Are spatial and temporal patterns of landslide triggering events reflected in topography and sediment dynamics?

Landslides alter the morphology and sediment dynamics of mountainous terrain. Here, we evaluate how the spatial and temporal variability of landslide triggering events adjust this footprint. We use the HyLands landscape evolution model that explicitly simulates the occurrence of landslide events as well as fluvial incision and sediment dynamics. Both existing landscapes as well as synthetically produced landscapes that evolve over geological timescales are considered. This enables us to identify the required magnitude and frequency of extreme events for them to be recorded in landscape morphology. Moreover, we compare the relative contribution of long-term tectonic processes versus spatially clustered extreme events in shaping mountainous terrain. Finally, we evaluate if and how the temporal occurrence of landslide-triggering events alter morphology. Here we compare two scenarios: a first one evaluates how a landslide-prone landscape responds to events that are uniformly spread through time, a second one tests how such a landscape responds to regionally synchronous events. This contribution aims to clarify the distinctive role of landsliding in shaping mountainous terrain, which will in turn contribute to understanding how landslide prone regions respond to spatial and temporal changes in extreme events.