The Occurrence of Catastrophic Multiple-Fatality Flash Floods in the Eastern Mediterranean Region

Despite recent technological advances, many parts of the world continue to experience flood disasters accompanied by significant loss of human lives. Understanding how frequent these deadly catastrophes are creates many uncertainties, especially in areas where disaster records are scarce or have short timeframes. It is, however, very important from a preparedness and civil protection standpoint to assess the frequency of such high-mortality events, especially considering the threat of climate change. This work develops a high-mortality flood event database using multiple international sources, covering a relatively long time window (1882–2021), exploring the deadliest floods in the Eastern Mediterranean region, and examining their seasonal distribution, their temporal evolution, and their basic spatial patterns. The study identifies 132 flash flood events (causing ≥10 fatalities) with a return period of only 1.56 years. Additionally, higher-magnitude events (>85th percentile) were found to be less common but still not very rare (return period = 9.1 years). The number of events shows an increase in recent decades, while seasonal and spatial patterns were identified as well. Overall, the findings provide a foundation for understanding how common catastrophic flood events are in the region, are beneficial for policymakers and relevant professionals, and are an important stepping stone towards a complete understanding of how extreme floods have changed in the last century or will change in the near future.