Impact of climate change on the groundwater run-off in south-west Poland

The article discusses the variability of total runoff and groundwater run-off affected by global and local climate changes using the example of 17 selected river basins located in south-west Poland. Based on the data collected from 1966 to 2005, the average annual values of the total and groundwater run-off, aswell as the seven-day annual minimum flows, were estimated, which provided useful information about droughts. The calculated parameters were compared with precipitation, air temperature, aridity index (the ratio of the precipitation and potential evapotranspiration), and the NAO (North Atlantic Oscillation) and AMO (Atlantic Multidecadal Oscillation) indices. There were no significant changes in the total run-off in the research area; however, there was a reduction in the groundwater run-off, which indicates change in groundwater recharge. The strongest relationship of total run-off, groundwater run-off and seven-day annual flow minimum was obtained from the NAO index,which confirms that the run-off from the study area is dependent on global factors. This is important for the estimation of changes in the runoff from the study area in response to the climate scenarios for the years 2011-2030, which indicate a fairly significant increase in air temperature and slight differences in precipitation. Based on extensive investigations, a reduction in the groundwater run-off in favour of increased surface run-off should be expected in the research area