Experimental data on the flow evolution and deposit morphology of granular debris flows over erodible beds with varying solid density

<p>Debris flows are highly dynamic events in which the erosion and entrainment of basal sediment can greatly enhance debris-flow mobility and energy, extending travel distances and intensifying impact forces. However, the underlying physical conditions and mechanical controls that cause some debris flows to accelerate during erosion while others decelerate are still insufficiently understood, and existing empirical models are limited in quantifying and predicting these dynamics accurately.</p>

<p>This data publication supplements the study on debris-flow mobility over erodible beds by Wetterauer et al. (2026), which investigates how variations in bed inertia influence the mobility and runout of erosive granular debris flows using controlled laboratory experiments. A total of 24 dry, single-phase debris-flow experiments were conducted in a steep flume, testing four distinct slide-bed configurations called “scenarios”. These include three erosive scenarios representing inertially weak, neutral, and strong conditions, achieved by systematically varying the solid density of the bed material (expanded glass, quartz, and magnetite) relative to a sliding mass (quartz) of constant density, as well as a reference scenario without erosion. Each scenario was performed for a finer (sand-sized) and a coarser (sand-to-gravel-sized) size fraction to assess potential grain-size-dependent effects and repeated three times to evaluate reproducibility.</p>

<p>Here, we provide high-resolution spatiotemporal data on the debris-flow evolution and deposit morphology for all 24 experiments together with information on the material properties of slide and bed. The data were collected as part of the project “Landslide mobility with erosion: Proof-of-concept and application”, which investigates entrainment processes and their effects on the mobility of erosive debris flows based on debris-flow experiments conducted in a newly designed laboratory flume at the Hydraulic Laboratory of the University of the Bundeswehr Munich, Germany. This research receives funding from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project number: 522201978.</p>

<p>Comprehensive details on experimental procedures, data acquisition, and processing are provided in the associated study by Wetterauer et al. (2026).<p>