Economic consequences of cascading drought-flood events: Evidence from Central Europe

Abstract Cascading drought-flood events (CDFEs), also referred to as “drought-to-flood transitions” or “drought–flood abrupt alternations,” in which a flood follows a period of drought, may have different flood generation mechanisms than floods occurring independently from drought, as the drought could affect soil infiltration rates and, consequently, runoff dynamics. With the increasing frequency of extreme weather events driven by climate change, understanding the cascading nature of drought and flood events has become crucial for effective disaster risk management. However, there is a lack of empirical evidence on how these drought-flood interactions work and translate to economic losses. This study addresses this gap by identifying CDFEs and flood-only events (FEs) across Central Europe and linking them to their flood impacts from the modelled Historical Analysis of Natural Hazards in Europe (HANZE) database. CDFEs are associated with significantly higher maximum daily mean streamflow (58.51 m³/s vs. 38.20 m³/s), deeper mean water depths (1.90m vs. 1.88m), and greater economic losses (€33.09 million/km² vs. €29.75 million/km²) compared to FEs. These findings underscore the special features of cascading drought-flood events and the need to take them into account in flood risk management.