A Global Analysis of Future Compound Flood-Drought Events

Droughts and floods are commonly studied independently of one another, largely overlooking their possible co-occurrence and interdependencies. This may lead to significant risk underestimation, especially as climate change is expected to intensify both hazards. In this study, global changes in Compound Flood-Drought (CFD) events were investigated, based on modelled streamflow and soil moisture data over historical (1964-2014) and future (2050-2100) periods, under two SSP-RCP scenarios (SSP1-2.6 and SSP3-7.0). We distinguished between three CFD types: Drought & Flood (D&F) events for simultaneous occurrences, and Drought-to-Flood (DtoF) or Flood-to-Drought (FtoD) for successive occurrences within 6 months. DtoF and FtoD events were further classified as slow (>90 days lag), rapid (>30 and