Current emphasis in geomorphology recognizes the need for the accurate
representation of topographic form, reflected in the growth of digital
terrain and elevation modelling. A key requirement of such strategies
is the efficient acquisition of information in an appropriate form and
at an appropriate resolution to the landform under consideration. The
traditional use of photographs in geomorphology has been for
interpretation, but developments in photogrammetry may allow the full
advantages of the photograph as a means of acquiring and storing
quantitative information to be used. The photograph can provide
information on all areas visible on a photograph; the information is
acquired retrodictively; the photograph preserves the spatial
relationship of morphological units; the collection of photographs
requires minimal landform contact; the photograph records extra
explanatory information; and photographs can be obtained at an
appropriate temporal resolution to the landform under investigation.
However, optical and mechanical limitations imposed by traditional
photogrammetric approaches have prevented its rigorous and widespread
application to geomorphology. Developments within photogrammetry,
notably the analytical approach, now open up wider geomorphological
possibilities. The analytical approach overcomes these limitations
through the use of an interactive mathematical model at the stage of
photographic analysis. The obtained information is in a form directly
suited to the construction of digital terrain or elevation models. This
technique can be used both for landform monitoring and for the analysis
of archival photographs to reconstruct historical landform change.