Groundwater Modelling and Hydrological System Analysis of Wetlands in the Middle Biebrza Basin

In the presented approach, a three dimensional finite-difference steady-state groundwater model was applied to analyze the groundwater flow system of the Middle Biebrza Basin. Study contains analysis of hydrogeological and morphological outline of the area, as well as the description of developed groundwater model including conceptual model description, model calibration and sensitivity analysis of parameters. Analysis of volumetric water budget of the model within assumed boundary conditions indicated that groundwater resources of the analyzed part of the Middle Biebrza Basin in approximately 80% come from lateral inflow from the adjacent plateaus. Analysis of spatial distribution of groundwater discharge indicated that the most intensive groundwater inflow to the top peat layer is concentrated within the "Czerwone Bagno", where the peatlands are not degraded and wetland habitats develop naturally, not being directly impacted by drainage ditches and canals.