Bedload flux quantification remains challenging in river dynamics due to variable transport modes. We used a passive monitoring device to record the acoustic signals generated by the impacts of bedload particles with different transport modes, and established the relationship between the triggered signals and bedload characteristics. The findings of this study could improve our understanding of the monitoring system and bedload transport process, and contribute to bedload size classification.

One of the most interesting problems in geomorphology concerns the conditions that mobilise sediments grains in rivers. Newly developed smart pebbles allow for the measurement of those conditions directly if a suitable framework for analysis is followed. This paper connects such a framework with the physics used to described sediment motion and presents a series of laboratory and field smart-pebble deployments. Those quantify how grain shape affects the motion of coarse sediments in rivers.

The open-source fluid dynamic solver presented in v. Boetticher et al. (2016) combines a Coulomb viscosplastic rheological model with a Herschel–Bulkley model based on material properties for 3-D debris flow simulations. Here, we validate the solver and illustrate the model sensitivity to water content, channel curvature, content of fine material and channel bed roughness. We simulate both laboratory-scale and large-scale debris-flow experiments, using only one of the two calibration parameters.

The Swiss plate geophone system is a bedload surrogate measuring technique. Calibration measurements for this technique were performed in two mountain streams in Austria, using geophone impulse rates (a summary value) and directly measured bedload transport rates. Implausible geophone impulse counts are discussed that were recorded during periods with smaller discharges without any bedload transport, and that are likely caused by vehicle movement very near to the measuring sites.

Debris flows are characterized by unsteady flows of water with different content of clay, silt, sand, gravel, and large particles, resulting in a dense moving mixture mass. Here we present a three-dimensional fluid dynamic solver that simulates the flow as a mixture of a pressure-dependent rheology model of the gravel mixed with a Herschel–Bulkley rheology of the fine material suspension. We link rheological parameters to the material composition. The user must specify two free model parameters.