Changes in groundwater regime during vegetation period in Groundwater Dependent Ecosystems

Abstract

Abstract An analysis of the dynamics of groundwater levels in the Groundwater Dependent Ecosystems (GDEs), which cover a vast part of the middle Vistula River valley in central Poland was carried out. The study area, typical of large river valleys, was investigated by detailed monitoring of groundwater levels. Based on statistical analysis and the geo-statistical modeling of monitoring data for 1999-2013, the range and dynamics of groundwater level fluctuations were determined for the entire interval and for the vegetation periods. The values of retention and infiltration recharge in various periods were compared with average values, indicating intervals of potential groundwater deficiency in GDEs. The amplitude of groundwater fluctuations, retention and infiltration were determined for vegetation periods characterized by the highest water intake by plants and the highest evapotranspiration. Particular attention has been drawn to the analysis of low groundwater levels in the vegetation periods, with water deficiencies potentially threatening the correct functioning of plant communities in GDEs. Moreover, the study has allowed us to indicate areas with insufficient groundwater levels during vegetation periods that may be hazardous to plant communities. The results may be a basis for the elaboration of correct management plans, protection measures and projects, or GDE renaturalization.