Fatalities from Debris Flows: Worldwide Distribution and Trends

Debris flows are the extremely rapid (often channelized) movement of unconsolidated and saturated slope forming materials. Once triggered, these mass movements can gain enough momentum to destroy life and infrastructure exposed to their travel path. Exceptional historic debris flows have even killed thousands of people in one single event (for example, 15,000 deaths due to debris flows in 1999 in Venezuela). However, not enough studies have addressed the societal risk of global debris-flow occurrences in isolation, as they are mostly considered/combined together with all other types of landslides (sliding or rotational failure, rockfalls, etc.). In one study, (Dowling and Santi, Natural Hazards 71:203–227, 2013) compiled a database of 213 fatal debris flows that occurred from 1950 to 2011, recording 77,779 fatalities (1275 fatalities/year). However, no similar global database was created after this study, which is essential to understand the evolution of fatal debris flow occurrence over the last decade. To help address this gap, we created a new database of all fatal debris-flow events in 2019 that recorded 72 events causing 1628 fatalities. The debris flows accounted for ~46% of the total landslide fatalities of 2019.