What characterizes rainfall triggered landslides and the places they impact?

Mapping landslides using high resolution imagery has transformed the availability of large landslide inventories. Extreme rainfall events in particular can trigger thousands of landslides, which when mapped are an exceptional source of information on the characteristics of places where landslides occur. In this study, we compiled a large number of published landslide inventories from extreme rainfall events as well as several newly mapped examples to assess the topographic characteristics of the source regions as well as the areas impacted by immediate landslide runout. We find that average upstream angle and compound topographic index are strong predictors of landslide scar location, while local relief and topographic position index provide a stronger sense of where landslide material may end up (and thus where hazard may be highest). The global scope of the inventories allow us to draw some conclusions about common characteristics of landslide zones, providing information for the statistical susceptibility and hazard assessment tools. Emberson (2023) What characterizes rainfall triggered landslides and the places they impact?, USGS Landslide Hazards Seminar, 21 June 2023. ===== USGS video: