Digital photogrammetry is now increasingly recognized as being a
powerful tool in geomorphology. However, the high material costs and
skills required by digital photogrammetry may deter
non-photogrammetrists from using this technique in their research. This
paper demonstrates the use of a close-range digital photogrammetric
methodology accessible to non-photogrammetrists and yet capable of
yielding good quality topographic information on coarse gravel
riverbeds at minimal cost. Digital Elevation Models (DEMs) were derived
from 1:165 scale imagery obtained with a 35 mm film SLR camera, a
commercial desktop scanner and a softcopy photogrammetry package.
Quality assessment based upon independent checkpoints and scaling
analysis showed that the precision of the DEMs was consistently less
than 10% of the D 50 of the bed particles. This translates into
sub-centimetric precision. Whilst photogrammetry is presently capable
of a better data quality at this scale, quality must be judged with
respect to the requirements of the geomorphological applications under
consideration. Thus, the methodological simplifications adopted in this
research are acceptable in order to make photogrammetry both
cost-effective and accessible.