COMPARISON OF LOCAL AND REGIONAL GROUNDWATER FLOW MODELING APPROACHES OF THE MULTILAYER GROUNDWATER SYSTEM IN THE VICINITY OF THE LIS GROUNDWATER INTAKE

We analyzed 27 km2 of the Prosna valley aquifer near Kalisz. The region was previously a subject of four model-based studies of local and regional range. Furthermore, additional modelling researches were conducted that aimed at evaluation of Upper Jurassic aquifer exploitation, which seems to be a separate groundwater circulation system. The models used in the analyses differed in terms of grid size (100, 125, 250 and 500 m), groundwater circulation scheme (two-, three- or seven-layered), and the software used (Hydrylib or Modflow). The results of groundwater steady-state flow indicate the essential influence of the groundwater circulation scheme and the mesh size on groundwater flow balance. It also emphasizes the importance of deep aquifers in the detailed model-based study in the case of groundwater intakes located within the river valleys of regional drainage range.