Numerical simulation study on the impact of high intensity mining activities on groundwater

In order to explore the impact of high-intensity mining activities on groundwater, a mine field in Shendong Coal Mine Area of Inner Mongolia is selected as the research object. This mine is characterized by a large proportion of mining area on the plane, a large mining size in space and a fast mining speed in time. Based on the collection of relevant hydrometeorological and survey data, the Groundwater Modeling System numerical simulation software was used to establish a Groundwater flow model in accordance with the hydrogeological conditions of the study area. The Groundwater level and flow field under the influence of mining in the study area in the next 10 years were predicted and analyzed. The equilibrium state of groundwater is also analyzed. The results show that the disturbance of Zhiluo group Aquifer is most affected by high intensity mining, and several water level drop funnels are formed in the mining area. The water level in the center of the drop funnels increases from 105 m at the end of the first year to 351 m at the end of the tenth year, and the overall groundwater level and runoff conditions of this layer are changed. The influence of high intensity mining on the aquifer of Zhidan Group is small, and the water flow field changes only in the local position above the mine. In 10 years, the water level at the mining center decreases from 20 m to 116 m. According to the water balance analysis, the total groundwater recharge is 357 589.74 m³/d, and the total excretion is 357 563.62 m³/d, with an error of 0.0073%. Rainfall infiltration is the main recharge source in the study area, accounting for 51.90%, followed by river recharge, accounting for 45.21%. River drainage was the main way of discharge, accounting for 78.24%, followed by phreatic evaporation, accounting for 9.82%, and mine drainage, accounting for 4.52%. The recharge and discharge of the Zhidan group and Zhiluo group account for 12.0% and 5.7% of the total mean measurement in the region, respectively, and mine drainage is the main discharge mode of the Zhiluo Formation aquifers, accounting for 71.3%. The research results provide some basis for the protection of production safety and sustainable development in mining areas.