological conditions,groundwater environment characteristics and monitoring data,and first In the year,the underground water level buried deep and water chemical components are analyzed,find the correlation between the water levels of the study area and the hydration component,and then study the groundwater level fluctuations from different spatial scale and time scale.The effect of water chemical components.In order to further seek the response law of the groundwater chemical component on the water level fluctuations,indoor simulation experiments are used to analyze the indoor simulation experiment using the pumping full well simulation device and the vertical water level fluctuation simulation device,and the variation of each ion content underground water level fluctuations and its change mechanism.Finally,numerical simulation technology establishes a groundwater flow model and water quality model for artificial diving aquifer,and uses model predicting different mining strength and changes in water chemical components at different positions of pumping wells.Finally,the following conclusions were obtained:(1)The degree of correlation between the underground water level and the degree of deposition of the underground water level and the hydration component of the hydration component is different.The larger the water level fluctuation,the greater the relationship between the two.Low water casings,the degree of association between the water level and the water chemical component is more responsive,and the response in the water is greater.The effect of underground water level fluctuations on the water chemical components exists"lag"phenomenon,and the water level fluctuation has different times of different ions,the longest lag time is about one month.The implications of hysteresis,there is a significant positive correlation between the depth of the groundwater depth and the hydration component.(2)Using the diving full well simulation device to migrate the groundwater chemical component migration simulation experiment,different ionic content of each position of the aquifer has evolved as the fluctuation of the water level is evolved;the ion content of the upper portion of the aqueous layer is generally higher than The content of the lower ions,but the degree of ion variation in the lower aqueous layer is more intense.The higher the position of the pumping well,the higher the ion concentration in the groundwater,the more intense the degree of ion changes.(3)Cl^-,SO₄^2-concentration change was mainly affected by mixing.In addition to the impact of the mixing effect,Na⁺,Ca²⁺and Mg²⁺,in addition to the hybrid effect,HCO3-content is mainly affected by CO₂ in the system.According to the chlor-alkali index,after the water level decreases and the water level increases,the groundwater system has a forward cation exchange,the Na+content is increased,and the content of Ca²⁺,Mg²⁺is reduced,but due to the dissolution of the calcite,the Ca²⁺content before the water level is not reduced;The reverse cation exchange occurs during water level fluctuations,and the Na⁺content is reduced,and the content of Ca²⁺and Mg²⁺is increased.(4)Quantitative analysis of the ion content in the groundwater and soil layer in the vertical water level fluctuation,a water level fluctuation period,Na⁺in groundwater decreased by 18.4 mg/L,Na⁺in the soil layer was increased by 8.8 mg/kg,Ca²⁺in groundwater increased by 54.5 mg/L,Ca²⁺in the soil layer decreased by 1.64 mg/kg,the mg²⁺in the groundwater system did not change before and after the water level fluctuation,the Cl^-increased in the groundwater increased by 6.9mg/L,soil layer Cl^-has no change,SO₄^2-in groundwater increased by 33 mg/L,SO₄^2-in the soil layer increased by 5.17 mg/kg,and HCO₃^-in groundwater was reduced by 71.9mg/L,and HCO₃^-in the soil layer increased.17.38mg/kg.The above results indicate that the groundwater system is affected by the effect of mineral dissolution,cation exchange,and decarbonation in addition to the effects of convection,dispersion etc.(5)Using Visual MODFLOW to construct a ground water flow model and water quality model,the water level value and ion content value of the simulation calculation are well fitted,and can be used for model prediction.Using the model to simulate different mining strength and ion content change in different positions of the pumping well.The results show that the greater the intensity of the mining,the more obvious the water level,the more convective of the water chemical component,the stronger the diffusion,the greater the corresponding ion content change.The closer the pumping well,the more obvious the degree of change in the ion content,and the ion content at different positions has gradually approached to the fixed water head concentration as the fluctuations in the water level.