Coupling of hydrological drought and flood extremes under climate change in the Kamp catchment, Austria

Study region Kamp catchment, Austria Study focus This study developed a comprehensive framework to assess consecutive hydrological drought-to-flood (D-F) events. The framework integrates a performance-based selection of ÖKS15 climate projections for RCP2.6, RCP4.5, and RCP8.5, hydrological modelling with SWAT+, and ensemble-based assessment of D-F events. New hydrological insights Consecutive D-F events are projected to decline across all scenarios by the end of the century (EOC), with a median reduction of 22–44% relative to the reference period (1976–2005). However, only five climate projections are statistically significant. The direction of change in ensemble signal remains consistent despite uncertainties. This decline in D-F events results from reduced future drought frequency (14–42%) rather than weakened coupling. Both short- and long-duration droughts preceded floods at comparable frequencies (12 each) in the reference period, with future projections showing high inter-model variability (–77 to +47%). The proportion of D-F events among total flood events is projected to decrease from 18– 22% to 10–16% at the EOC, indicating a temporal separation. Projections reveal a decline in winter and spring D-F events and an increase in autumn events. Median transition times between drought termination and flood onset are projected to increase from 37 to 49 days in the EOC (RCP8.5). A future with a compositional shift towards more independent hydrological extremes is anticipated. These results are essential for water resources management in the Kamp catchment.