Evaluation of Groundwater Inflow Using Pumping Test in Wells and Visual MODFLOW in an Area with Developed Faults

Abstract

Due to the water inrush from driving and mining at coal and mines, which is a great threat to human life and safety and to coal and mineral production, it is important to accurately evaluate the groundwater inflow in areas with developed faults. We calculated groundwater inflow by Visual MODFLOW and pumping tests in observation wells under specific conditions of the study area with the developed faults and fractures. It built a 3D groundwater flow model based on the topographic map of the study area, which included faults and fractures. The test and observation wells were built based on in-situ data, and evaluated the equivalent water level contour was evaluated, as well as groundwater inflow in the developing area and mining area. It predicts groundwater inflow from the mining area under steady flow conditions by making six conceptual layers with a total thickness of 280 m, two main faults (F1, F2), and three major river boundaries. The results showed 20668 m³/d, 17592 m³/d, 14408 m³/d, and 12775 m³/d for each developing level (–110m, –150m, –190m, –270m) throughout the mining area, respectively. The accuracy of the prediction of the measured values and simulated values for 36 wells was 3.1%. The findings of this study can help to realize the hydrogeological 3D modelling of the study area with developed faults, and to estimate the groundwater inflow into the mining area.