Rainfall Intensity Temporal Patterns Affect Shallow Landslide Triggering and Hazard Evolution

Abstract

AbstractA characteristic of rainfall‐induced landslides is the gradual loading by infiltrating rainwater that weakens the soil mantle and could progress to abrupt soil mass release. The temporal patterns of similar rainfall amounts affect the hydrological response of a catchment and thus influence landslide dynamics. We use a novel catchment scale landslide hydromechanical triggering model to systematically study how different asymmetric distributions of rainfall intensities affect landslide dynamics and hazard evolution. Evaluating rainfall events with similar durations and total amounts shows that early rainfall peak intensity exerts stronger destabilizing effects, relative to delayed rainfall peak intensity. Intense rainfall events reduce landslide triggering relative to uniform‐intensity rainfall events due to reduced water infiltration. With advances in highly resolved and real‐time precipitation observations, the study offers a means for improving prediction of landslide timing and hazard evolution and identifying hydrological scenarios that enhance landslide activity.