Abstract

The numerical simulation of groundwater for the single aquifer layer system of Baoyang irrigation area was performed. Visual MODFLOW was carried out to estimate the sustainability of the groundwater resource and to delineate suitable plan for future groundwater use. The conceptual model was built by analyzing the hydrogeological data, aquifer properties, pumping wells, head observations; etc. A groundwater model for Baoyang Irrigation Aquifer was developed, calibrated, and validated using observed groundwater levels for the period of 2006 to 2009. The reliability of the model is tested by long series historical groundwater monitoring data and the model is then used to predict the impact of groundwater exploitation until 2048, during this period; all parameters and well exploitation of 2009 were maintained constants. The water balance was checked for differences between the volume of water that is leaving and entering into the system. Calibration model was performed by adjusting the input parameters; the optimization results of parameters were calibrated automatically during the model processing using the Parameter Estimation Package “PEST”. The results show that the computed water heads fit into with perfectly the measured data, which indicate that the conceptual model and the parameters used in the model can reflect the actual physical system of the study domain. Also the results found that the water table in the aquifer is slightly falling down due to continuous withdrawal of water. Finally, the model applications were reported.

Key words: Numerical simulation model, finite difference method, groundwater, MODFLOW, Baoyang irrigation, Shaanxi, Northern China.