The development of an automated correction procedure for digital photogrammetry for the study of wide, shallow, gravel-bed rivers

Détails

ID Serval
serval:BIB_7EA81CE283F3
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
The development of an automated correction procedure for digital photogrammetry for the study of wide, shallow, gravel-bed rivers
Périodique
Earth Surface Processes and Landforms
Auteur(s)
Westaway R.M., Lane S.N., Hicks D.M.
ISSN
0197-9337
Statut éditorial
Publié
Date de publication
2000
Volume
25
Numéro
2
Pages
209-226
Langue
anglais
Notes
Publication type : Article
Résumé
This paper develops an automated correction procedure for dealing with
point errors associated with through-water photogrammetry, for
application in the study of clear-water, shallow gravel-bed rivers. The
procedure involves combining digital photogrammetry and image analysis
techniques to: (i) correct for the effects of refraction at an
air-water interface; and (ii) eliminate and reinterpolate points where
the bed has not been `seen'. The correction procedure was applied to
raw digital elevation models (DEMs) generated using digital
photogrammetry from 1:3000 scale aerial photography of a small reach of
the North Ashburton River, New Zealand. The accuracy of corrected and
uncorrected DEMs is evaluated using an independent data set. A measure
of `geomorphological usefulness' as well as DEM external reliability is
obtained from calculations of water depth distributions and mean bed
level. Results show that digital photogrammetry, used in conjunction
with image analysis techniques, can successfully be used for extracting
high-resolution DEMs of gravel river beds. In exposed areas, errors are
small and random, tending to cancel out over large numbers of points.
Where water is shallow, and following correction, point elevation
errors are statistically no different from those for exposed zones. In
deeper water, despite an improvement following application of the
correction procedure, elevation errors scale with water depth. The
geomorphological potential of photogrammetric survey of large, gravel
riverbeds is demonstrated by the ease and accuracy of calculations of
water depth distribution (important for the assessment of a river's
ecological and recreational characteristics) and mean bed level
(important for the calculation of reach-scale sediment volumes).
Mots-clé
DEM quality, correction procedure, image analysis, digital photogrammetry, submerged zones, BANK EROSION, TRANSPORT, CHANNEL, TOPOGRAPHY, MODELS
Web of science
Création de la notice
03/02/2011 14:41
Dernière modification de la notice
20/08/2019 14:39
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