Study On Hydrochemical Characteristics Of Longde Coal Mine And Influence Of Coal Mining On Groundwater

The exploitation of coal resources is closely related to water resources.The Longde coal mine is located in the western part of the country where the Mu Us Sandyland and Some Random Place Somewhere meet.The ecological environment in the area is very fragile and there is not enough water,therefore,it is the premise of Mine Water Resources Protection and management to fully understand the influence of coal mining process on groundwater resources.In this paper,the geological and hydrogeological conditions of Longde coal mine are analyzed systematically for the purpose of the influence of coal mining on groundwater in Lund coal mine Mathematical Statistics,Piper plot,Ion Ratio and hydrogen and oxygen isotope were used to analyze the chemical characteristics of each aquifer and the hydraulic relationship among them.Based on the numerical simulation,the influence of coal mining on groundwater level and water flow field is analyzed,and the influence degree of Longde coal mining on underground aquifer is analyzed:（1）From shallow to deep,the hydrochemical type of the mining area has changed from HCO₃-Ca type to Cl·SO₄-Na type.The chemical composition of groundwater is mainly controlled by rock weathering,and the goaf water is the mixed water mainly composed of bedrock water.（2）The main recharge source of groundwater in the study area is atmospheric precipitation,the fracture zone of coal seam mining will direct the normal bedrock aquifer and weathered bedrock aquifer,and the local area will direct the phreatic water of Quaternary loose bed,through the simulation of water flow field and water balance,it is concluded that coal mining has little influence on the phreatic water of Quaternary unconsolidated bed,but has great influence on weathered bedrock aquifer.（3）By using the thickness of aquifer,comprehensive permeability coefficient,lithologic combination index and core recovery rate,the water-rich property of weathered bedrock aquifer is evaluated and subdivided,and the height of superimposed water-conducting fracture zone is calculated,the regional prediction results of the influence degree of 2^-2coal seam mining on weathered bedrock aquifer are obtained.The results show that the weak and weak impact areas are located in the western part of Well-field system,accounting for about 54%of the total area.The medium and strong impact areas are located in the northeastern and southern parts of Well-field system,accounting for about 40.6%of the total area,the strong impact area is located in the southwest of Well-field system,accounting for about 5.4%of the total area.This paper has 40 pictures,24 tables and 81 references.