Abstract. For decades researchers have used the micro-erosion meter and its successor
the traversing micro-erosion meter to measure micro-scale rates of vertical
erosion (downwearing) on shore platforms. Difficulties with “upscaling” of
micro-scale field data in order to explain long-term platform evolution have
led to calls to introduce other methods which allow for the measurement of platform
erosion at different scales. Structure from motion photogrammetry is fast
emerging as a reliable, cost-effective tool for geomorphic change detection,
providing a valuable means for detecting micro-scale to mesoscale geomorphic
change over different terrain types. Here we present the results of an
experiment in which we test the efficacy of structure from motion photogrammetry
for measuring change on shore platforms due to different erosion processes
(sweeping abrasion, scratching, and percussion). Key to this approach is the
development of the coordinate reference system used to reference and scale
the models, which can be easily deployed in the field. Experiments were
carried out on three simulated platform surfaces with low to high relative
rugosity to assess the influence of surface roughness. We find that
structure from motion photogrammetry can be used to reliably detect micro-scale
(sub-millimetre) and mesoscale (cm) erosion on shore platforms with a low rugosity
index. As topographic complexity increases, the scale of detection is
reduced. We also provide a detailed comparison of the two methods across a
range of categories including cost, data collection, analysis, and output. We
find that structure from motion offers several advantages over the micro-erosion meter, most notably
the ability to detect and measure the erosion of
shore platforms at different scales.
The precision and accuracy of measuring micro-scale erosion on shore platforms
