We introduce a novel, cost-effective photogrammetry-based method
designed for measuring rapidly evolving three-dimensional surface
topography in particle-fluid flow experiments. This method offers
high-resolution results over a considerable surface area, enabling the
capture of dynamic flow events with temporal granularity limited only by
removable memory card capacity. Multiple WiFi-enabled security cameras,
meticulously calibrated with precision-measured reference points on
calibration boards, are employed in this methodology. External
synchronization, facilitated by strategically-positioned flash lamps,
allows calibration among cameras without additional precise tools.
Validating our method through an alluvial fan experiment showcases its
efficacy in tracking the growth and evolution of experimental debris
flows, particularly in capturing the dynamic evolution of debris flow
deposits on a growing alluvial fan. This example illustrates the
method's ability to link local flow, evolution, and deposition to
multiple channel avulsion events, highlighting its success in capturing
distinct slope and height dependencies associated with these phenomena.
Overall, our method transcends conventional measurement approaches,
providing a significant advancement in capturing the intricacies of
rapidly evolving three-dimensional surface topography in particle-fluid
flow experiments. Its cost-effectiveness and robustness make it a
valuable tool for diverse, dynamic scenarios, presenting a promising
solution for experimental laboratory-scale landscape studies.