The grain-size distribution of ancient alluvial systems is commonly determined from sections of gravel deposits exposed vertically to reconstruct paleo-environments or changes in tectonics and/or climate. To test whether such a grain-size distribution is equivalent to one of the sediments that was in direct contact with the flow at the time of deposition, we dug a large trench in an active gravel-bedded, braided river. We show that the granulometry is uniform at the scale of the active layer.

In most models of river morphodynamics, sediment mass conservation is described by the Exner equation, which may take either the flux form or the entrainment form. Here we compare the two forms of the Exner equation under conditions typical of the lower Yellow River. We find that when using a single sediment grain size, there is little difference between the two forms. But when considering sediment mixtures, the two forms will show very different patterns of grain sorting.

We show a new use for the SRTM-C digital elevation model from February 2000 and the newer TanDEM-X dataset from ~ 2015. We difference the datasets over hillslopes and gravel-bed channels to extract vertical land-level changes. These signals are associated with incision, aggradation, and landsliding. This requires careful correction of the SRTM-C biases using the TanDEM-X and propagation of significant uncertainties. The method can be applied to moderate relief areas with SRTM-C coverage.

The work demonstrates how seismic networks installed in the Alps can be used for country-wide real-time monitoring of rockslide activity. We suggest simple methods that allow us to detect, locate, and characterize rockslides using the seismic signals they generate. We developed an automatic procedure to locate rockslides with kilometer accuracy over hundreds of kilometers of distance. Our findings highlight how seismic networks can help us to understand the triggering of rockslides.

The challenge to measure three-dimensional bank irregularities in a mid-sized river reach can be quickly solved in the field flying a drone with ground-control points and later applying structure from motion photogrammetry. We tested a simple approach that achieved sufficient resolution and accuracy to identify the full bank erosion cycle, including undermining. This is an easy-to-use and quickly deployed survey alternative to measure bank erosion processes along extended distances.