Impacts of MODFLOW Grid Size on Simulated Drawdown

MODFLOW models can be used to estimate drawdown either at pumping wells or observation wells. Though well loss is not considered at the pumping wells, such studies are often required to evaluate maximum pumping rate, pumping impacts on adjacent water wells, capture zone analysis, and groundwater resources management.

Presented in this study includes hypothetic MODFLOW models with different grid sizes. The MODFLOW models contain uniform but relatively large grids, uniformly but relatively small grids, and varied grids in both horizontal and vertical directions, respectively.  Leaving all other conditions the same, the impacts of grid size on maximum sustainable pumping and drawdown are investigated.