Simulation model for water resource management in North MAHYAR aquifer by using of Modflow Model

In the world today, along the development of computer science and improvement of mathematical techniques, mathematical models can used as a strong and useful mean to solve different problems of ground water. By means of these models, acceptable and relatively precise results can be obtained with the lowest cost. The precision of results obtained from mathematical model are completely dependent on the precision of required data and definition of boundary conditions. In this research, a widespread mathematical model (Modflow) used to simulate ground water flow in North Mahyar aquifer. The necessary data for the model were obtained from the information collected by Isfahan regional water organization, and field surveys. The model was calibrated in two cases, steady and unsteady state, using information of water year 1995-96. In steady state, calibration of model was done by a one- month time step with change of hydraulic conductivity using trial and error method. In unsteady state, it was done by one eight-month period with 30-day time step and changing storage coefficient. Then for every selected hydrodynamic coefficient in calibration stage, a sensitivity analysis was done. Finally, the model was verificated using water year 1996-97 data and after the validity of results was proved, the model was used to assess future condition of aquifer and effect of different management alternatives. To do these, different methods of multiple operations of regional ground water and the water transferred from Zayandeh-Rud River to Mahyar plain was investigated and superior alternative was selected. Keywords: Groundwater modeling, Modflow, North Mahyar plain and water resource management.