شبیه سازی عددی مسیر جریان آب زیرزمینی آبخوان دشت همدان–بهار

Background and Objective: Groundwater resources are very important for the survival of living beings. Hence, groundwater modeling has a special importance in water management and planning of each region .In this study, numerically simulation of Hamedan–Bahar aquifer flow path was done by GMS software using geological, hydraulic and hydrologic information. Materials and Methods: First, a 3D hydrogeological model of the aquifer was prepared and then the aquifer flow was simulated by MODFLOW numerical code. The model was calibrated using a trial and error method. Estimation of groundwater flow path was done with MODPATH numeric code. Finally, the capture area was studied and piezometers and direction of groundwater movement in different time were built. Results: The results of calibration showed that the difference between observed head and computed head was in allowable range (  35 m). Estimation of pollution with MODPATH numeric code indicated that in forward moving, the longest way of pollution transport was 43400 m and in backward moveing, the longest way of flow transport was 8270.65 m. The results of the groundwater flow path indicated that the flow transport direction was from southwest to northeast in line with the hydraulic gradient. Conclusion: It can be concluded that the current trend of groundwater flow will increase aquifer pollution level, which will damage groundwater aquifer.