MODFLOW-based groundwater rebound forecast in abandoned coal mine

With the depletion of shallow coal resources and the adjustment of state supply structure, the number of closed mines in China is increasing year by year. Groundwater will not be drainaged any more after coal mine is closed. The groundwater level keeps rising until it is balanced with the regional groundwater level, and this may pose a threat to the adjacent active coal mines. Daihe coal mine located at Huaibei mining area was taken as a research target, and visual MODFLOW software was used to research the groundwater rebound process. Results show that as time goes on, the groundwater level rises gradually, and the rate of recovery is faster in the early stage and slower in the later period, revealing that the regional groundwater flow field has a significant impact on the recovery of the water level of the mine. The dynamic change process of water level with time was obtained, and the recharge time of groundwater needed about 2 000 days. The research results provide a basis and reference for the prevention and control of goaf water in adjacent active mines.