Ground Water Modeling to Determine Hydrodynamics Coefficients in Unconfined Aquifer (Case Study: Kermanshah Plain)

The water movement in the aquifer is studied using the basic equations of flow, i.e. Darcy, continuity and mass survival equations, which are differently analyzed in the case of confined and unconfined aquifers. In these equations, hydrodynamic coefficients and other characteristics of the aquifer are used. Therefore, the determination of hydrodynamic coefficients of aquifer is necessary for groundwater studies. The most important characteristics of the aquifer i.e. hydrodynamic coefficients can be determined across the aquifer using modeling. If the aquifer model is properly provided, it can be a useful tool for better recognition of aquifer characteristics and also predicting the impact of different management plans on the water resources of the region. In this study, groundwater modeling was performed to determine the hydrodynamic coefficients in the unconfined aquifer of Kermanshah plain using GMS 7.1 software. The results showed that the amount of hydraulic conductivity in the Kermanshah plain aquifer varies from 0.1 to 30 meter per day and the amount of specific yield varies from 0.02 to 0.4. The amounts of computed water table by the model and the observed water table in the piezometers have high correlation and the root mean square error value is always less than one, which indicates the acceptable accuracy of the model for simulating the aquifer status.