National-scale patterns and controls of hydrological drought recovery in Poland

Study region Poland, Central Europe. Study focus Hydrological drought recovery remains much less studied than drought onset, duration, and severity, despite its importance for understanding river-system resilience. This study investigates the recovery phase of hydrological drought in Poland using a daily variable-threshold approach. Drought events were identified and characterized in terms of recovery duration. Geographical variation in recovery behaviour was assessed at the station scale, and catchment controls on median recovery duration were examined using descriptors of topography, land cover, and soils. The aim was to determine whether recovery represents a distinct hydrological phase and to identify the basin characteristics associated with slower or faster return above drought-threshold conditions. New hydrological insights for the region Hydrological drought recovery in Poland was generally short, but highly variable across events and catchments. Recovery was often faster than drought development, although substantial asymmetry occurred and slow-recovery events were widespread. Recovery metrics showed marked geographical variation across the national gauging network. Catchment-level analyses identified statistical associations between median recovery duration and soil-profile properties, terrain steepness, and surface-water share. Steeper catchments tended to recover more rapidly, whereas catchments with a greater proportion of water surfaces tended to recover more slowly. However, the reduced multivariable model explained only part of the observed variability, indicating that these static catchment descriptors provide an incomplete representation of the factors associated with hydrological drought recovery.