The consequences of debris flows in Brazil: a historical analysis based on recorded events in the last 100 years
Victor Carvalho Cabral, Fábio Augusto Gomes Vieira Reis, Vinícius Queiroz Veloso, Claudia Vanessa dos Santos Corrêa, Caiubi Emanuel Souza Kuhn, Christiane Zarfl
Abstract
or more fatalities vs. the number of fatalities), based on a compilation of debris-flow-related disasters from 1920 to 2021. In total, 45 debris-flow events were documented in the considered period, responsible for 5771 fatalities and more than 5.5 billion USD in economic losses. The Serra do Mar Mountain Range is the main site of reported debris-flow occurrences (64.5%), followed by Serra da Mantiqueira (13.3%), and Serra Geral (13.3%). Southeast Brazil (SEB) is the region most affected by debris-flow events, due to the highest population density and the development of several cities in hilly areas, such as Petrópolis (Rio de Janeiro state) and Cubatão (São Paulo state). The debris-flow MR of SEB is higher than any other region in Brazil, pushing the national debris-flow MR upwards, and the F-N curve of SEB consolidates the region as the one with the highest risk to the phenomenon, indicating a higher probability of fatal events. The F-N plots further show that debris-flow events in Brazil represent a higher societal risk than in countries such as China, Japan and Italy. While there are differences in country size and the scale effect should be considered, these results highlight the urgent need for investments in disaster prevention and preparedness programs. Supplementary Information: The online version contains supplementary material available at 10.1007/s10346-022-01984-7.