Numerical Simulation of the Flow and Contaminant Transport in Groundwater, Case Study: Nahavand Plain Aquifer

Numerical simulation of the groundwater flow in order to hydraulic and hydrologic parameters estimation is an important tool for management of aquifers. This study presents results of a mathematical model developed for simulation of groundwater flow in Nahavand plain aquifer in southwest of Hamedan province. For this purpose Groundwater Modeling Software (GMS) was used which supports the MODFLOW-2000 code. After gathering required data same as hydrological, hydrogeological data and topography maps, first 3D hydrogeological model of plain was constructed using boreholes and surface elevation data. Then MODFLOW was used for simulation of flow. After initial simulation of flow, model was calibrated in steady state with trial- and-error and parameter estimation methods and groundwater table monitoring data. Results of calibration show that error between observed head and computed head is in allowable range (±20m). Also results of computed head with model show that groundwater flow is in direct of dominant slope (southeast to northwest). Finally MODPATH code which simulates advective transport of particles was used for estimation of flow path and source of contaminants.