We evaluate the 12 m TanDEM-X DEM for geomorphometry and compare elevation accuracy (using over 300 000 dGPS measurements) and geomorphic metrics (e.g., slope and curvature) to other modern satellite-derived DEMs. The optically generated 5 m ALOS World 3D is less useful due to high-frequency noise. Despite improvements in radar-derived satellite DEMs, which are useful for elevation differencing and catchment analysis, lidar data are still necessary for fine-scale analysis of hillslope processes.

Alluvial fans are sedimentary deposits that take place at the outlet of mountain range. This location makes them the first sedimentary archive where sediments, eroded from mountains, are deposed. Their morphology is controlled by the water and sediment discharges and sediment characteristics. By using controlled laboratory experiments, we show that an alluvial fan composed of two distinct sediments has a characteristic shape; it can be decomposed into two fans made up of one sediment.

An assessment of connectivity will help in describing coupling patterns and scale dependence of erosional processes to understand and predict how policies at catchment scale may supply sediments to the river system (dismantlement of hydraulic infrastructures, changes in terms of land use, etc.).

Suspension of particles in turbulent flows is one of the most widely occurring physical phenomena in nature, yet no theory predicts the sediment transport capacity of the wind, avalanches, pyroclastic flows, rivers, and estuarine or marine currents. We derive such a theory from universal turbulence characteristics and fluid and particle properties alone. It compares favourably with measurements and previous empiric formulations, making it the first process-based theory for particle suspension.

We developed and tested an automated terrestrial laser scanning (ATLS) system with near-real-time change detection at the Séchilienne landslide. We monitored the landslide for a 6-week period collecting a point cloud every 30 min. We detected various slope processes including movement of scree material, pre-failure deformation of discrete rockfall events and deformation of the main landslide body. This system allows the study of slope processes a high level of temporal detail.

Bedrock incision by rivers is driven by the impacts of sediment particles moved by the water flow. Sediment residing on the bed can protect the rock from impacts, thereby reducing erosion rates, a phenomenon known as the cover effect. The cover effect has been shown to be important in many field and laboratory experiments. Here, we develop a mathematical framework to describe the cover effect which can be used to compare data and to predict the extent of cover in streams.