Assessing the impact of grid cell properties in spatial discretization of groundwater model

In groundwater modelling the validity of both calibration and validation processes depends on how well the hydrogeological properties of the investigated area are conceptually, spatially and temporally represented in the model. A good discretization represented by optimal choice of size and number of cells would essentially improve the accuracy and efficiency of the model while reducing the complexity of model through lesser time and cost consumption. In this study, models with five different spatial discretization schemes; 10 x 10 m, 20 x 20 m, 30 x 30 m, 40 x 40 m and 50 x 50 m were developed. The trends of the performances were calculated at each observation well and compared with grid cell size and distance between centre of grid and observation well. It is confirmed that the deterioration of model performance is mainly controlled by the increase of distance between well and centre of the cell, and the cell size.