Research On Numerical Simulation And Transform Quantity Between Surface Water And Groundwater Under The Condition Of Mining Subsidence

Large-scale mining in Panxie mining area causes ground surface subsidence of large area, then a wide range of water area has been formed, which leads to changes of surface water and shallow groundwater in subsidence area. Researching the change rules and influence factors of shallow groundwater under mining subsidence conditions and searching for the transformation rule between surface water and shallow groundwater have very important practical significance on the recovery management of Huainan coal mining subsidence and the reasonable exploitation of water resources.In this paper, on the basis of depth investigation of topography, hydro-geological conditions, ground subsidence history, current status and scope of water area in Huainan Panxie mining, the surface water and shallow groundwater of subsidence area have been systematically researched by taking two types of subsidence, closed and open, as the research object and using Guqiao subsidence area as the water level monitoring contrast area.Using remote sensing data to survey the range of water conditions in Panxie mine subsidence area, emphatically survey the area of recharge and discharge, combined with ground hydrological dynamic data and mining subsidence area prediction data, and then to determine the boundaries of the subsidence area and catchment area. Through on-site monitoring of surface water and shallow groundwater levels, conducting soil particle size and permeability coefficient test, get dynamic characteristics of subsidence shallow groundwater level under precipitation and evaporation.on the basis of analyzing the hydro-geological conditions between the surface water and shallow groundwater of subsidence area, generalize the two types of subsidence area aquifers, build the mathematical model between the water and groundwater which based on the’hanging river’ model, and by using the Visual MODFLOW software to establish the groundwater flow model in the study area, recognize the aquifer hydro-geological parameters, then get shallow groundwater flow field in various periods.According to the calibrated hydro-geological model, program and compute transform quantity between surface water and shallow groundwater of subsidence area in different periods. The results show that shallow groundwater recharges surface water but the recharge is small; with rainfall increases, the transform quantity decreases. On the other hand, surface water and shallow groundwater are complementary in the open subsidence area.