A numerical groundwater flow model of Bursa Başköy aquifer

Abstract

In this study, the aim is to determine the groundwater storage and distribution in the Baskoy aquifer inside the city of Bursa, Turkey. Preliminary studies were conducted in the GIS environment, and afterwards, groundwater flow simulations were performed in MODFLOW which uses finite differences method to solve groundwater flow equations. From point elevation data, a digital elevation model (DEM) was constructed. The subbasins and drainage network were delineated through hydrological analysis of the DEM. The data were transferred to MODFLOW interface and a grid with a cell size of 15 m x 15 m was generated. Hourly groundwater level measurements at 7 observation wells were obtained from State Hydraulic Works. The observation data were used for calibration of unknown parameters such as hydraulic conductivity and storage coefficient. Calibration process was expedited by using the Parameter Estimation (PEST) model. Transient simulations were performed in daily timesteps and according to the results, model output was dependent on the initial condition, hydraulic conductivity and storage coefficient. In most of the wells the general dynamics of groundwater were successfully predicted.