Method and system for predicting and evaluating influence of coal mining on underground water

The invention relates to a method and system for predicting and evaluating the influence of coal mining on groundwater, and the method comprises the steps: S1, setting a time range, a space range and a computational grid in a groundwater flow simulation period, and all source and sink items and boundary conditions in the simulation period for a groundwater numerical model; s2, setting corresponding parameters in the underground water numerical model according to the coal mining scheme, the drainage scheme, the development height of the water flowing fractured zone and the permeability coefficients of different lithologic rocks of coal seam roof and floor rocks in different strain stages; s3, operating the underground water numerical model to obtain underground water dynamic parameters of different time steps of the simulation area; and S4, according to the obtained groundwater dynamic parameter of each time step of the simulation area and a threshold range corresponding to each type of preset groundwater dyna