NUMERICAL ANALYSIS OF HUMAN PRESSURE ON GROUNDWATER BUDGET IN THE AREA OF THE ŻURAWINIEC PEAT BOG NATURE RESERVE IN POZNAŃ

Growth of a city, which is linked with intensive urban development, systematically affects groundwater recharge by diminishing its rate. Thus, the phenomenon influences groundwater resources in a hydrogeological unit and, in turn, it causes negative environmental consequences which are difficult or even impossible to reverse. This study analyses the effect of urban development on water budget and its impact on the water-dependent ecosystem. In 1959, a peat bog nature reserve – the Żurawiniec Nature Reserve – was established in the north of Poznań, covering an area of ca. 1.5 ha. During many years the area was losing its original character, which resulted in desiccation and complete deterioration of peatland plants. The analysis of water budget reduction was done through the integration of a spatially distributed water balance model and a numerical hydrogeological model. The simulations were based on data collected for the years 1952, 2001 and 2014. The results of simulations emphasize the significant human impact on groundwater budget leading to a continuous groundwater level dropdown, resulting in over 2 m lower groundwater level in year 2001 in relation to year 1952. The main reason for negative repercussion was a constant decrease of groundwater recharge due to urbanization.