THE ROLE OF LANDSLIDES IN SHAPING TOPOGRAPHY AND CONTROLLING SEDIMENT DYNAMICS

Bedrock landslides are prominent geomorphologic features that mobilize most of the sediment in tectonically active regions. Despite their important influence in shaping topography, the mechanisms by which landslides generate specific features observed in topography are not well understood. Here, we present a model that explicitly simulates stochastic landsliding and associated sediment dynamics. Our model produces slope distributions with a proportion of slopes exceeding theoretical stability angles and quasi-planar hillslopes decorated with straight, closely spaced channel-like features often observed in steep terrain. At dynamic equilibrium, landslide-derived sediment dynamics generate persistent landscape dynamism through the formation of autogenic knickzones and by triggering lateral channel mobility. Our results suggest that bedrock landslides create diagnostic topographical patterns observed in steep terrain and explain persistent landscape dynamism observed in experimental and field settings.