Relationships of Hydrological Seasons in Rivers and Groundwaters in Selected Catchments in Poland

The study applied the method of hydrological season identification in a time series river total and base flows groundwater levels. analysis covered daily measurements from period 2008–2017 nine catchments located different geographical regions Poland. basis classification seasons, previously for discharges only, was transformation original variables into reflecting three statistical features estimated single-name days year multiyear: average value, variation coefficient, autocorrelation coefficient. New were standardized after hierarchical clustering, every day had defined type, valorizing which refer to quantity, variability, stochastic nature flow as well stage. Finally, sequences grouped basic (homogenous) seasons types transitional including mixed days. Analysis indicated determinants types, length, frequency identified especially related regime, hydrogeological hydrometeorological conditions physiographical background directly influenced by location. co-occurrence same allowed, some catchments, periods synchronic alimentation (groundwater flow, mainly cold half-year) water shortages (all components, warm be identified.