River bedrock erosion can occur by polishing and by the removal of entire blocks. We observe that when there is no to little fractures most erosion occurs by polishing whereas with more fractures, blocks can be removed at once leading to different patterns of erosion and riverbed morphology. Fractures affect barely mean erosion rate but change the location and occurrence of block removal. Our results highlight how river bedrock properties influence erosion processes and thus landscape evolution.

We use computer models to study how landscapes respond to changes in rainfall and tectonic uplift. We find that rainfall rate changes produce unique slope change reversals near the headwaters, which differ from the simpler responses caused by uplift rate changes. These reversals are more pronounced when hillslope diffusion is dominant. These findings help us understand how climate and tectonic forcing shape the landscape differently and may allow scientists to tell their effects apart in nature.

Mid-channel bars in estuaries are important habitats and bird foraging areas. We measured current velocities on and along the tidal flat of an estuarine mid-channel bar. Our analysis shows that the intertidal currents have a much more three-dimensional pattern than those on shore-connected tidal flats. Existing models for tidal flats underestimate flow velocities on the mid-channel bar, which has consequences for sediment transport and morphodynamics.

Our study presents a computer-based method to detect and measure pebbles in 3D models reconstructed from camera photos. We tested it in a controlled setup and achieved 98 % accuracy in detecting pebbles. Unlike traditional 2D methods, our approach provides full 3D size and orientation data. This improves sediment analysis and riverbed studies by offering more precise measurements. Our work highlights the potential of 3D modeling for studying natural surfaces.

In natural rivers, flow variability and sediment heterogeneity affect how sediment grains are transported. A unique law that predicts the total amount of sediment transportable by a river for a wide range of sediment mixtures and flow conditions exist but unclear trends remain. Two improvements of this law, a standardized onset of sediment transport and a common reference transport height across all sizes, appear to be critical to have a functional multi grain-size total sediment load.

Changes in sediment mass is accompanied by shape change. We studied downstream changes in particle shape near a channel head using image-based analysis. Although the particles tended to become smoother and more circular, such trend was significantly disrupted by the addition of rock fragment supplied from hillslopes or detached from larger particles during transport. Our findings indicated the dominant process that determine particle shape changes over short distance in headwater streams.

On 13 June 2023, a freestanding rock pillar on the Matterhorn Hörnligrat ridge collapsed after years of weakening. Our study explores how seasonal temperature changes and water infiltration into frozen rock contributed to its failure. By combining field data, lab tests, and modeling, we reveal how warming permafrost increases rockfall risks. Our findings highlight the need for multi-method monitoring and modeling to understand rock slope failure and its links to climate change.

Water level suddenly rises during flash floods in dry regions having a distinct impact on bedload – large sediment rolling and saltating on the riverbed. Using sensor-equipped pebbles and seismic monitoring in a field setting, we demonstrate that bedload activity is very high in both shallow and deep sudden flows. These findings can help improve bedload transport models, particularly when using seismic sensors, by providing new insights into bedload dynamics.

Ribbed moraines are a common, but poorly understood landform within formerly glaciated regions. There are many competing theories for their formation. As such, this paper addresses some of these theories by taking modelled ice conditions and physical characteristics of the landscapes in which they form and, then comparing them to the location of ribbed moraines. Using this we can identify conditions where ribbed moraines are more often present, and therefore we identify the most likely theories.

We try to understand how the sediment supply from the upstream river reach affect the downstream river morphology using a numerical model. If the supplied sediment is composed of variety of size class of particles, a small size bed wave that is composed of mainly fine particles (sorting wave) can propagate to downstream very long distance. However, presence of bars suppresses the effect of sorting wave greatly, and thus the sediment supply has limited role in the downstream river morphology.

The use of new Artificial Intelligence (AI) techniques to learn how landscapes evolve is demonstrated. A few ‘snapshots' of an eroding landscape at different stages of its history provide enough information for AI to ascertain rules governing its evolution. Once the rules are known, predicting landscape evolution is extremely rapid and efficient, providing new tools to understand landscape change.

This publication presents a field study measuring sediment transport and wind velocities across a single dune, and provides an approximation of the annual volume of transported sediment for the entire dune systems on the East Frisian island of Spiekeroog. Data from the field study shows that sediment transport on a dune occurs deep into the vegetation. The approximation surpasses the actual volume changes of the dune systems as expected, with variations depending on the compared beach section.