Application of MODFLOW to Groundwater Drainage Numerical Simulation in Sanmenxia Bauxite

Based on the stratigraphic distribution,the geologic structure and hydrogeologic conditions of Sanmenxia bauxite,the hydrogeologic conceptual model of karst-fracture aquifer system of water enrichment Cambrian-Ordovirian Period limestone was generalized,and the numerical model of groundwater flow was established with the finite difference method of Visual MODFLOW to simulate variation of groundwater level and to predict water discharging.The groundwater flow mathematical model was corrected and the hydrogeolocical parameters were inversed in combination with the observation value of groundwater level of group drilling pumping tests in mining area boreholes,and then the corrected mathematical model and parameters were adopted to predict the groundwater level distribution and mine discharge changes at different designed mining drainage level in well.The reliable basis is provided for controlling groundwater effectively and safe rational mining bauxite.