Hillslope torrential hazard cascades in tropical mountains
Year: 2025
Type: article
Abstract: . Torrential hazards refer to the spectrum of water-sediment flows that include debris flows, debris floods, hyperconcentrated flows, and flash floods. These processes often occur in cascading sequences with landslides and have been highly destructive in tropical and humid subtropical mountains, particularly. We compiled a database of 22 cascade events from 2009 to 2024 and analyzed topographic, sediment and the intensity and extremity of both antecedent and triggering rainfall to identify common traits of these events. The results showed that only a few cases were linked to the most extreme rainfall recorded, suggesting that other controls, such as sediment availability, may be needed for initiating hazard cascades. Clustering analysis revealed that regions with steeper slopes and finer soils experienced hazard cascades even under lower-intensity rainfall, whereas gentler slopes with coarser material required more extreme triggering rainfall. Cascades triggered by both earthquakes and rainfall showed that these triggers can interact across time, such as a rainy season preceding an earthquake or vice versa, or even simultaneously, highlighting the susceptibility of tectonically active tropical regions to cascading hazards. Our findings highlight the importance of prioritizing hazard assessment and risk reduction strategies in tropical mountains, especially in underreported areas such as Africa.
Language: English
Subfield: Management, Monitoring, Policy and Law
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,553
OpenAlex ID: W4414557006