Riverbeds are often composed of different scales of dunes, whose sizes and shapes are highly variable over time and space. Characterization of these dunes is important in many research studies focused on fluvial processes. A tool is presented here that aims to identify different scales of dunes from riverbed elevation maps. A first step is to separate two scales of bedforms without smoothing steep slopes of the larger dunes. In a second step, dunes are identified and properties are computed.

Drainage reorganization redistributes drainage area across basins, resulting in channel and valley widths that may be unproportional to the new drainage area. We demonstrate scaling between valley width and drainage area in reorganized drainages that deviates from scaling in non-reorganized drainages. Further, deviation patterns are associated with different reorganization categories. Our findings are consequential for studies that rely on this scaling for valley width estimation.

Channel processes under flood conditions are important for river science and management as they involve high volumes of sediment transport and erosion. However, these processes remain poorly understood as the data are difficult to collect. Using a physical model of a river, we found that simple equations based on the mean shear stress and median grain size predicted sediment transport as accurately as ones that accounted for the full range of shear stresses.

Glacial and non-glacial processes have left a strong imprint on the landscape of the European Alps, but further research is needed to better understand their long-term effects. We apply a new technique combining two methods for bedrock surface dating to calculate post-glacier erosion rates next to a Swiss glacier. Interestingly, the results suggest non-glacial erosion rates are higher than previously thought, but glacial erosion remains the most influential on landscape evolution.

Monitoring sediment transport is relevant for flood safety and river restoration. However, the spatial and temporal variability of sediment transport processes makes their prediction challenging. We investigate the feasibility of a general calibration relationship between sediment transport rates and the impact signals recorded by metal plates installed in the channel bed. We present a new calibration method based on flume experiments and apply it to an extensive dataset of field measurements.

Grain size data are important for studying and managing rivers, but they are difficult to obtain in the field. Therefore, methods have been developed that use images from small and remotely piloted aircraft. However, uncertainty in grain size data from such image-based products is understudied. Here we present a new way of uncertainty estimation that includes fully modeled errors. We use this technique to assess the effect of several image acquisition aspects on grain size uncertainty.

In northern Norway we have observed several rock glaciers at sea level. Rock glaciers are landforms that only form under the influence of permafrost, which is frozen ground. Our investigations show that the rock glaciers are probably not active under the current climate but most likely were active in the recent past. This shows how the Arctic now changes due to climate changes and also how similar areas in currently colder climates will change in the future.

We estimate global changes in frost cracking intensity (FCI) using process-based models for four time slices in the late Cenozoic ranging from the Pliocene (∼ 3 Ma) to pre-industrial (∼ 1850 CE, PI). For all time slices, results indicate that FCI was most prevalent in middle to high latitudes and high-elevation lower-latitude areas such as Tibet. Larger deviations (relative to PI) were observed in colder (LGM) and warmer climates (Pliocene) due to differences in temperature and glaciation.

In long-lived areas, relief rejuvenation can be greatly controlled by both the geometry of reactivated structures and the kinematics setting. We have applied geomorphological qualitative analyses, geomorphic index, and knickpoint modelling to detect the Quaternary reactivation of fractures in the Betic foreland (southern Spain). The obtained relief rejuvenation pattern and fault kinematics agree with propagation of transpressional deformation from the Betic fold-and-thrust belt.

To understand landscape evolution in the mineral resource-rich Yukon River basin (Alaska and Canada), we mapped and cosmogenic isotope-dated river terraces along the Charley River. Results imply widespread Yukon River incision that drove increased Bering Sea sedimentation and carbon sequestration during global climate changes 2.6 and 1 million years ago. Such erosion may have fed back to late Cenozoic climate change by reducing atmospheric carbon as observed in many records worldwide.