Prediction And Evaluation Of The Impact Of Coal Mining On Aquifers

Underground coal mining activities in research started in the 1980s, due to economic development, the growth of coal demand in the energy structure, are large-scale exploitation of coal resources, for the stability of our country economy make great contribution to the development of continuous coal mining brings the ecological environment of the damage, however, ecological damage caused by coal mining can not be ignored, especially the impact on groundwater resources, not only cause damage to groundwater quality, but also exacerbated the shortage of water resources, resulting in decline of groundwater level, causing frequent coal mine water inrush development and land subsidence phenomenon.From the change of water quality and water quantity, this paper analysed the influence of coal mining on the groundwater environment characteristics, and take the ShanXi Jilong Qinglong coal company’s coal mining coal group as the research background, combined with the natural geography of the area and the corresponding environmental monitoring and field test, understand the hydrogeological characteristics in the study area and the groundwater environment present situation, and through Visual Modflow software to simulate the process of change in groundwater levels during the coal mining, and to determine the extent of groundwater impact of coal mining on the study area, providing safe water for area residents scientific basis, and the corresponding groundwater protection measures based on the findings.By numerical simulation model, the paper has made the following findings:(1) Coal mining caused effects on the overlying aquifers, in goaf formed precipitation funnel irregular as the center, the mining time is longer, the funnel and the depth and area is more and more big, the center gradually draining aquifer.(2) The study area in coal mining in 8.2 years, will drain of Carboniferous sandstone fissure aquifer and the Carboniferous Taiyuan group limestone fractured aquifer. Mining area as the center to form precipitation funnel, the funnel center water level drawdown is about 63 m influence area is about 6.32km2.(3) According to the calculation of water inrush coefficient, research of mining area of No.9, No.11 coal seam, water inrush coefficient is lower than 0.06MPa/m, there is no water inrush risk area. Water inrush coefficient of No. 13 coal seam in borehole G101, J104, K102 greater than 0.06MPa/m, will pose a threat to the Ordovician limestone aquifer.