Drainage initiation, expansion, and channel-head arrest in heterogenous bedrock landscapes of the Colorado Plateau

The transition between hillslopes and channels defines landscape characteristics such as drainage density, ridge spacing, hillslope length. Previous studies of the location this have demonstrated that soil advection diffusion work either individually or in concert to set limits channelization largely soil-mantled landscapes. However, no model explaining bedrock landscapes has been established. In study, we explore morphologic signatures processes channel initiation, headward elongation, eventual arrest Raplee Ridge monocline, Utah, USA. monocline provides an opportunity test whether a threshold shear stress controls initiation through inspection slope upstream area at varyingly incised portions landscape. Using combination lidar structure-from-motion data, find unincised occupy overlapping but separable slope-upstream space, while geomorphic mapping field-based observations allow for further distinction erosional with values range from ∼60 Pa 160 Pa. We develop conceptual expansion these using field observations, which first initiate by vertical plucking blocks, disaggregate limestone block sliding, elongate upslope knickpoint retreat variably erosive lithologies, eventually predictable positions due buttressing. These results suggest stress-controlled play fundamental role setting degree landscapes; however, thresholds erosion can change response local geologic factors lithology structural geometry. This implies detailed knowledge may be necessary interpretation modeling fluvial terrestrial those on other planets.